proxmark3/common/mbedtls/cipher.c
2019-03-10 11:20:22 +01:00

1018 lines
32 KiB
C

/**
* \file cipher.c
*
* \brief Generic cipher wrapper for mbed TLS
*
* \author Adriaan de Jong <dejong@fox-it.com>
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: GPL-2.0
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_CIPHER_C)
#include "mbedtls/cipher.h"
#include "mbedtls/cipher_internal.h"
#include "mbedtls/platform_util.h"
#include <stdlib.h>
#include <string.h>
#if defined(MBEDTLS_CHACHAPOLY_C)
#include "mbedtls/chachapoly.h"
#endif
#if defined(MBEDTLS_GCM_C)
#include "mbedtls/gcm.h"
#endif
#if defined(MBEDTLS_CCM_C)
#include "mbedtls/ccm.h"
#endif
#if defined(MBEDTLS_CHACHA20_C)
#include "mbedtls/chacha20.h"
#endif
#if defined(MBEDTLS_CMAC_C)
#include "mbedtls/cmac.h"
#endif
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
/* Compare the contents of two buffers in constant time.
* Returns 0 if the contents are bitwise identical, otherwise returns
* a non-zero value.
* This is currently only used by GCM and ChaCha20+Poly1305.
*/
static int mbedtls_constant_time_memcmp(const void *v1, const void *v2, size_t len) {
const unsigned char *p1 = (const unsigned char *) v1;
const unsigned char *p2 = (const unsigned char *) v2;
size_t i;
unsigned char diff;
for (diff = 0, i = 0; i < len; i++)
diff |= p1[i] ^ p2[i];
return (int)diff;
}
#endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
static int supported_init = 0;
const int *mbedtls_cipher_list(void) {
const mbedtls_cipher_definition_t *def;
int *type;
if (! supported_init) {
def = mbedtls_cipher_definitions;
type = mbedtls_cipher_supported;
while (def->type != 0)
*type++ = (*def++).type;
*type = 0;
supported_init = 1;
}
return (mbedtls_cipher_supported);
}
const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type(const mbedtls_cipher_type_t cipher_type) {
const mbedtls_cipher_definition_t *def;
for (def = mbedtls_cipher_definitions; def->info != NULL; def++)
if (def->type == cipher_type)
return (def->info);
return (NULL);
}
const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string(const char *cipher_name) {
const mbedtls_cipher_definition_t *def;
if (NULL == cipher_name)
return (NULL);
for (def = mbedtls_cipher_definitions; def->info != NULL; def++)
if (! strcmp(def->info->name, cipher_name))
return (def->info);
return (NULL);
}
const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values(const mbedtls_cipher_id_t cipher_id,
int key_bitlen,
const mbedtls_cipher_mode_t mode) {
const mbedtls_cipher_definition_t *def;
for (def = mbedtls_cipher_definitions; def->info != NULL; def++)
if (def->info->base->cipher == cipher_id &&
def->info->key_bitlen == (unsigned) key_bitlen &&
def->info->mode == mode)
return (def->info);
return (NULL);
}
void mbedtls_cipher_init(mbedtls_cipher_context_t *ctx) {
memset(ctx, 0, sizeof(mbedtls_cipher_context_t));
}
void mbedtls_cipher_free(mbedtls_cipher_context_t *ctx) {
if (ctx == NULL)
return;
#if defined(MBEDTLS_CMAC_C)
if (ctx->cmac_ctx) {
mbedtls_platform_zeroize(ctx->cmac_ctx,
sizeof(mbedtls_cmac_context_t));
mbedtls_free(ctx->cmac_ctx);
}
#endif
if (ctx->cipher_ctx)
ctx->cipher_info->base->ctx_free_func(ctx->cipher_ctx);
mbedtls_platform_zeroize(ctx, sizeof(mbedtls_cipher_context_t));
}
int mbedtls_cipher_setup(mbedtls_cipher_context_t *ctx, const mbedtls_cipher_info_t *cipher_info) {
if (NULL == cipher_info || NULL == ctx)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
memset(ctx, 0, sizeof(mbedtls_cipher_context_t));
if (NULL == (ctx->cipher_ctx = cipher_info->base->ctx_alloc_func()))
return (MBEDTLS_ERR_CIPHER_ALLOC_FAILED);
