917 lines
26 KiB
C
917 lines
26 KiB
C
/**
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* \file cipher.c
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*
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* \brief Generic cipher wrapper for mbed TLS
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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) 2006-2015, ARM Limited, All Rights Reserved
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* This file is part of mbed TLS (https://tls.mbed.org)
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*/
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#if !defined(MBEDTLS_CONFIG_FILE)
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#include "mbedtls/config.h"
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#else
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#include MBEDTLS_CONFIG_FILE
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#endif
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#if defined(MBEDTLS_CIPHER_C)
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#include "mbedtls/cipher.h"
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#include "mbedtls/cipher_internal.h"
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#include <stdlib.h>
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#include <string.h>
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#if defined(MBEDTLS_GCM_C)
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#include "mbedtls/gcm.h"
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#endif
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#if defined(MBEDTLS_CCM_C)
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#include "mbedtls/ccm.h"
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#endif
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#if defined(MBEDTLS_CMAC_C)
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#include "mbedtls/cmac.h"
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#endif
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#if defined(MBEDTLS_PLATFORM_C)
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#include "mbedtls/platform.h"
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#else
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#define mbedtls_calloc calloc
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#define mbedtls_free free
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#endif
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#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
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#define MBEDTLS_CIPHER_MODE_STREAM
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#endif
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/* Implementation that should never be optimized out by the compiler */
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static void mbedtls_zeroize( void *v, size_t n ) {
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volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
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}
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static int supported_init = 0;
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const int *mbedtls_cipher_list( void )
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{
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const mbedtls_cipher_definition_t *def;
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int *type;
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if( ! supported_init )
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{
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def = mbedtls_cipher_definitions;
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type = mbedtls_cipher_supported;
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while( def->type != 0 )
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*type++ = (*def++).type;
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*type = 0;
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supported_init = 1;
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}
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return( mbedtls_cipher_supported );
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}
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const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type )
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{
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const mbedtls_cipher_definition_t *def;
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for( def = mbedtls_cipher_definitions; def->info != NULL; def++ )
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if( def->type == cipher_type )
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return( def->info );
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return( NULL );
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}
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const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name )
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{
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const mbedtls_cipher_definition_t *def;
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if( NULL == cipher_name )
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return( NULL );
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for( def = mbedtls_cipher_definitions; def->info != NULL; def++ )
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if( ! strcmp( def->info->name, cipher_name ) )
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return( def->info );
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return( NULL );
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}
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const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
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int key_bitlen,
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const mbedtls_cipher_mode_t mode )
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{
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const mbedtls_cipher_definition_t *def;
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for( def = mbedtls_cipher_definitions; def->info != NULL; def++ )
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if( def->info->base->cipher == cipher_id &&
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def->info->key_bitlen == (unsigned) key_bitlen &&
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def->info->mode == mode )
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return( def->info );
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return( NULL );
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}
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void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx )
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{
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memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
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}
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void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx )
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{
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if( ctx == NULL )
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return;
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#if defined(MBEDTLS_CMAC_C)
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if( ctx->cmac_ctx )
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{
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mbedtls_zeroize( ctx->cmac_ctx, sizeof( mbedtls_cmac_context_t ) );
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mbedtls_free( ctx->cmac_ctx );
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}
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#endif
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if( ctx->cipher_ctx )
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ctx->cipher_info->base->ctx_free_func( ctx->cipher_ctx );
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mbedtls_zeroize( ctx, sizeof(mbedtls_cipher_context_t) );
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}
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int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx, const mbedtls_cipher_info_t *cipher_info )
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{
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if( NULL == cipher_info || NULL == ctx )
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
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if( NULL == ( ctx->cipher_ctx = cipher_info->base->ctx_alloc_func() ) )
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return( MBEDTLS_ERR_CIPHER_ALLOC_FAILED );
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ctx->cipher_info = cipher_info;
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#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
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/*
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* Ignore possible errors caused by a cipher mode that doesn't use padding
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*/
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#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
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(void) mbedtls_cipher_set_padding_mode( ctx, MBEDTLS_PADDING_PKCS7 );
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#else
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(void) mbedtls_cipher_set_padding_mode( ctx, MBEDTLS_PADDING_NONE );
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#endif
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#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
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return( 0 );
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}
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int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx, const unsigned char *key,
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int key_bitlen, const mbedtls_operation_t operation )
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{
