| /** |
| * \file cipher.c |
| * |
| * \brief Generic cipher wrapper for mbed TLS |
| * |
| * \author Adriaan de Jong <dejong@fox-it.com> |
| * |
| * Copyright (C) 2006-2014, ARM Limited, All Rights Reserved |
| * |
| * This file is part of mbed TLS (https://polarssl.org) |
| * |
| * 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. |
| */ |
| |
| #if !defined(POLARSSL_CONFIG_FILE) |
| #include "polarssl/config.h" |
| #else |
| #include POLARSSL_CONFIG_FILE |
| #endif |
| |
| #if defined(POLARSSL_CIPHER_C) |
| |
| #include "polarssl/cipher.h" |
| #include "polarssl/cipher_wrap.h" |
| |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #if defined(POLARSSL_GCM_C) |
| #include "polarssl/gcm.h" |
| #endif |
| |
| #if defined(POLARSSL_CCM_C) |
| #include "polarssl/ccm.h" |
| #endif |
| |
| #if defined(POLARSSL_ARC4_C) || defined(POLARSSL_CIPHER_NULL_CIPHER) |
| #define POLARSSL_CIPHER_MODE_STREAM |
| #endif |
| |
| #if defined(_MSC_VER) && !defined strcasecmp && !defined(EFIX64) && \ |
| !defined(EFI32) |
| #define strcasecmp _stricmp |
| #endif |
| |
| /* Implementation that should never be optimized out by the compiler */ |
| static void polarssl_zeroize( void *v, size_t n ) { |
| volatile unsigned char *p = v; while( n-- ) *p++ = 0; |
| } |
| |
| static int supported_init = 0; |
| |
| const int *cipher_list( void ) |
| { |
| const cipher_definition_t *def; |
| int *type; |
| |
| if( ! supported_init ) |
| { |
| def = cipher_definitions; |
| type = supported_ciphers; |
| |
| while( def->type != 0 ) |
| *type++ = (*def++).type; |
| |
| *type = 0; |
| |
| supported_init = 1; |
| } |
| |
| return( supported_ciphers ); |
| } |
| |
| const cipher_info_t *cipher_info_from_type( const cipher_type_t cipher_type ) |
| { |
| const cipher_definition_t *def; |
| |
| for( def = cipher_definitions; def->info != NULL; def++ ) |
| if( def->type == cipher_type ) |
| return( def->info ); |
| |
| return( NULL ); |
| } |
| |
| const cipher_info_t *cipher_info_from_string( const char *cipher_name ) |
| { |
| const cipher_definition_t *def; |
| |
| if( NULL == cipher_name ) |
| return( NULL ); |
| |
| for( def = cipher_definitions; def->info != NULL; def++ ) |
| if( ! strcasecmp( def->info->name, cipher_name ) ) |
| return( def->info ); |
| |
| return( NULL ); |
| } |
| |
| const cipher_info_t *cipher_info_from_values( const cipher_id_t cipher_id, |
| int key_length, |
| const cipher_mode_t mode ) |
| { |
| const cipher_definition_t *def; |
| |
| for( def = cipher_definitions; def->info != NULL; def++ ) |
| if( def->info->base->cipher == cipher_id && |
| def->info->key_length == (unsigned) key_length && |
| def->info->mode == mode ) |
| return( def->info ); |
| |
| return( NULL ); |
| } |
| |
| void cipher_init( cipher_context_t *ctx ) |
| { |
| memset( ctx, 0, sizeof( cipher_context_t ) ); |
| } |
| |
| void cipher_free( cipher_context_t *ctx ) |
| { |
| if( ctx == NULL ) |
| return; |
| |
| if( ctx->cipher_ctx ) |
| ctx->cipher_info->base->ctx_free_func( ctx->cipher_ctx ); |
| |
| polarssl_zeroize( ctx, sizeof(cipher_context_t) ); |
| } |
| |
| int cipher_init_ctx( cipher_context_t *ctx, const cipher_info_t *cipher_info ) |
| { |
| if( NULL == cipher_info || NULL == ctx ) |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| memset( ctx, 0, sizeof( cipher_context_t ) ); |
| |
| if( NULL == ( ctx->cipher_ctx = cipher_info->base->ctx_alloc_func() ) ) |
| return( POLARSSL_ERR_CIPHER_ALLOC_FAILED ); |
| |
| ctx->cipher_info = cipher_info; |
| |
| #if defined(POLARSSL_CIPHER_MODE_WITH_PADDING) |
| /* |
| * Ignore possible errors caused by a cipher mode that doesn't use padding |