ctx->cipher_info = cipher_info;
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
/*
* Ignore possible errors caused by a cipher mode that doesn't use padding
*/
#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
(void) mbedtls_cipher_set_padding_mode(ctx, MBEDTLS_PADDING_PKCS7);
#else
(void) mbedtls_cipher_set_padding_mode(ctx, MBEDTLS_PADDING_NONE);
#endif
#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
return (0);
}
int mbedtls_cipher_setkey(mbedtls_cipher_context_t *ctx, const unsigned char *key,
int key_bitlen, const mbedtls_operation_t operation) {
if (NULL == ctx || NULL == ctx->cipher_info)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
if ((ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_KEY_LEN) == 0 &&
(int) ctx->cipher_info->key_bitlen != key_bitlen) {
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
}
ctx->key_bitlen = key_bitlen;
ctx->operation = operation;
/*
* For OFB, CFB and CTR mode always use the encryption key schedule
*/
if (MBEDTLS_ENCRYPT == operation ||
MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
MBEDTLS_MODE_CTR == ctx->cipher_info->mode) {
return ctx->cipher_info->base->setkey_enc_func(ctx->cipher_ctx, key,
ctx->key_bitlen);
}
if (MBEDTLS_DECRYPT == operation)
return ctx->cipher_info->base->setkey_dec_func(ctx->cipher_ctx, key,
ctx->key_bitlen);
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
}
int mbedtls_cipher_set_iv(mbedtls_cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len) {
size_t actual_iv_size;
if (NULL == ctx || NULL == ctx->cipher_info || NULL == iv)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
/* avoid buffer overflow in ctx->iv */
if (iv_len > MBEDTLS_MAX_IV_LENGTH)
return (MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE);
if ((ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_IV_LEN) != 0)
actual_iv_size = iv_len;
else {
actual_iv_size = ctx->cipher_info->iv_size;
/* avoid reading past the end of input buffer */
if (actual_iv_size > iv_len)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
}
#if defined(MBEDTLS_CHACHA20_C)
if (ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20) {
if (0 != mbedtls_chacha20_starts((mbedtls_chacha20_context *)ctx->cipher_ctx,
iv,
0U)) { /* Initial counter value */
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
}
}
#endif
memcpy(ctx->iv, iv, actual_iv_size);
ctx->iv_size = actual_iv_size;
return (0);
}
int mbedtls_cipher_reset(mbedtls_cipher_context_t *ctx) {
if (NULL == ctx || NULL == ctx->cipher_info)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
ctx->unprocessed_len = 0;
return (0);
}
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
int mbedtls_cipher_update_ad(mbedtls_cipher_context_t *ctx,
const unsigned char *ad, size_t ad_len) {
if (NULL == ctx || NULL == ctx->cipher_info)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
#if defined(MBEDTLS_GCM_C)
if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode) {
return mbedtls_gcm_starts((mbedtls_gcm_context *) ctx->cipher_ctx, ctx->operation,
ctx->iv, ctx->iv_size, ad, ad_len);
}
#endif
#if defined(MBEDTLS_CHACHAPOLY_C)
if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type) {
int result;
mbedtls_chachapoly_mode_t mode;
mode = (ctx->operation == MBEDTLS_ENCRYPT)
? MBEDTLS_CHACHAPOLY_ENCRYPT
: MBEDTLS_CHACHAPOLY_DECRYPT;
result = mbedtls_chachapoly_starts((mbedtls_chachapoly_context *) ctx->cipher_ctx,
ctx->iv,
mode);
if (result != 0)
return (result);
return mbedtls_chachapoly_update_aad((mbedtls_chachapoly_context *) ctx->cipher_ctx,
ad, ad_len);
}
#endif
return (0);
}
#endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
int mbedtls_cipher_update(mbedtls_cipher_context_t *ctx, const unsigned char *input,
size_t ilen, unsigned char *output, size_t *olen) {
int ret;
size_t block_size = 0;
if (NULL == ctx || NULL == ctx->cipher_info || NULL == olen) {
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
}
*olen = 0;
block_size = mbedtls_cipher_get_block_size(ctx);
if (ctx->cipher_info->mode == MBEDTLS_MODE_ECB) {
if (ilen != block_size)
return (MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED);
*olen = ilen;
if (0 != (ret = ctx->cipher_info->base->ecb_func(ctx->cipher_ctx,
ctx->operation, input, output))) {
return (ret);
}
return (0);
}
#if defined(MBEDTLS_GCM_C)
if (ctx->cipher_info->mode == MBEDTLS_MODE_GCM) {
*olen = ilen;
return mbedtls_gcm_update((mbedtls_gcm_context *) ctx->cipher_ctx, ilen, input,
output);
}
#endif
#if defined(MBEDTLS_CHACHAPOLY_C)
if (ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305) {
*olen = ilen;
return mbedtls_chachapoly_update((mbedtls_chachapoly_context *) ctx->cipher_ctx,
ilen, input, output);
}
#endif
if (0 == block_size) {
return MBEDTLS_ERR_CIPHER_INVALID_CONTEXT;
}
if (input == output &&
(ctx->unprocessed_len != 0 || ilen % block_size)) {
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
}
#if defined(MBEDTLS_CIPHER_MODE_CBC)
if (ctx->cipher_info->mode == MBEDTLS_MODE_CBC) {
size_t copy_len = 0;
/*
* If there is not enough data for a full block, cache it.
*/
if ((ctx->operation == MBEDTLS_DECRYPT && NULL != ctx->add_padding &&
ilen <= block_size - ctx->unprocessed_len) ||
(ctx->operation == MBEDTLS_DECRYPT && NULL == ctx->add_padding &&
ilen < block_size - ctx->unprocessed_len) ||
(ctx->operation == MBEDTLS_ENCRYPT &&
ilen < block_size - ctx->unprocessed_len)) {
memcpy(&(ctx->unprocessed_data[ctx->unprocessed_len]), input,
ilen);
ctx->unprocessed_len += ilen;
return (0);
}
/*
* Process cached data first
*/
if (0 != ctx->unprocessed_len) {
copy_len = block_size - ctx->unprocessed_len;
memcpy(&(ctx->unprocessed_data[ctx->unprocessed_len]), input,
copy_len);
if (0 != (ret = ctx->cipher_info->base->cbc_func(ctx->cipher_ctx,
ctx->operation, block_size, ctx->iv,
ctx->unprocessed_data, output))) {
return (ret);
}
*olen += block_size;
output += block_size;
ctx->unprocessed_len = 0;
input += copy_len;
ilen -= copy_len;
}
/*
* Cache final, incomplete block
*/
if (0 != ilen) {
if (0 == block_size) {
return MBEDTLS_ERR_CIPHER_INVALID_CONTEXT;
}
/* Encryption: only cache partial blocks
* Decryption w/ padding: always keep at least one whole block
* Decryption w/o padding: only cache partial blocks
*/
copy_len = ilen % block_size;
if (copy_len == 0 &&
ctx->operation == MBEDTLS_DECRYPT &&
NULL != ctx->add_padding) {
copy_len = block_size;
}
memcpy(ctx->unprocessed_data, &(input[ilen - copy_len]),
copy_len);
ctx->unprocessed_len += copy_len;
ilen -= copy_len;
}
/*
* Process remaining full blocks
*/
if (ilen) {
if (0 != (ret = ctx->cipher_info->base->cbc_func(ctx->cipher_ctx,
ctx->operation, ilen, ctx->iv, input, output))) {
return (ret);
}
*olen += ilen;
}
return (0);
}
#endif /* MBEDTLS_CIPHER_MODE_CBC */
#if defined(MBEDTLS_CIPHER_MODE_CFB)
if (ctx->cipher_info->mode == MBEDTLS_MODE_CFB) {
if (0 != (ret = ctx->cipher_info->base->cfb_func(ctx->cipher_ctx,
ctx->operation, ilen, &ctx->unprocessed_len, ctx->iv,
input, output))) {
return (ret);
}
*olen = ilen;
return (0);
}
#endif /* MBEDTLS_CIPHER_MODE_CFB */
#if defined(MBEDTLS_CIPHER_MODE_OFB)
if (ctx->cipher_info->mode == MBEDTLS_MODE_OFB) {
if (0 != (ret = ctx->cipher_info->base->ofb_func(ctx->cipher_ctx,
