/*
* PSA crypto layer on top of Mbed TLS crypto
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "common.h"
#if defined(MBEDTLS_PSA_CRYPTO_C)
#if defined(MBEDTLS_PSA_CRYPTO_CONFIG)
#include "check_crypto_config.h"
#endif
#include "psa_crypto_service_integration.h"
#include "psa/crypto.h"
#include "psa_crypto_core.h"
#include "psa_crypto_invasive.h"
#include "psa_crypto_driver_wrappers.h"
#include "psa_crypto_ecp.h"
#include "psa_crypto_rsa.h"
#include "psa_crypto_ecp.h"
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
#include "psa_crypto_se.h"
#endif
#include "psa_crypto_slot_management.h"
/* Include internal declarations that are useful for implementing persistently
* stored keys. */
#include "psa_crypto_storage.h"
#include "psa_crypto_random_impl.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "mbedtls/platform.h"
#if !defined(MBEDTLS_PLATFORM_C)
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#include "mbedtls/aes.h"
#include "mbedtls/arc4.h"
#include "mbedtls/asn1.h"
#include "mbedtls/asn1write.h"
#include "mbedtls/bignum.h"
#include "mbedtls/blowfish.h"
#include "mbedtls/camellia.h"
#include "mbedtls/chacha20.h"
#include "mbedtls/chachapoly.h"
#include "mbedtls/cipher.h"
#include "mbedtls/ccm.h"
#include "mbedtls/cmac.h"
#include "mbedtls/des.h"
#include "mbedtls/ecdh.h"
#include "mbedtls/ecp.h"
#include "mbedtls/entropy.h"
#include "mbedtls/error.h"
#include "mbedtls/gcm.h"
#include "mbedtls/md2.h"
#include "mbedtls/md4.h"
#include "mbedtls/md5.h"
#include "mbedtls/md.h"
#include "mbedtls/md_internal.h"
#include "mbedtls/pk.h"
#include "mbedtls/pk_internal.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"
#include "mbedtls/ripemd160.h"
#include "mbedtls/rsa.h"
#include "mbedtls/sha1.h"
#include "mbedtls/sha256.h"
#include "mbedtls/sha512.h"
#include "mbedtls/xtea.h"
#define ARRAY_LENGTH( array ) ( sizeof( array ) / sizeof( *( array ) ) )
/* constant-time buffer comparison */
static inline int safer_memcmp(const uint8_t *a, const uint8_t *b, size_t n) {
size_t i;
unsigned char diff = 0;
for (i = 0; i < n; i++)
diff |= a[i] ^ b[i];
return (diff);
}
/****************************************************************/
/* Global data, support functions and library management */
/****************************************************************/
static int key_type_is_raw_bytes(psa_key_type_t type) {
return (PSA_KEY_TYPE_IS_UNSTRUCTURED(type));
}
/* Values for psa_global_data_t::rng_state */
#define RNG_NOT_INITIALIZED 0
#define RNG_INITIALIZED 1
#define RNG_SEEDED 2
typedef struct {
mbedtls_psa_random_context_t rng;
unsigned initialized : 1;
unsigned rng_state : 2;
} psa_global_data_t;
static psa_global_data_t global_data;
#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
mbedtls_psa_drbg_context_t *const mbedtls_psa_random_state =
&global_data.rng.drbg;
#endif
#define GUARD_MODULE_INITIALIZED \
if( global_data.initialized == 0 ) \
return( PSA_ERROR_BAD_STATE );
psa_status_t mbedtls_to_psa_error(int ret) {
/* Mbed TLS error codes can combine a high-level error code and a
* low-level error code. The low-level error usually reflects the
* root cause better, so dispatch on that preferably. */
int low_level_ret = - (-ret & 0x007f);
switch (low_level_ret != 0 ? low_level_ret : ret) {
case 0:
return (PSA_SUCCESS);
case MBEDTLS_ERR_AES_INVALID_KEY_LENGTH:
case MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH:
case MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_AES_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_ARC4_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_ASN1_OUT_OF_DATA:
case MBEDTLS_ERR_ASN1_UNEXPECTED_TAG:
case MBEDTLS_ERR_ASN1_INVALID_LENGTH:
case MBEDTLS_ERR_ASN1_LENGTH_MISMATCH:
case MBEDTLS_ERR_ASN1_INVALID_DATA:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_ASN1_ALLOC_FAILED:
return (PSA_ERROR_INSUFFICIENT_MEMORY);
case MBEDTLS_ERR_ASN1_BUF_TOO_SMALL:
return (PSA_ERROR_BUFFER_TOO_SMALL);
#if defined(MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA)
case MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA:
#elif defined(MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH)
case MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH:
#endif
case MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_BLOWFISH_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
#if defined(MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA)
case MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA:
#elif defined(MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH)
case MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH:
#endif
case MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_CAMELLIA_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_CCM_BAD_INPUT:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_CCM_AUTH_FAILED:
return (PSA_ERROR_INVALID_SIGNATURE);
case MBEDTLS_ERR_CCM_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_CHACHAPOLY_BAD_STATE:
return (PSA_ERROR_BAD_STATE);
case MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED:
return (PSA_ERROR_INVALID_SIGNATURE);
case MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_CIPHER_ALLOC_FAILED:
return (PSA_ERROR_INSUFFICIENT_MEMORY);
case MBEDTLS_ERR_CIPHER_INVALID_PADDING:
return (PSA_ERROR_INVALID_PADDING);
case MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_CIPHER_AUTH_FAILED:
return (PSA_ERROR_INVALID_SIGNATURE);
case MBEDTLS_ERR_CIPHER_INVALID_CONTEXT:
return (PSA_ERROR_CORRUPTION_DETECTED);
case MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
#if !( defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) || \
defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE) )
/* Only check CTR_DRBG error codes if underlying mbedtls_xxx
* functions are passed a CTR_DRBG instance. */
case MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED:
return (PSA_ERROR_INSUFFICIENT_ENTROPY);
case MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG:
case MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR:
return (PSA_ERROR_INSUFFICIENT_ENTROPY);
#endif
case MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_DES_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED:
case MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE:
case MBEDTLS_ERR_ENTROPY_SOURCE_FAILED:
return (PSA_ERROR_INSUFFICIENT_ENTROPY);
case MBEDTLS_ERR_GCM_AUTH_FAILED:
return (PSA_ERROR_INVALID_SIGNATURE);
case MBEDTLS_ERR_GCM_BAD_INPUT:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_GCM_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) && \
defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE)
/* Only check HMAC_DRBG error codes if underlying mbedtls_xxx
* functions are passed a HMAC_DRBG instance. */
case MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED:
return (PSA_ERROR_INSUFFICIENT_ENTROPY);
case MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG:
case MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR:
return (PSA_ERROR_INSUFFICIENT_ENTROPY);
#endif
case MBEDTLS_ERR_MD2_HW_ACCEL_FAILED:
case MBEDTLS_ERR_MD4_HW_ACCEL_FAILED:
case MBEDTLS_ERR_MD5_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_MD_BAD_INPUT_DATA:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_MD_ALLOC_FAILED:
return (PSA_ERROR_INSUFFICIENT_MEMORY);
case MBEDTLS_ERR_MD_FILE_IO_ERROR:
return (PSA_ERROR_STORAGE_FAILURE);
case MBEDTLS_ERR_MD_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_MPI_FILE_IO_ERROR:
return (PSA_ERROR_STORAGE_FAILURE);
case MBEDTLS_ERR_MPI_BAD_INPUT_DATA:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_MPI_INVALID_CHARACTER:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL:
return (PSA_ERROR_BUFFER_TOO_SMALL);
case MBEDTLS_ERR_MPI_NEGATIVE_VALUE:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_MPI_DIVISION_BY_ZERO:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_MPI_NOT_ACCEPTABLE:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_MPI_ALLOC_FAILED:
return (PSA_ERROR_INSUFFICIENT_MEMORY);
case MBEDTLS_ERR_PK_ALLOC_FAILED:
return (PSA_ERROR_INSUFFICIENT_MEMORY);
case MBEDTLS_ERR_PK_TYPE_MISMATCH:
case MBEDTLS_ERR_PK_BAD_INPUT_DATA:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_PK_FILE_IO_ERROR:
return (PSA_ERROR_STORAGE_FAILURE);
case MBEDTLS_ERR_PK_KEY_INVALID_VERSION:
case MBEDTLS_ERR_PK_KEY_INVALID_FORMAT:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_PK_UNKNOWN_PK_ALG:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_PK_PASSWORD_REQUIRED:
case MBEDTLS_ERR_PK_PASSWORD_MISMATCH:
return (PSA_ERROR_NOT_PERMITTED);
case MBEDTLS_ERR_PK_INVALID_PUBKEY:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_PK_INVALID_ALG:
case MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE:
case MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_PK_SIG_LEN_MISMATCH:
return (PSA_ERROR_INVALID_SIGNATURE);
case MBEDTLS_ERR_PK_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_RIPEMD160_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_RSA_BAD_INPUT_DATA:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_RSA_INVALID_PADDING:
return (PSA_ERROR_INVALID_PADDING);
case MBEDTLS_ERR_RSA_KEY_GEN_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_RSA_KEY_CHECK_FAILED:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_RSA_PUBLIC_FAILED:
case MBEDTLS_ERR_RSA_PRIVATE_FAILED:
return (PSA_ERROR_CORRUPTION_DETECTED);
case MBEDTLS_ERR_RSA_VERIFY_FAILED:
return (PSA_ERROR_INVALID_SIGNATURE);
case MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE:
return (PSA_ERROR_BUFFER_TOO_SMALL);
case MBEDTLS_ERR_RSA_RNG_FAILED:
return (PSA_ERROR_INSUFFICIENT_ENTROPY);
case MBEDTLS_ERR_RSA_UNSUPPORTED_OPERATION:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_RSA_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_SHA1_HW_ACCEL_FAILED:
case MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED:
case MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_XTEA_INVALID_INPUT_LENGTH:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_XTEA_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_ECP_BAD_INPUT_DATA:
case MBEDTLS_ERR_ECP_INVALID_KEY:
return (PSA_ERROR_INVALID_ARGUMENT);
case MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL:
return (PSA_ERROR_BUFFER_TOO_SMALL);
case MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE:
return (PSA_ERROR_NOT_SUPPORTED);
case MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH:
case MBEDTLS_ERR_ECP_VERIFY_FAILED:
return (PSA_ERROR_INVALID_SIGNATURE);
case MBEDTLS_ERR_ECP_ALLOC_FAILED:
return (PSA_ERROR_INSUFFICIENT_MEMORY);
case MBEDTLS_ERR_ECP_RANDOM_FAILED:
return (PSA_ERROR_INSUFFICIENT_ENTROPY);
case MBEDTLS_ERR_ECP_HW_ACCEL_FAILED:
return (PSA_ERROR_HARDWARE_FAILURE);
case MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED:
return (PSA_ERROR_CORRUPTION_DETECTED);
default:
return (PSA_ERROR_GENERIC_ERROR);
}
}
/****************************************************************/
/* Key management */
/****************************************************************/
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
static inline int psa_key_slot_is_external(const psa_key_slot_t *slot) {
return (psa_key_lifetime_is_external(slot->attr.lifetime));
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
/* For now the MBEDTLS_PSA_ACCEL_ guards are also used here since the
* current test driver in key_management.c is using this function
* when accelerators are used for ECC key pair and public key.
* Once that dependency is resolved these guards can be removed.
*/
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || \
defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_ECC_KEY_PAIR) || \
defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_ECC_PUBLIC_KEY)
mbedtls_ecp_group_id mbedtls_ecc_group_of_psa(psa_ecc_family_t curve,
size_t bits,
int bits_is_sloppy) {
switch (curve) {
case PSA_ECC_FAMILY_SECP_R1:
switch (bits) {
case 192:
return (MBEDTLS_ECP_DP_SECP192R1);
case 224:
return (MBEDTLS_ECP_DP_SECP224R1);
case 256:
return (MBEDTLS_ECP_DP_SECP256R1);
case 384:
return (MBEDTLS_ECP_DP_SECP384R1);
case 521:
return (MBEDTLS_ECP_DP_SECP521R1);
case 528:
if (bits_is_sloppy)
return (MBEDTLS_ECP_DP_SECP521R1);
break;
}
break;
case PSA_ECC_FAMILY_BRAINPOOL_P_R1:
switch (bits) {
case 256:
return (MBEDTLS_ECP_DP_BP256R1);
case 384:
return (MBEDTLS_ECP_DP_BP384R1);
case 512:
return (MBEDTLS_ECP_DP_BP512R1);
}
break;
case PSA_ECC_FAMILY_MONTGOMERY:
switch (bits) {
case 255:
return (MBEDTLS_ECP_DP_CURVE25519);
case 256:
if (bits_is_sloppy)
return (MBEDTLS_ECP_DP_CURVE25519);
break;
case 448:
return (MBEDTLS_ECP_DP_CURVE448);
}
break;
case PSA_ECC_FAMILY_SECP_K1:
switch (bits) {
case 192:
return (MBEDTLS_ECP_DP_SECP192K1);
case 224:
return (MBEDTLS_ECP_DP_SECP224K1);
case 256:
return (MBEDTLS_ECP_DP_SECP256K1);
}
break;
}
return (MBEDTLS_ECP_DP_NONE);
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) ||
* defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_ECC_KEY_PAIR) ||
* defined(MBEDTLS_PSA_ACCEL_KEY_TYPE_ECC_PUBLIC_KEY) */
static psa_status_t validate_unstructured_key_bit_size(psa_key_type_t type,
size_t bits) {
/* Check that the bit size is acceptable for the key type */
switch (type) {
case PSA_KEY_TYPE_RAW_DATA:
case PSA_KEY_TYPE_HMAC:
case PSA_KEY_TYPE_DERIVE:
break;
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_AES)
case PSA_KEY_TYPE_AES:
if (bits != 128 && bits != 192 && bits != 256)
return (PSA_ERROR_INVALID_ARGUMENT);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_CAMELLIA)
case PSA_KEY_TYPE_CAMELLIA:
if (bits != 128 && bits != 192 && bits != 256)
return (PSA_ERROR_INVALID_ARGUMENT);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
case PSA_KEY_TYPE_DES:
if (bits != 64 && bits != 128 && bits != 192)
return (PSA_ERROR_INVALID_ARGUMENT);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ARC4)
case PSA_KEY_TYPE_ARC4:
if (bits < 8 || bits > 2048)
return (PSA_ERROR_INVALID_ARGUMENT);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_CHACHA20)
case PSA_KEY_TYPE_CHACHA20:
if (bits != 256)
return (PSA_ERROR_INVALID_ARGUMENT);
break;
#endif
default:
return (PSA_ERROR_NOT_SUPPORTED);
}
if (bits % 8 != 0)
return (PSA_ERROR_INVALID_ARGUMENT);
return (PSA_SUCCESS);
}
/** Return the size of the key in the given slot, in bits.
*
* \param[in] slot A key slot.
*
* \return The key size in bits, read from the metadata in the slot.
*/
static inline size_t psa_get_key_slot_bits(const psa_key_slot_t *slot) {
return (slot->attr.bits);
}
/** Check whether a given key type is valid for use with a given MAC algorithm
*
* Upon successful return of this function, the behavior of #PSA_MAC_LENGTH
* when called with the validated \p algorithm and \p key_type is well-defined.
*
* \param[in] algorithm The specific MAC algorithm (can be wildcard).
* \param[in] key_type The key type of the key to be used with the
* \p algorithm.
*
* \retval #PSA_SUCCESS
* The \p key_type is valid for use with the \p algorithm
* \retval #PSA_ERROR_INVALID_ARGUMENT
* The \p key_type is not valid for use with the \p algorithm
*/
MBEDTLS_STATIC_TESTABLE psa_status_t psa_mac_key_can_do(
psa_algorithm_t algorithm,
psa_key_type_t key_type) {
if (PSA_ALG_IS_HMAC(algorithm)) {
if (key_type == PSA_KEY_TYPE_HMAC)
return (PSA_SUCCESS);
}
if (PSA_ALG_IS_BLOCK_CIPHER_MAC(algorithm)) {
/* Check that we're calling PSA_BLOCK_CIPHER_BLOCK_LENGTH with a cipher
* key. */
if ((key_type & PSA_KEY_TYPE_CATEGORY_MASK) ==
PSA_KEY_TYPE_CATEGORY_SYMMETRIC) {
/* PSA_BLOCK_CIPHER_BLOCK_LENGTH returns 1 for stream ciphers and
* the block length (larger than 1) for block ciphers. */
if (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1)
return (PSA_SUCCESS);
}
}
return (PSA_ERROR_INVALID_ARGUMENT);
}
/** Try to allocate a buffer to an empty key slot.
*
* \param[in,out] slot Key slot to attach buffer to.
* \param[in] buffer_length Requested size of the buffer.
*
* \retval #PSA_SUCCESS
* The buffer has been successfully allocated.
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
* Not enough memory was available for allocation.
* \retval #PSA_ERROR_ALREADY_EXISTS
* Trying to allocate a buffer to a non-empty key slot.
*/
static psa_status_t psa_allocate_buffer_to_slot(psa_key_slot_t *slot,
size_t buffer_length) {
if (slot->key.data != NULL)
return (PSA_ERROR_ALREADY_EXISTS);
slot->key.data = mbedtls_calloc(1, buffer_length);
if (slot->key.data == NULL)
return (PSA_ERROR_INSUFFICIENT_MEMORY);
slot->key.bytes = buffer_length;
return (PSA_SUCCESS);
}
psa_status_t psa_copy_key_material_into_slot(psa_key_slot_t *slot,
const uint8_t *data,
size_t data_length) {
psa_status_t status = psa_allocate_buffer_to_slot(slot,
data_length);
if (status != PSA_SUCCESS)
return (status);
memcpy(slot->key.data, data, data_length);
return (PSA_SUCCESS);
}
psa_status_t psa_import_key_into_slot(
const psa_key_attributes_t *attributes,
const uint8_t *data, size_t data_length,
uint8_t *key_buffer, size_t key_buffer_size,
size_t *key_buffer_length, size_t *bits) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_type_t type = attributes->core.type;
/* zero-length keys are never supported. */
if (data_length == 0)
return (PSA_ERROR_NOT_SUPPORTED);
if (key_type_is_raw_bytes(type)) {
*bits = PSA_BYTES_TO_BITS(data_length);
/* Ensure that the bytes-to-bits conversion hasn't overflown. */
if (data_length > SIZE_MAX / 8)
return (PSA_ERROR_NOT_SUPPORTED);
/* Enforce a size limit, and in particular ensure that the bit
* size fits in its representation type. */
if ((*bits) > PSA_MAX_KEY_BITS)
return (PSA_ERROR_NOT_SUPPORTED);
status = validate_unstructured_key_bit_size(type, *bits);
if (status != PSA_SUCCESS)
return (status);
/* Copy the key material. */
memcpy(key_buffer, data, data_length);
*key_buffer_length = data_length;
(void)key_buffer_size;
return (PSA_SUCCESS);
} else if (PSA_KEY_TYPE_IS_ASYMMETRIC(type)) {
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY)
if (PSA_KEY_TYPE_IS_ECC(type)) {
return (mbedtls_psa_ecp_import_key(attributes,
data, data_length,
key_buffer, key_buffer_size,
key_buffer_length,
bits));
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
if (PSA_KEY_TYPE_IS_RSA(type)) {
return (mbedtls_psa_rsa_import_key(attributes,
data, data_length,
key_buffer, key_buffer_size,
key_buffer_length,
bits));
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
}
return (PSA_ERROR_NOT_SUPPORTED);
}
/** Calculate the intersection of two algorithm usage policies.
*
* Return 0 (which allows no operation) on incompatibility.
*/
static psa_algorithm_t psa_key_policy_algorithm_intersection(
psa_key_type_t key_type,
psa_algorithm_t alg1,
psa_algorithm_t alg2) {
/* Common case: both sides actually specify the same policy. */
if (alg1 == alg2)
return (alg1);
/* If the policies are from the same hash-and-sign family, check
* if one is a wildcard. If so the other has the specific algorithm. */
if (PSA_ALG_IS_HASH_AND_SIGN(alg1) &&
PSA_ALG_IS_HASH_AND_SIGN(alg2) &&
(alg1 & ~PSA_ALG_HASH_MASK) == (alg2 & ~PSA_ALG_HASH_MASK)) {
if (PSA_ALG_SIGN_GET_HASH(alg1) == PSA_ALG_ANY_HASH)
return (alg2);
if (PSA_ALG_SIGN_GET_HASH(alg2) == PSA_ALG_ANY_HASH)
return (alg1);
}
/* If the policies are from the same AEAD family, check whether
* one of them is a minimum-tag-length wildcard. Calculate the most
* restrictive tag length. */
if (PSA_ALG_IS_AEAD(alg1) && PSA_ALG_IS_AEAD(alg2) &&
(PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg1, 0) ==
PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg2, 0))) {
size_t alg1_len = PSA_ALG_AEAD_GET_TAG_LENGTH(alg1);
size_t alg2_len = PSA_ALG_AEAD_GET_TAG_LENGTH(alg2);
size_t restricted_len = alg1_len > alg2_len ? alg1_len : alg2_len;
/* If both are wildcards, return most restrictive wildcard */
if (((alg1 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0) &&
((alg2 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0)) {
return (PSA_ALG_AEAD_WITH_AT_LEAST_THIS_LENGTH_TAG(
alg1, restricted_len));
}
/* If only one is a wildcard, return specific algorithm if compatible. */
if (((alg1 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0) &&
(alg1_len <= alg2_len)) {
return (alg2);
}
if (((alg2 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0) &&
(alg2_len <= alg1_len)) {
return (alg1);
}
}
/* If the policies are from the same MAC family, check whether one
* of them is a minimum-MAC-length policy. Calculate the most
* restrictive tag length. */
if (PSA_ALG_IS_MAC(alg1) && PSA_ALG_IS_MAC(alg2) &&
(PSA_ALG_FULL_LENGTH_MAC(alg1) ==
PSA_ALG_FULL_LENGTH_MAC(alg2))) {
/* Validate the combination of key type and algorithm. Since the base
* algorithm of alg1 and alg2 are the same, we only need this once. */
if (PSA_SUCCESS != psa_mac_key_can_do(alg1, key_type))
return (0);
/* Get the (exact or at-least) output lengths for both sides of the
* requested intersection. None of the currently supported algorithms
* have an output length dependent on the actual key size, so setting it
* to a bogus value of 0 is currently OK.