| */ |
| #if defined(POLARSSL_CIPHER_PADDING_PKCS7) |
| (void) cipher_set_padding_mode( ctx, POLARSSL_PADDING_PKCS7 ); |
| #else |
| (void) cipher_set_padding_mode( ctx, POLARSSL_PADDING_NONE ); |
| #endif |
| #endif /* POLARSSL_CIPHER_MODE_WITH_PADDING */ |
| |
| return( 0 ); |
| } |
| |
| /* Deprecated, redirects to cipher_free() */ |
| int cipher_free_ctx( cipher_context_t *ctx ) |
| { |
| cipher_free( ctx ); |
| |
| return( 0 ); |
| } |
| |
| int cipher_setkey( cipher_context_t *ctx, const unsigned char *key, |
| int key_length, const operation_t operation ) |
| { |
| if( NULL == ctx || NULL == ctx->cipher_info ) |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| if( ( ctx->cipher_info->flags & POLARSSL_CIPHER_VARIABLE_KEY_LEN ) == 0 && |
| (int) ctx->cipher_info->key_length != key_length ) |
| { |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| } |
| |
| ctx->key_length = key_length; |
| ctx->operation = operation; |
| |
| /* |
| * For CFB and CTR mode always use the encryption key schedule |
| */ |
| if( POLARSSL_ENCRYPT == operation || |
| POLARSSL_MODE_CFB == ctx->cipher_info->mode || |
| POLARSSL_MODE_CTR == ctx->cipher_info->mode ) |
| { |
| return ctx->cipher_info->base->setkey_enc_func( ctx->cipher_ctx, key, |
| ctx->key_length ); |
| } |
| |
| if( POLARSSL_DECRYPT == operation ) |
| return ctx->cipher_info->base->setkey_dec_func( ctx->cipher_ctx, key, |
| ctx->key_length ); |
| |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| } |
| |
| int cipher_set_iv( 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( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| /* avoid buffer overflow in ctx->iv */ |
| if( iv_len > POLARSSL_MAX_IV_LENGTH ) |
| return( POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE ); |
| |
| if( ( ctx->cipher_info->flags & POLARSSL_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( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| } |
| |
| memcpy( ctx->iv, iv, actual_iv_size ); |
| ctx->iv_size = actual_iv_size; |
| |
| return( 0 ); |
| } |
| |
| int cipher_reset( cipher_context_t *ctx ) |
| { |
| if( NULL == ctx || NULL == ctx->cipher_info ) |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| ctx->unprocessed_len = 0; |
| |
| return( 0 ); |
| } |
| |
| #if defined(POLARSSL_GCM_C) |
| int cipher_update_ad( cipher_context_t *ctx, |
| const unsigned char *ad, size_t ad_len ) |
| { |
| if( NULL == ctx || NULL == ctx->cipher_info ) |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| if( POLARSSL_MODE_GCM == ctx->cipher_info->mode ) |
| { |
| return gcm_starts( (gcm_context *) ctx->cipher_ctx, ctx->operation, |
| ctx->iv, ctx->iv_size, ad, ad_len ); |
| } |
| |
| return( 0 ); |
| } |
| #endif /* POLARSSL_GCM_C */ |
| |
| int cipher_update( cipher_context_t *ctx, const unsigned char *input, |
| size_t ilen, unsigned char *output, size_t *olen ) |
| { |
| int ret; |
| |
| if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen ) |
| { |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| } |
| |
| *olen = 0; |
| |
| if( ctx->cipher_info->mode == POLARSSL_MODE_ECB ) |
| { |
| if( ilen != cipher_get_block_size( ctx ) ) |
| return( POLARSSL_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(POLARSSL_GCM_C) |
| if( ctx->cipher_info->mode == POLARSSL_MODE_GCM ) |
| { |
| *olen = ilen; |
| return gcm_update( (gcm_context *) ctx->cipher_ctx, ilen, input, |
| output ); |
| } |
| #endif |
| |
| if( input == output && |
| ( ctx->unprocessed_len != 0 || ilen % cipher_get_block_size( ctx ) ) ) |
| { |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| } |
| |