ilen, &ctx->unprocessed_len, ctx->iv, input, output))) {
return (ret);
}
*olen = ilen;
return (0);
}
#endif /* MBEDTLS_CIPHER_MODE_OFB */
#if defined(MBEDTLS_CIPHER_MODE_CTR)
if (ctx->cipher_info->mode == MBEDTLS_MODE_CTR) {
if (0 != (ret = ctx->cipher_info->base->ctr_func(ctx->cipher_ctx,
ilen, &ctx->unprocessed_len, ctx->iv,
ctx->unprocessed_data, input, output))) {
return (ret);
}
*olen = ilen;
return (0);
}
#endif /* MBEDTLS_CIPHER_MODE_CTR */
#if defined(MBEDTLS_CIPHER_MODE_XTS)
if (ctx->cipher_info->mode == MBEDTLS_MODE_XTS) {
if (ctx->unprocessed_len > 0) {
/* We can only process an entire data unit at a time. */
return (MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE);
}
ret = ctx->cipher_info->base->xts_func(ctx->cipher_ctx,
ctx->operation, ilen, ctx->iv, input, output);
if (ret != 0) {
return (ret);
}
*olen = ilen;
return (0);
}
#endif /* MBEDTLS_CIPHER_MODE_XTS */
#if defined(MBEDTLS_CIPHER_MODE_STREAM)
if (ctx->cipher_info->mode == MBEDTLS_MODE_STREAM) {
if (0 != (ret = ctx->cipher_info->base->stream_func(ctx->cipher_ctx,
ilen, input, output))) {
return (ret);
}
*olen = ilen;
return (0);
}
#endif /* MBEDTLS_CIPHER_MODE_STREAM */
return (MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE);
}
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
/*
* PKCS7 (and PKCS5) padding: fill with ll bytes, with ll = padding_len
*/
static void add_pkcs_padding(unsigned char *output, size_t output_len,
size_t data_len) {
size_t padding_len = output_len - data_len;
unsigned char i;
for (i = 0; i < padding_len; i++)
output[data_len + i] = (unsigned char) padding_len;
}
static int get_pkcs_padding(unsigned char *input, size_t input_len,
size_t *data_len) {
size_t i, pad_idx;
unsigned char padding_len, bad = 0;
if (NULL == input || NULL == data_len)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
padding_len = input[input_len - 1];
*data_len = input_len - padding_len;
/* Avoid logical || since it results in a branch */
bad |= padding_len > input_len;
bad |= padding_len == 0;
/* The number of bytes checked must be independent of padding_len,
* so pick input_len, which is usually 8 or 16 (one block) */
pad_idx = input_len - padding_len;
for (i = 0; i < input_len; i++)
bad |= (input[i] ^ padding_len) * (i >= pad_idx);
return (MBEDTLS_ERR_CIPHER_INVALID_PADDING * (bad != 0));
}
#endif /* MBEDTLS_CIPHER_PADDING_PKCS7 */
#if defined(MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS)
/*
* One and zeros padding: fill with 80 00 ... 00
*/
static void add_one_and_zeros_padding(unsigned char *output,
size_t output_len, size_t data_len) {
size_t padding_len = output_len - data_len;
unsigned char i = 0;
output[data_len] = 0x80;
for (i = 1; i < padding_len; i++)
output[data_len + i] = 0x00;
}
static int get_one_and_zeros_padding(unsigned char *input, size_t input_len,
size_t *data_len) {
size_t i;
unsigned char done = 0, prev_done, bad;
if (NULL == input || NULL == data_len)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
bad = 0x80;
*data_len = 0;
for (i = input_len; i > 0; i--) {
prev_done = done;
done |= (input[i - 1] != 0);
*data_len |= (i - 1) * (done != prev_done);
bad ^= input[i - 1] * (done != prev_done);
}
return (MBEDTLS_ERR_CIPHER_INVALID_PADDING * (bad != 0));
}
#endif /* MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS */
#if defined(MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN)
/*
* Zeros and len padding: fill with 00 ... 00 ll, where ll is padding length
*/
static void add_zeros_and_len_padding(unsigned char *output,
size_t output_len, size_t data_len) {
