proxmark3/common/mbedtls/x509write_csr.c
2021-05-14 14:07:59 +02:00

323 lines
11 KiB
C

/*
* X.509 Certificate Signing Request writing
*
* 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.
*/
/*
* References:
* - CSRs: PKCS#10 v1.7 aka RFC 2986
* - attributes: PKCS#9 v2.0 aka RFC 2985
*/
#include "common.h"
#if defined(MBEDTLS_X509_CSR_WRITE_C)
#include "mbedtls/x509_csr.h"
#include "mbedtls/asn1write.h"
#include "mbedtls/error.h"
#include "mbedtls/oid.h"
#include "mbedtls/platform_util.h"
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#include "mbedtls/psa_util.h"
#endif
#include <string.h>
#include <stdlib.h>
#if defined(MBEDTLS_PEM_WRITE_C)
#include "mbedtls/pem.h"
#endif
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
void mbedtls_x509write_csr_init(mbedtls_x509write_csr *ctx) {
memset(ctx, 0, sizeof(mbedtls_x509write_csr));
}
void mbedtls_x509write_csr_free(mbedtls_x509write_csr *ctx) {
mbedtls_asn1_free_named_data_list(&ctx->subject);
mbedtls_asn1_free_named_data_list(&ctx->extensions);
mbedtls_platform_zeroize(ctx, sizeof(mbedtls_x509write_csr));
}
void mbedtls_x509write_csr_set_md_alg(mbedtls_x509write_csr *ctx, mbedtls_md_type_t md_alg) {
ctx->md_alg = md_alg;
}
void mbedtls_x509write_csr_set_key(mbedtls_x509write_csr *ctx, mbedtls_pk_context *key) {
ctx->key = key;
}
int mbedtls_x509write_csr_set_subject_name(mbedtls_x509write_csr *ctx,
const char *subject_name) {
return mbedtls_x509_string_to_names(&ctx->subject, subject_name);
}
int mbedtls_x509write_csr_set_extension(mbedtls_x509write_csr *ctx,
const char *oid, size_t oid_len,
const unsigned char *val, size_t val_len) {
return mbedtls_x509_set_extension(&ctx->extensions, oid, oid_len,
0, val, val_len);
}
int mbedtls_x509write_csr_set_key_usage(mbedtls_x509write_csr *ctx, unsigned char key_usage) {
unsigned char buf[4];
unsigned char *c;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
c = buf + 4;
ret = mbedtls_asn1_write_named_bitstring(&c, buf, &key_usage, 8);
if (ret < 3 || ret > 4)
return (ret);
ret = mbedtls_x509write_csr_set_extension(ctx, MBEDTLS_OID_KEY_USAGE,
MBEDTLS_OID_SIZE(MBEDTLS_OID_KEY_USAGE),
c, (size_t)ret);
if (ret != 0)
return (ret);
return (0);
}
int mbedtls_x509write_csr_set_ns_cert_type(mbedtls_x509write_csr *ctx,
unsigned char ns_cert_type) {
unsigned char buf[4];
unsigned char *c;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
c = buf + 4;
ret = mbedtls_asn1_write_named_bitstring(&c, buf, &ns_cert_type, 8);
if (ret < 3 || ret > 4)
return (ret);
ret = mbedtls_x509write_csr_set_extension(ctx, MBEDTLS_OID_NS_CERT_TYPE,
MBEDTLS_OID_SIZE(MBEDTLS_OID_NS_CERT_TYPE),
c, (size_t)ret);
if (ret != 0)
return (ret);
return (0);
}
static int x509write_csr_der_internal(mbedtls_x509write_csr *ctx,
unsigned char *buf,
size_t size,
unsigned char *sig,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng) {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
const char *sig_oid;
size_t sig_oid_len = 0;
unsigned char *c, *c2;
unsigned char hash[64];
size_t pub_len = 0, sig_and_oid_len = 0, sig_len;
size_t len = 0;
mbedtls_pk_type_t pk_alg;
#if defined(MBEDTLS_USE_PSA_CRYPTO)
psa_hash_operation_t hash_operation = PSA_HASH_OPERATION_INIT;
size_t hash_len;
psa_algorithm_t hash_alg = mbedtls_psa_translate_md(ctx->md_alg);
#endif /* MBEDTLS_USE_PSA_CRYPTO */
/* Write the CSR backwards starting from the end of buf */
c = buf + size;
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_x509_write_extensions(&c, buf,
ctx->extensions));
if (len) {
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
MBEDTLS_ASN1_CHK_ADD(len,
mbedtls_asn1_write_tag(
&c, buf,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
MBEDTLS_ASN1_CHK_ADD(len,
mbedtls_asn1_write_tag(
&c, buf,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SET));
MBEDTLS_ASN1_CHK_ADD(len,
mbedtls_asn1_write_oid(
&c, buf, MBEDTLS_OID_PKCS9_CSR_EXT_REQ,
MBEDTLS_OID_SIZE(MBEDTLS_OID_PKCS9_CSR_EXT_REQ)));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