| #if defined(POLARSSL_CIPHER_MODE_CBC) |
| if( ctx->cipher_info->mode == POLARSSL_MODE_CBC ) |
| { |
| size_t copy_len = 0; |
| |
| /* |
| * If there is not enough data for a full block, cache it. |
| */ |
| if( ( ctx->operation == POLARSSL_DECRYPT && |
| ilen + ctx->unprocessed_len <= cipher_get_block_size( ctx ) ) || |
| ( ctx->operation == POLARSSL_ENCRYPT && |
| ilen + ctx->unprocessed_len < cipher_get_block_size( ctx ) ) ) |
| { |
| memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input, |
| ilen ); |
| |
| ctx->unprocessed_len += ilen; |
| return( 0 ); |
| } |
| |
| /* |
| * Process cached data first |
| */ |
| if( ctx->unprocessed_len != 0 ) |
| { |
| copy_len = cipher_get_block_size( ctx ) - 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, cipher_get_block_size( ctx ), ctx->iv, |
| ctx->unprocessed_data, output ) ) ) |
| { |
| return( ret ); |
| } |
| |
| *olen += cipher_get_block_size( ctx ); |
| output += cipher_get_block_size( ctx ); |
| ctx->unprocessed_len = 0; |
| |
| input += copy_len; |
| ilen -= copy_len; |
| } |
| |
| /* |
| * Cache final, incomplete block |
| */ |
| if( 0 != ilen ) |
| { |
| copy_len = ilen % cipher_get_block_size( ctx ); |
| if( copy_len == 0 && ctx->operation == POLARSSL_DECRYPT ) |
| copy_len = cipher_get_block_size( ctx ); |
| |
| 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 /* POLARSSL_CIPHER_MODE_CBC */ |
| |
| #if defined(POLARSSL_CIPHER_MODE_CFB) |
| if( ctx->cipher_info->mode == POLARSSL_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 /* POLARSSL_CIPHER_MODE_CFB */ |
| |
| #if defined(POLARSSL_CIPHER_MODE_CTR) |
| if( ctx->cipher_info->mode == POLARSSL_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 /* POLARSSL_CIPHER_MODE_CTR */ |
| |
| #if defined(POLARSSL_CIPHER_MODE_STREAM) |
| if( ctx->cipher_info->mode == POLARSSL_MODE_STREAM ) |
| { |
| if( 0 != ( ret = ctx->cipher_info->base->stream_func( ctx->cipher_ctx, |
| ilen, input, output ) ) ) |
| { |
| return( ret ); |
| } |
| |
| *olen = ilen; |
| |
| return( 0 ); |
| } |
| #endif /* POLARSSL_CIPHER_MODE_STREAM */ |
| |
| return( POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE ); |
| } |
| |
| #if defined(POLARSSL_CIPHER_MODE_WITH_PADDING) |
| #if defined(POLARSSL_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( POLARSSL_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( POLARSSL_ERR_CIPHER_INVALID_PADDING * ( bad != 0 ) ); |
| } |
| #endif /* POLARSSL_CIPHER_PADDING_PKCS7 */ |
| |
| #if defined(POLARSSL_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( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| bad = 0xFF; |
| *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] ^ 0x80 ) | ( done == prev_done ); |
| } |
| |
| return( POLARSSL_ERR_CIPHER_INVALID_PADDING * ( bad != 0 ) ); |
| |
| } |
| #endif /* POLARSSL_CIPHER_PADDING_ONE_AND_ZEROS */ |
| |
| #if defined(POLARSSL_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( POLARSSL_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( POLARSSL_ERR_CIPHER_INVALID_PADDING * ( bad != 0 ) ); |
| } |
| #endif /* POLARSSL_CIPHER_PADDING_ZEROS_AND_LEN */ |
| |
| #if defined(POLARSSL_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( POLARSSL_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 /* POLARSSL_CIPHER_PADDING_ZEROS */ |
| |
| /* |
| * No padding: don't pad :) |
| * |
| * There is no add_padding function (check for NULL in 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( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| *data_len = input_len; |
| |
| return( 0 ); |
| } |
| #endif /* POLARSSL_CIPHER_MODE_WITH_PADDING */ |