size_t padding_len = output_len - data_len;
unsigned char i = 0;
for (i = 1; i < padding_len; i++)
output[data_len + i - 1] = 0x00;
output[output_len - 1] = (unsigned char) padding_len;
}
static int get_zeros_and_len_padding(unsigned char *input, size_t input_len,
size_t *data_len) {
size_t i, pad_idx;
unsigned char padding_len, bad = 0;
if (NULL == input || NULL == data_len)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
padding_len = input[input_len - 1];
*data_len = input_len - padding_len;
/* Avoid logical || since it results in a branch */
bad |= padding_len > input_len;
bad |= padding_len == 0;
/* The number of bytes checked must be independent of padding_len */
pad_idx = input_len - padding_len;
for (i = 0; i < input_len - 1; i++)
bad |= input[i] * (i >= pad_idx);
return (MBEDTLS_ERR_CIPHER_INVALID_PADDING * (bad != 0));
}
#endif /* MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN */
#if defined(MBEDTLS_CIPHER_PADDING_ZEROS)
/*
* Zero padding: fill with 00 ... 00
*/
static void add_zeros_padding(unsigned char *output,
size_t output_len, size_t data_len) {
size_t i;
for (i = data_len; i < output_len; i++)
output[i] = 0x00;
}
static int get_zeros_padding(unsigned char *input, size_t input_len,
size_t *data_len) {
size_t i;
unsigned char done = 0, prev_done;
if (NULL == input || NULL == data_len)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
*data_len = 0;
for (i = input_len; i > 0; i--) {
prev_done = done;
done |= (input[i - 1] != 0);
*data_len |= i * (done != prev_done);
}
return (0);
}
#endif /* MBEDTLS_CIPHER_PADDING_ZEROS */
/*
* No padding: don't pad :)
*
* There is no add_padding function (check for NULL in mbedtls_cipher_finish)
* but a trivial get_padding function
*/
static int get_no_padding(unsigned char *input, size_t input_len,
size_t *data_len) {
if (NULL == input || NULL == data_len)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
*data_len = input_len;
return (0);
}
#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
int mbedtls_cipher_finish(mbedtls_cipher_context_t *ctx,
unsigned char *output, size_t *olen) {
if (NULL == ctx || NULL == ctx->cipher_info || NULL == olen)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
*olen = 0;
if (MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
MBEDTLS_MODE_OFB == ctx->cipher_info->mode ||
MBEDTLS_MODE_CTR == ctx->cipher_info->mode ||
MBEDTLS_MODE_GCM == ctx->cipher_info->mode ||
MBEDTLS_MODE_XTS == ctx->cipher_info->mode ||
MBEDTLS_MODE_STREAM == ctx->cipher_info->mode) {
return (0);
}
if ((MBEDTLS_CIPHER_CHACHA20 == ctx->cipher_info->type) ||
(MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type)) {
return (0);
}
if (MBEDTLS_MODE_ECB == ctx->cipher_info->mode) {
if (ctx->unprocessed_len != 0)
return (MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED);
return (0);
}
#if defined(MBEDTLS_CIPHER_MODE_CBC)
if (MBEDTLS_MODE_CBC == ctx->cipher_info->mode) {
int ret = 0;
if (MBEDTLS_ENCRYPT == ctx->operation) {
/* check for 'no padding' mode */
if (NULL == ctx->add_padding) {
if (0 != ctx->unprocessed_len)
return (MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED);
return (0);
}
ctx->add_padding(ctx->unprocessed_data, mbedtls_cipher_get_iv_size(ctx),
ctx->unprocessed_len);
} else if (mbedtls_cipher_get_block_size(ctx) != ctx->unprocessed_len) {
/*
* For decrypt operations, expect a full block,
* or an empty block if no padding
*/
if (NULL == ctx->add_padding && 0 == ctx->unprocessed_len)
return (0);
return (MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED);
}
/* cipher block */
if (0 != (ret = ctx->cipher_info->base->cbc_func(ctx->cipher_ctx,