*
* Note that for at-least-this-length wildcard algorithms, the output
* length is set to the shortest allowed length, which allows us to
* calculate the most restrictive tag length for the intersection. */
size_t alg1_len = PSA_MAC_LENGTH(key_type, 0, alg1);
size_t alg2_len = PSA_MAC_LENGTH(key_type, 0, alg2);
size_t restricted_len = alg1_len > alg2_len ? alg1_len : alg2_len;
/* If both are wildcards, return most restrictive wildcard */
if (((alg1 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) &&
((alg2 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0)) {
return (PSA_ALG_AT_LEAST_THIS_LENGTH_MAC(alg1, restricted_len));
}
/* If only one is an at-least-this-length policy, the intersection would
* be the other (fixed-length) policy as long as said fixed length is
* equal to or larger than the shortest allowed length. */
if ((alg1 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) {
return ((alg1_len <= alg2_len) ? alg2 : 0);
}
if ((alg2 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) {
return ((alg2_len <= alg1_len) ? alg1 : 0);
}
/* If none of them are wildcards, check whether they define the same tag
* length. This is still possible here when one is default-length and
* the other specific-length. Ensure to always return the
* specific-length version for the intersection. */
if (alg1_len == alg2_len)
return (PSA_ALG_TRUNCATED_MAC(alg1, alg1_len));
}
/* If the policies are incompatible, allow nothing. */
return (0);
}
static int psa_key_algorithm_permits(psa_key_type_t key_type,
psa_algorithm_t policy_alg,
psa_algorithm_t requested_alg) {
/* Common case: the policy only allows requested_alg. */
if (requested_alg == policy_alg)
return (1);
/* If policy_alg is a hash-and-sign with a wildcard for the hash,
* and requested_alg is the same hash-and-sign family with any hash,
* then requested_alg is compliant with policy_alg. */
if (PSA_ALG_IS_HASH_AND_SIGN(requested_alg) &&
PSA_ALG_SIGN_GET_HASH(policy_alg) == PSA_ALG_ANY_HASH) {
return ((policy_alg & ~PSA_ALG_HASH_MASK) ==
(requested_alg & ~PSA_ALG_HASH_MASK));
}
/* If policy_alg is a wildcard AEAD algorithm of the same base as
* the requested algorithm, check the requested tag length to be
* equal-length or longer than the wildcard-specified length. */
if (PSA_ALG_IS_AEAD(policy_alg) &&
PSA_ALG_IS_AEAD(requested_alg) &&
(PSA_ALG_AEAD_WITH_SHORTENED_TAG(policy_alg, 0) ==
PSA_ALG_AEAD_WITH_SHORTENED_TAG(requested_alg, 0)) &&
((policy_alg & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0)) {
return (PSA_ALG_AEAD_GET_TAG_LENGTH(policy_alg) <=
PSA_ALG_AEAD_GET_TAG_LENGTH(requested_alg));
}
/* If policy_alg is a MAC algorithm of the same base as the requested
* algorithm, check whether their MAC lengths are compatible. */
if (PSA_ALG_IS_MAC(policy_alg) &&
PSA_ALG_IS_MAC(requested_alg) &&
(PSA_ALG_FULL_LENGTH_MAC(policy_alg) ==
PSA_ALG_FULL_LENGTH_MAC(requested_alg))) {
/* Validate the combination of key type and algorithm. Since the policy
* and requested algorithms are the same, we only need this once. */
if (PSA_SUCCESS != psa_mac_key_can_do(policy_alg, key_type))
return (0);
/* Get both the requested output length for the algorithm which is to be
* verified, and the default output length for the base algorithm.
* Note that none of the currently supported algorithms have an output
* length dependent on actual key size, so setting it to a bogus value
* of 0 is currently OK. */
size_t requested_output_length = PSA_MAC_LENGTH(
key_type, 0, requested_alg);
size_t default_output_length = PSA_MAC_LENGTH(
key_type, 0,
PSA_ALG_FULL_LENGTH_MAC(requested_alg));
/* If the policy is default-length, only allow an algorithm with
* a declared exact-length matching the default. */
if (PSA_MAC_TRUNCATED_LENGTH(policy_alg) == 0)
return (requested_output_length == default_output_length);
/* If the requested algorithm is default-length, allow it if the policy
* length exactly matches the default length. */
if (PSA_MAC_TRUNCATED_LENGTH(requested_alg) == 0 &&
PSA_MAC_TRUNCATED_LENGTH(policy_alg) == default_output_length) {
return (1);
}
/* If policy_alg is an at-least-this-length wildcard MAC algorithm,
* check for the requested MAC length to be equal to or longer than the
* minimum allowed length. */
if ((policy_alg & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) {
return (PSA_MAC_TRUNCATED_LENGTH(policy_alg) <=
requested_output_length);
}
}
/* If policy_alg is a generic key agreement operation, then using it for
* a key derivation with that key agreement should also be allowed. This
* behaviour is expected to be defined in a future specification version. */
if (PSA_ALG_IS_RAW_KEY_AGREEMENT(policy_alg) &&
PSA_ALG_IS_KEY_AGREEMENT(requested_alg)) {
return (PSA_ALG_KEY_AGREEMENT_GET_BASE(requested_alg) ==
policy_alg);
}
/* If it isn't explicitly permitted, it's forbidden. */
return (0);
}
/** Test whether a policy permits an algorithm.
*
* The caller must test usage flags separately.
*
* \note This function requires providing the key type for which the policy is
* being validated, since some algorithm policy definitions (e.g. MAC)
* have different properties depending on what kind of cipher it is
* combined with.
*
* \retval PSA_SUCCESS When \p alg is a specific algorithm
* allowed by the \p policy.
* \retval PSA_ERROR_INVALID_ARGUMENT When \p alg is not a specific algorithm
* \retval PSA_ERROR_NOT_PERMITTED When \p alg is a specific algorithm, but
* the \p policy does not allow it.
*/
static psa_status_t psa_key_policy_permits(const psa_key_policy_t *policy,
psa_key_type_t key_type,
psa_algorithm_t alg) {
/* '0' is not a valid algorithm */
if (alg == 0)
return (PSA_ERROR_INVALID_ARGUMENT);
/* A requested algorithm cannot be a wildcard. */
if (PSA_ALG_IS_WILDCARD(alg))
return (PSA_ERROR_INVALID_ARGUMENT);
if (psa_key_algorithm_permits(key_type, policy->alg, alg) ||
psa_key_algorithm_permits(key_type, policy->alg2, alg))
return (PSA_SUCCESS);
else
return (PSA_ERROR_NOT_PERMITTED);
}
/** Restrict a key policy based on a constraint.
*
* \note This function requires providing the key type for which the policy is
* being restricted, since some algorithm policy definitions (e.g. MAC)
* have different properties depending on what kind of cipher it is
* combined with.
*
* \param[in] key_type The key type for which to restrict the policy
* \param[in,out] policy The policy to restrict.
* \param[in] constraint The policy constraint to apply.
*
* \retval #PSA_SUCCESS
* \c *policy contains the intersection of the original value of
* \c *policy and \c *constraint.
* \retval #PSA_ERROR_INVALID_ARGUMENT
* \c key_type, \c *policy and \c *constraint are incompatible.
* \c *policy is unchanged.
*/
static psa_status_t psa_restrict_key_policy(
psa_key_type_t key_type,
psa_key_policy_t *policy,
const psa_key_policy_t *constraint) {
psa_algorithm_t intersection_alg =
psa_key_policy_algorithm_intersection(key_type, policy->alg,
constraint->alg);
psa_algorithm_t intersection_alg2 =
psa_key_policy_algorithm_intersection(key_type, policy->alg2,
constraint->alg2);
if (intersection_alg == 0 && policy->alg != 0 && constraint->alg != 0)
return (PSA_ERROR_INVALID_ARGUMENT);
if (intersection_alg2 == 0 && policy->alg2 != 0 && constraint->alg2 != 0)
return (PSA_ERROR_INVALID_ARGUMENT);
policy->usage &= constraint->usage;
policy->alg = intersection_alg;
policy->alg2 = intersection_alg2;
return (PSA_SUCCESS);
}
/** Get the description of a key given its identifier and policy constraints
* and lock it.
*
* The key must have allow all the usage flags set in \p usage. If \p alg is
* nonzero, the key must allow operations with this algorithm. If \p alg is
* zero, the algorithm is not checked.
*
* In case of a persistent key, the function loads the description of the key
* into a key slot if not already done.
*
* On success, the returned key slot is locked. It is the responsibility of
* the caller to unlock the key slot when it does not access it anymore.
*/
static psa_status_t psa_get_and_lock_key_slot_with_policy(
mbedtls_svc_key_id_t key,
psa_key_slot_t **p_slot,
psa_key_usage_t usage,
psa_algorithm_t alg) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
status = psa_get_and_lock_key_slot(key, p_slot);
if (status != PSA_SUCCESS)
return (status);
slot = *p_slot;
/* Enforce that usage policy for the key slot contains all the flags
* required by the usage parameter. There is one exception: public
* keys can always be exported, so we treat public key objects as
* if they had the export flag. */
if (PSA_KEY_TYPE_IS_PUBLIC_KEY(slot->attr.type))
usage &= ~PSA_KEY_USAGE_EXPORT;
if ((slot->attr.policy.usage & usage) != usage) {
status = PSA_ERROR_NOT_PERMITTED;
goto error;
}
/* Enforce that the usage policy permits the requested algortihm. */
if (alg != 0) {
status = psa_key_policy_permits(&slot->attr.policy,
slot->attr.type,
alg);
if (status != PSA_SUCCESS)
goto error;
}
return (PSA_SUCCESS);
error:
*p_slot = NULL;
psa_unlock_key_slot(slot);
return (status);
}
/** Get a key slot containing a transparent key and lock it.
*
* A transparent key is a key for which the key material is directly
* available, as opposed to a key in a secure element.
*
* This is a temporary function to use instead of
* psa_get_and_lock_key_slot_with_policy() until secure element support is
* fully implemented.
*
* On success, the returned key slot is locked. It is the responsibility of the
* caller to unlock the key slot when it does not access it anymore.
*/
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
static psa_status_t psa_get_and_lock_transparent_key_slot_with_policy(
mbedtls_svc_key_id_t key,
psa_key_slot_t **p_slot,
psa_key_usage_t usage,
psa_algorithm_t alg) {
psa_status_t status = psa_get_and_lock_key_slot_with_policy(key, p_slot,
usage, alg);
if (status != PSA_SUCCESS)
return (status);
if (psa_key_slot_is_external(*p_slot)) {
psa_unlock_key_slot(*p_slot);
*p_slot = NULL;
return (PSA_ERROR_NOT_SUPPORTED);
}
return (PSA_SUCCESS);
}
#else /* MBEDTLS_PSA_CRYPTO_SE_C */
/* With no secure element support, all keys are transparent. */
#define psa_get_and_lock_transparent_key_slot_with_policy( key, p_slot, usage, alg ) \
psa_get_and_lock_key_slot_with_policy( key, p_slot, usage, alg )
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
/** Wipe key data from a slot. Preserve metadata such as the policy. */
static psa_status_t psa_remove_key_data_from_memory(psa_key_slot_t *slot) {
/* Data pointer will always be either a valid pointer or NULL in an
* initialized slot, so we can just free it. */
if (slot->key.data != NULL)
mbedtls_platform_zeroize(slot->key.data, slot->key.bytes);
mbedtls_free(slot->key.data);
slot->key.data = NULL;
slot->key.bytes = 0;
return (PSA_SUCCESS);
}
/** Completely wipe a slot in memory, including its policy.
* Persistent storage is not affected. */
psa_status_t psa_wipe_key_slot(psa_key_slot_t *slot) {
psa_status_t status = psa_remove_key_data_from_memory(slot);
/*
* As the return error code may not be handled in case of multiple errors,
* do our best to report an unexpected lock counter: if available
* call MBEDTLS_PARAM_FAILED that may terminate execution (if called as
* part of the execution of a test suite this will stop the test suite
* execution).
*/
if (slot->lock_count != 1) {
#ifdef MBEDTLS_CHECK_PARAMS
MBEDTLS_PARAM_FAILED(slot->lock_count == 1);
#endif
status = PSA_ERROR_CORRUPTION_DETECTED;
}
/* Multipart operations may still be using the key. This is safe
* because all multipart operation objects are independent from
* the key slot: if they need to access the key after the setup
* phase, they have a copy of the key. Note that this means that
* key material can linger until all operations are completed. */
/* At this point, key material and other type-specific content has
* been wiped. Clear remaining metadata. We can call memset and not
* zeroize because the metadata is not particularly sensitive. */
memset(slot, 0, sizeof(*slot));
return (status);
}
psa_status_t psa_destroy_key(mbedtls_svc_key_id_t key) {
psa_key_slot_t *slot;
psa_status_t status; /* status of the last operation */
psa_status_t overall_status = PSA_SUCCESS;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
psa_se_drv_table_entry_t *driver;
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
if (mbedtls_svc_key_id_is_null(key))
return (PSA_SUCCESS);
/*
* Get the description of the key in a key slot. In case of a persistent
* key, this will load the key description from persistent memory if not
* done yet. We cannot avoid this loading as without it we don't know if
* the key is operated by an SE or not and this information is needed by
* the current implementation.
*/
status = psa_get_and_lock_key_slot(key, &slot);
if (status != PSA_SUCCESS)
return (status);
/*
* If the key slot containing the key description is under access by the
* library (apart from the present access), the key cannot be destroyed
* yet. For the time being, just return in error. Eventually (to be
* implemented), the key should be destroyed when all accesses have
* stopped.
*/
if (slot->lock_count > 1) {
psa_unlock_key_slot(slot);
return (PSA_ERROR_GENERIC_ERROR);
}
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
driver = psa_get_se_driver_entry(slot->attr.lifetime);
if (driver != NULL) {
/* For a key in a secure element, we need to do three things:
* remove the key file in internal storage, destroy the
* key inside the secure element, and update the driver's
* persistent data. Start a transaction that will encompass these
* three actions. */
psa_crypto_prepare_transaction(PSA_CRYPTO_TRANSACTION_DESTROY_KEY);
psa_crypto_transaction.key.lifetime = slot->attr.lifetime;
psa_crypto_transaction.key.slot = psa_key_slot_get_slot_number(slot);
psa_crypto_transaction.key.id = slot->attr.id;
status = psa_crypto_save_transaction();
if (status != PSA_SUCCESS) {
(void) psa_crypto_stop_transaction();
/* We should still try to destroy the key in the secure
* element and the key metadata in storage. This is especially
* important if the error is that the storage is full.
* But how to do it exactly without risking an inconsistent
* state after a reset?
* https://github.com/ARMmbed/mbed-crypto/issues/215
*/
overall_status = status;
goto exit;
}
status = psa_destroy_se_key(driver,
psa_key_slot_get_slot_number(slot));
if (overall_status == PSA_SUCCESS)
overall_status = status;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
if (! PSA_KEY_LIFETIME_IS_VOLATILE(slot->attr.lifetime)) {
status = psa_destroy_persistent_key(slot->attr.id);
if (overall_status == PSA_SUCCESS)
overall_status = status;
/* TODO: other slots may have a copy of the same key. We should
* invalidate them.
* https://github.com/ARMmbed/mbed-crypto/issues/214
*/
}
#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if (driver != NULL) {
status = psa_save_se_persistent_data(driver);
if (overall_status == PSA_SUCCESS)
overall_status = status;
status = psa_crypto_stop_transaction();
if (overall_status == PSA_SUCCESS)
overall_status = status;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
exit:
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
status = psa_wipe_key_slot(slot);
/* Prioritize CORRUPTION_DETECTED from wiping over a storage error */
if (overall_status == PSA_SUCCESS)
overall_status = status;
return (overall_status);
}
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
static psa_status_t psa_get_rsa_public_exponent(
const mbedtls_rsa_context *rsa,
psa_key_attributes_t *attributes) {
mbedtls_mpi mpi;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
uint8_t *buffer = NULL;
size_t buflen;
mbedtls_mpi_init(&mpi);
ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &mpi);
if (ret != 0)
goto exit;
if (mbedtls_mpi_cmp_int(&mpi, 65537) == 0) {
/* It's the default value, which is reported as an empty string,
* so there's nothing to do. */
goto exit;
}
buflen = mbedtls_mpi_size(&mpi);
buffer = mbedtls_calloc(1, buflen);
if (buffer == NULL) {
ret = MBEDTLS_ERR_MPI_ALLOC_FAILED;
goto exit;
}
ret = mbedtls_mpi_write_binary(&mpi, buffer, buflen);
if (ret != 0)
goto exit;
attributes->domain_parameters = buffer;
attributes->domain_parameters_size = buflen;
exit:
mbedtls_mpi_free(&mpi);
if (ret != 0)
mbedtls_free(buffer);
return (mbedtls_to_psa_error(ret));
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
/** Retrieve all the publicly-accessible attributes of a key.
*/
psa_status_t psa_get_key_attributes(mbedtls_svc_key_id_t key,
psa_key_attributes_t *attributes) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
psa_reset_key_attributes(attributes);
status = psa_get_and_lock_key_slot_with_policy(key, &slot, 0, 0);
if (status != PSA_SUCCESS)
return (status);
attributes->core = slot->attr;
attributes->core.flags &= (MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY |
MBEDTLS_PSA_KA_MASK_DUAL_USE);
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if (psa_key_slot_is_external(slot))
psa_set_key_slot_number(attributes,
psa_key_slot_get_slot_number(slot));
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
switch (slot->attr.type) {
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
case PSA_KEY_TYPE_RSA_KEY_PAIR:
case PSA_KEY_TYPE_RSA_PUBLIC_KEY:
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* TODO: reporting the public exponent for opaque keys
* is not yet implemented.
* https://github.com/ARMmbed/mbed-crypto/issues/216
*/
if (psa_key_slot_is_external(slot))
break;
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
{
mbedtls_rsa_context *rsa = NULL;
status = mbedtls_psa_rsa_load_representation(
slot->attr.type,
slot->key.data,
slot->key.bytes,
&rsa);
if (status != PSA_SUCCESS)
break;
status = psa_get_rsa_public_exponent(rsa,
attributes);
mbedtls_rsa_free(rsa);
mbedtls_free(rsa);
}
break;
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
default:
/* Nothing else to do. */
break;
}
if (status != PSA_SUCCESS)
psa_reset_key_attributes(attributes);
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
psa_status_t psa_get_key_slot_number(
const psa_key_attributes_t *attributes,
psa_key_slot_number_t *slot_number) {
if (attributes->core.flags & MBEDTLS_PSA_KA_FLAG_HAS_SLOT_NUMBER) {
*slot_number = attributes->slot_number;
return (PSA_SUCCESS);
} else
return (PSA_ERROR_INVALID_ARGUMENT);
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
static psa_status_t psa_export_key_buffer_internal(const uint8_t *key_buffer,
size_t key_buffer_size,
uint8_t *data,
size_t data_size,
size_t *data_length) {
if (key_buffer_size > data_size)
return (PSA_ERROR_BUFFER_TOO_SMALL);
memcpy(data, key_buffer, key_buffer_size);
memset(data + key_buffer_size, 0,
data_size - key_buffer_size);
*data_length = key_buffer_size;
return (PSA_SUCCESS);
}
psa_status_t psa_export_key_internal(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer, size_t key_buffer_size,
uint8_t *data, size_t data_size, size_t *data_length) {
psa_key_type_t type = attributes->core.type;
if (key_type_is_raw_bytes(type) ||
PSA_KEY_TYPE_IS_RSA(type) ||
PSA_KEY_TYPE_IS_ECC(type)) {
return (psa_export_key_buffer_internal(
key_buffer, key_buffer_size,
data, data_size, data_length));
} else {
/* This shouldn't happen in the reference implementation, but
it is valid for a special-purpose implementation to omit
support for exporting certain key types. */
return (PSA_ERROR_NOT_SUPPORTED);
}
}
psa_status_t psa_export_key(mbedtls_svc_key_id_t key,
uint8_t *data,
size_t data_size,
size_t *data_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
/* Reject a zero-length output buffer now, since this can never be a
* valid key representation. This way we know that data must be a valid
* pointer and we can do things like memset(data, ..., data_size). */
if (data_size == 0)
return (PSA_ERROR_BUFFER_TOO_SMALL);
/* Set the key to empty now, so that even when there are errors, we always
* set data_length to a value between 0 and data_size. On error, setting
* the key to empty is a good choice because an empty key representation is
* unlikely to be accepted anywhere. */
*data_length = 0;
/* Export requires the EXPORT flag. There is an exception for public keys,
* which don't require any flag, but
* psa_get_and_lock_key_slot_with_policy() takes care of this.