| |
| int cipher_finish( cipher_context_t *ctx, |
| unsigned char *output, size_t *olen ) |
| { |
| if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen ) |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| *olen = 0; |
| |
| if( POLARSSL_MODE_CFB == ctx->cipher_info->mode || |
| POLARSSL_MODE_CTR == ctx->cipher_info->mode || |
| POLARSSL_MODE_GCM == ctx->cipher_info->mode || |
| POLARSSL_MODE_STREAM == ctx->cipher_info->mode ) |
| { |
| return( 0 ); |
| } |
| |
| if( POLARSSL_MODE_ECB == ctx->cipher_info->mode ) |
| { |
| if( ctx->unprocessed_len != 0 ) |
| return( POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED ); |
| |
| return( 0 ); |
| } |
| |
| #if defined(POLARSSL_CIPHER_MODE_CBC) |
| if( POLARSSL_MODE_CBC == ctx->cipher_info->mode ) |
| { |
| int ret = 0; |
| |
| if( POLARSSL_ENCRYPT == ctx->operation ) |
| { |
| /* check for 'no padding' mode */ |
| if( NULL == ctx->add_padding ) |
| { |
| if( 0 != ctx->unprocessed_len ) |
| return( POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED ); |
| |
| return( 0 ); |
| } |
| |
| ctx->add_padding( ctx->unprocessed_data, cipher_get_iv_size( ctx ), |
| ctx->unprocessed_len ); |
| } |
| else if( 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( POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED ); |
| } |
| |
| /* cipher block */ |
| if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx, |
| ctx->operation, cipher_get_block_size( ctx ), ctx->iv, |
| ctx->unprocessed_data, output ) ) ) |
| { |
| return( ret ); |
| } |
| |
| /* Set output size for decryption */ |
| if( POLARSSL_DECRYPT == ctx->operation ) |
| return ctx->get_padding( output, cipher_get_block_size( ctx ), |
| olen ); |
| |
| /* Set output size for encryption */ |
| *olen = cipher_get_block_size( ctx ); |
| return( 0 ); |
| } |
| #else |
| ((void) output); |
| #endif /* POLARSSL_CIPHER_MODE_CBC */ |
| |
| return( POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE ); |
| } |
| |
| #if defined(POLARSSL_CIPHER_MODE_WITH_PADDING) |
| int cipher_set_padding_mode( cipher_context_t *ctx, cipher_padding_t mode ) |
| { |
| if( NULL == ctx || |
| POLARSSL_MODE_CBC != ctx->cipher_info->mode ) |
| { |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| } |
| |
| switch( mode ) |
| { |
| #if defined(POLARSSL_CIPHER_PADDING_PKCS7) |
| case POLARSSL_PADDING_PKCS7: |
| ctx->add_padding = add_pkcs_padding; |
| ctx->get_padding = get_pkcs_padding; |
| break; |
| #endif |
| #if defined(POLARSSL_CIPHER_PADDING_ONE_AND_ZEROS) |
| case POLARSSL_PADDING_ONE_AND_ZEROS: |
| ctx->add_padding = add_one_and_zeros_padding; |
| ctx->get_padding = get_one_and_zeros_padding; |
| break; |
| #endif |
| #if defined(POLARSSL_CIPHER_PADDING_ZEROS_AND_LEN) |
| case POLARSSL_PADDING_ZEROS_AND_LEN: |
| ctx->add_padding = add_zeros_and_len_padding; |
| ctx->get_padding = get_zeros_and_len_padding; |
| break; |
| #endif |
| #if defined(POLARSSL_CIPHER_PADDING_ZEROS) |
| case POLARSSL_PADDING_ZEROS: |
| ctx->add_padding = add_zeros_padding; |
| ctx->get_padding = get_zeros_padding; |
| break; |
| #endif |
| case POLARSSL_PADDING_NONE: |
| ctx->add_padding = NULL; |
| ctx->get_padding = get_no_padding; |
| break; |
| |
| default: |
| return( POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE ); |
| } |
| |
| return( 0 ); |
| } |
| #endif /* POLARSSL_CIPHER_MODE_WITH_PADDING */ |
| |
| #if defined(POLARSSL_GCM_C) |
| int cipher_write_tag( cipher_context_t *ctx, |
| unsigned char *tag, size_t tag_len ) |
| { |
