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Diffstat (limited to 'thirdparty/mbedtls/library/cipher.c')
| -rw-r--r-- | thirdparty/mbedtls/library/cipher.c | 917 |
1 files changed, 917 insertions, 0 deletions
diff --git a/thirdparty/mbedtls/library/cipher.c b/thirdparty/mbedtls/library/cipher.c new file mode 100644 index 0000000000..ff0327380c --- /dev/null +++ b/thirdparty/mbedtls/library/cipher.c @@ -0,0 +1,917 @@ +/** + * \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: 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. + * + * 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 <stdlib.h> +#include <string.h> + +#if defined(MBEDTLS_GCM_C) +#include "mbedtls/gcm.h" +#endif + +#if defined(MBEDTLS_CCM_C) +#include "mbedtls/ccm.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_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) +#define MBEDTLS_CIPHER_MODE_STREAM +#endif + +/* Implementation that should never be optimized out by the compiler */ +static void mbedtls_zeroize( void *v, size_t n ) { + volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0; +} + +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_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_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 CFB and CTR mode always use the encryption key schedule + */ + if( MBEDTLS_ENCRYPT == operation || + MBEDTLS_MODE_CFB == 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 ); + } + + 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) +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( 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 ); + } + + return( 0 ); +} +#endif /* MBEDTLS_GCM_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 ( 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 && + 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; + } + + copy_len = ilen % block_size; + if( copy_len == 0 && ctx->operation == MBEDTLS_DECRYPT ) + 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_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_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_CTR == ctx->cipher_info->mode || + MBEDTLS_MODE_GCM == ctx->cipher_info->mode || + MBEDTLS_MODE_STREAM == ctx->cipher_info->mode ) + { + 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) +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( MBEDTLS_MODE_GCM == ctx->cipher_info->mode ) + return mbedtls_gcm_finish( (mbedtls_gcm_context *) ctx->cipher_ctx, tag, tag_len ); + + return( 0 ); +} + +int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx, + const unsigned char *tag, size_t tag_len ) +{ + int ret; + + if( NULL == ctx || NULL == ctx->cipher_info || + MBEDTLS_DECRYPT != ctx->operation ) + { + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + } + + if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode ) + { + unsigned char check_tag[16]; + size_t i; + int diff; + + 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" */ + for( diff = 0, i = 0; i < tag_len; i++ ) + diff |= tag[i] ^ check_tag[i]; + + if( diff != 0 ) + return( MBEDTLS_ERR_CIPHER_AUTH_FAILED ); + + return( 0 ); + } + + return( 0 ); +} +#endif /* MBEDTLS_GCM_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 */ + + 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 */ + + return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE ); +} +#endif /* MBEDTLS_CIPHER_MODE_AEAD */ + +#endif /* MBEDTLS_CIPHER_C */ |