MBEDTLS_ASN1_CHK_ADD(len,
mbedtls_asn1_write_tag(
&c, buf,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE));
}
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
MBEDTLS_ASN1_CHK_ADD(len,
mbedtls_asn1_write_tag(
&c, buf,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_CONTEXT_SPECIFIC));
MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_pk_write_pubkey_der(ctx->key,
buf, c - buf));
c -= pub_len;
len += pub_len;
/*
* Subject ::= Name
*/
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_x509_write_names(&c, buf,
ctx->subject));
/*
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(&c, buf, 0));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
MBEDTLS_ASN1_CHK_ADD(len,
mbedtls_asn1_write_tag(
&c, buf,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE));
/*
* Sign the written CSR data into the sig buffer
* Note: hash errors can happen only after an internal error
*/
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if (psa_hash_setup(&hash_operation, hash_alg) != PSA_SUCCESS)
return (MBEDTLS_ERR_X509_FATAL_ERROR);
if (psa_hash_update(&hash_operation, c, len) != PSA_SUCCESS)
return (MBEDTLS_ERR_X509_FATAL_ERROR);
if (psa_hash_finish(&hash_operation, hash, sizeof(hash), &hash_len)
!= PSA_SUCCESS) {
return (MBEDTLS_ERR_X509_FATAL_ERROR);
}
#else /* MBEDTLS_USE_PSA_CRYPTO */
ret = mbedtls_md(mbedtls_md_info_from_type(ctx->md_alg), c, len, hash);
if (ret != 0)
return (ret);
#endif
if ((ret = mbedtls_pk_sign(ctx->key, ctx->md_alg, hash, 0, sig, &sig_len,
f_rng, p_rng)) != 0) {
return (ret);
}
if (mbedtls_pk_can_do(ctx->key, MBEDTLS_PK_RSA))
pk_alg = MBEDTLS_PK_RSA;
else if (mbedtls_pk_can_do(ctx->key, MBEDTLS_PK_ECDSA))
pk_alg = MBEDTLS_PK_ECDSA;
else
return (MBEDTLS_ERR_X509_INVALID_ALG);
if ((ret = mbedtls_oid_get_oid_by_sig_alg(pk_alg, ctx->md_alg,
&sig_oid, &sig_oid_len)) != 0) {
return (ret);
}
/*
* Move the written CSR data to the start of buf to create space for
* writing the signature into buf.
*/
memmove(buf, c, len);
/*
* Write sig and its OID into buf backwards from the end of buf.
* Note: mbedtls_x509_write_sig will check for c2 - ( buf + len ) < sig_len
* and return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL if needed.
*/
c2 = buf + size;
MBEDTLS_ASN1_CHK_ADD(sig_and_oid_len,
mbedtls_x509_write_sig(&c2, buf + len, sig_oid, sig_oid_len,
sig, sig_len));
/*
* Compact the space between the CSR data and signature by moving the
* CSR data to the start of the signature.
*/
c2 -= len;
memmove(c2, buf, len);
/* ASN encode the total size and tag the CSR data with it. */
len += sig_and_oid_len;
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c2, buf, len));
MBEDTLS_ASN1_CHK_ADD(len,
mbedtls_asn1_write_tag(
&c2, buf,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE));
/* Zero the unused bytes at the start of buf */
memset(buf, 0, c2 - buf);
return ((int) len);
}
int mbedtls_x509write_csr_der(mbedtls_x509write_csr *ctx, unsigned char *buf,
size_t size,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng) {
int ret;
unsigned char *sig;
if ((sig = mbedtls_calloc(1, MBEDTLS_PK_SIGNATURE_MAX_SIZE)) == NULL) {
return (MBEDTLS_ERR_X509_ALLOC_FAILED);
}
ret = x509write_csr_der_internal(ctx, buf, size, sig, f_rng, p_rng);
mbedtls_free(sig);
return (ret);
}
#define PEM_BEGIN_CSR "-----BEGIN CERTIFICATE REQUEST-----\n"
#define PEM_END_CSR "-----END CERTIFICATE REQUEST-----\n"
#if defined(MBEDTLS_PEM_WRITE_C)
int mbedtls_x509write_csr_pem(mbedtls_x509write_csr *ctx, unsigned char *buf, size_t size,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng) {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t olen = 0;
if ((ret = mbedtls_x509write_csr_der(ctx, buf, size,
f_rng, p_rng)) < 0) {
return (ret);
}
if ((ret = mbedtls_pem_write_buffer(PEM_BEGIN_CSR, PEM_END_CSR,
buf + size - ret,
ret, buf, size, &olen)) != 0) {
return (ret);
}
return (0);
}
#endif /* MBEDTLS_PEM_WRITE_C */
#endif /* MBEDTLS_X509_CSR_WRITE_C */