| /** |
| * \file cipher.c |
| * |
| * \brief Generic cipher wrapper for PolarSSL |
| * |
| * \author Adriaan de Jong <dejong@fox-it.com> |
| * |
| * Copyright (C) 2006-2010, Brainspark B.V. |
| * |
| * This file is part of PolarSSL (http://www.polarssl.org) |
| * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> |
| * |
| * All rights reserved. |
| * |
| * 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. |
| */ |
| |
| #include "polarssl/config.h" |
| |
| #if defined(POLARSSL_CIPHER_C) |
| |
| #include "polarssl/cipher.h" |
| #include "polarssl/cipher_wrap.h" |
| |
| #include <stdlib.h> |
| |
| #if defined _MSC_VER && !defined strcasecmp |
| #define strcasecmp _stricmp |
| #endif |
| |
| static const int supported_ciphers[] = { |
| |
| #if defined(POLARSSL_AES_C) |
| POLARSSL_CIPHER_AES_128_CBC, |
| POLARSSL_CIPHER_AES_192_CBC, |
| POLARSSL_CIPHER_AES_256_CBC, |
| #endif /* defined(POLARSSL_AES_C) */ |
| |
| #if defined(POLARSSL_CAMELLIA_C) |
| POLARSSL_CIPHER_CAMELLIA_128_CBC, |
| POLARSSL_CIPHER_CAMELLIA_192_CBC, |
| POLARSSL_CIPHER_CAMELLIA_256_CBC, |
| #endif /* defined(POLARSSL_CAMELLIA_C) */ |
| |
| #if defined(POLARSSL_DES_C) |
| POLARSSL_CIPHER_DES_CBC, |
| POLARSSL_CIPHER_DES_EDE_CBC, |
| POLARSSL_CIPHER_DES_EDE3_CBC, |
| #endif /* defined(POLARSSL_DES_C) */ |
| |
| 0 |
| }; |
| |
| const int *cipher_list( void ) |
| { |
| return supported_ciphers; |
| } |
| |
| const cipher_info_t *cipher_info_from_type( cipher_type_t cipher_type ) |
| { |
| /* Find static cipher information */ |
| switch ( cipher_type ) |
| { |
| #if defined(POLARSSL_AES_C) |
| case POLARSSL_CIPHER_AES_128_CBC: |
| return &aes_128_cbc_info; |
| case POLARSSL_CIPHER_AES_192_CBC: |
| return &aes_192_cbc_info; |
| case POLARSSL_CIPHER_AES_256_CBC: |
| return &aes_256_cbc_info; |
| #endif |
| |
| #if defined(POLARSSL_CAMELLIA_C) |
| case POLARSSL_CIPHER_CAMELLIA_128_CBC: |
| return &camellia_128_cbc_info; |
| case POLARSSL_CIPHER_CAMELLIA_192_CBC: |
| return &camellia_192_cbc_info; |
| case POLARSSL_CIPHER_CAMELLIA_256_CBC: |
| return &camellia_256_cbc_info; |
| #endif |
| |
| #if defined(POLARSSL_DES_C) |
| case POLARSSL_CIPHER_DES_CBC: |
| return &des_cbc_info; |
| case POLARSSL_CIPHER_DES_EDE_CBC: |
| return &des_ede_cbc_info; |
| case POLARSSL_CIPHER_DES_EDE3_CBC: |
| return &des_ede3_cbc_info; |
| #endif |
| |
| default: |
| return NULL; |
| } |
| } |
| |
| const cipher_info_t *cipher_info_from_string( const char *cipher_name ) |
| { |
| if( NULL == cipher_name ) |
| return NULL; |
| |
| /* Get the appropriate digest information */ |
| #if defined(POLARSSL_CAMELLIA_C) |
| if( !strcasecmp( "CAMELLIA-128-CBC", cipher_name ) ) |
| return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_128_CBC ); |
| if( !strcasecmp( "CAMELLIA-192-CBC", cipher_name ) ) |
| return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_192_CBC ); |
| if( !strcasecmp( "CAMELLIA-256-CBC", cipher_name ) ) |
| return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_256_CBC ); |
| #endif |
| #if defined(POLARSSL_AES_C) |
| if( !strcasecmp( "AES-128-CBC", cipher_name ) ) |
| return cipher_info_from_type( POLARSSL_CIPHER_AES_128_CBC ); |
| if( !strcasecmp( "AES-192-CBC", cipher_name ) ) |
| return cipher_info_from_type( POLARSSL_CIPHER_AES_192_CBC ); |
| if( !strcasecmp( "AES-256-CBC", cipher_name ) ) |
| return cipher_info_from_type( POLARSSL_CIPHER_AES_256_CBC ); |
| #endif |
| #if defined(POLARSSL_DES_C) |
| if( !strcasecmp( "DES-CBC", cipher_name ) ) |
| return cipher_info_from_type( POLARSSL_CIPHER_DES_CBC ); |
| if( !strcasecmp( "DES-EDE-CBC", cipher_name ) ) |
| return cipher_info_from_type( POLARSSL_CIPHER_DES_EDE_CBC ); |
| if( !strcasecmp( "DES-EDE3-CBC", cipher_name ) ) |
| return cipher_info_from_type( POLARSSL_CIPHER_DES_EDE3_CBC ); |
| #endif |
| return NULL; |
| } |
| |
| int cipher_init_ctx( cipher_context_t *ctx, const cipher_info_t *cipher_info ) |
