374 lines
10 KiB
C
374 lines
10 KiB
C
/**
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* \file cipher.c
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*
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* \brief Generic cipher wrapper for PolarSSL
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*
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* \author Adriaan de Jong <dejong@fox-it.com>
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*
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* Copyright (C) 2006-2010, Brainspark B.V.
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*
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* This file is part of PolarSSL (http://www.polarssl.org)
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* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
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*
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "polarssl/config.h"
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#if defined(POLARSSL_CIPHER_C)
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#include "polarssl/cipher.h"
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#include "polarssl/cipher_wrap.h"
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#include <string.h>
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#include <stdlib.h>
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static const int supported_ciphers[] = {
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#if defined(POLARSSL_AES_C)
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POLARSSL_CIPHER_AES_128_CBC,
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POLARSSL_CIPHER_AES_192_CBC,
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POLARSSL_CIPHER_AES_256_CBC,
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#endif /* defined(POLARSSL_AES_C) */
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#if defined(POLARSSL_CAMELLIA_C)
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POLARSSL_CIPHER_CAMELLIA_128_CBC,
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POLARSSL_CIPHER_CAMELLIA_192_CBC,
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POLARSSL_CIPHER_CAMELLIA_256_CBC,
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#endif /* defined(POLARSSL_CAMELLIA_C) */
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#if defined(POLARSSL_DES_C)
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POLARSSL_CIPHER_DES_CBC,
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POLARSSL_CIPHER_DES_EDE_CBC,
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POLARSSL_CIPHER_DES_EDE3_CBC,
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#endif /* defined(POLARSSL_DES_C) */
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0
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};
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const int *cipher_list( void )
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{
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return supported_ciphers;
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}
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const cipher_info_t *cipher_info_from_type( cipher_type_t cipher_type )
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{
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/* Find static cipher information */
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switch ( cipher_type )
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{
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#if defined(POLARSSL_AES_C)
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case POLARSSL_CIPHER_AES_128_CBC:
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return &aes_128_cbc_info;
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case POLARSSL_CIPHER_AES_192_CBC:
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return &aes_192_cbc_info;
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case POLARSSL_CIPHER_AES_256_CBC:
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return &aes_256_cbc_info;
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#endif
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#if defined(POLARSSL_CAMELLIA_C)
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case POLARSSL_CIPHER_CAMELLIA_128_CBC:
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return &camellia_128_cbc_info;
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case POLARSSL_CIPHER_CAMELLIA_192_CBC:
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return &camellia_192_cbc_info;
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case POLARSSL_CIPHER_CAMELLIA_256_CBC:
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return &camellia_256_cbc_info;
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#endif
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#if defined(POLARSSL_DES_C)
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case POLARSSL_CIPHER_DES_CBC:
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return &des_cbc_info;
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case POLARSSL_CIPHER_DES_EDE_CBC:
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return &des_ede_cbc_info;
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case POLARSSL_CIPHER_DES_EDE3_CBC:
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return &des_ede3_cbc_info;
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#endif
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default:
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return NULL;
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}
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}
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const cipher_info_t *cipher_info_from_string( const char *cipher_name )
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{
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if( NULL == cipher_name )
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return NULL;
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/* Get the appropriate digest information */
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#if defined(POLARSSL_CAMELLIA_C)
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if( !strcasecmp( "CAMELLIA-128-CBC", cipher_name ) )
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return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_128_CBC );
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if( !strcasecmp( "CAMELLIA-192-CBC", cipher_name ) )
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return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_192_CBC );
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if( !strcasecmp( "CAMELLIA-256-CBC", cipher_name ) )
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return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_256_CBC );
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#endif
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#if defined(POLARSSL_AES_C)
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if( !strcasecmp( "AES-128-CBC", cipher_name ) )
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return cipher_info_from_type( POLARSSL_CIPHER_AES_128_CBC );
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if( !strcasecmp( "AES-192-CBC", cipher_name ) )
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return cipher_info_from_type( POLARSSL_CIPHER_AES_192_CBC );
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if( !strcasecmp( "AES-256-CBC", cipher_name ) )
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return cipher_info_from_type( POLARSSL_CIPHER_AES_256_CBC );
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#endif
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#if defined(POLARSSL_DES_C)
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if( !strcasecmp( "DES-CBC", cipher_name ) )
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return cipher_info_from_type( POLARSSL_CIPHER_DES_CBC );
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if( !strcasecmp( "DES-EDE-CBC", cipher_name ) )
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return cipher_info_from_type( POLARSSL_CIPHER_DES_EDE_CBC );
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if( !strcasecmp( "DES-EDE3-CBC", cipher_name ) )
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return cipher_info_from_type( POLARSSL_CIPHER_DES_EDE3_CBC );
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#endif
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return NULL;
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}
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int cipher_init_ctx( cipher_context_t *ctx, const cipher_info_t *cipher_info )
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{
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if( NULL == cipher_info || NULL == ctx )
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return 1;
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memset( ctx, 0, sizeof( ctx ) );
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if( NULL == ( ctx->cipher_ctx = cipher_info->ctx_alloc_func() ) )
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return 2;
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ctx->cipher_info = cipher_info;
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return 0;
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}
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int cipher_free_ctx( cipher_context_t *ctx )
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{
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if( ctx == NULL || ctx->cipher_info == NULL )
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return 1;
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ctx->cipher_info->ctx_free_func( ctx->cipher_ctx );
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return 0;
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}
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int cipher_setkey( cipher_context_t *ctx, const unsigned char *key,
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int key_length, const operation_t operation )
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{
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if( NULL == ctx || NULL == ctx->cipher_info )
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return 1;
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ctx->key_length = key_length;
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ctx->operation = operation;
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if (POLARSSL_ENCRYPT == operation)
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return ctx->cipher_info->setkey_enc_func( ctx->cipher_ctx, key,
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ctx->key_length );
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if (POLARSSL_DECRYPT == operation)
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return ctx->cipher_info->setkey_dec_func( ctx->cipher_ctx, key,
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ctx->key_length );
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return 1;
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}
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int cipher_reset( cipher_context_t *ctx, const unsigned char *iv )
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{
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if( NULL == ctx || NULL == ctx->cipher_info || NULL == iv )
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return 1;
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ctx->unprocessed_len = 0;
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memcpy( ctx->iv, iv, cipher_get_iv_size( ctx ) );
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return 0;
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}
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int cipher_update( cipher_context_t *ctx, const unsigned char *input, int ilen,
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unsigned char *output, int *olen )
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{
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int copy_len = 0;
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if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen )
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return 1;
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*olen = 0;
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if( ctx->cipher_info->mode == POLARSSL_MODE_CBC )
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{
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/*
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* If there is not enough data for a full block, cache it.