ctx->operation, mbedtls_cipher_get_block_size(ctx), ctx->iv,
ctx->unprocessed_data, output))) {
return (ret);
}
/* Set output size for decryption */
if (MBEDTLS_DECRYPT == ctx->operation)
return ctx->get_padding(output, mbedtls_cipher_get_block_size(ctx),
olen);
/* Set output size for encryption */
*olen = mbedtls_cipher_get_block_size(ctx);
return (0);
}
#else
((void) output);
#endif /* MBEDTLS_CIPHER_MODE_CBC */
return (MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE);
}
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
int mbedtls_cipher_set_padding_mode(mbedtls_cipher_context_t *ctx, mbedtls_cipher_padding_t mode) {
if (NULL == ctx ||
MBEDTLS_MODE_CBC != ctx->cipher_info->mode) {
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
}
switch (mode) {
#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
case MBEDTLS_PADDING_PKCS7:
ctx->add_padding = add_pkcs_padding;
ctx->get_padding = get_pkcs_padding;
break;
#endif
#if defined(MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS)
case MBEDTLS_PADDING_ONE_AND_ZEROS:
ctx->add_padding = add_one_and_zeros_padding;
ctx->get_padding = get_one_and_zeros_padding;
break;
#endif
#if defined(MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN)
case MBEDTLS_PADDING_ZEROS_AND_LEN:
ctx->add_padding = add_zeros_and_len_padding;
ctx->get_padding = get_zeros_and_len_padding;
break;
#endif
#if defined(MBEDTLS_CIPHER_PADDING_ZEROS)
case MBEDTLS_PADDING_ZEROS:
ctx->add_padding = add_zeros_padding;
ctx->get_padding = get_zeros_padding;
break;
#endif
case MBEDTLS_PADDING_NONE:
ctx->add_padding = NULL;
ctx->get_padding = get_no_padding;
break;
default:
return (MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE);
}
return (0);
}
#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
int mbedtls_cipher_write_tag(mbedtls_cipher_context_t *ctx,
unsigned char *tag, size_t tag_len) {
if (NULL == ctx || NULL == ctx->cipher_info || NULL == tag)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
if (MBEDTLS_ENCRYPT != ctx->operation)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
#if defined(MBEDTLS_GCM_C)
if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode)
return mbedtls_gcm_finish((mbedtls_gcm_context *) ctx->cipher_ctx, tag, tag_len);
#endif
#if defined(MBEDTLS_CHACHAPOLY_C)
if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type) {
/* Don't allow truncated MAC for Poly1305 */
if (tag_len != 16U)
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
return mbedtls_chachapoly_finish((mbedtls_chachapoly_context *) ctx->cipher_ctx,
tag);
}
#endif
return (0);
}
int mbedtls_cipher_check_tag(mbedtls_cipher_context_t *ctx,
const unsigned char *tag, size_t tag_len) {
unsigned char check_tag[16];
int ret;
if (NULL == ctx || NULL == ctx->cipher_info ||
MBEDTLS_DECRYPT != ctx->operation) {
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
}
#if defined(MBEDTLS_GCM_C)
if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode) {
if (tag_len > sizeof(check_tag))
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
if (0 != (ret = mbedtls_gcm_finish((mbedtls_gcm_context *) ctx->cipher_ctx,
check_tag, tag_len))) {
return (ret);
}
/* Check the tag in "constant-time" */
if (mbedtls_constant_time_memcmp(tag, check_tag, tag_len) != 0)
return (MBEDTLS_ERR_CIPHER_AUTH_FAILED);
return (0);
}
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type) {
/* Don't allow truncated MAC for Poly1305 */
if (tag_len != sizeof(check_tag))
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
ret = mbedtls_chachapoly_finish((mbedtls_chachapoly_context *) ctx->cipher_ctx,