*/
status = psa_get_and_lock_key_slot_with_policy(key, &slot,
PSA_KEY_USAGE_EXPORT, 0);
if (status != PSA_SUCCESS)
return (status);
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_driver_wrapper_export_key(&attributes,
slot->key.data, slot->key.bytes,
data, data_size, data_length);
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
psa_status_t psa_export_public_key_internal(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer,
size_t key_buffer_size,
uint8_t *data,
size_t data_size,
size_t *data_length) {
psa_key_type_t type = attributes->core.type;
if (PSA_KEY_TYPE_IS_RSA(type) || PSA_KEY_TYPE_IS_ECC(type)) {
if (PSA_KEY_TYPE_IS_PUBLIC_KEY(type)) {
/* Exporting public -> public */
return (psa_export_key_buffer_internal(
key_buffer, key_buffer_size,
data, data_size, data_length));
}
if (PSA_KEY_TYPE_IS_RSA(type)) {
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
return (mbedtls_psa_rsa_export_public_key(attributes,
key_buffer,
key_buffer_size,
data,
data_size,
data_length));
#else
/* We don't know how to convert a private RSA key to public. */
return (PSA_ERROR_NOT_SUPPORTED);
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
} else {
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY)
return (mbedtls_psa_ecp_export_public_key(attributes,
key_buffer,
key_buffer_size,
data,
data_size,
data_length));
#else
/* We don't know how to convert a private ECC key to public */
return (PSA_ERROR_NOT_SUPPORTED);
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */
}
} else {
/* This shouldn't happen in the reference implementation, but
it is valid for a special-purpose implementation to omit
support for exporting certain key types. */
return (PSA_ERROR_NOT_SUPPORTED);
}
}
psa_status_t psa_export_public_key(mbedtls_svc_key_id_t key,
uint8_t *data,
size_t data_size,
size_t *data_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
/* Reject a zero-length output buffer now, since this can never be a
* valid key representation. This way we know that data must be a valid
* pointer and we can do things like memset(data, ..., data_size). */
if (data_size == 0)
return (PSA_ERROR_BUFFER_TOO_SMALL);
/* Set the key to empty now, so that even when there are errors, we always
* set data_length to a value between 0 and data_size. On error, setting
* the key to empty is a good choice because an empty key representation is
* unlikely to be accepted anywhere. */
*data_length = 0;
/* Exporting a public key doesn't require a usage flag. */
status = psa_get_and_lock_key_slot_with_policy(key, &slot, 0, 0);
if (status != PSA_SUCCESS)
return (status);
if (! PSA_KEY_TYPE_IS_ASYMMETRIC(slot->attr.type)) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_driver_wrapper_export_public_key(
&attributes, slot->key.data, slot->key.bytes,
data, data_size, data_length);
exit:
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
#if defined(static_assert)
static_assert((MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY &MBEDTLS_PSA_KA_MASK_DUAL_USE) == 0,
"One or more key attribute flag is listed as both external-only and dual-use");
static_assert((PSA_KA_MASK_INTERNAL_ONLY &MBEDTLS_PSA_KA_MASK_DUAL_USE) == 0,
"One or more key attribute flag is listed as both internal-only and dual-use");
static_assert((PSA_KA_MASK_INTERNAL_ONLY &MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY) == 0,
"One or more key attribute flag is listed as both internal-only and external-only");
#endif
/** Validate that a key policy is internally well-formed.
*
* This function only rejects invalid policies. It does not validate the
* consistency of the policy with respect to other attributes of the key
* such as the key type.
*/
static psa_status_t psa_validate_key_policy(const psa_key_policy_t *policy) {
if ((policy->usage & ~(PSA_KEY_USAGE_EXPORT |
PSA_KEY_USAGE_COPY |
PSA_KEY_USAGE_ENCRYPT |
PSA_KEY_USAGE_DECRYPT |
PSA_KEY_USAGE_SIGN_HASH |
PSA_KEY_USAGE_VERIFY_HASH |
PSA_KEY_USAGE_DERIVE)) != 0)
return (PSA_ERROR_INVALID_ARGUMENT);
return (PSA_SUCCESS);
}
/** Validate the internal consistency of key attributes.
*
* This function only rejects invalid attribute values. If does not
* validate the consistency of the attributes with any key data that may
* be involved in the creation of the key.
*
* Call this function early in the key creation process.
*
* \param[in] attributes Key attributes for the new key.
* \param[out] p_drv On any return, the driver for the key, if any.
* NULL for a transparent key.
*
*/
static psa_status_t psa_validate_key_attributes(
const psa_key_attributes_t *attributes,
psa_se_drv_table_entry_t **p_drv) {
psa_status_t status = PSA_ERROR_INVALID_ARGUMENT;
psa_key_lifetime_t lifetime = psa_get_key_lifetime(attributes);
mbedtls_svc_key_id_t key = psa_get_key_id(attributes);
status = psa_validate_key_location(lifetime, p_drv);
if (status != PSA_SUCCESS)
return (status);
status = psa_validate_key_persistence(lifetime);
if (status != PSA_SUCCESS)
return (status);
if (PSA_KEY_LIFETIME_IS_VOLATILE(lifetime)) {
if (MBEDTLS_SVC_KEY_ID_GET_KEY_ID(key) != 0)
return (PSA_ERROR_INVALID_ARGUMENT);
} else {
status = psa_validate_key_id(psa_get_key_id(attributes), 0);
if (status != PSA_SUCCESS)
return (status);
}
status = psa_validate_key_policy(&attributes->core.policy);
if (status != PSA_SUCCESS)
return (status);
/* Refuse to create overly large keys.
* Note that this doesn't trigger on import if the attributes don't
* explicitly specify a size (so psa_get_key_bits returns 0), so
* psa_import_key() needs its own checks. */
if (psa_get_key_bits(attributes) > PSA_MAX_KEY_BITS)
return (PSA_ERROR_NOT_SUPPORTED);
/* Reject invalid flags. These should not be reachable through the API. */
if (attributes->core.flags & ~(MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY |
MBEDTLS_PSA_KA_MASK_DUAL_USE))
return (PSA_ERROR_INVALID_ARGUMENT);
return (PSA_SUCCESS);
}
/** Prepare a key slot to receive key material.
*
* This function allocates a key slot and sets its metadata.
*
* If this function fails, call psa_fail_key_creation().
*
* This function is intended to be used as follows:
* -# Call psa_start_key_creation() to allocate a key slot, prepare
* it with the specified attributes, and in case of a volatile key assign it
* a volatile key identifier.
* -# Populate the slot with the key material.
* -# Call psa_finish_key_creation() to finalize the creation of the slot.
* In case of failure at any step, stop the sequence and call
* psa_fail_key_creation().
*
* On success, the key slot is locked. It is the responsibility of the caller
* to unlock the key slot when it does not access it anymore.
*
* \param method An identification of the calling function.
* \param[in] attributes Key attributes for the new key.
* \param[out] p_slot On success, a pointer to the prepared slot.
* \param[out] p_drv On any return, the driver for the key, if any.
* NULL for a transparent key.
*
* \retval #PSA_SUCCESS
* The key slot is ready to receive key material.
* \return If this function fails, the key slot is an invalid state.
* You must call psa_fail_key_creation() to wipe and free the slot.
*/
static psa_status_t psa_start_key_creation(
psa_key_creation_method_t method,
const psa_key_attributes_t *attributes,
psa_key_slot_t **p_slot,
psa_se_drv_table_entry_t **p_drv) {
psa_status_t status;
psa_key_id_t volatile_key_id;
psa_key_slot_t *slot;
(void) method;
*p_drv = NULL;
status = psa_validate_key_attributes(attributes, p_drv);
if (status != PSA_SUCCESS)
return (status);
status = psa_get_empty_key_slot(&volatile_key_id, p_slot);
if (status != PSA_SUCCESS)
return (status);
slot = *p_slot;
/* We're storing the declared bit-size of the key. It's up to each
* creation mechanism to verify that this information is correct.
* It's automatically correct for mechanisms that use the bit-size as
* an input (generate, device) but not for those where the bit-size
* is optional (import, copy). In case of a volatile key, assign it the
* volatile key identifier associated to the slot returned to contain its
* definition. */
slot->attr = attributes->core;
if (PSA_KEY_LIFETIME_IS_VOLATILE(slot->attr.lifetime)) {
#if !defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER)
slot->attr.id = volatile_key_id;
#else
slot->attr.id.key_id = volatile_key_id;
#endif
}
/* Erase external-only flags from the internal copy. To access
* external-only flags, query `attributes`. Thanks to the check
* in psa_validate_key_attributes(), this leaves the dual-use
* flags and any internal flag that psa_get_empty_key_slot()
* may have set. */
slot->attr.flags &= ~MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* For a key in a secure element, we need to do three things
* when creating or registering a persistent key:
* create the key file in internal storage, create the
* key inside the secure element, and update the driver's
* persistent data. This is done by starting a transaction that will
* encompass these three actions.
* For registering a volatile key, we just need to find an appropriate
* slot number inside the SE. Since the key is designated volatile, creating
* a transaction is not required. */
/* The first thing to do is to find a slot number for the new key.
* We save the slot number in persistent storage as part of the
* transaction data. It will be needed to recover if the power
* fails during the key creation process, to clean up on the secure
* element side after restarting. Obtaining a slot number from the
* secure element driver updates its persistent state, but we do not yet
* save the driver's persistent state, so that if the power fails,
* we can roll back to a state where the key doesn't exist. */
if (*p_drv != NULL) {
psa_key_slot_number_t slot_number;
status = psa_find_se_slot_for_key(attributes, method, *p_drv,
&slot_number);
if (status != PSA_SUCCESS)
return (status);
if (! PSA_KEY_LIFETIME_IS_VOLATILE(attributes->core.lifetime)) {
psa_crypto_prepare_transaction(PSA_CRYPTO_TRANSACTION_CREATE_KEY);
psa_crypto_transaction.key.lifetime = slot->attr.lifetime;
psa_crypto_transaction.key.slot = slot_number;
psa_crypto_transaction.key.id = slot->attr.id;
status = psa_crypto_save_transaction();
if (status != PSA_SUCCESS) {
(void) psa_crypto_stop_transaction();
return (status);
}
}
status = psa_copy_key_material_into_slot(
slot, (uint8_t *)(&slot_number), sizeof(slot_number));
}
if (*p_drv == NULL && method == PSA_KEY_CREATION_REGISTER) {
/* Key registration only makes sense with a secure element. */
return (PSA_ERROR_INVALID_ARGUMENT);
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
return (PSA_SUCCESS);
}
/** Finalize the creation of a key once its key material has been set.
*
* This entails writing the key to persistent storage.
*
* If this function fails, call psa_fail_key_creation().
* See the documentation of psa_start_key_creation() for the intended use
* of this function.
*
* If the finalization succeeds, the function unlocks the key slot (it was
* locked by psa_start_key_creation()) and the key slot cannot be accessed
* anymore as part of the key creation process.
*
* \param[in,out] slot Pointer to the slot with key material.
* \param[in] driver The secure element driver for the key,
* or NULL for a transparent key.
* \param[out] key On success, identifier of the key. Note that the
* key identifier is also stored in the key slot.
*
* \retval #PSA_SUCCESS
* The key was successfully created.
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
* \retval #PSA_ERROR_INSUFFICIENT_STORAGE
* \retval #PSA_ERROR_ALREADY_EXISTS
* \retval #PSA_ERROR_DATA_INVALID
* \retval #PSA_ERROR_DATA_CORRUPT
* \retval #PSA_ERROR_STORAGE_FAILURE
*
* \return If this function fails, the key slot is an invalid state.
* You must call psa_fail_key_creation() to wipe and free the slot.
*/
static psa_status_t psa_finish_key_creation(
psa_key_slot_t *slot,
psa_se_drv_table_entry_t *driver,
mbedtls_svc_key_id_t *key) {
psa_status_t status = PSA_SUCCESS;
(void) slot;
(void) driver;
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
if (! PSA_KEY_LIFETIME_IS_VOLATILE(slot->attr.lifetime)) {
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if (driver != NULL) {
psa_se_key_data_storage_t data;
psa_key_slot_number_t slot_number =
psa_key_slot_get_slot_number(slot) ;
#if defined(static_assert)
static_assert(sizeof(slot_number) ==
sizeof(data.slot_number),
"Slot number size does not match psa_se_key_data_storage_t");
#endif
memcpy(&data.slot_number, &slot_number, sizeof(slot_number));
status = psa_save_persistent_key(&slot->attr,
(uint8_t *) &data,
sizeof(data));
} else
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
{
/* Key material is saved in export representation in the slot, so
* just pass the slot buffer for storage. */
status = psa_save_persistent_key(&slot->attr,
slot->key.data,
slot->key.bytes);
}
}
#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* Finish the transaction for a key creation. This does not
* happen when registering an existing key. Detect this case
* by checking whether a transaction is in progress (actual
* creation of a persistent key in a secure element requires a transaction,
* but registration or volatile key creation doesn't use one). */
if (driver != NULL &&
psa_crypto_transaction.unknown.type == PSA_CRYPTO_TRANSACTION_CREATE_KEY) {
status = psa_save_se_persistent_data(driver);
if (status != PSA_SUCCESS) {
psa_destroy_persistent_key(slot->attr.id);
return (status);
}
status = psa_crypto_stop_transaction();
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
if (status == PSA_SUCCESS) {
*key = slot->attr.id;
status = psa_unlock_key_slot(slot);
if (status != PSA_SUCCESS)
*key = MBEDTLS_SVC_KEY_ID_INIT;
}
return (status);
}
/** Abort the creation of a key.
*
* You may call this function after calling psa_start_key_creation(),
* or after psa_finish_key_creation() fails. In other circumstances, this
* function may not clean up persistent storage.
* See the documentation of psa_start_key_creation() for the intended use
* of this function.
*
* \param[in,out] slot Pointer to the slot with key material.
* \param[in] driver The secure element driver for the key,
* or NULL for a transparent key.
*/
static void psa_fail_key_creation(psa_key_slot_t *slot,
psa_se_drv_table_entry_t *driver) {
(void) driver;
if (slot == NULL)
return;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* TODO: If the key has already been created in the secure
* element, and the failure happened later (when saving metadata
* to internal storage), we need to destroy the key in the secure
* element.
* https://github.com/ARMmbed/mbed-crypto/issues/217
*/
/* Abort the ongoing transaction if any (there may not be one if
* the creation process failed before starting one, or if the
* key creation is a registration of a key in a secure element).
* Earlier functions must already have done what it takes to undo any
* partial creation. All that's left is to update the transaction data
* itself. */
(void) psa_crypto_stop_transaction();
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
psa_wipe_key_slot(slot);
}
/** Validate optional attributes during key creation.
*
* Some key attributes are optional during key creation. If they are
* specified in the attributes structure, check that they are consistent
* with the data in the slot.
*
* This function should be called near the end of key creation, after
* the slot in memory is fully populated but before saving persistent data.
*/
static psa_status_t psa_validate_optional_attributes(
const psa_key_slot_t *slot,
const psa_key_attributes_t *attributes) {
if (attributes->core.type != 0) {
if (attributes->core.type != slot->attr.type)
return (PSA_ERROR_INVALID_ARGUMENT);
}
if (attributes->domain_parameters_size != 0) {
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
if (PSA_KEY_TYPE_IS_RSA(slot->attr.type)) {
mbedtls_rsa_context *rsa = NULL;
mbedtls_mpi actual, required;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
psa_status_t status = mbedtls_psa_rsa_load_representation(
slot->attr.type,
slot->key.data,
slot->key.bytes,
&rsa);
if (status != PSA_SUCCESS)
return (status);
mbedtls_mpi_init(&actual);
mbedtls_mpi_init(&required);
ret = mbedtls_rsa_export(rsa,
NULL, NULL, NULL, NULL, &actual);
mbedtls_rsa_free(rsa);
mbedtls_free(rsa);
if (ret != 0)
goto rsa_exit;
ret = mbedtls_mpi_read_binary(&required,
attributes->domain_parameters,
attributes->domain_parameters_size);
if (ret != 0)
goto rsa_exit;
if (mbedtls_mpi_cmp_mpi(&actual, &required) != 0)
ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
rsa_exit:
mbedtls_mpi_free(&actual);
mbedtls_mpi_free(&required);
if (ret != 0)
return (mbedtls_to_psa_error(ret));
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
{
return (PSA_ERROR_INVALID_ARGUMENT);
}
}
if (attributes->core.bits != 0) {
if (attributes->core.bits != slot->attr.bits)
return (PSA_ERROR_INVALID_ARGUMENT);
}
return (PSA_SUCCESS);
}
psa_status_t psa_import_key(const psa_key_attributes_t *attributes,
const uint8_t *data,
size_t data_length,
mbedtls_svc_key_id_t *key) {
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
size_t bits;
*key = MBEDTLS_SVC_KEY_ID_INIT;
/* Reject zero-length symmetric keys (including raw data key objects).
* This also rejects any key which might be encoded as an empty string,
* which is never valid. */
if (data_length == 0)
return (PSA_ERROR_INVALID_ARGUMENT);
status = psa_start_key_creation(PSA_KEY_CREATION_IMPORT, attributes,
&slot, &driver);
if (status != PSA_SUCCESS)
goto exit;
/* In the case of a transparent key or an opaque key stored in local
* storage (thus not in the case of generating a key in a secure element
* or cryptoprocessor with storage), we have to allocate a buffer to
* hold the generated key material. */
if (slot->key.data == NULL) {
status = psa_allocate_buffer_to_slot(slot, data_length);
if (status != PSA_SUCCESS)
goto exit;
}
bits = slot->attr.bits;
status = psa_driver_wrapper_import_key(attributes,
data, data_length,
slot->key.data,
slot->key.bytes,
&slot->key.bytes, &bits);
if (status != PSA_SUCCESS)
goto exit;
if (slot->attr.bits == 0)
slot->attr.bits = (psa_key_bits_t) bits;
else if (bits != slot->attr.bits) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_validate_optional_attributes(slot, attributes);
if (status != PSA_SUCCESS)
goto exit;
status = psa_finish_key_creation(slot, driver, key);
exit:
if (status != PSA_SUCCESS)
psa_fail_key_creation(slot, driver);
return (status);
}
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
psa_status_t mbedtls_psa_register_se_key(
const psa_key_attributes_t *attributes) {
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT;
/* Leaving attributes unspecified is not currently supported.
* It could make sense to query the key type and size from the
* secure element, but not all secure elements support this
* and the driver HAL doesn't currently support it. */
if (psa_get_key_type(attributes) == PSA_KEY_TYPE_NONE)
return (PSA_ERROR_NOT_SUPPORTED);
if (psa_get_key_bits(attributes) == 0)
return (PSA_ERROR_NOT_SUPPORTED);
status = psa_start_key_creation(PSA_KEY_CREATION_REGISTER, attributes,
&slot, &driver);
if (status != PSA_SUCCESS)
goto exit;
status = psa_finish_key_creation(slot, driver, &key);
exit:
if (status != PSA_SUCCESS)
psa_fail_key_creation(slot, driver);
/* Registration doesn't keep the key in RAM. */
psa_close_key(key);
return (status);
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
static psa_status_t psa_copy_key_material(const psa_key_slot_t *source,
psa_key_slot_t *target) {
psa_status_t status = psa_copy_key_material_into_slot(target,
source->key.data,
source->key.bytes);
if (status != PSA_SUCCESS)
return (status);
target->attr.type = source->attr.type;
target->attr.bits = source->attr.bits;
return (PSA_SUCCESS);
}
psa_status_t psa_copy_key(mbedtls_svc_key_id_t source_key,
const psa_key_attributes_t *specified_attributes,
mbedtls_svc_key_id_t *target_key) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *source_slot = NULL;
psa_key_slot_t *target_slot = NULL;
psa_key_attributes_t actual_attributes = *specified_attributes;
psa_se_drv_table_entry_t *driver = NULL;
*target_key = MBEDTLS_SVC_KEY_ID_INIT;
status = psa_get_and_lock_transparent_key_slot_with_policy(
source_key, &source_slot, PSA_KEY_USAGE_COPY, 0);
if (status != PSA_SUCCESS)
goto exit;
status = psa_validate_optional_attributes(source_slot,
specified_attributes);
if (status != PSA_SUCCESS)
goto exit;
status = psa_restrict_key_policy(source_slot->attr.type,
&actual_attributes.core.policy,
&source_slot->attr.policy);
if (status != PSA_SUCCESS)
goto exit;
status = psa_start_key_creation(PSA_KEY_CREATION_COPY, &actual_attributes,
&target_slot, &driver);
if (status != PSA_SUCCESS)
goto exit;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if (driver != NULL) {
/* Copying to a secure element is not implemented yet. */
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
status = psa_copy_key_material(source_slot, target_slot);
if (status != PSA_SUCCESS)
goto exit;
status = psa_finish_key_creation(target_slot, driver, target_key);
exit:
if (status != PSA_SUCCESS)
psa_fail_key_creation(target_slot, driver);
unlock_status = psa_unlock_key_slot(source_slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
/****************************************************************/
/* Message digests */
/****************************************************************/
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
const mbedtls_md_info_t *mbedtls_md_info_from_psa(psa_algorithm_t alg) {
switch (alg) {
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
case PSA_ALG_MD2:
return (&mbedtls_md2_info);
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
case PSA_ALG_MD4:
return (&mbedtls_md4_info);
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
case PSA_ALG_MD5:
return (&mbedtls_md5_info);
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
case PSA_ALG_RIPEMD160:
return (&mbedtls_ripemd160_info);
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
case PSA_ALG_SHA_1:
return (&mbedtls_sha1_info);
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
case PSA_ALG_SHA_224:
return (&mbedtls_sha224_info);
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
case PSA_ALG_SHA_256:
return (&mbedtls_sha256_info);
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
case PSA_ALG_SHA_384:
return (&mbedtls_sha384_info);
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
case PSA_ALG_SHA_512:
return (&mbedtls_sha512_info);
#endif
default:
return (NULL);
}
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
psa_status_t psa_hash_abort(psa_hash_operation_t *operation) {
switch (operation->alg) {
case 0:
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
break;
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
case PSA_ALG_MD2:
mbedtls_md2_free(&operation->ctx.md2);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
case PSA_ALG_MD4:
mbedtls_md4_free(&operation->ctx.md4);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
case PSA_ALG_MD5:
mbedtls_md5_free(&operation->ctx.md5);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
case PSA_ALG_RIPEMD160:
mbedtls_ripemd160_free(&operation->ctx.ripemd160);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
case PSA_ALG_SHA_1:
mbedtls_sha1_free(&operation->ctx.sha1);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
case PSA_ALG_SHA_224:
mbedtls_sha256_free(&operation->ctx.sha256);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
case PSA_ALG_SHA_256:
mbedtls_sha256_free(&operation->ctx.sha256);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
case PSA_ALG_SHA_384:
mbedtls_sha512_free(&operation->ctx.sha512);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
case PSA_ALG_SHA_512:
mbedtls_sha512_free(&operation->ctx.sha512);
break;
#endif
default:
return (PSA_ERROR_BAD_STATE);
}
operation->alg = 0;
return (PSA_SUCCESS);
}
psa_status_t psa_hash_setup(psa_hash_operation_t *operation,
psa_algorithm_t alg) {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
/* A context must be freshly initialized before it can be set up. */
if (operation->alg != 0) {
return (PSA_ERROR_BAD_STATE);
}
switch (alg) {
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
case PSA_ALG_MD2:
mbedtls_md2_init(&operation->ctx.md2);
ret = mbedtls_md2_starts_ret(&operation->ctx.md2);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
case PSA_ALG_MD4:
mbedtls_md4_init(&operation->ctx.md4);
ret = mbedtls_md4_starts_ret(&operation->ctx.md4);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
case PSA_ALG_MD5:
mbedtls_md5_init(&operation->ctx.md5);
ret = mbedtls_md5_starts_ret(&operation->ctx.md5);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
case PSA_ALG_RIPEMD160:
mbedtls_ripemd160_init(&operation->ctx.ripemd160);
ret = mbedtls_ripemd160_starts_ret(&operation->ctx.ripemd160);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
case PSA_ALG_SHA_1:
mbedtls_sha1_init(&operation->ctx.sha1);
ret = mbedtls_sha1_starts_ret(&operation->ctx.sha1);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
case PSA_ALG_SHA_224:
mbedtls_sha256_init(&operation->ctx.sha256);
ret = mbedtls_sha256_starts_ret(&operation->ctx.sha256, 1);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
case PSA_ALG_SHA_256:
mbedtls_sha256_init(&operation->ctx.sha256);
ret = mbedtls_sha256_starts_ret(&operation->ctx.sha256, 0);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
case PSA_ALG_SHA_384:
mbedtls_sha512_init(&operation->ctx.sha512);
ret = mbedtls_sha512_starts_ret(&operation->ctx.sha512, 1);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
case PSA_ALG_SHA_512:
mbedtls_sha512_init(&operation->ctx.sha512);
ret = mbedtls_sha512_starts_ret(&operation->ctx.sha512, 0);
break;
#endif
default:
return (PSA_ALG_IS_HASH(alg) ?