| if( NULL == ctx || NULL == ctx->cipher_info || NULL == tag ) |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| if( POLARSSL_ENCRYPT != ctx->operation ) |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| if( POLARSSL_MODE_GCM == ctx->cipher_info->mode ) |
| return gcm_finish( (gcm_context *) ctx->cipher_ctx, tag, tag_len ); |
| |
| return( 0 ); |
| } |
| |
| int cipher_check_tag( cipher_context_t *ctx, |
| const unsigned char *tag, size_t tag_len ) |
| { |
| int ret; |
| |
| if( NULL == ctx || NULL == ctx->cipher_info || |
| POLARSSL_DECRYPT != ctx->operation ) |
| { |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| } |
| |
| if( POLARSSL_MODE_GCM == ctx->cipher_info->mode ) |
| { |
| unsigned char check_tag[16]; |
| size_t i; |
| int diff; |
| |
| if( tag_len > sizeof( check_tag ) ) |
| return( POLARSSL_ERR_CIPHER_BAD_INPUT_DATA ); |
| |
| if( 0 != ( ret = gcm_finish( (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( POLARSSL_ERR_CIPHER_AUTH_FAILED ); |
| |
| return( 0 ); |
| } |
| |
| return( 0 ); |
| } |
| #endif /* POLARSSL_GCM_C */ |
| |
| /* |
| * Packet-oriented wrapper for non-AEAD modes |
| */ |
| int cipher_crypt( 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 = cipher_set_iv( ctx, iv, iv_len ) ) != 0 ) |
| return( ret ); |
| |
| if( ( ret = cipher_reset( ctx ) ) != 0 ) |
| return( ret ); |
| |
| if( ( ret = cipher_update( ctx, input, ilen, output, olen ) ) != 0 ) |
| return( ret ); |
| |
| if( ( ret = cipher_finish( ctx, output + *olen, &finish_olen ) ) != 0 ) |
| return( ret ); |
| |
| *olen += finish_olen; |
| |
| return( 0 ); |
| } |
| |
| #if defined(POLARSSL_CIPHER_MODE_AEAD) |
| /* |
| * Packet-oriented encryption for AEAD modes |
| */ |
| int cipher_auth_encrypt( 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(POLARSSL_GCM_C) |
| if( POLARSSL_MODE_GCM == ctx->cipher_info->mode ) |
| { |
| *olen = ilen; |
| return( gcm_crypt_and_tag( ctx->cipher_ctx, GCM_ENCRYPT, ilen, |
| iv, iv_len, ad, ad_len, input, output, |
| tag_len, tag ) ); |
| } |
| #endif /* POLARSSL_GCM_C */ |
| #if defined(POLARSSL_CCM_C) |
| if( POLARSSL_MODE_CCM == ctx->cipher_info->mode ) |
| { |
| *olen = ilen; |
| return( ccm_encrypt_and_tag( ctx->cipher_ctx, ilen, |
| iv, iv_len, ad, ad_len, input, output, |
| tag, tag_len ) ); |
| } |
| #endif /* POLARSSL_CCM_C */ |
| |
| return( POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE ); |
| } |
| |
| /* |
| * Packet-oriented decryption for AEAD modes |
| */ |
| int cipher_auth_decrypt( 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(POLARSSL_GCM_C) |
| if( POLARSSL_MODE_GCM == ctx->cipher_info->mode ) |
| { |
| int ret; |
| |
| *olen = ilen; |
| ret = gcm_auth_decrypt( ctx->cipher_ctx, ilen, |
| iv, iv_len, ad, ad_len, |
| tag, tag_len, input, output ); |
| |
| if( ret == POLARSSL_ERR_GCM_AUTH_FAILED ) |
| ret = POLARSSL_ERR_CIPHER_AUTH_FAILED; |
| |
| return( ret ); |
| } |
| #endif /* POLARSSL_GCM_C */ |
| #if defined(POLARSSL_CCM_C) |
| if( POLARSSL_MODE_CCM == ctx->cipher_info->mode ) |
| { |
| int ret; |
| |
| *olen = ilen; |
| ret = ccm_auth_decrypt( ctx->cipher_ctx, ilen, |
| iv, iv_len, ad, ad_len, |
| input, output, tag, tag_len ); |
| |
| if( ret == POLARSSL_ERR_CCM_AUTH_FAILED ) |
| ret = POLARSSL_ERR_CIPHER_AUTH_FAILED; |
| |
| return( ret ); |
| } |
| #endif /* POLARSSL_CCM_C */ |
| |
| return( POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE ); |
| } |
| #endif /* POLARSSL_CIPHER_MODE_AEAD */ |
| |
| |
| #if defined(POLARSSL_SELF_TEST) |
| |
| /* |
| * Checkup routine |
| */ |
| int cipher_self_test( int verbose ) |
| { |
| ((void) verbose); |
| |
| return( 0 ); |
| } |
| |
| #endif /* POLARSSL_SELF_TEST */ |
| |
| #endif /* POLARSSL_CIPHER_C */ |