| { |
| if( NULL == cipher_info || NULL == ctx ) |
| return 1; |
| |
| memset( ctx, 0, sizeof( ctx ) ); |
| |
| if( NULL == ( ctx->cipher_ctx = cipher_info->ctx_alloc_func() ) ) |
| return 2; |
| |
| ctx->cipher_info = cipher_info; |
| |
| return 0; |
| } |
| |
| int cipher_free_ctx( cipher_context_t *ctx ) |
| { |
| if( ctx == NULL || ctx->cipher_info == NULL ) |
| return 1; |
| |
| ctx->cipher_info->ctx_free_func( ctx->cipher_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 1; |
| |
| ctx->key_length = key_length; |
| ctx->operation = operation; |
| |
| if (POLARSSL_ENCRYPT == operation) |
| return ctx->cipher_info->setkey_enc_func( ctx->cipher_ctx, key, |
| ctx->key_length ); |
| |
| if (POLARSSL_DECRYPT == operation) |
| return ctx->cipher_info->setkey_dec_func( ctx->cipher_ctx, key, |
| ctx->key_length ); |
| |
| return 1; |
| } |
| |
| int cipher_reset( cipher_context_t *ctx, const unsigned char *iv ) |
| { |
| if( NULL == ctx || NULL == ctx->cipher_info || NULL == iv ) |
| return 1; |
| |
| ctx->unprocessed_len = 0; |
| |
| memcpy( ctx->iv, iv, cipher_get_iv_size( ctx ) ); |
| |
| return 0; |
| } |
| |
| int cipher_update( cipher_context_t *ctx, const unsigned char *input, size_t ilen, |
| unsigned char *output, size_t *olen ) |
| { |
| size_t copy_len = 0; |
| |
| if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen || |
| input == output ) |
| { |
| return 1; |
| } |
| |
| *olen = 0; |
| |
| if( ctx->cipher_info->mode == POLARSSL_MODE_CBC ) |
| { |
| /* |
| * 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 != ctx->cipher_info->cbc_func( ctx->cipher_ctx, |
| ctx->operation, cipher_get_block_size( ctx ), ctx->iv, |
| ctx->unprocessed_data, output) ) |
| { |
| return 1; |
| } |
| |
| *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 != ctx->cipher_info->cbc_func( ctx->cipher_ctx, |
| ctx->operation, ilen, ctx->iv, input, output ) ) |
| { |
| return 1; |
| } |
| *olen += ilen; |
| } |
| |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| 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 = 0; |
| |
| for( i = 0; i < padding_len; i++ ) |
| output[data_len + i] = (unsigned char) padding_len; |
| } |
| |
| static int get_pkcs_padding( unsigned char *input, unsigned char input_len, |
| size_t *data_len) |
| { |
| int i = 0; |
| unsigned char padding_len = 0; |
| |
| if( NULL == input || NULL == data_len ) |
| return 1; |
| |
| padding_len = input[input_len - 1]; |
| |
| if( padding_len > input_len ) |
| return 2; |
| |
| for( i = input_len - padding_len; i < input_len; i++ ) |
| if( input[i] != padding_len ) |
| return 2; |
| |
| *data_len = input_len - padding_len; |
| |
| return 0; |
| } |
| |
| int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen) |
| { |
| if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen ) |
| return 1; |
| |
| *olen = 0; |
| |
| if( POLARSSL_MODE_CBC == ctx->cipher_info->mode ) |
| { |
| if( POLARSSL_ENCRYPT == ctx->operation ) |
| { |
| add_pkcs_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 */ |
| return 1; |
| } |
| |
| /* cipher block */ |
| if( 0 != ctx->cipher_info->cbc_func( ctx->cipher_ctx, ctx->operation, |
| cipher_get_block_size( ctx ), ctx->iv, ctx->unprocessed_data, |
| output ) ) |
| { |
| return 1; |
| } |
| |
| /* Set output size for decryption */ |
| if( POLARSSL_DECRYPT == ctx->operation ) |
| return get_pkcs_padding( output, cipher_get_block_size( ctx ), olen ); |
| |
| /* Set output size for encryption */ |
| *olen = cipher_get_block_size( ctx ); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| #if defined(POLARSSL_SELF_TEST) |
| |
| #include <stdio.h> |
| |
| #define ASSERT(x) if (!(x)) { \ |
| printf( "failed with %i at %s\n", value, (#x) ); \ |
| return( 1 ); \ |
| } |
| /* |
| * Checkup routine |
| */ |
| |
| int cipher_self_test( int verbose ) |
| { |
| ((void) verbose); |
| |
| return( 0 ); |
| } |
| |
| #endif |
| |
| #endif |