PSA_ERROR_NOT_SUPPORTED :
PSA_ERROR_INVALID_ARGUMENT);
}
if (ret == 0)
operation->alg = alg;
else
psa_hash_abort(operation);
return (mbedtls_to_psa_error(ret));
}
psa_status_t psa_hash_update(psa_hash_operation_t *operation,
const uint8_t *input,
size_t input_length) {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
/* Don't require hash implementations to behave correctly on a
* zero-length input, which may have an invalid pointer. */
if (input_length == 0)
return (PSA_SUCCESS);
switch (operation->alg) {
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
case PSA_ALG_MD2:
ret = mbedtls_md2_update_ret(&operation->ctx.md2,
input, input_length);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
case PSA_ALG_MD4:
ret = mbedtls_md4_update_ret(&operation->ctx.md4,
input, input_length);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
case PSA_ALG_MD5:
ret = mbedtls_md5_update_ret(&operation->ctx.md5,
input, input_length);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
case PSA_ALG_RIPEMD160:
ret = mbedtls_ripemd160_update_ret(&operation->ctx.ripemd160,
input, input_length);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
case PSA_ALG_SHA_1:
ret = mbedtls_sha1_update_ret(&operation->ctx.sha1,
input, input_length);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
case PSA_ALG_SHA_224:
ret = mbedtls_sha256_update_ret(&operation->ctx.sha256,
input, input_length);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
case PSA_ALG_SHA_256:
ret = mbedtls_sha256_update_ret(&operation->ctx.sha256,
input, input_length);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
case PSA_ALG_SHA_384:
ret = mbedtls_sha512_update_ret(&operation->ctx.sha512,
input, input_length);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
case PSA_ALG_SHA_512:
ret = mbedtls_sha512_update_ret(&operation->ctx.sha512,
input, input_length);
break;
#endif
default:
(void)input;
return (PSA_ERROR_BAD_STATE);
}
if (ret != 0)
psa_hash_abort(operation);
return (mbedtls_to_psa_error(ret));
}
psa_status_t psa_hash_finish(psa_hash_operation_t *operation,
uint8_t *hash,
size_t hash_size,
size_t *hash_length) {
psa_status_t status;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t actual_hash_length = PSA_HASH_LENGTH(operation->alg);
/* Fill the output buffer with something that isn't a valid hash
* (barring an attack on the hash and deliberately-crafted input),
* in case the caller doesn't check the return status properly. */
*hash_length = hash_size;
/* If hash_size is 0 then hash may be NULL and then the
* call to memset would have undefined behavior. */
if (hash_size != 0)
memset(hash, '!', hash_size);
if (hash_size < actual_hash_length) {
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
switch (operation->alg) {
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
case PSA_ALG_MD2:
ret = mbedtls_md2_finish_ret(&operation->ctx.md2, hash);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
case PSA_ALG_MD4:
ret = mbedtls_md4_finish_ret(&operation->ctx.md4, hash);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
case PSA_ALG_MD5:
ret = mbedtls_md5_finish_ret(&operation->ctx.md5, hash);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
case PSA_ALG_RIPEMD160:
ret = mbedtls_ripemd160_finish_ret(&operation->ctx.ripemd160, hash);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
case PSA_ALG_SHA_1:
ret = mbedtls_sha1_finish_ret(&operation->ctx.sha1, hash);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
case PSA_ALG_SHA_224:
ret = mbedtls_sha256_finish_ret(&operation->ctx.sha256, hash);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
case PSA_ALG_SHA_256:
ret = mbedtls_sha256_finish_ret(&operation->ctx.sha256, hash);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
case PSA_ALG_SHA_384:
ret = mbedtls_sha512_finish_ret(&operation->ctx.sha512, hash);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
case PSA_ALG_SHA_512:
ret = mbedtls_sha512_finish_ret(&operation->ctx.sha512, hash);
break;
#endif
default:
return (PSA_ERROR_BAD_STATE);
}
status = mbedtls_to_psa_error(ret);
exit:
if (status == PSA_SUCCESS) {
*hash_length = actual_hash_length;
return (psa_hash_abort(operation));
} else {
psa_hash_abort(operation);
return (status);
}
}
psa_status_t psa_hash_verify(psa_hash_operation_t *operation,
const uint8_t *hash,
size_t hash_length) {
uint8_t actual_hash[MBEDTLS_MD_MAX_SIZE];
size_t actual_hash_length;
psa_status_t status = psa_hash_finish(operation,
actual_hash, sizeof(actual_hash),
&actual_hash_length);
if (status != PSA_SUCCESS)
return (status);
if (actual_hash_length != hash_length)
return (PSA_ERROR_INVALID_SIGNATURE);
if (safer_memcmp(hash, actual_hash, actual_hash_length) != 0)
return (PSA_ERROR_INVALID_SIGNATURE);
return (PSA_SUCCESS);
}
psa_status_t psa_hash_compute(psa_algorithm_t alg,
const uint8_t *input, size_t input_length,
uint8_t *hash, size_t hash_size,
size_t *hash_length) {
psa_hash_operation_t operation = PSA_HASH_OPERATION_INIT;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
*hash_length = hash_size;
status = psa_hash_setup(&operation, alg);
if (status != PSA_SUCCESS)
goto exit;
status = psa_hash_update(&operation, input, input_length);
if (status != PSA_SUCCESS)
goto exit;
status = psa_hash_finish(&operation, hash, hash_size, hash_length);
if (status != PSA_SUCCESS)
goto exit;
exit:
if (status == PSA_SUCCESS)
status = psa_hash_abort(&operation);
else
psa_hash_abort(&operation);
return (status);
}
psa_status_t psa_hash_compare(psa_algorithm_t alg,
const uint8_t *input, size_t input_length,
const uint8_t *hash, size_t hash_length) {
psa_hash_operation_t operation = PSA_HASH_OPERATION_INIT;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
status = psa_hash_setup(&operation, alg);
if (status != PSA_SUCCESS)
goto exit;
status = psa_hash_update(&operation, input, input_length);
if (status != PSA_SUCCESS)
goto exit;
status = psa_hash_verify(&operation, hash, hash_length);
if (status != PSA_SUCCESS)
goto exit;
exit:
if (status == PSA_SUCCESS)
status = psa_hash_abort(&operation);
else
psa_hash_abort(&operation);
return (status);
}
psa_status_t psa_hash_clone(const psa_hash_operation_t *source_operation,
psa_hash_operation_t *target_operation) {
if (target_operation->alg != 0)
return (PSA_ERROR_BAD_STATE);
switch (source_operation->alg) {
case 0:
return (PSA_ERROR_BAD_STATE);
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD2)
case PSA_ALG_MD2:
mbedtls_md2_clone(&target_operation->ctx.md2,
&source_operation->ctx.md2);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD4)
case PSA_ALG_MD4:
mbedtls_md4_clone(&target_operation->ctx.md4,
&source_operation->ctx.md4);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_MD5)
case PSA_ALG_MD5:
mbedtls_md5_clone(&target_operation->ctx.md5,
&source_operation->ctx.md5);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RIPEMD160)
case PSA_ALG_RIPEMD160:
mbedtls_ripemd160_clone(&target_operation->ctx.ripemd160,
&source_operation->ctx.ripemd160);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_1)
case PSA_ALG_SHA_1:
mbedtls_sha1_clone(&target_operation->ctx.sha1,
&source_operation->ctx.sha1);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_224)
case PSA_ALG_SHA_224:
mbedtls_sha256_clone(&target_operation->ctx.sha256,
&source_operation->ctx.sha256);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_256)
case PSA_ALG_SHA_256:
mbedtls_sha256_clone(&target_operation->ctx.sha256,
&source_operation->ctx.sha256);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_384)
case PSA_ALG_SHA_384:
mbedtls_sha512_clone(&target_operation->ctx.sha512,
&source_operation->ctx.sha512);
break;
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_SHA_512)
case PSA_ALG_SHA_512:
mbedtls_sha512_clone(&target_operation->ctx.sha512,
&source_operation->ctx.sha512);
break;
#endif
default:
return (PSA_ERROR_NOT_SUPPORTED);
}
target_operation->alg = source_operation->alg;
return (PSA_SUCCESS);
}
/****************************************************************/
/* MAC */
/****************************************************************/
static const mbedtls_cipher_info_t *mbedtls_cipher_info_from_psa(
psa_algorithm_t alg,
psa_key_type_t key_type,
size_t key_bits,
mbedtls_cipher_id_t *cipher_id) {
mbedtls_cipher_mode_t mode;
mbedtls_cipher_id_t cipher_id_tmp;
if (PSA_ALG_IS_AEAD(alg))
alg = PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg, 0);
if (PSA_ALG_IS_CIPHER(alg) || PSA_ALG_IS_AEAD(alg)) {
switch (alg) {
case PSA_ALG_STREAM_CIPHER:
mode = MBEDTLS_MODE_STREAM;
break;
case PSA_ALG_CTR:
mode = MBEDTLS_MODE_CTR;
break;
case PSA_ALG_CFB:
mode = MBEDTLS_MODE_CFB;
break;
case PSA_ALG_OFB:
mode = MBEDTLS_MODE_OFB;
break;
case PSA_ALG_ECB_NO_PADDING:
mode = MBEDTLS_MODE_ECB;
break;
case PSA_ALG_CBC_NO_PADDING:
mode = MBEDTLS_MODE_CBC;
break;
case PSA_ALG_CBC_PKCS7:
mode = MBEDTLS_MODE_CBC;
break;
case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CCM, 0):
mode = MBEDTLS_MODE_CCM;
break;
case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 0):
mode = MBEDTLS_MODE_GCM;
break;
case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CHACHA20_POLY1305, 0):
mode = MBEDTLS_MODE_CHACHAPOLY;
break;
default:
return (NULL);
}
} else if (alg == PSA_ALG_CMAC)
mode = MBEDTLS_MODE_ECB;
else
return (NULL);
switch (key_type) {
case PSA_KEY_TYPE_AES:
cipher_id_tmp = MBEDTLS_CIPHER_ID_AES;
break;
case PSA_KEY_TYPE_DES:
/* key_bits is 64 for Single-DES, 128 for two-key Triple-DES,
* and 192 for three-key Triple-DES. */
if (key_bits == 64)
cipher_id_tmp = MBEDTLS_CIPHER_ID_DES;
else
cipher_id_tmp = MBEDTLS_CIPHER_ID_3DES;
/* mbedtls doesn't recognize two-key Triple-DES as an algorithm,
* but two-key Triple-DES is functionally three-key Triple-DES
* with K1=K3, so that's how we present it to mbedtls. */
if (key_bits == 128)
key_bits = 192;
break;
case PSA_KEY_TYPE_CAMELLIA:
cipher_id_tmp = MBEDTLS_CIPHER_ID_CAMELLIA;
break;
case PSA_KEY_TYPE_ARC4:
cipher_id_tmp = MBEDTLS_CIPHER_ID_ARC4;
break;
case PSA_KEY_TYPE_CHACHA20:
cipher_id_tmp = MBEDTLS_CIPHER_ID_CHACHA20;
break;
default:
return (NULL);
}
if (cipher_id != NULL)
*cipher_id = cipher_id_tmp;
return (mbedtls_cipher_info_from_values(cipher_id_tmp,
(int) key_bits, mode));
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
static size_t psa_get_hash_block_size(psa_algorithm_t alg) {
switch (alg) {
case PSA_ALG_MD2:
return (16);
case PSA_ALG_MD4:
return (64);
case PSA_ALG_MD5:
return (64);
case PSA_ALG_RIPEMD160:
return (64);
case PSA_ALG_SHA_1:
return (64);
case PSA_ALG_SHA_224:
return (64);
case PSA_ALG_SHA_256:
return (64);
case PSA_ALG_SHA_384:
return (128);
case PSA_ALG_SHA_512:
return (128);
default:
return (0);
}
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC) */
/* Initialize the MAC operation structure. Once this function has been
* called, psa_mac_abort can run and will do the right thing. */
static psa_status_t psa_mac_init(psa_mac_operation_t *operation,
psa_algorithm_t alg) {
psa_status_t status = PSA_ERROR_NOT_SUPPORTED;
operation->alg = PSA_ALG_FULL_LENGTH_MAC(alg);
operation->key_set = 0;
operation->iv_set = 0;
operation->iv_required = 0;
operation->has_input = 0;
operation->is_sign = 0;
#if defined(MBEDTLS_CMAC_C)
if (operation->alg == PSA_ALG_CMAC) {
operation->iv_required = 0;
mbedtls_cipher_init(&operation->ctx.cmac);
status = PSA_SUCCESS;
} else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
if (PSA_ALG_IS_HMAC(operation->alg)) {
/* We'll set up the hash operation later in psa_hmac_setup_internal. */
operation->ctx.hmac.hash_ctx.alg = 0;
status = PSA_SUCCESS;
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
{
if (! PSA_ALG_IS_MAC(alg))
status = PSA_ERROR_INVALID_ARGUMENT;
}
if (status != PSA_SUCCESS)
memset(operation, 0, sizeof(*operation));
return (status);
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
static psa_status_t psa_hmac_abort_internal(psa_hmac_internal_data *hmac) {
mbedtls_platform_zeroize(hmac->opad, sizeof(hmac->opad));
return (psa_hash_abort(&hmac->hash_ctx));
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
psa_status_t psa_mac_abort(psa_mac_operation_t *operation) {
if (operation->alg == 0) {
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
return (PSA_SUCCESS);
} else
#if defined(MBEDTLS_CMAC_C)
if (operation->alg == PSA_ALG_CMAC) {
mbedtls_cipher_free(&operation->ctx.cmac);
} else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
if (PSA_ALG_IS_HMAC(operation->alg)) {
psa_hmac_abort_internal(&operation->ctx.hmac);
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
{
/* Sanity check (shouldn't happen: operation->alg should
* always have been initialized to a valid value). */
goto bad_state;
}
operation->alg = 0;
operation->key_set = 0;
operation->iv_set = 0;
operation->iv_required = 0;
operation->has_input = 0;
operation->is_sign = 0;
return (PSA_SUCCESS);
bad_state:
/* If abort is called on an uninitialized object, we can't trust
* anything. Wipe the object in case it contains confidential data.