check_tag);
if (ret != 0) {
return (ret);
}
/* Check the tag in "constant-time" */
if (mbedtls_constant_time_memcmp(tag, check_tag, tag_len) != 0)
return (MBEDTLS_ERR_CIPHER_AUTH_FAILED);
return (0);
}
#endif /* MBEDTLS_CHACHAPOLY_C */
return (0);
}
#endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
/*
* Packet-oriented wrapper for non-AEAD modes
*/
int mbedtls_cipher_crypt(mbedtls_cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen) {
int ret;
size_t finish_olen;
if ((ret = mbedtls_cipher_set_iv(ctx, iv, iv_len)) != 0)
return (ret);
if ((ret = mbedtls_cipher_reset(ctx)) != 0)
return (ret);
if ((ret = mbedtls_cipher_update(ctx, input, ilen, output, olen)) != 0)
return (ret);
if ((ret = mbedtls_cipher_finish(ctx, output + *olen, &finish_olen)) != 0)
return (ret);
*olen += finish_olen;
return (0);
}
#if defined(MBEDTLS_CIPHER_MODE_AEAD)
/*
* Packet-oriented encryption for AEAD modes
*/
int mbedtls_cipher_auth_encrypt(mbedtls_cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen,
unsigned char *tag, size_t tag_len) {
#if defined(MBEDTLS_GCM_C)
if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode) {
*olen = ilen;
return (mbedtls_gcm_crypt_and_tag(ctx->cipher_ctx, MBEDTLS_GCM_ENCRYPT, ilen,
iv, iv_len, ad, ad_len, input, output,
tag_len, tag));
}
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CCM_C)
if (MBEDTLS_MODE_CCM == ctx->cipher_info->mode) {
*olen = ilen;
return (mbedtls_ccm_encrypt_and_tag(ctx->cipher_ctx, ilen,
iv, iv_len, ad, ad_len, input, output,
tag, tag_len));
}
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type) {
/* ChachaPoly has fixed length nonce and MAC (tag) */
if ((iv_len != ctx->cipher_info->iv_size) ||
(tag_len != 16U)) {
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
}
*olen = ilen;
return (mbedtls_chachapoly_encrypt_and_tag(ctx->cipher_ctx,
ilen, iv, ad, ad_len, input, output, tag));
}
#endif /* MBEDTLS_CHACHAPOLY_C */
return (MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE);
}
/*
* Packet-oriented decryption for AEAD modes
*/
int mbedtls_cipher_auth_decrypt(mbedtls_cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen,
const unsigned char *tag, size_t tag_len) {
#if defined(MBEDTLS_GCM_C)
if (MBEDTLS_MODE_GCM == ctx->cipher_info->mode) {
int ret;
*olen = ilen;
ret = mbedtls_gcm_auth_decrypt(ctx->cipher_ctx, ilen,
iv, iv_len, ad, ad_len,
tag, tag_len, input, output);
if (ret == MBEDTLS_ERR_GCM_AUTH_FAILED)
ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
return (ret);
}
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CCM_C)
if (MBEDTLS_MODE_CCM == ctx->cipher_info->mode) {
int ret;
*olen = ilen;
ret = mbedtls_ccm_auth_decrypt(ctx->cipher_ctx, ilen,
iv, iv_len, ad, ad_len,
input, output, tag, tag_len);
if (ret == MBEDTLS_ERR_CCM_AUTH_FAILED)
ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
return (ret);
}
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
if (MBEDTLS_CIPHER_CHACHA20_POLY1305 == ctx->cipher_info->type) {
int ret;
/* ChachaPoly has fixed length nonce and MAC (tag) */
if ((iv_len != ctx->cipher_info->iv_size) ||
(tag_len != 16U)) {
return (MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA);
}
*olen = ilen;
ret = mbedtls_chachapoly_auth_decrypt(ctx->cipher_ctx, ilen,
iv, ad, ad_len, tag, input, output);
if (ret == MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED)
ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED;
return (ret);
}
#endif /* MBEDTLS_CHACHAPOLY_C */
return (MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE);
}
#endif /* MBEDTLS_CIPHER_MODE_AEAD */
#endif /* MBEDTLS_CIPHER_C */