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*/
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if( ( ctx->operation == POLARSSL_DECRYPT &&
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ilen + ctx->unprocessed_len <= cipher_get_block_size( ctx ) ) ||
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( ctx->operation == POLARSSL_ENCRYPT &&
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ilen + ctx->unprocessed_len < cipher_get_block_size( ctx ) ) )
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{
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memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input,
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ilen );
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ctx->unprocessed_len += ilen;
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return 0;
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}
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/*
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* Process cached data first
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*/
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if( ctx->unprocessed_len != 0 )
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{
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copy_len = cipher_get_block_size( ctx ) - ctx->unprocessed_len;
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memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input,
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copy_len );
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if( 0 != ctx->cipher_info->cbc_func( ctx->cipher_ctx,
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ctx->operation, cipher_get_block_size( ctx ), ctx->iv,
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ctx->unprocessed_data, output) )
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{
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return 1;
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}
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*olen += cipher_get_block_size( ctx );
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output += cipher_get_block_size( ctx );
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ctx->unprocessed_len = 0;
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input += copy_len;
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ilen -= copy_len;
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}
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/*
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* Cache final, incomplete block
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*/
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if( 0 != ilen )
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{
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copy_len = ilen % cipher_get_block_size( ctx );
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if( copy_len == 0 && ctx->operation == POLARSSL_DECRYPT )
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copy_len = cipher_get_block_size(ctx);
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memcpy( ctx->unprocessed_data, &( input[ilen - copy_len] ),
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copy_len );
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ctx->unprocessed_len += copy_len;
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ilen -= copy_len;
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}
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/*
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* Process remaining full blocks
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*/
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if( ilen )
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{
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if( 0 != ctx->cipher_info->cbc_func( ctx->cipher_ctx,
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ctx->operation, ilen, ctx->iv, input, output ) )
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{
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return 1;
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}
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*olen += ilen;
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}
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return 0;
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}
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return 1;
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}
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static void add_pkcs_padding( unsigned char *output, unsigned char output_len,
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int data_len )
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{
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unsigned char padding_len = output_len - data_len;
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unsigned char i = 0;
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for( i = 0; i < padding_len; i++ )
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output[data_len + i] = padding_len;
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}
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static int get_pkcs_padding( unsigned char *input, unsigned char input_len,
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int *data_len)
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{
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int i = 0;
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unsigned char padding_len = 0;
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if ( NULL == input || NULL == data_len )
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return 1;
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padding_len = input[input_len - 1];
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if ( padding_len > input_len )
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return 2;
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for ( i = input_len - padding_len; i < input_len; i++ )
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if ( input[i] != padding_len )
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return 2;
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*data_len = input_len - padding_len;
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return 0;
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}
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int cipher_finish( cipher_context_t *ctx, unsigned char *output, int *olen)
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{
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if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen )
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return 1;
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*olen = 0;
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if( POLARSSL_MODE_CBC == ctx->cipher_info->mode )
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{
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if( POLARSSL_ENCRYPT == ctx->operation )
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{
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add_pkcs_padding( ctx->unprocessed_data, cipher_get_iv_size( ctx ),
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ctx->unprocessed_len );
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}
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else if ( cipher_get_block_size( ctx ) != ctx->unprocessed_len )
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{
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/* For decrypt operations, expect a full block */
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return 1;
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}
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/* cipher block */
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if( 0 != ctx->cipher_info->cbc_func( ctx->cipher_ctx, ctx->operation,
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cipher_get_block_size( ctx ), ctx->iv, ctx->unprocessed_data,
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output ) )
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{
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return 1;
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}
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/* Set output size for decryption */
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if( POLARSSL_DECRYPT == ctx->operation )
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return get_pkcs_padding( output, cipher_get_block_size( ctx ), olen );
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/* Set output size for encryption */
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*olen = cipher_get_block_size( ctx );
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return 0;
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}
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return 1;
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}
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#if defined(POLARSSL_SELF_TEST)
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#include <stdio.h>
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#define ASSERT(x) if (!(x)) { \
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printf( "failed with %i at %s\n", value, (#x) ); \
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return( 1 ); \
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}
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/*
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* Checkup routine
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*/
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int cipher_self_test( int verbose )
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{
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return( 0 );
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}
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#endif
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#endif
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