* This may result in a memory leak if a pointer gets overwritten,
* but it's too late to do anything about this. */
memset(operation, 0, sizeof(*operation));
return (PSA_ERROR_BAD_STATE);
}
#if defined(MBEDTLS_CMAC_C)
static psa_status_t psa_cmac_setup(psa_mac_operation_t *operation,
psa_key_slot_t *slot) {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
const mbedtls_cipher_info_t *cipher_info =
mbedtls_cipher_info_from_psa(PSA_ALG_CMAC,
slot->attr.type, slot->attr.bits,
NULL);
if (cipher_info == NULL)
return (PSA_ERROR_NOT_SUPPORTED);
ret = mbedtls_cipher_setup(&operation->ctx.cmac, cipher_info);
if (ret != 0)
goto exit;
ret = mbedtls_cipher_cmac_starts(&operation->ctx.cmac,
slot->key.data,
slot->attr.bits);
exit:
return (mbedtls_to_psa_error(ret));
}
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
static psa_status_t psa_hmac_setup_internal(psa_hmac_internal_data *hmac,
const uint8_t *key,
size_t key_length,
psa_algorithm_t hash_alg) {
uint8_t ipad[PSA_HMAC_MAX_HASH_BLOCK_SIZE];
size_t i;
size_t hash_size = PSA_HASH_LENGTH(hash_alg);
size_t block_size = psa_get_hash_block_size(hash_alg);
psa_status_t status;
/* Sanity checks on block_size, to guarantee that there won't be a buffer
* overflow below. This should never trigger if the hash algorithm
* is implemented correctly. */
/* The size checks against the ipad and opad buffers cannot be written
* `block_size > sizeof( ipad ) || block_size > sizeof( hmac->opad )`
* because that triggers -Wlogical-op on GCC 7.3. */
if (block_size > sizeof(ipad))
return (PSA_ERROR_NOT_SUPPORTED);
if (block_size > sizeof(hmac->opad))
return (PSA_ERROR_NOT_SUPPORTED);
if (block_size < hash_size)
return (PSA_ERROR_NOT_SUPPORTED);
if (key_length > block_size) {
status = psa_hash_compute(hash_alg, key, key_length,
ipad, sizeof(ipad), &key_length);
if (status != PSA_SUCCESS)
goto cleanup;
}
/* A 0-length key is not commonly used in HMAC when used as a MAC,
* but it is permitted. It is common when HMAC is used in HKDF, for
* example. Don't call `memcpy` in the 0-length because `key` could be
* an invalid pointer which would make the behavior undefined. */
else if (key_length != 0)
memcpy(ipad, key, key_length);
/* ipad contains the key followed by garbage. Xor and fill with 0x36
* to create the ipad value. */
for (i = 0; i < key_length; i++)
ipad[i] ^= 0x36;
memset(ipad + key_length, 0x36, block_size - key_length);
/* Copy the key material from ipad to opad, flipping the requisite bits,
* and filling the rest of opad with the requisite constant. */
for (i = 0; i < key_length; i++)
hmac->opad[i] = ipad[i] ^ 0x36 ^ 0x5C;
memset(hmac->opad + key_length, 0x5C, block_size - key_length);
status = psa_hash_setup(&hmac->hash_ctx, hash_alg);
if (status != PSA_SUCCESS)
goto cleanup;
status = psa_hash_update(&hmac->hash_ctx, ipad, block_size);
cleanup:
mbedtls_platform_zeroize(ipad, sizeof(ipad));
return (status);
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
static psa_status_t psa_mac_setup(psa_mac_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
int is_sign) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
psa_key_usage_t usage =
is_sign ? PSA_KEY_USAGE_SIGN_HASH : PSA_KEY_USAGE_VERIFY_HASH;
/* A context must be freshly initialized before it can be set up. */
if (operation->alg != 0) {
return (PSA_ERROR_BAD_STATE);
}
status = psa_mac_init(operation, alg);
if (status != PSA_SUCCESS)
return (status);
if (is_sign)
operation->is_sign = 1;
status = psa_get_and_lock_transparent_key_slot_with_policy(
key, &slot, usage, alg);
if (status != PSA_SUCCESS)
goto exit;
/* Validate the combination of key type and algorithm */
status = psa_mac_key_can_do(alg, slot->attr.type);
if (status != PSA_SUCCESS)
goto exit;
/* Get the output length for the algorithm and key combination. None of the
* currently supported algorithms have an output length dependent on actual
* key size, so setting it to a bogus value is currently OK. */
operation->mac_size = PSA_MAC_LENGTH(slot->attr.type, 0, alg);
if (operation->mac_size < 4) {
/* A very short MAC is too short for security since it can be
* brute-forced. Ancient protocols with 32-bit MACs do exist,
* so we make this our minimum, even though 32 bits is still
* too small for security. */
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
if (operation->mac_size >
PSA_MAC_LENGTH(slot->attr.type, 0, PSA_ALG_FULL_LENGTH_MAC(alg))) {
/* It's impossible to "truncate" to a larger length than the full length
* of the algorithm. */
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
#if defined(MBEDTLS_CMAC_C)
if (PSA_ALG_FULL_LENGTH_MAC(alg) == PSA_ALG_CMAC) {
status = psa_cmac_setup(operation, slot);
} else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
if (PSA_ALG_IS_HMAC(alg)) {
/* Sanity check. This shouldn't fail on a valid configuration. */
if (operation->mac_size > sizeof(operation->ctx.hmac.opad)) {
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
if (slot->attr.type != PSA_KEY_TYPE_HMAC) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_hmac_setup_internal(&operation->ctx.hmac,
slot->key.data,
slot->key.bytes,
PSA_ALG_HMAC_GET_HASH(alg));
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
{
status = PSA_ERROR_NOT_SUPPORTED;
}
exit:
if (status != PSA_SUCCESS) {
psa_mac_abort(operation);
} else {
operation->key_set = 1;
}
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
psa_status_t psa_mac_sign_setup(psa_mac_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg) {
return (psa_mac_setup(operation, key, alg, 1));
}
psa_status_t psa_mac_verify_setup(psa_mac_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg) {
return (psa_mac_setup(operation, key, alg, 0));
}
psa_status_t psa_mac_update(psa_mac_operation_t *operation,
const uint8_t *input,
size_t input_length) {
psa_status_t status = PSA_ERROR_BAD_STATE;
if (! operation->key_set)
return (PSA_ERROR_BAD_STATE);
if (operation->iv_required && ! operation->iv_set)
return (PSA_ERROR_BAD_STATE);
operation->has_input = 1;
#if defined(MBEDTLS_CMAC_C)
if (operation->alg == PSA_ALG_CMAC) {
int ret = mbedtls_cipher_cmac_update(&operation->ctx.cmac,
input, input_length);
status = mbedtls_to_psa_error(ret);
} else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
if (PSA_ALG_IS_HMAC(operation->alg)) {
status = psa_hash_update(&operation->ctx.hmac.hash_ctx, input,
input_length);
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
{
/* This shouldn't happen if `operation` was initialized by
* a setup function. */
return (PSA_ERROR_BAD_STATE);
}
if (status != PSA_SUCCESS)
psa_mac_abort(operation);
return (status);
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
static psa_status_t psa_hmac_finish_internal(psa_hmac_internal_data *hmac,
uint8_t *mac,
size_t mac_size) {
uint8_t tmp[MBEDTLS_MD_MAX_SIZE];
psa_algorithm_t hash_alg = hmac->hash_ctx.alg;
size_t hash_size = 0;
size_t block_size = psa_get_hash_block_size(hash_alg);
psa_status_t status;
status = psa_hash_finish(&hmac->hash_ctx, tmp, sizeof(tmp), &hash_size);
if (status != PSA_SUCCESS)
return (status);
/* From here on, tmp needs to be wiped. */
status = psa_hash_setup(&hmac->hash_ctx, hash_alg);
if (status != PSA_SUCCESS)
goto exit;
status = psa_hash_update(&hmac->hash_ctx, hmac->opad, block_size);
if (status != PSA_SUCCESS)
goto exit;
status = psa_hash_update(&hmac->hash_ctx, tmp, hash_size);
if (status != PSA_SUCCESS)
goto exit;
status = psa_hash_finish(&hmac->hash_ctx, tmp, sizeof(tmp), &hash_size);
if (status != PSA_SUCCESS)
goto exit;
memcpy(mac, tmp, mac_size);
exit:
mbedtls_platform_zeroize(tmp, hash_size);
return (status);
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
static psa_status_t psa_mac_finish_internal(psa_mac_operation_t *operation,
uint8_t *mac,
size_t mac_size) {
if (! operation->key_set)
return (PSA_ERROR_BAD_STATE);
if (operation->iv_required && ! operation->iv_set)
return (PSA_ERROR_BAD_STATE);
if (mac_size < operation->mac_size)
return (PSA_ERROR_BUFFER_TOO_SMALL);
#if defined(MBEDTLS_CMAC_C)
if (operation->alg == PSA_ALG_CMAC) {
uint8_t tmp[PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE];
int ret = mbedtls_cipher_cmac_finish(&operation->ctx.cmac, tmp);
if (ret == 0)
memcpy(mac, tmp, operation->mac_size);
mbedtls_platform_zeroize(tmp, sizeof(tmp));
return (mbedtls_to_psa_error(ret));
} else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HMAC)
if (PSA_ALG_IS_HMAC(operation->alg)) {
return (psa_hmac_finish_internal(&operation->ctx.hmac,
mac, operation->mac_size));
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HMAC */
{
/* This shouldn't happen if `operation` was initialized by
* a setup function. */
return (PSA_ERROR_BAD_STATE);
}
}
psa_status_t psa_mac_sign_finish(psa_mac_operation_t *operation,
uint8_t *mac,
size_t mac_size,
size_t *mac_length) {
psa_status_t status;
if (operation->alg == 0) {
return (PSA_ERROR_BAD_STATE);
}
/* Fill the output buffer with something that isn't a valid mac
* (barring an attack on the mac and deliberately-crafted input),
* in case the caller doesn't check the return status properly. */
*mac_length = mac_size;
/* If mac_size is 0 then mac may be NULL and then the
* call to memset would have undefined behavior. */
if (mac_size != 0)
memset(mac, '!', mac_size);
if (! operation->is_sign) {
return (PSA_ERROR_BAD_STATE);
}
status = psa_mac_finish_internal(operation, mac, mac_size);
if (status == PSA_SUCCESS) {
status = psa_mac_abort(operation);
if (status == PSA_SUCCESS)
*mac_length = operation->mac_size;
else
memset(mac, '!', mac_size);
} else
psa_mac_abort(operation);
return (status);
}
psa_status_t psa_mac_verify_finish(psa_mac_operation_t *operation,
const uint8_t *mac,
size_t mac_length) {
uint8_t actual_mac[PSA_MAC_MAX_SIZE];
psa_status_t status;
if (operation->alg == 0) {
return (PSA_ERROR_BAD_STATE);
}
if (operation->is_sign) {
return (PSA_ERROR_BAD_STATE);
}
if (operation->mac_size != mac_length) {
status = PSA_ERROR_INVALID_SIGNATURE;
goto cleanup;
}
status = psa_mac_finish_internal(operation,
actual_mac, sizeof(actual_mac));
if (status != PSA_SUCCESS)
goto cleanup;
if (safer_memcmp(mac, actual_mac, mac_length) != 0)
status = PSA_ERROR_INVALID_SIGNATURE;
cleanup:
if (status == PSA_SUCCESS)
status = psa_mac_abort(operation);
else
psa_mac_abort(operation);
mbedtls_platform_zeroize(actual_mac, sizeof(actual_mac));
return (status);
}
/****************************************************************/
/* Asymmetric cryptography */
/****************************************************************/
psa_status_t psa_sign_hash_internal(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer, size_t key_buffer_size,
psa_algorithm_t alg, const uint8_t *hash, size_t hash_length,
uint8_t *signature, size_t signature_size, size_t *signature_length) {
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
if (attributes->core.type == PSA_KEY_TYPE_RSA_KEY_PAIR) {
return (mbedtls_psa_rsa_sign_hash(
attributes,
key_buffer, key_buffer_size,
alg, hash, hash_length,
signature, signature_size, signature_length));
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
if (PSA_KEY_TYPE_IS_ECC(attributes->core.type)) {
if (PSA_ALG_IS_ECDSA(alg)) {
return (mbedtls_psa_ecdsa_sign_hash(
attributes,
key_buffer, key_buffer_size,
alg, hash, hash_length,
signature, signature_size, signature_length));
} else {
return (PSA_ERROR_INVALID_ARGUMENT);
}
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
{
(void)attributes;
(void)key_buffer;
(void)key_buffer_size;
(void)alg;
(void)hash;
(void)hash_length;
(void)signature;
(void)signature_size;
(void)signature_length;
return (PSA_ERROR_NOT_SUPPORTED);
}
}
psa_status_t psa_sign_hash(mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
uint8_t *signature,
size_t signature_size,
size_t *signature_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
*signature_length = signature_size;
/* Immediately reject a zero-length signature buffer. This guarantees
* that signature must be a valid pointer. (On the other hand, the hash
* buffer can in principle be empty since it doesn't actually have
* to be a hash.) */
if (signature_size == 0)
return (PSA_ERROR_BUFFER_TOO_SMALL);
status = psa_get_and_lock_key_slot_with_policy(key, &slot,
PSA_KEY_USAGE_SIGN_HASH,
alg);
if (status != PSA_SUCCESS)
goto exit;
if (! PSA_KEY_TYPE_IS_KEY_PAIR(slot->attr.type)) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_driver_wrapper_sign_hash(
&attributes, slot->key.data, slot->key.bytes,
alg, hash, hash_length,
signature, signature_size, signature_length);
exit:
/* Fill the unused part of the output buffer (the whole buffer on error,
* the trailing part on success) with something that isn't a valid mac
* (barring an attack on the mac and deliberately-crafted input),
* in case the caller doesn't check the return status properly. */
if (status == PSA_SUCCESS)
memset(signature + *signature_length, '!',
signature_size - *signature_length);
else
memset(signature, '!', signature_size);
/* If signature_size is 0 then we have nothing to do. We must not call
* memset because signature may be NULL in this case. */
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
psa_status_t psa_verify_hash_internal(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer, size_t key_buffer_size,
psa_algorithm_t alg, const uint8_t *hash, size_t hash_length,
const uint8_t *signature, size_t signature_length) {
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
if (PSA_KEY_TYPE_IS_RSA(attributes->core.type)) {
return (mbedtls_psa_rsa_verify_hash(
attributes,
key_buffer, key_buffer_size,
alg, hash, hash_length,
signature, signature_length));
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) */
if (PSA_KEY_TYPE_IS_ECC(attributes->core.type)) {
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
if (PSA_ALG_IS_ECDSA(alg)) {
return (mbedtls_psa_ecdsa_verify_hash(
attributes,
key_buffer, key_buffer_size,
alg, hash, hash_length,
signature, signature_length));
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
{
return (PSA_ERROR_INVALID_ARGUMENT);
}
} else {
(void)key_buffer;
(void)key_buffer_size;
(void)alg;
(void)hash;
(void)hash_length;
(void)signature;
(void)signature_length;
return (PSA_ERROR_NOT_SUPPORTED);
}
}
psa_status_t psa_verify_hash(mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
const uint8_t *signature,
size_t signature_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
status = psa_get_and_lock_key_slot_with_policy(key, &slot,
PSA_KEY_USAGE_VERIFY_HASH,
alg);
if (status != PSA_SUCCESS)
return (status);
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_driver_wrapper_verify_hash(
&attributes, slot->key.data, slot->key.bytes,
alg, hash, hash_length,
signature, signature_length);
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP)
static void psa_rsa_oaep_set_padding_mode(psa_algorithm_t alg,
mbedtls_rsa_context *rsa) {
psa_algorithm_t hash_alg = PSA_ALG_RSA_OAEP_GET_HASH(alg);
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_psa(hash_alg);
mbedtls_md_type_t md_alg = mbedtls_md_get_type(md_info);
mbedtls_rsa_set_padding(rsa, MBEDTLS_RSA_PKCS_V21, md_alg);
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) */
psa_status_t psa_asymmetric_encrypt(mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
const uint8_t *salt,
size_t salt_length,
uint8_t *output,
size_t output_size,
size_t *output_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
(void) input;
(void) input_length;
(void) salt;
(void) output;
(void) output_size;
*output_length = 0;
if (! PSA_ALG_IS_RSA_OAEP(alg) && salt_length != 0)
return (PSA_ERROR_INVALID_ARGUMENT);
status = psa_get_and_lock_transparent_key_slot_with_policy(
key, &slot, PSA_KEY_USAGE_ENCRYPT, alg);
if (status != PSA_SUCCESS)
return (status);
if (!(PSA_KEY_TYPE_IS_PUBLIC_KEY(slot->attr.type) ||
PSA_KEY_TYPE_IS_KEY_PAIR(slot->attr.type))) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP)
if (PSA_KEY_TYPE_IS_RSA(slot->attr.type)) {
mbedtls_rsa_context *rsa = NULL;
status = mbedtls_psa_rsa_load_representation(slot->attr.type,
slot->key.data,
slot->key.bytes,
&rsa);
if (status != PSA_SUCCESS)
goto rsa_exit;
if (output_size < mbedtls_rsa_get_len(rsa)) {
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto rsa_exit;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT)
if (alg == PSA_ALG_RSA_PKCS1V15_CRYPT) {
status = mbedtls_to_psa_error(
mbedtls_rsa_pkcs1_encrypt(rsa,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE,
MBEDTLS_RSA_PUBLIC,
input_length,
input,
output));
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP)
if (PSA_ALG_IS_RSA_OAEP(alg)) {
psa_rsa_oaep_set_padding_mode(alg, rsa);
status = mbedtls_to_psa_error(
mbedtls_rsa_rsaes_oaep_encrypt(rsa,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE,
MBEDTLS_RSA_PUBLIC,
salt, salt_length,
input_length,
input,
output));
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP */
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto rsa_exit;
}
rsa_exit:
if (status == PSA_SUCCESS)
*output_length = mbedtls_rsa_get_len(rsa);
mbedtls_rsa_free(rsa);
mbedtls_free(rsa);
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) */
{
status = PSA_ERROR_NOT_SUPPORTED;
}
exit:
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
psa_status_t psa_asymmetric_decrypt(mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
const uint8_t *salt,
size_t salt_length,
uint8_t *output,
size_t output_size,
size_t *output_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
(void) input;
(void) input_length;
(void) salt;
(void) output;
(void) output_size;
*output_length = 0;
if (! PSA_ALG_IS_RSA_OAEP(alg) && salt_length != 0)
return (PSA_ERROR_INVALID_ARGUMENT);
status = psa_get_and_lock_transparent_key_slot_with_policy(
key, &slot, PSA_KEY_USAGE_DECRYPT, alg);
if (status != PSA_SUCCESS)
return (status);
if (! PSA_KEY_TYPE_IS_KEY_PAIR(slot->attr.type)) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP)
if (slot->attr.type == PSA_KEY_TYPE_RSA_KEY_PAIR) {
mbedtls_rsa_context *rsa = NULL;
status = mbedtls_psa_rsa_load_representation(slot->attr.type,
slot->key.data,
slot->key.bytes,
&rsa);
if (status != PSA_SUCCESS)
goto exit;
if (input_length != mbedtls_rsa_get_len(rsa)) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto rsa_exit;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT)
if (alg == PSA_ALG_RSA_PKCS1V15_CRYPT) {
status = mbedtls_to_psa_error(
mbedtls_rsa_pkcs1_decrypt(rsa,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE,
MBEDTLS_RSA_PRIVATE,
output_length,
input,
output,
output_size));
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP)
if (PSA_ALG_IS_RSA_OAEP(alg)) {
psa_rsa_oaep_set_padding_mode(alg, rsa);
status = mbedtls_to_psa_error(
mbedtls_rsa_rsaes_oaep_decrypt(rsa,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE,
MBEDTLS_RSA_PRIVATE,
salt, salt_length,
output_length,
input,
output,
output_size));
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP */
{
status = PSA_ERROR_INVALID_ARGUMENT;
}
rsa_exit:
mbedtls_rsa_free(rsa);
mbedtls_free(rsa);
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) */
{
status = PSA_ERROR_NOT_SUPPORTED;
}
exit:
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
/****************************************************************/
/* Symmetric cryptography */
/****************************************************************/
static psa_status_t psa_cipher_setup(psa_cipher_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
mbedtls_operation_t cipher_operation) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
int ret = 0;
psa_key_slot_t *slot;
size_t key_bits;
const mbedtls_cipher_info_t *cipher_info = NULL;
psa_key_usage_t usage = (cipher_operation == MBEDTLS_ENCRYPT ?
PSA_KEY_USAGE_ENCRYPT :
PSA_KEY_USAGE_DECRYPT);
/* A context must be freshly initialized before it can be set up. */
if (operation->alg != 0)
return (PSA_ERROR_BAD_STATE);
/* The requested algorithm must be one that can be processed by cipher. */
if (! PSA_ALG_IS_CIPHER(alg))
return (PSA_ERROR_INVALID_ARGUMENT);
/* Fetch key material from key storage. */
status = psa_get_and_lock_key_slot_with_policy(key, &slot, usage, alg);
if (status != PSA_SUCCESS)
goto exit;
/* Initialize the operation struct members, except for alg. The alg member
* is used to indicate to psa_cipher_abort that there are resources to free,
* so we only set it after resources have been allocated/initialized. */
operation->key_set = 0;
operation->iv_set = 0;
operation->mbedtls_in_use = 0;
operation->iv_size = 0;
operation->block_size = 0;
if (alg == PSA_ALG_ECB_NO_PADDING)
operation->iv_required = 0;
else
operation->iv_required = 1;
/* Try doing the operation through a driver before using software fallback. */
if (cipher_operation == MBEDTLS_ENCRYPT)
status = psa_driver_wrapper_cipher_encrypt_setup(&operation->ctx.driver,
slot,
alg);
else
status = psa_driver_wrapper_cipher_decrypt_setup(&operation->ctx.driver,
slot,
alg);
if (status == PSA_SUCCESS) {
/* Once the driver context is initialised, it needs to be freed using
* psa_cipher_abort. Indicate this through setting alg. */
operation->alg = alg;
}
if (status != PSA_ERROR_NOT_SUPPORTED ||
psa_key_lifetime_is_external(slot->attr.lifetime))
goto exit;
/* Proceed with initializing an mbed TLS cipher context if no driver is
* available for the given algorithm & key. */
mbedtls_cipher_init(&operation->ctx.cipher);
/* Once the cipher context is initialised, it needs to be freed using
* psa_cipher_abort. Indicate there is something to be freed through setting
* alg, and indicate the operation is being done using mbedtls crypto through
* setting mbedtls_in_use. */
operation->alg = alg;
operation->mbedtls_in_use = 1;
key_bits = psa_get_key_slot_bits(slot);
cipher_info = mbedtls_cipher_info_from_psa(alg, slot->attr.type, key_bits, NULL);
if (cipher_info == NULL) {
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
ret = mbedtls_cipher_setup(&operation->ctx.cipher, cipher_info);
if (ret != 0)
goto exit;
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
if (slot->attr.type == PSA_KEY_TYPE_DES && key_bits == 128) {
/* Two-key Triple-DES is 3-key Triple-DES with K1=K3 */
uint8_t keys[24];
memcpy(keys, slot->key.data, 16);
memcpy(keys + 16, slot->key.data, 8);
ret = mbedtls_cipher_setkey(&operation->ctx.cipher,
keys,
192, cipher_operation);
} else
#endif
{
ret = mbedtls_cipher_setkey(&operation->ctx.cipher,
slot->key.data,
(int) key_bits, cipher_operation);
}
if (ret != 0)
goto exit;
#if defined(MBEDTLS_PSA_BUILTIN_ALG_CBC_NO_PADDING) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_CBC_PKCS7)
switch (alg) {
case PSA_ALG_CBC_NO_PADDING:
ret = mbedtls_cipher_set_padding_mode(&operation->ctx.cipher,
MBEDTLS_PADDING_NONE);
break;
case PSA_ALG_CBC_PKCS7:
ret = mbedtls_cipher_set_padding_mode(&operation->ctx.cipher,
MBEDTLS_PADDING_PKCS7);
break;
default:
/* The algorithm doesn't involve padding. */
ret = 0;
break;
}
if (ret != 0)
goto exit;
#endif /* MBEDTLS_PSA_BUILTIN_ALG_CBC_NO_PADDING || MBEDTLS_PSA_BUILTIN_ALG_CBC_PKCS7 */
operation->block_size = (PSA_ALG_IS_STREAM_CIPHER(alg) ? 1 :
PSA_BLOCK_CIPHER_BLOCK_LENGTH(slot->attr.type));
if ((alg & PSA_ALG_CIPHER_FROM_BLOCK_FLAG) != 0 &&
alg != PSA_ALG_ECB_NO_PADDING) {
operation->iv_size = PSA_BLOCK_CIPHER_BLOCK_LENGTH(slot->attr.type);
}
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_CHACHA20)
else if (alg == PSA_ALG_STREAM_CIPHER && slot->attr.type == PSA_KEY_TYPE_CHACHA20)
operation->iv_size = 12;
#endif
status = PSA_SUCCESS;
exit:
if (ret != 0)
status = mbedtls_to_psa_error(ret);
if (status == PSA_SUCCESS) {
/* Update operation flags for both driver and software implementations */
operation->key_set = 1;
} else
psa_cipher_abort(operation);
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
psa_status_t psa_cipher_encrypt_setup(psa_cipher_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg) {
return (psa_cipher_setup(operation, key, alg, MBEDTLS_ENCRYPT));
}
psa_status_t psa_cipher_decrypt_setup(psa_cipher_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg) {
return (psa_cipher_setup(operation, key, alg, MBEDTLS_DECRYPT));
}
psa_status_t psa_cipher_generate_iv(psa_cipher_operation_t *operation,
uint8_t *iv,
size_t iv_size,
size_t *iv_length) {
psa_status_t status;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if (operation->iv_set || ! operation->iv_required) {
return (PSA_ERROR_BAD_STATE);
}
if (operation->mbedtls_in_use == 0) {
status = psa_driver_wrapper_cipher_generate_iv(&operation->ctx.driver,
iv,
iv_size,
iv_length);
goto exit;
}
if (iv_size < operation->iv_size) {
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
ret = mbedtls_psa_get_random(MBEDTLS_PSA_RANDOM_STATE,
iv, operation->iv_size);
if (ret != 0) {
status = mbedtls_to_psa_error(ret);
goto exit;
}
*iv_length = operation->iv_size;
status = psa_cipher_set_iv(operation, iv, *iv_length);
exit:
if (status == PSA_SUCCESS)
operation->iv_set = 1;
else
psa_cipher_abort(operation);
return (status);
}
psa_status_t psa_cipher_set_iv(psa_cipher_operation_t *operation,
const uint8_t *iv,
size_t iv_length) {
psa_status_t status;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if (operation->iv_set || ! operation->iv_required) {
return (PSA_ERROR_BAD_STATE);
}
if (operation->mbedtls_in_use == 0) {
status = psa_driver_wrapper_cipher_set_iv(&operation->ctx.driver,
iv,
iv_length);
goto exit;
}
if (iv_length != operation->iv_size) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
ret = mbedtls_cipher_set_iv(&operation->ctx.cipher, iv, iv_length);
status = mbedtls_to_psa_error(ret);
exit:
if (status == PSA_SUCCESS)
operation->iv_set = 1;
else
psa_cipher_abort(operation);
return (status);
}
/* Process input for which the algorithm is set to ECB mode. This requires
* manual processing, since the PSA API is defined as being able to process
* arbitrary-length calls to psa_cipher_update() with ECB mode, but the
* underlying mbedtls_cipher_update only takes full blocks. */
static psa_status_t psa_cipher_update_ecb_internal(
mbedtls_cipher_context_t *ctx,
const uint8_t *input,
size_t input_length,
uint8_t *output,
size_t output_size,
size_t *output_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
size_t block_size = ctx->cipher_info->block_size;
size_t internal_output_length = 0;
*output_length = 0;
if (input_length == 0) {
status = PSA_SUCCESS;
goto exit;
}
if (ctx->unprocessed_len > 0) {
/* Fill up to block size, and run the block if there's a full one. */
size_t bytes_to_copy = block_size - ctx->unprocessed_len;
if (input_length < bytes_to_copy)
bytes_to_copy = input_length;
memcpy(&(ctx->unprocessed_data[ctx->unprocessed_len]),
input, bytes_to_copy);
input_length -= bytes_to_copy;
input += bytes_to_copy;
ctx->unprocessed_len += bytes_to_copy;
if (ctx->unprocessed_len == block_size) {
status = mbedtls_to_psa_error(
mbedtls_cipher_update(ctx,
ctx->unprocessed_data,
block_size,
output, &internal_output_length));
if (status != PSA_SUCCESS)
goto exit;
output += internal_output_length;
output_size -= internal_output_length;
*output_length += internal_output_length;
ctx->unprocessed_len = 0;
}
}
while (input_length >= block_size) {
/* Run all full blocks we have, one by one */
status = mbedtls_to_psa_error(
mbedtls_cipher_update(ctx, input,
block_size,
output, &internal_output_length));
if (status != PSA_SUCCESS)
goto exit;
input_length -= block_size;
input += block_size;
output += internal_output_length;
output_size -= internal_output_length;
*output_length += internal_output_length;
}
if (input_length > 0) {
/* Save unprocessed bytes for later processing */
memcpy(&(ctx->unprocessed_data[ctx->unprocessed_len]),
input, input_length);
ctx->unprocessed_len += input_length;
}
status = PSA_SUCCESS;
exit:
return (status);
}
psa_status_t psa_cipher_update(psa_cipher_operation_t *operation,
const uint8_t *input,
size_t input_length,
uint8_t *output,
size_t output_size,
size_t *output_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
size_t expected_output_size;
if (operation->alg == 0) {
return (PSA_ERROR_BAD_STATE);
}
if (operation->iv_required && ! operation->iv_set) {
return (PSA_ERROR_BAD_STATE);
}
if (operation->mbedtls_in_use == 0) {
status = psa_driver_wrapper_cipher_update(&operation->ctx.driver,
input,
input_length,
output,
output_size,
output_length);
goto exit;
}
if (! PSA_ALG_IS_STREAM_CIPHER(operation->alg)) {
/* Take the unprocessed partial block left over from previous
* update calls, if any, plus the input to this call. Remove
* the last partial block, if any. You get the data that will be
* output in this call. */
expected_output_size =
(operation->ctx.cipher.unprocessed_len + input_length)
/ operation->block_size * operation->block_size;
} else {
expected_output_size = input_length;
}
if (output_size < expected_output_size) {
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
if (operation->alg == PSA_ALG_ECB_NO_PADDING) {
/* mbedtls_cipher_update has an API inconsistency: it will only
* process a single block at a time in ECB mode. Abstract away that
* inconsistency here to match the PSA API behaviour. */
status = psa_cipher_update_ecb_internal(&operation->ctx.cipher,
input,
input_length,
output,
output_size,
output_length);
} else {
status = mbedtls_to_psa_error(
mbedtls_cipher_update(&operation->ctx.cipher, input,
input_length, output, output_length));
}
exit:
if (status != PSA_SUCCESS)
psa_cipher_abort(operation);
return (status);
}
psa_status_t psa_cipher_finish(psa_cipher_operation_t *operation,
uint8_t *output,
size_t output_size,
size_t *output_length) {
psa_status_t status = PSA_ERROR_GENERIC_ERROR;
uint8_t temp_output_buffer[MBEDTLS_MAX_BLOCK_LENGTH];
if (operation->alg == 0) {
return (PSA_ERROR_BAD_STATE);
}
if (operation->iv_required && ! operation->iv_set) {
return (PSA_ERROR_BAD_STATE);
}
if (operation->mbedtls_in_use == 0) {
status = psa_driver_wrapper_cipher_finish(&operation->ctx.driver,
output,
output_size,
output_length);
goto exit;
}
if (operation->ctx.cipher.unprocessed_len != 0) {
if (operation->alg == PSA_ALG_ECB_NO_PADDING ||
operation->alg == PSA_ALG_CBC_NO_PADDING) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
}
status = mbedtls_to_psa_error(
mbedtls_cipher_finish(&operation->ctx.cipher,
temp_output_buffer,
output_length));
if (status != PSA_SUCCESS)
goto exit;
if (*output_length == 0)
; /* Nothing to copy. Note that output may be NULL in this case. */
else if (output_size >= *output_length)
memcpy(output, temp_output_buffer, *output_length);
else
status = PSA_ERROR_BUFFER_TOO_SMALL;
exit:
if (operation->mbedtls_in_use == 1)
mbedtls_platform_zeroize(temp_output_buffer, sizeof(temp_output_buffer));
if (status == PSA_SUCCESS)
return (psa_cipher_abort(operation));
else {
*output_length = 0;
(void) psa_cipher_abort(operation);
return (status);
}
}
psa_status_t psa_cipher_abort(psa_cipher_operation_t *operation) {
if (operation->alg == 0) {
/* The object has (apparently) been initialized but it is not (yet)
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
return (PSA_SUCCESS);
}
/* Sanity check (shouldn't happen: operation->alg should
* always have been initialized to a valid value). */
if (! PSA_ALG_IS_CIPHER(operation->alg))
return (PSA_ERROR_BAD_STATE);
if (operation->mbedtls_in_use == 0)
psa_driver_wrapper_cipher_abort(&operation->ctx.driver);
else
mbedtls_cipher_free(&operation->ctx.cipher);
operation->alg = 0;
operation->key_set = 0;
operation->iv_set = 0;
operation->mbedtls_in_use = 0;
operation->iv_size = 0;
operation->block_size = 0;
operation->iv_required = 0;
return (PSA_SUCCESS);
}
/****************************************************************/
/* AEAD */
/****************************************************************/
typedef struct {
psa_key_slot_t *slot;
const mbedtls_cipher_info_t *cipher_info;
union {
unsigned dummy; /* Make the union non-empty even with no supported algorithms. */
#if defined(MBEDTLS_CCM_C)
mbedtls_ccm_context ccm;
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_GCM_C)
mbedtls_gcm_context gcm;
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
mbedtls_chachapoly_context chachapoly;
#endif /* MBEDTLS_CHACHAPOLY_C */
} ctx;
psa_algorithm_t core_alg;
uint8_t full_tag_length;
uint8_t tag_length;
} aead_operation_t;
#define AEAD_OPERATION_INIT {0, 0, {0}, 0, 0, 0}
static void psa_aead_abort_internal(aead_operation_t *operation) {
switch (operation->core_alg) {
#if defined(MBEDTLS_CCM_C)
case PSA_ALG_CCM:
mbedtls_ccm_free(&operation->ctx.ccm);
break;
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_GCM_C)
case PSA_ALG_GCM:
mbedtls_gcm_free(&operation->ctx.gcm);
break;
#endif /* MBEDTLS_GCM_C */
}
psa_unlock_key_slot(operation->slot);
}
static psa_status_t psa_aead_setup(aead_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_key_usage_t usage,
psa_algorithm_t alg) {
psa_status_t status;
size_t key_bits;
mbedtls_cipher_id_t cipher_id;
status = psa_get_and_lock_transparent_key_slot_with_policy(
key, &operation->slot, usage, alg);
if (status != PSA_SUCCESS)
return (status);
key_bits = psa_get_key_slot_bits(operation->slot);
operation->cipher_info =
mbedtls_cipher_info_from_psa(alg, operation->slot->attr.type, key_bits,
&cipher_id);
if (operation->cipher_info == NULL) {
status = PSA_ERROR_NOT_SUPPORTED;
goto cleanup;
}
switch (PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg, 0)) {
#if defined(MBEDTLS_CCM_C)
case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CCM, 0):
operation->core_alg = PSA_ALG_CCM;
operation->full_tag_length = 16;
/* CCM allows the following tag lengths: 4, 6, 8, 10, 12, 14, 16.
* The call to mbedtls_ccm_encrypt_and_tag or
* mbedtls_ccm_auth_decrypt will validate the tag length. */
if (PSA_BLOCK_CIPHER_BLOCK_LENGTH(operation->slot->attr.type) != 16) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto cleanup;
}
mbedtls_ccm_init(&operation->ctx.ccm);
status = mbedtls_to_psa_error(
mbedtls_ccm_setkey(&operation->ctx.ccm, cipher_id,
operation->slot->key.data,
(unsigned int) key_bits));
if (status != 0)
goto cleanup;
break;
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_GCM_C)
case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 0):
operation->core_alg = PSA_ALG_GCM;
operation->full_tag_length = 16;
/* GCM allows the following tag lengths: 4, 8, 12, 13, 14, 15, 16.
* The call to mbedtls_gcm_crypt_and_tag or
* mbedtls_gcm_auth_decrypt will validate the tag length. */
if (PSA_BLOCK_CIPHER_BLOCK_LENGTH(operation->slot->attr.type) != 16) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto cleanup;
}
mbedtls_gcm_init(&operation->ctx.gcm);
status = mbedtls_to_psa_error(
mbedtls_gcm_setkey(&operation->ctx.gcm, cipher_id,
operation->slot->key.data,
(unsigned int) key_bits));
if (status != 0)
goto cleanup;
break;
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CHACHA20_POLY1305, 0):
operation->core_alg = PSA_ALG_CHACHA20_POLY1305;
operation->full_tag_length = 16;
/* We only support the default tag length. */
if (alg != PSA_ALG_CHACHA20_POLY1305) {
status = PSA_ERROR_NOT_SUPPORTED;
goto cleanup;
}
mbedtls_chachapoly_init(&operation->ctx.chachapoly);
status = mbedtls_to_psa_error(
mbedtls_chachapoly_setkey(&operation->ctx.chachapoly,
operation->slot->key.data));
if (status != 0)
goto cleanup;
break;
#endif /* MBEDTLS_CHACHAPOLY_C */
default:
status = PSA_ERROR_NOT_SUPPORTED;
goto cleanup;
}
if (PSA_AEAD_TAG_LENGTH(alg) > operation->full_tag_length) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto cleanup;
}
operation->tag_length = PSA_AEAD_TAG_LENGTH(alg);
return (PSA_SUCCESS);
cleanup:
psa_aead_abort_internal(operation);
return (status);
}
psa_status_t psa_aead_encrypt(mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *nonce,
size_t nonce_length,
const uint8_t *additional_data,
size_t additional_data_length,
const uint8_t *plaintext,
size_t plaintext_length,
uint8_t *ciphertext,
size_t ciphertext_size,
size_t *ciphertext_length) {
psa_status_t status;
aead_operation_t operation = AEAD_OPERATION_INIT;
uint8_t *tag;
*ciphertext_length = 0;
status = psa_aead_setup(&operation, key, PSA_KEY_USAGE_ENCRYPT, alg);
if (status != PSA_SUCCESS)
return (status);
/* For all currently supported modes, the tag is at the end of the
* ciphertext. */
if (ciphertext_size < (plaintext_length + operation.tag_length)) {
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
tag = ciphertext + plaintext_length;
#if defined(MBEDTLS_GCM_C)
if (operation.core_alg == PSA_ALG_GCM) {
status = mbedtls_to_psa_error(
mbedtls_gcm_crypt_and_tag(&operation.ctx.gcm,
MBEDTLS_GCM_ENCRYPT,
plaintext_length,
nonce, nonce_length,
additional_data, additional_data_length,
plaintext, ciphertext,
operation.tag_length, tag));
} else
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CCM_C)
if (operation.core_alg == PSA_ALG_CCM) {
status = mbedtls_to_psa_error(
mbedtls_ccm_encrypt_and_tag(&operation.ctx.ccm,
plaintext_length,
nonce, nonce_length,
additional_data,
additional_data_length,
plaintext, ciphertext,
tag, operation.tag_length));
} else
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
if (operation.core_alg == PSA_ALG_CHACHA20_POLY1305) {
if (nonce_length != 12 || operation.tag_length != 16) {
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
status = mbedtls_to_psa_error(
mbedtls_chachapoly_encrypt_and_tag(&operation.ctx.chachapoly,
plaintext_length,
nonce,
additional_data,
additional_data_length,
plaintext,
ciphertext,
tag));
} else
#endif /* MBEDTLS_CHACHAPOLY_C */
{
(void) tag;
return (PSA_ERROR_NOT_SUPPORTED);
}
if (status != PSA_SUCCESS && ciphertext_size != 0)
memset(ciphertext, 0, ciphertext_size);
exit:
psa_aead_abort_internal(&operation);
if (status == PSA_SUCCESS)
*ciphertext_length = plaintext_length + operation.tag_length;
return (status);
}
/* Locate the tag in a ciphertext buffer containing the encrypted data
* followed by the tag. Return the length of the part preceding the tag in
* *plaintext_length. This is the size of the plaintext in modes where
* the encrypted data has the same size as the plaintext, such as
* CCM and GCM. */
static psa_status_t psa_aead_unpadded_locate_tag(size_t tag_length,
const uint8_t *ciphertext,
size_t ciphertext_length,
size_t plaintext_size,
const uint8_t **p_tag) {
size_t payload_length;
if (tag_length > ciphertext_length)
return (PSA_ERROR_INVALID_ARGUMENT);
payload_length = ciphertext_length - tag_length;
if (payload_length > plaintext_size)
return (PSA_ERROR_BUFFER_TOO_SMALL);
*p_tag = ciphertext + payload_length;
return (PSA_SUCCESS);
}
psa_status_t psa_aead_decrypt(mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *nonce,
size_t nonce_length,
const uint8_t *additional_data,
size_t additional_data_length,
const uint8_t *ciphertext,
size_t ciphertext_length,
uint8_t *plaintext,
size_t plaintext_size,
size_t *plaintext_length) {
psa_status_t status;
aead_operation_t operation = AEAD_OPERATION_INIT;
const uint8_t *tag = NULL;
*plaintext_length = 0;
status = psa_aead_setup(&operation, key, PSA_KEY_USAGE_DECRYPT, alg);
if (status != PSA_SUCCESS)
return (status);
status = psa_aead_unpadded_locate_tag(operation.tag_length,
ciphertext, ciphertext_length,
plaintext_size, &tag);
if (status != PSA_SUCCESS)
goto exit;
#if defined(MBEDTLS_GCM_C)
if (operation.core_alg == PSA_ALG_GCM) {
status = mbedtls_to_psa_error(
mbedtls_gcm_auth_decrypt(&operation.ctx.gcm,
ciphertext_length - operation.tag_length,
nonce, nonce_length,
additional_data,
additional_data_length,
tag, operation.tag_length,
ciphertext, plaintext));
} else
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CCM_C)
if (operation.core_alg == PSA_ALG_CCM) {
status = mbedtls_to_psa_error(
mbedtls_ccm_auth_decrypt(&operation.ctx.ccm,
ciphertext_length - operation.tag_length,
nonce, nonce_length,
additional_data,
additional_data_length,
ciphertext, plaintext,
tag, operation.tag_length));
} else
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
if (operation.core_alg == PSA_ALG_CHACHA20_POLY1305) {
if (nonce_length != 12 || operation.tag_length != 16) {
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
status = mbedtls_to_psa_error(
mbedtls_chachapoly_auth_decrypt(&operation.ctx.chachapoly,
ciphertext_length - operation.tag_length,
nonce,
additional_data,
additional_data_length,
tag,
ciphertext,
plaintext));
} else
#endif /* MBEDTLS_CHACHAPOLY_C */
{
return (PSA_ERROR_NOT_SUPPORTED);
}
if (status != PSA_SUCCESS && plaintext_size != 0)
memset(plaintext, 0, plaintext_size);
exit:
psa_aead_abort_internal(&operation);
if (status == PSA_SUCCESS)
*plaintext_length = ciphertext_length - operation.tag_length;
return (status);
}
/****************************************************************/
/* Generators */
/****************************************************************/
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
#define AT_LEAST_ONE_BUILTIN_KDF
#endif
#define HKDF_STATE_INIT 0 /* no input yet */
#define HKDF_STATE_STARTED 1 /* got salt */
#define HKDF_STATE_KEYED 2 /* got key */
#define HKDF_STATE_OUTPUT 3 /* output started */
static psa_algorithm_t psa_key_derivation_get_kdf_alg(
const psa_key_derivation_operation_t *operation) {
if (PSA_ALG_IS_KEY_AGREEMENT(operation->alg))
return (PSA_ALG_KEY_AGREEMENT_GET_KDF(operation->alg));
else
return (operation->alg);
}
psa_status_t psa_key_derivation_abort(psa_key_derivation_operation_t *operation) {
psa_status_t status = PSA_SUCCESS;
psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation);
if (kdf_alg == 0) {
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
} else
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF)
if (PSA_ALG_IS_HKDF(kdf_alg)) {
mbedtls_free(operation->ctx.hkdf.info);
status = psa_hmac_abort_internal(&operation->ctx.hkdf.hmac);
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
if (PSA_ALG_IS_TLS12_PRF(kdf_alg) ||
/* TLS-1.2 PSK-to-MS KDF uses the same core as TLS-1.2 PRF */
PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) {
if (operation->ctx.tls12_prf.seed != NULL) {
mbedtls_platform_zeroize(operation->ctx.tls12_prf.seed,
operation->ctx.tls12_prf.seed_length);
mbedtls_free(operation->ctx.tls12_prf.seed);
}
if (operation->ctx.tls12_prf.label != NULL) {
mbedtls_platform_zeroize(operation->ctx.tls12_prf.label,
operation->ctx.tls12_prf.label_length);
mbedtls_free(operation->ctx.tls12_prf.label);
}
status = psa_hmac_abort_internal(&operation->ctx.tls12_prf.hmac);
/* We leave the fields Ai and output_block to be erased safely by the
* mbedtls_platform_zeroize() in the end of this function. */
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) */
{
status = PSA_ERROR_BAD_STATE;
}
mbedtls_platform_zeroize(operation, sizeof(*operation));
return (status);
}
psa_status_t psa_key_derivation_get_capacity(const psa_key_derivation_operation_t *operation,
size_t *capacity) {
if (operation->alg == 0) {
/* This is a blank key derivation operation. */
return (PSA_ERROR_BAD_STATE);
}
*capacity = operation->capacity;
return (PSA_SUCCESS);
}
psa_status_t psa_key_derivation_set_capacity(psa_key_derivation_operation_t *operation,
size_t capacity) {
if (operation->alg == 0)
return (PSA_ERROR_BAD_STATE);
if (capacity > operation->capacity)
return (PSA_ERROR_INVALID_ARGUMENT);
operation->capacity = capacity;
return (PSA_SUCCESS);
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF)
/* Read some bytes from an HKDF-based operation. This performs a chunk
* of the expand phase of the HKDF algorithm. */
static psa_status_t psa_key_derivation_hkdf_read(psa_hkdf_key_derivation_t *hkdf,
psa_algorithm_t hash_alg,
uint8_t *output,
size_t output_length) {
uint8_t hash_length = PSA_HASH_LENGTH(hash_alg);
psa_status_t status;
if (hkdf->state < HKDF_STATE_KEYED || ! hkdf->info_set)
return (PSA_ERROR_BAD_STATE);
hkdf->state = HKDF_STATE_OUTPUT;
while (output_length != 0) {
/* Copy what remains of the current block */
uint8_t n = hash_length - hkdf->offset_in_block;
if (n > output_length)
n = (uint8_t) output_length;
memcpy(output, hkdf->output_block + hkdf->offset_in_block, n);
output += n;
output_length -= n;
hkdf->offset_in_block += n;
if (output_length == 0)
break;
/* We can't be wanting more output after block 0xff, otherwise
* the capacity check in psa_key_derivation_output_bytes() would have
* prevented this call. It could happen only if the operation
* object was corrupted or if this function is called directly
* inside the library. */
if (hkdf->block_number == 0xff)
return (PSA_ERROR_BAD_STATE);
/* We need a new block */
++hkdf->block_number;
hkdf->offset_in_block = 0;
status = psa_hmac_setup_internal(&hkdf->hmac,
hkdf->prk, hash_length,
hash_alg);
if (status != PSA_SUCCESS)
return (status);
if (hkdf->block_number != 1) {
status = psa_hash_update(&hkdf->hmac.hash_ctx,
hkdf->output_block,
hash_length);
if (status != PSA_SUCCESS)
return (status);
}
status = psa_hash_update(&hkdf->hmac.hash_ctx,
hkdf->info,
hkdf->info_length);
if (status != PSA_SUCCESS)
return (status);
status = psa_hash_update(&hkdf->hmac.hash_ctx,
&hkdf->block_number, 1);
if (status != PSA_SUCCESS)
return (status);
status = psa_hmac_finish_internal(&hkdf->hmac,
hkdf->output_block,
sizeof(hkdf->output_block));
if (status != PSA_SUCCESS)
return (status);
}
return (PSA_SUCCESS);
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
static psa_status_t psa_key_derivation_tls12_prf_generate_next_block(
psa_tls12_prf_key_derivation_t *tls12_prf,
psa_algorithm_t alg) {
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH(alg);
uint8_t hash_length = PSA_HASH_LENGTH(hash_alg);
psa_hash_operation_t backup = PSA_HASH_OPERATION_INIT;
psa_status_t status, cleanup_status;
/* We can't be wanting more output after block 0xff, otherwise
* the capacity check in psa_key_derivation_output_bytes() would have
* prevented this call. It could happen only if the operation
* object was corrupted or if this function is called directly
* inside the library. */
if (tls12_prf->block_number == 0xff)
return (PSA_ERROR_CORRUPTION_DETECTED);
/* We need a new block */
++tls12_prf->block_number;
tls12_prf->left_in_block = hash_length;
/* Recall the definition of the TLS-1.2-PRF from RFC 5246:
*
* PRF(secret, label, seed) = P_<hash>(secret, label + seed)
*
* P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
* HMAC_hash(secret, A(2) + seed) +
* HMAC_hash(secret, A(3) + seed) + ...
*
* A(0) = seed
* A(i) = HMAC_hash(secret, A(i-1))
*
* The `psa_tls12_prf_key_derivation` structure saves the block
* `HMAC_hash(secret, A(i) + seed)` from which the output
* is currently extracted as `output_block` and where i is
* `block_number`.
*/
/* Save the hash context before using it, to preserve the hash state with
* only the inner padding in it. We need this, because inner padding depends
* on the key (secret in the RFC's terminology). */
status = psa_hash_clone(&tls12_prf->hmac.hash_ctx, &backup);
if (status != PSA_SUCCESS)
goto cleanup;
/* Calculate A(i) where i = tls12_prf->block_number. */
if (tls12_prf->block_number == 1) {
/* A(1) = HMAC_hash(secret, A(0)), where A(0) = seed. (The RFC overloads
* the variable seed and in this instance means it in the context of the
* P_hash function, where seed = label + seed.) */
status = psa_hash_update(&tls12_prf->hmac.hash_ctx,
tls12_prf->label, tls12_prf->label_length);
if (status != PSA_SUCCESS)
goto cleanup;
status = psa_hash_update(&tls12_prf->hmac.hash_ctx,
tls12_prf->seed, tls12_prf->seed_length);
if (status != PSA_SUCCESS)
goto cleanup;
} else {
/* A(i) = HMAC_hash(secret, A(i-1)) */
status = psa_hash_update(&tls12_prf->hmac.hash_ctx,
tls12_prf->Ai, hash_length);
if (status != PSA_SUCCESS)
goto cleanup;
}
status = psa_hmac_finish_internal(&tls12_prf->hmac,
tls12_prf->Ai, hash_length);
if (status != PSA_SUCCESS)
goto cleanup;
status = psa_hash_clone(&backup, &tls12_prf->hmac.hash_ctx);
if (status != PSA_SUCCESS)
goto cleanup;
/* Calculate HMAC_hash(secret, A(i) + label + seed). */
status = psa_hash_update(&tls12_prf->hmac.hash_ctx,
tls12_prf->Ai, hash_length);
if (status != PSA_SUCCESS)
goto cleanup;
status = psa_hash_update(&tls12_prf->hmac.hash_ctx,
tls12_prf->label, tls12_prf->label_length);
if (status != PSA_SUCCESS)
goto cleanup;
status = psa_hash_update(&tls12_prf->hmac.hash_ctx,
tls12_prf->seed, tls12_prf->seed_length);
if (status != PSA_SUCCESS)
goto cleanup;
status = psa_hmac_finish_internal(&tls12_prf->hmac,
tls12_prf->output_block, hash_length);
if (status != PSA_SUCCESS)
goto cleanup;
status = psa_hash_clone(&backup, &tls12_prf->hmac.hash_ctx);
if (status != PSA_SUCCESS)
goto cleanup;
cleanup:
cleanup_status = psa_hash_abort(&backup);
if (status == PSA_SUCCESS && cleanup_status != PSA_SUCCESS)
status = cleanup_status;
return (status);
}
static psa_status_t psa_key_derivation_tls12_prf_read(
psa_tls12_prf_key_derivation_t *tls12_prf,
psa_algorithm_t alg,
uint8_t *output,
size_t output_length) {
psa_algorithm_t hash_alg = PSA_ALG_TLS12_PRF_GET_HASH(alg);
uint8_t hash_length = PSA_HASH_LENGTH(hash_alg);
psa_status_t status;
uint8_t offset, length;
while (output_length != 0) {
/* Check if we have fully processed the current block. */
if (tls12_prf->left_in_block == 0) {
status = psa_key_derivation_tls12_prf_generate_next_block(tls12_prf,
alg);
if (status != PSA_SUCCESS)
return (status);
continue;
}
if (tls12_prf->left_in_block > output_length)
length = (uint8_t) output_length;
else
length = tls12_prf->left_in_block;
offset = hash_length - tls12_prf->left_in_block;
memcpy(output, tls12_prf->output_block + offset, length);
output += length;
output_length -= length;
tls12_prf->left_in_block -= length;
}
return (PSA_SUCCESS);
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF ||
* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
psa_status_t psa_key_derivation_output_bytes(
psa_key_derivation_operation_t *operation,
uint8_t *output,
size_t output_length) {
psa_status_t status;
psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation);
if (operation->alg == 0) {
/* This is a blank operation. */
return (PSA_ERROR_BAD_STATE);
}
if (output_length > operation->capacity) {
operation->capacity = 0;
/* Go through the error path to wipe all confidential data now
* that the operation object is useless. */
status = PSA_ERROR_INSUFFICIENT_DATA;
goto exit;
}
if (output_length == 0 && operation->capacity == 0) {
/* Edge case: this is a finished operation, and 0 bytes
* were requested. The right error in this case could
* be either INSUFFICIENT_CAPACITY or BAD_STATE. Return
* INSUFFICIENT_CAPACITY, which is right for a finished
* operation, for consistency with the case when
* output_length > 0. */
return (PSA_ERROR_INSUFFICIENT_DATA);
}
operation->capacity -= output_length;
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF)
if (PSA_ALG_IS_HKDF(kdf_alg)) {
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH(kdf_alg);
status = psa_key_derivation_hkdf_read(&operation->ctx.hkdf, hash_alg,
output, output_length);
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
if (PSA_ALG_IS_TLS12_PRF(kdf_alg) ||
PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) {
status = psa_key_derivation_tls12_prf_read(&operation->ctx.tls12_prf,
kdf_alg, output,
output_length);
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF ||
* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
{
(void) kdf_alg;
return (PSA_ERROR_BAD_STATE);
}
exit:
if (status != PSA_SUCCESS) {
/* Preserve the algorithm upon errors, but clear all sensitive state.
* This allows us to differentiate between exhausted operations and
* blank operations, so we can return PSA_ERROR_BAD_STATE on blank
* operations. */
psa_algorithm_t alg = operation->alg;
psa_key_derivation_abort(operation);
operation->alg = alg;
memset(output, '!', output_length);
}
return (status);
}
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
static void psa_des_set_key_parity(uint8_t *data, size_t data_size) {
if (data_size >= 8)
mbedtls_des_key_set_parity(data);
if (data_size >= 16)
mbedtls_des_key_set_parity(data + 8);
if (data_size >= 24)
mbedtls_des_key_set_parity(data + 16);
}
#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES */
static psa_status_t psa_generate_derived_key_internal(
psa_key_slot_t *slot,
size_t bits,
psa_key_derivation_operation_t *operation) {
uint8_t *data = NULL;
size_t bytes = PSA_BITS_TO_BYTES(bits);
psa_status_t status;
if (! key_type_is_raw_bytes(slot->attr.type))
return (PSA_ERROR_INVALID_ARGUMENT);
if (bits % 8 != 0)
return (PSA_ERROR_INVALID_ARGUMENT);
data = mbedtls_calloc(1, bytes);
if (data == NULL)
return (PSA_ERROR_INSUFFICIENT_MEMORY);
status = psa_key_derivation_output_bytes(operation, data, bytes);
if (status != PSA_SUCCESS)
goto exit;
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
if (slot->attr.type == PSA_KEY_TYPE_DES)
psa_des_set_key_parity(data, bytes);
#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES */
status = psa_allocate_buffer_to_slot(slot, bytes);
if (status != PSA_SUCCESS)
goto exit;
slot->attr.bits = (psa_key_bits_t) bits;
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_driver_wrapper_import_key(&attributes,
data, bytes,
slot->key.data,
slot->key.bytes,
&slot->key.bytes, &bits);
if (bits != slot->attr.bits)
status = PSA_ERROR_INVALID_ARGUMENT;
exit:
mbedtls_free(data);
return (status);
}
psa_status_t psa_key_derivation_output_key(const psa_key_attributes_t *attributes,
psa_key_derivation_operation_t *operation,
mbedtls_svc_key_id_t *key) {
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
*key = MBEDTLS_SVC_KEY_ID_INIT;
/* Reject any attempt to create a zero-length key so that we don't
* risk tripping up later, e.g. on a malloc(0) that returns NULL. */
if (psa_get_key_bits(attributes) == 0)
return (PSA_ERROR_INVALID_ARGUMENT);
if (! operation->can_output_key)
return (PSA_ERROR_NOT_PERMITTED);
status = psa_start_key_creation(PSA_KEY_CREATION_DERIVE, attributes,
&slot, &driver);
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if (driver != NULL) {
/* Deriving a key in a secure element is not implemented yet. */
status = PSA_ERROR_NOT_SUPPORTED;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
if (status == PSA_SUCCESS) {
status = psa_generate_derived_key_internal(slot,
attributes->core.bits,
operation);
}
if (status == PSA_SUCCESS)
status = psa_finish_key_creation(slot, driver, key);
if (status != PSA_SUCCESS)
psa_fail_key_creation(slot, driver);
return (status);
}
/****************************************************************/
/* Key derivation */
/****************************************************************/
#if defined(AT_LEAST_ONE_BUILTIN_KDF)
static psa_status_t psa_key_derivation_setup_kdf(
psa_key_derivation_operation_t *operation,
psa_algorithm_t kdf_alg) {
int is_kdf_alg_supported;
/* Make sure that operation->ctx is properly zero-initialised. (Macro
* initialisers for this union leave some bytes unspecified.) */
memset(&operation->ctx, 0, sizeof(operation->ctx));
/* Make sure that kdf_alg is a supported key derivation algorithm. */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF)
if (PSA_ALG_IS_HKDF(kdf_alg))
is_kdf_alg_supported = 1;
else
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF)
if (PSA_ALG_IS_TLS12_PRF(kdf_alg))
is_kdf_alg_supported = 1;
else
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
if (PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg))
is_kdf_alg_supported = 1;
else
#endif
is_kdf_alg_supported = 0;
if (is_kdf_alg_supported) {
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH(kdf_alg);
size_t hash_size = PSA_HASH_LENGTH(hash_alg);
if (hash_size == 0)
return (PSA_ERROR_NOT_SUPPORTED);
if ((PSA_ALG_IS_TLS12_PRF(kdf_alg) ||
PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) &&
!(hash_alg == PSA_ALG_SHA_256 || hash_alg == PSA_ALG_SHA_384)) {
return (PSA_ERROR_NOT_SUPPORTED);
}
operation->capacity = 255 * hash_size;
return (PSA_SUCCESS);
}
return (PSA_ERROR_NOT_SUPPORTED);
}
#endif /* AT_LEAST_ONE_BUILTIN_KDF */
psa_status_t psa_key_derivation_setup(psa_key_derivation_operation_t *operation,
psa_algorithm_t alg) {
psa_status_t status;
if (operation->alg != 0)
return (PSA_ERROR_BAD_STATE);
if (PSA_ALG_IS_RAW_KEY_AGREEMENT(alg))
return (PSA_ERROR_INVALID_ARGUMENT);
else if (PSA_ALG_IS_KEY_AGREEMENT(alg)) {
#if defined(AT_LEAST_ONE_BUILTIN_KDF)
psa_algorithm_t kdf_alg = PSA_ALG_KEY_AGREEMENT_GET_KDF(alg);
status = psa_key_derivation_setup_kdf(operation, kdf_alg);
#else
return (PSA_ERROR_NOT_SUPPORTED);
#endif /* AT_LEAST_ONE_BUILTIN_KDF */
} else if (PSA_ALG_IS_KEY_DERIVATION(alg)) {
#if defined(AT_LEAST_ONE_BUILTIN_KDF)
status = psa_key_derivation_setup_kdf(operation, alg);
#else
return (PSA_ERROR_NOT_SUPPORTED);
#endif /* AT_LEAST_ONE_BUILTIN_KDF */
} else
return (PSA_ERROR_INVALID_ARGUMENT);
if (status == PSA_SUCCESS)
operation->alg = alg;
return (status);
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF)
static psa_status_t psa_hkdf_input(psa_hkdf_key_derivation_t *hkdf,
psa_algorithm_t hash_alg,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length) {
psa_status_t status;
switch (step) {
case PSA_KEY_DERIVATION_INPUT_SALT:
if (hkdf->state != HKDF_STATE_INIT)
return (PSA_ERROR_BAD_STATE);
status = psa_hmac_setup_internal(&hkdf->hmac,
data, data_length,
hash_alg);
if (status != PSA_SUCCESS)
return (status);
hkdf->state = HKDF_STATE_STARTED;
return (PSA_SUCCESS);
case PSA_KEY_DERIVATION_INPUT_SECRET:
/* If no salt was provided, use an empty salt. */
if (hkdf->state == HKDF_STATE_INIT) {
status = psa_hmac_setup_internal(&hkdf->hmac,
NULL, 0,
hash_alg);
if (status != PSA_SUCCESS)
return (status);
hkdf->state = HKDF_STATE_STARTED;
}
if (hkdf->state != HKDF_STATE_STARTED)
return (PSA_ERROR_BAD_STATE);
status = psa_hash_update(&hkdf->hmac.hash_ctx,
data, data_length);
if (status != PSA_SUCCESS)
return (status);
status = psa_hmac_finish_internal(&hkdf->hmac,
hkdf->prk,
sizeof(hkdf->prk));
if (status != PSA_SUCCESS)
return (status);
hkdf->offset_in_block = PSA_HASH_LENGTH(hash_alg);
hkdf->block_number = 0;
hkdf->state = HKDF_STATE_KEYED;
return (PSA_SUCCESS);
case PSA_KEY_DERIVATION_INPUT_INFO:
if (hkdf->state == HKDF_STATE_OUTPUT)
return (PSA_ERROR_BAD_STATE);
if (hkdf->info_set)
return (PSA_ERROR_BAD_STATE);
hkdf->info_length = data_length;
if (data_length != 0) {
hkdf->info = mbedtls_calloc(1, data_length);
if (hkdf->info == NULL)
return (PSA_ERROR_INSUFFICIENT_MEMORY);
memcpy(hkdf->info, data, data_length);
}
hkdf->info_set = 1;
return (PSA_SUCCESS);
default:
return (PSA_ERROR_INVALID_ARGUMENT);
}
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
static psa_status_t psa_tls12_prf_set_seed(psa_tls12_prf_key_derivation_t *prf,
const uint8_t *data,
size_t data_length) {
if (prf->state != PSA_TLS12_PRF_STATE_INIT)
return (PSA_ERROR_BAD_STATE);
if (data_length != 0) {
prf->seed = mbedtls_calloc(1, data_length);
if (prf->seed == NULL)
return (PSA_ERROR_INSUFFICIENT_MEMORY);
memcpy(prf->seed, data, data_length);
prf->seed_length = data_length;
}
prf->state = PSA_TLS12_PRF_STATE_SEED_SET;
return (PSA_SUCCESS);
}
static psa_status_t psa_tls12_prf_set_key(psa_tls12_prf_key_derivation_t *prf,
psa_algorithm_t hash_alg,
const uint8_t *data,
size_t data_length) {
psa_status_t status;
if (prf->state != PSA_TLS12_PRF_STATE_SEED_SET)
return (PSA_ERROR_BAD_STATE);
status = psa_hmac_setup_internal(&prf->hmac, data, data_length, hash_alg);
if (status != PSA_SUCCESS)
return (status);
prf->state = PSA_TLS12_PRF_STATE_KEY_SET;
return (PSA_SUCCESS);
}
static psa_status_t psa_tls12_prf_set_label(psa_tls12_prf_key_derivation_t *prf,
const uint8_t *data,
size_t data_length) {
if (prf->state != PSA_TLS12_PRF_STATE_KEY_SET)
return (PSA_ERROR_BAD_STATE);
if (data_length != 0) {
prf->label = mbedtls_calloc(1, data_length);
if (prf->label == NULL)
return (PSA_ERROR_INSUFFICIENT_MEMORY);
memcpy(prf->label, data, data_length);
prf->label_length = data_length;
}
prf->state = PSA_TLS12_PRF_STATE_LABEL_SET;
return (PSA_SUCCESS);
}
static psa_status_t psa_tls12_prf_input(psa_tls12_prf_key_derivation_t *prf,
psa_algorithm_t hash_alg,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length) {
switch (step) {
case PSA_KEY_DERIVATION_INPUT_SEED:
return (psa_tls12_prf_set_seed(prf, data, data_length));
case PSA_KEY_DERIVATION_INPUT_SECRET:
return (psa_tls12_prf_set_key(prf, hash_alg, data, data_length));
case PSA_KEY_DERIVATION_INPUT_LABEL:
return (psa_tls12_prf_set_label(prf, data, data_length));
default:
return (PSA_ERROR_INVALID_ARGUMENT);
}
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) ||
* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
static psa_status_t psa_tls12_prf_psk_to_ms_set_key(
psa_tls12_prf_key_derivation_t *prf,
psa_algorithm_t hash_alg,
const uint8_t *data,
size_t data_length) {
psa_status_t status;
uint8_t pms[ 4 + 2 * PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE ];
uint8_t *cur = pms;
if (data_length > PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE)
return (PSA_ERROR_INVALID_ARGUMENT);
/* Quoting RFC 4279, Section 2:
*
* The premaster secret is formed as follows: if the PSK is N octets
* long, concatenate a uint16 with the value N, N zero octets, a second
* uint16 with the value N, and the PSK itself.
*/
*cur++ = (data_length >> 8) & 0xff;
*cur++ = (data_length >> 0) & 0xff;
memset(cur, 0, data_length);
cur += data_length;
*cur++ = pms[0];
*cur++ = pms[1];
memcpy(cur, data, data_length);
cur += data_length;
status = psa_tls12_prf_set_key(prf, hash_alg, pms, cur - pms);
mbedtls_platform_zeroize(pms, sizeof(pms));
return (status);
}
static psa_status_t psa_tls12_prf_psk_to_ms_input(
psa_tls12_prf_key_derivation_t *prf,
psa_algorithm_t hash_alg,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length) {
if (step == PSA_KEY_DERIVATION_INPUT_SECRET) {
return (psa_tls12_prf_psk_to_ms_set_key(prf, hash_alg,
data, data_length));
}
return (psa_tls12_prf_input(prf, hash_alg, step, data, data_length));
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
/** Check whether the given key type is acceptable for the given
* input step of a key derivation.
*
* Secret inputs must have the type #PSA_KEY_TYPE_DERIVE.
* Non-secret inputs must have the type #PSA_KEY_TYPE_RAW_DATA.
* Both secret and non-secret inputs can alternatively have the type
* #PSA_KEY_TYPE_NONE, which is never the type of a key object, meaning
* that the input was passed as a buffer rather than via a key object.
*/
static int psa_key_derivation_check_input_type(
psa_key_derivation_step_t step,
psa_key_type_t key_type) {
switch (step) {
case PSA_KEY_DERIVATION_INPUT_SECRET:
if (key_type == PSA_KEY_TYPE_DERIVE)
return (PSA_SUCCESS);
if (key_type == PSA_KEY_TYPE_NONE)
return (PSA_SUCCESS);
break;
case PSA_KEY_DERIVATION_INPUT_LABEL:
case PSA_KEY_DERIVATION_INPUT_SALT:
case PSA_KEY_DERIVATION_INPUT_INFO:
case PSA_KEY_DERIVATION_INPUT_SEED:
if (key_type == PSA_KEY_TYPE_RAW_DATA)
return (PSA_SUCCESS);
if (key_type == PSA_KEY_TYPE_NONE)
return (PSA_SUCCESS);
break;
}
return (PSA_ERROR_INVALID_ARGUMENT);
}
static psa_status_t psa_key_derivation_input_internal(
psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
psa_key_type_t key_type,
const uint8_t *data,
size_t data_length) {
psa_status_t status;
psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation);
status = psa_key_derivation_check_input_type(step, key_type);
if (status != PSA_SUCCESS)
goto exit;
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF)
if (PSA_ALG_IS_HKDF(kdf_alg)) {
status = psa_hkdf_input(&operation->ctx.hkdf,
PSA_ALG_HKDF_GET_HASH(kdf_alg),
step, data, data_length);
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF)
if (PSA_ALG_IS_TLS12_PRF(kdf_alg)) {
status = psa_tls12_prf_input(&operation->ctx.tls12_prf,
PSA_ALG_HKDF_GET_HASH(kdf_alg),
step, data, data_length);
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
if (PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) {
status = psa_tls12_prf_psk_to_ms_input(&operation->ctx.tls12_prf,
PSA_ALG_HKDF_GET_HASH(kdf_alg),
step, data, data_length);
} else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
{
/* This can't happen unless the operation object was not initialized */
(void) data;
(void) data_length;
(void) kdf_alg;
return (PSA_ERROR_BAD_STATE);
}
exit:
if (status != PSA_SUCCESS)
psa_key_derivation_abort(operation);
return (status);
}
psa_status_t psa_key_derivation_input_bytes(
psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length) {
return (psa_key_derivation_input_internal(operation, step,
PSA_KEY_TYPE_NONE,
data, data_length));
}
psa_status_t psa_key_derivation_input_key(
psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
mbedtls_svc_key_id_t key) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
status = psa_get_and_lock_transparent_key_slot_with_policy(
key, &slot, PSA_KEY_USAGE_DERIVE, operation->alg);
if (status != PSA_SUCCESS) {
psa_key_derivation_abort(operation);
return (status);
}
/* Passing a key object as a SECRET input unlocks the permission
* to output to a key object. */
if (step == PSA_KEY_DERIVATION_INPUT_SECRET)
operation->can_output_key = 1;
status = psa_key_derivation_input_internal(operation,
step, slot->attr.type,
slot->key.data,
slot->key.bytes);
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
/****************************************************************/
/* Key agreement */
/****************************************************************/
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
static psa_status_t psa_key_agreement_ecdh(const uint8_t *peer_key,
size_t peer_key_length,
const mbedtls_ecp_keypair *our_key,
uint8_t *shared_secret,
size_t shared_secret_size,
size_t *shared_secret_length) {
mbedtls_ecp_keypair *their_key = NULL;
mbedtls_ecdh_context ecdh;
psa_status_t status;
size_t bits = 0;
psa_ecc_family_t curve = mbedtls_ecc_group_to_psa(our_key->grp.id, &bits);
mbedtls_ecdh_init(&ecdh);
status = mbedtls_psa_ecp_load_representation(
PSA_KEY_TYPE_ECC_PUBLIC_KEY(curve),
bits,
peer_key,
peer_key_length,
&their_key);
if (status != PSA_SUCCESS)
goto exit;
status = mbedtls_to_psa_error(
mbedtls_ecdh_get_params(&ecdh, their_key, MBEDTLS_ECDH_THEIRS));
if (status != PSA_SUCCESS)
goto exit;
status = mbedtls_to_psa_error(
mbedtls_ecdh_get_params(&ecdh, our_key, MBEDTLS_ECDH_OURS));
if (status != PSA_SUCCESS)
goto exit;
status = mbedtls_to_psa_error(
mbedtls_ecdh_calc_secret(&ecdh,
shared_secret_length,
shared_secret, shared_secret_size,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE));
if (status != PSA_SUCCESS)
goto exit;
if (PSA_BITS_TO_BYTES(bits) != *shared_secret_length)
status = PSA_ERROR_CORRUPTION_DETECTED;
exit:
if (status != PSA_SUCCESS)
mbedtls_platform_zeroize(shared_secret, shared_secret_size);
mbedtls_ecdh_free(&ecdh);
mbedtls_ecp_keypair_free(their_key);
mbedtls_free(their_key);
return (status);
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_ECDH */
#define PSA_KEY_AGREEMENT_MAX_SHARED_SECRET_SIZE MBEDTLS_ECP_MAX_BYTES
static psa_status_t psa_key_agreement_raw_internal(psa_algorithm_t alg,
psa_key_slot_t *private_key,
const uint8_t *peer_key,
size_t peer_key_length,
uint8_t *shared_secret,
size_t shared_secret_size,
size_t *shared_secret_length) {
switch (alg) {
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
case PSA_ALG_ECDH:
if (! PSA_KEY_TYPE_IS_ECC_KEY_PAIR(private_key->attr.type))
return (PSA_ERROR_INVALID_ARGUMENT);
mbedtls_ecp_keypair *ecp = NULL;
psa_status_t status = mbedtls_psa_ecp_load_representation(
private_key->attr.type,
private_key->attr.bits,
private_key->key.data,
private_key->key.bytes,
&ecp);
if (status != PSA_SUCCESS)
return (status);
status = psa_key_agreement_ecdh(peer_key, peer_key_length,
ecp,
shared_secret, shared_secret_size,
shared_secret_length);
mbedtls_ecp_keypair_free(ecp);
mbedtls_free(ecp);
return (status);
#endif /* MBEDTLS_PSA_BUILTIN_ALG_ECDH */
default:
(void) private_key;
(void) peer_key;
(void) peer_key_length;
(void) shared_secret;
(void) shared_secret_size;
(void) shared_secret_length;
return (PSA_ERROR_NOT_SUPPORTED);
}
}
/* Note that if this function fails, you must call psa_key_derivation_abort()
* to potentially free embedded data structures and wipe confidential data.
*/
static psa_status_t psa_key_agreement_internal(psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
psa_key_slot_t *private_key,
const uint8_t *peer_key,
size_t peer_key_length) {
psa_status_t status;
uint8_t shared_secret[PSA_KEY_AGREEMENT_MAX_SHARED_SECRET_SIZE];
size_t shared_secret_length = 0;
psa_algorithm_t ka_alg = PSA_ALG_KEY_AGREEMENT_GET_BASE(operation->alg);
/* Step 1: run the secret agreement algorithm to generate the shared
* secret. */
status = psa_key_agreement_raw_internal(ka_alg,
private_key,
peer_key, peer_key_length,
shared_secret,
sizeof(shared_secret),
&shared_secret_length);
if (status != PSA_SUCCESS)
goto exit;
/* Step 2: set up the key derivation to generate key material from
* the shared secret. A shared secret is permitted wherever a key
* of type DERIVE is permitted. */
status = psa_key_derivation_input_internal(operation, step,
PSA_KEY_TYPE_DERIVE,
shared_secret,
shared_secret_length);
exit:
mbedtls_platform_zeroize(shared_secret, shared_secret_length);
return (status);
}
psa_status_t psa_key_derivation_key_agreement(psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
mbedtls_svc_key_id_t private_key,
const uint8_t *peer_key,
size_t peer_key_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
if (! PSA_ALG_IS_KEY_AGREEMENT(operation->alg))
return (PSA_ERROR_INVALID_ARGUMENT);
status = psa_get_and_lock_transparent_key_slot_with_policy(
private_key, &slot, PSA_KEY_USAGE_DERIVE, operation->alg);
if (status != PSA_SUCCESS)
return (status);
status = psa_key_agreement_internal(operation, step,
slot,
peer_key, peer_key_length);
if (status != PSA_SUCCESS)
psa_key_derivation_abort(operation);
else {
/* If a private key has been added as SECRET, we allow the derived
* key material to be used as a key in PSA Crypto. */
if (step == PSA_KEY_DERIVATION_INPUT_SECRET)
operation->can_output_key = 1;
}
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
psa_status_t psa_raw_key_agreement(psa_algorithm_t alg,
mbedtls_svc_key_id_t private_key,
const uint8_t *peer_key,
size_t peer_key_length,
uint8_t *output,
size_t output_size,
size_t *output_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot = NULL;
if (! PSA_ALG_IS_KEY_AGREEMENT(alg)) {
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_get_and_lock_transparent_key_slot_with_policy(
private_key, &slot, PSA_KEY_USAGE_DERIVE, alg);
if (status != PSA_SUCCESS)
goto exit;
status = psa_key_agreement_raw_internal(alg, slot,
peer_key, peer_key_length,
output, output_size,
output_length);
exit:
if (status != PSA_SUCCESS) {
/* If an error happens and is not handled properly, the output
* may be used as a key to protect sensitive data. Arrange for such
* a key to be random, which is likely to result in decryption or
* verification errors. This is better than filling the buffer with
* some constant data such as zeros, which would result in the data
* being protected with a reproducible, easily knowable key.
*/
psa_generate_random(output, output_size);
*output_length = output_size;
}
unlock_status = psa_unlock_key_slot(slot);
return ((status == PSA_SUCCESS) ? unlock_status : status);
}
/****************************************************************/
/* Random generation */
/****************************************************************/
/** Initialize the PSA random generator.
*/
static void mbedtls_psa_random_init(mbedtls_psa_random_context_t *rng) {
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
memset(rng, 0, sizeof(*rng));
#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
/* Set default configuration if
* mbedtls_psa_crypto_configure_entropy_sources() hasn't been called. */
if (rng->entropy_init == NULL)
rng->entropy_init = mbedtls_entropy_init;
if (rng->entropy_free == NULL)
rng->entropy_free = mbedtls_entropy_free;
rng->entropy_init(&rng->entropy);
#if defined(MBEDTLS_PSA_INJECT_ENTROPY) && \
defined(MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES)
/* The PSA entropy injection feature depends on using NV seed as an entropy
* source. Add NV seed as an entropy source for PSA entropy injection. */
mbedtls_entropy_add_source(&rng->entropy,
mbedtls_nv_seed_poll, NULL,
MBEDTLS_ENTROPY_BLOCK_SIZE,
MBEDTLS_ENTROPY_SOURCE_STRONG);
#endif
mbedtls_psa_drbg_init(MBEDTLS_PSA_RANDOM_STATE);
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
}
/** Deinitialize the PSA random generator.
*/
static void mbedtls_psa_random_free(mbedtls_psa_random_context_t *rng) {
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
memset(rng, 0, sizeof(*rng));
#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
mbedtls_psa_drbg_free(MBEDTLS_PSA_RANDOM_STATE);
rng->entropy_free(&rng->entropy);
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
}
/** Seed the PSA random generator.
*/
static psa_status_t mbedtls_psa_random_seed(mbedtls_psa_random_context_t *rng) {
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
/* Do nothing: the external RNG seeds itself. */
(void) rng;
return (PSA_SUCCESS);
#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
const unsigned char drbg_seed[] = "PSA";
int ret = mbedtls_psa_drbg_seed(&rng->entropy,
drbg_seed, sizeof(drbg_seed) - 1);
return mbedtls_to_psa_error(ret);
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
}
psa_status_t psa_generate_random(uint8_t *output,
size_t output_size) {
GUARD_MODULE_INITIALIZED;
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
size_t output_length = 0;
psa_status_t status = mbedtls_psa_external_get_random(&global_data.rng,
output, output_size,
&output_length);
if (status != PSA_SUCCESS)
return (status);
/* Breaking up a request into smaller chunks is currently not supported
* for the extrernal RNG interface. */
if (output_length != output_size)
return (PSA_ERROR_INSUFFICIENT_ENTROPY);
return (PSA_SUCCESS);
#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
while (output_size > 0) {
size_t request_size =
(output_size > MBEDTLS_PSA_RANDOM_MAX_REQUEST ?
MBEDTLS_PSA_RANDOM_MAX_REQUEST :
output_size);
int ret = mbedtls_psa_get_random(MBEDTLS_PSA_RANDOM_STATE,
output, request_size);
if (ret != 0)
return (mbedtls_to_psa_error(ret));
output_size -= request_size;
output += request_size;
}
return (PSA_SUCCESS);
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
}
/* Wrapper function allowing the classic API to use the PSA RNG.
*
* `mbedtls_psa_get_random(MBEDTLS_PSA_RANDOM_STATE, ...)` calls
* `psa_generate_random(...)`. The state parameter is ignored since the
* PSA API doesn't support passing an explicit state.
*
* In the non-external case, psa_generate_random() calls an
* `mbedtls_xxx_drbg_random` function which has exactly the same signature
* and semantics as mbedtls_psa_get_random(). As an optimization,
* instead of doing this back-and-forth between the PSA API and the
* classic API, psa_crypto_random_impl.h defines `mbedtls_psa_get_random`
* as a constant function pointer to `mbedtls_xxx_drbg_random`.
*/
#if defined (MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
int mbedtls_psa_get_random(void *p_rng,
unsigned char *output,
size_t output_size) {
/* This function takes a pointer to the RNG state because that's what
* classic mbedtls functions using an RNG expect. The PSA RNG manages
* its own state internally and doesn't let the caller access that state.
* So we just ignore the state parameter, and in practice we'll pass
* NULL. */
(void) p_rng;
psa_status_t status = psa_generate_random(output, output_size);
if (status == PSA_SUCCESS)
return (0);
else
return (MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
}
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
#if defined(MBEDTLS_PSA_INJECT_ENTROPY)
#include "mbedtls/entropy_poll.h"
psa_status_t mbedtls_psa_inject_entropy(const uint8_t *seed,
size_t seed_size) {
if (global_data.initialized)
return (PSA_ERROR_NOT_PERMITTED);
if (((seed_size < MBEDTLS_ENTROPY_MIN_PLATFORM) ||
(seed_size < MBEDTLS_ENTROPY_BLOCK_SIZE)) ||
(seed_size > MBEDTLS_ENTROPY_MAX_SEED_SIZE))
return (PSA_ERROR_INVALID_ARGUMENT);
return (mbedtls_psa_storage_inject_entropy(seed, seed_size));
}
#endif /* MBEDTLS_PSA_INJECT_ENTROPY */
/** Validate the key type and size for key generation
*
* \param type The key type
* \param bits The number of bits of the key
*
* \retval #PSA_SUCCESS
* The key type and size are valid.
* \retval #PSA_ERROR_INVALID_ARGUMENT
* The size in bits of the key is not valid.
* \retval #PSA_ERROR_NOT_SUPPORTED
* The type and/or the size in bits of the key or the combination of
* the two is not supported.
*/
static psa_status_t psa_validate_key_type_and_size_for_key_generation(
psa_key_type_t type, size_t bits) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if (key_type_is_raw_bytes(type)) {
status = validate_unstructured_key_bit_size(type, bits);
if (status != PSA_SUCCESS)
return (status);
} else
#if defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR)
if (PSA_KEY_TYPE_IS_RSA(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) {
if (bits > PSA_VENDOR_RSA_MAX_KEY_BITS)
return (PSA_ERROR_NOT_SUPPORTED);
/* Accept only byte-aligned keys, for the same reasons as
* in psa_import_rsa_key(). */
if (bits % 8 != 0)
return (PSA_ERROR_NOT_SUPPORTED);
} else
#endif /* defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR) */
#if defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR)
if (PSA_KEY_TYPE_IS_ECC(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) {
/* To avoid empty block, return successfully here. */
return (PSA_SUCCESS);
} else
#endif /* defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR) */
{
return (PSA_ERROR_NOT_SUPPORTED);
}
return (PSA_SUCCESS);
}
psa_status_t psa_generate_key_internal(
const psa_key_attributes_t *attributes,
uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length) {
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_type_t type = attributes->core.type;
if ((attributes->domain_parameters == NULL) &&
(attributes->domain_parameters_size != 0))
return (PSA_ERROR_INVALID_ARGUMENT);
if (key_type_is_raw_bytes(type)) {
status = psa_generate_random(key_buffer, key_buffer_size);
if (status != PSA_SUCCESS)
return (status);
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
if (type == PSA_KEY_TYPE_DES)
psa_des_set_key_parity(key_buffer, key_buffer_size);
#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES */
} else
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR)
if (type == PSA_KEY_TYPE_RSA_KEY_PAIR) {
return (mbedtls_psa_rsa_generate_key(attributes,
key_buffer,
key_buffer_size,
key_buffer_length));
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) */
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR)
if (PSA_KEY_TYPE_IS_ECC(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) {
return (mbedtls_psa_ecp_generate_key(attributes,
key_buffer,
key_buffer_size,
key_buffer_length));
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) */
{
(void)key_buffer_length;
return (PSA_ERROR_NOT_SUPPORTED);
}
return (PSA_SUCCESS);
}
psa_status_t psa_generate_key(const psa_key_attributes_t *attributes,
mbedtls_svc_key_id_t *key) {
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
size_t key_buffer_size;
*key = MBEDTLS_SVC_KEY_ID_INIT;
/* Reject any attempt to create a zero-length key so that we don't
* risk tripping up later, e.g. on a malloc(0) that returns NULL. */
if (psa_get_key_bits(attributes) == 0)
return (PSA_ERROR_INVALID_ARGUMENT);
status = psa_start_key_creation(PSA_KEY_CREATION_GENERATE, attributes,
&slot, &driver);
if (status != PSA_SUCCESS)
goto exit;
/* In the case of a transparent key or an opaque key stored in local
* storage (thus not in the case of generating a key in a secure element
* or cryptoprocessor with storage), we have to allocate a buffer to
* hold the generated key material. */
if (slot->key.data == NULL) {
if (PSA_KEY_LIFETIME_GET_LOCATION(attributes->core.lifetime) ==
PSA_KEY_LOCATION_LOCAL_STORAGE) {
status = psa_validate_key_type_and_size_for_key_generation(
attributes->core.type, attributes->core.bits);
if (status != PSA_SUCCESS)
goto exit;
key_buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(
attributes->core.type,
attributes->core.bits);
} else {
status = psa_driver_wrapper_get_key_buffer_size(
attributes, &key_buffer_size);
if (status != PSA_SUCCESS)
goto exit;
}
status = psa_allocate_buffer_to_slot(slot, key_buffer_size);
if (status != PSA_SUCCESS)
goto exit;
}
status = psa_driver_wrapper_generate_key(attributes,
slot->key.data, slot->key.bytes, &slot->key.bytes);
if (status != PSA_SUCCESS)
psa_remove_key_data_from_memory(slot);
exit:
if (status == PSA_SUCCESS)
status = psa_finish_key_creation(slot, driver, key);
if (status != PSA_SUCCESS)
psa_fail_key_creation(slot, driver);
return (status);
}
/****************************************************************/
/* Module setup */
/****************************************************************/
#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
psa_status_t mbedtls_psa_crypto_configure_entropy_sources(
void (* entropy_init)(mbedtls_entropy_context *ctx),
void (* entropy_free)(mbedtls_entropy_context *ctx)) {
if (global_data.rng_state != RNG_NOT_INITIALIZED)
return (PSA_ERROR_BAD_STATE);
global_data.rng.entropy_init = entropy_init;
global_data.rng.entropy_free = entropy_free;
return (PSA_SUCCESS);
}
#endif /* !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) */
void mbedtls_psa_crypto_free(void) {
psa_wipe_all_key_slots();
if (global_data.rng_state != RNG_NOT_INITIALIZED) {
mbedtls_psa_random_free(&global_data.rng);
}
/* Wipe all remaining data, including configuration.
* In particular, this sets all state indicator to the value
* indicating "uninitialized". */
mbedtls_platform_zeroize(&global_data, sizeof(global_data));
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* Unregister all secure element drivers, so that we restart from
* a pristine state. */
psa_unregister_all_se_drivers();
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
}
#if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS)
/** Recover a transaction that was interrupted by a power failure.
*
* This function is called during initialization, before psa_crypto_init()
* returns. If this function returns a failure status, the initialization
* fails.
*/
static psa_status_t psa_crypto_recover_transaction(
const psa_crypto_transaction_t *transaction) {
switch (transaction->unknown.type) {
case PSA_CRYPTO_TRANSACTION_CREATE_KEY:
case PSA_CRYPTO_TRANSACTION_DESTROY_KEY:
/* TODO - fall through to the failure case until this
* is implemented.
* https://github.com/ARMmbed/mbed-crypto/issues/218
*/
default:
/* We found an unsupported transaction in the storage.
* We don't know what state the storage is in. Give up. */
return (PSA_ERROR_DATA_INVALID);
}
}
#endif /* PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS */
psa_status_t psa_crypto_init(void) {
psa_status_t status;
/* Double initialization is explicitly allowed. */
if (global_data.initialized != 0)
return (PSA_SUCCESS);
/* Initialize and seed the random generator. */
mbedtls_psa_random_init(&global_data.rng);
global_data.rng_state = RNG_INITIALIZED;
status = mbedtls_psa_random_seed(&global_data.rng);
if (status != PSA_SUCCESS)
goto exit;
global_data.rng_state = RNG_SEEDED;
status = psa_initialize_key_slots();
if (status != PSA_SUCCESS)
goto exit;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
status = psa_init_all_se_drivers();
if (status != PSA_SUCCESS)
goto exit;
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
#if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS)
status = psa_crypto_load_transaction();
if (status == PSA_SUCCESS) {
status = psa_crypto_recover_transaction(&psa_crypto_transaction);
if (status != PSA_SUCCESS)
goto exit;
status = psa_crypto_stop_transaction();
} else if (status == PSA_ERROR_DOES_NOT_EXIST) {
/* There's no transaction to complete. It's all good. */
status = PSA_SUCCESS;
}
#endif /* PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS */
/* All done. */
global_data.initialized = 1;
exit:
if (status != PSA_SUCCESS)
mbedtls_psa_crypto_free();
return (status);
}
#endif /* MBEDTLS_PSA_CRYPTO_C */