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if( NULL == ctx || NULL == ctx->cipher_info )
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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if( ( ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_KEY_LEN ) == 0 &&
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(int) ctx->cipher_info->key_bitlen != key_bitlen )
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{
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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}
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ctx->key_bitlen = key_bitlen;
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ctx->operation = operation;
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/*
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* For CFB and CTR mode always use the encryption key schedule
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*/
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if( MBEDTLS_ENCRYPT == operation ||
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MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
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MBEDTLS_MODE_CTR == ctx->cipher_info->mode )
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{
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return ctx->cipher_info->base->setkey_enc_func( ctx->cipher_ctx, key,
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ctx->key_bitlen );
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}
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if( MBEDTLS_DECRYPT == operation )
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return ctx->cipher_info->base->setkey_dec_func( ctx->cipher_ctx, key,
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ctx->key_bitlen );
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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}
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int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
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const unsigned char *iv, size_t iv_len )
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{
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size_t actual_iv_size;
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if( NULL == ctx || NULL == ctx->cipher_info || NULL == iv )
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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/* avoid buffer overflow in ctx->iv */
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if( iv_len > MBEDTLS_MAX_IV_LENGTH )
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return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
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if( ( ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_IV_LEN ) != 0 )
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actual_iv_size = iv_len;
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else
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{
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actual_iv_size = ctx->cipher_info->iv_size;
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/* avoid reading past the end of input buffer */
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if( actual_iv_size > iv_len )
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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}
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memcpy( ctx->iv, iv, actual_iv_size );
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ctx->iv_size = actual_iv_size;
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return( 0 );
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}
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int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx )
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{
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if( NULL == ctx || NULL == ctx->cipher_info )
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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ctx->unprocessed_len = 0;
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return( 0 );
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}
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#if defined(MBEDTLS_GCM_C)
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int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
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const unsigned char *ad, size_t ad_len )
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{
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if( NULL == ctx || NULL == ctx->cipher_info )
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
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{
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return mbedtls_gcm_starts( (mbedtls_gcm_context *) ctx->cipher_ctx, ctx->operation,
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ctx->iv, ctx->iv_size, ad, ad_len );
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}
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return( 0 );
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}
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#endif /* MBEDTLS_GCM_C */
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int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *input,
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size_t ilen, unsigned char *output, size_t *olen )
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{
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int ret;
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size_t block_size = 0;
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if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen )
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{
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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}
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*olen = 0;
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block_size = mbedtls_cipher_get_block_size( ctx );
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if( ctx->cipher_info->mode == MBEDTLS_MODE_ECB )
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{
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if( ilen != block_size )
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return( MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED );
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*olen = ilen;
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if( 0 != ( ret = ctx->cipher_info->base->ecb_func( ctx->cipher_ctx,
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ctx->operation, input, output ) ) )
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{
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return( ret );
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}
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return( 0 );
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}
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#if defined(MBEDTLS_GCM_C)
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if( ctx->cipher_info->mode == MBEDTLS_MODE_GCM )
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{
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*olen = ilen;
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return mbedtls_gcm_update( (mbedtls_gcm_context *) ctx->cipher_ctx, ilen, input,
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output );
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}
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#endif
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if ( 0 == block_size )
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{
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return MBEDTLS_ERR_CIPHER_INVALID_CONTEXT;
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}
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if( input == output &&
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( ctx->unprocessed_len != 0 || ilen % block_size ) )
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{
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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}
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#if defined(MBEDTLS_CIPHER_MODE_CBC)
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if( ctx->cipher_info->mode == MBEDTLS_MODE_CBC )
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{
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size_t copy_len = 0;
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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 == MBEDTLS_DECRYPT &&
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ilen + ctx->unprocessed_len <= block_size ) ||
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( ctx->operation == MBEDTLS_ENCRYPT &&
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ilen + ctx->unprocessed_len < block_size ) )
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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( 0 != ctx->unprocessed_len )
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{
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copy_len = block_size - 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 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx,
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ctx->operation, block_size, ctx->iv,
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ctx->unprocessed_data, output ) ) )
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{
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return( ret );
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}
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*olen += block_size;
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output += block_size;
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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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if( 0 == block_size )
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{
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return MBEDTLS_ERR_CIPHER_INVALID_CONTEXT;
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}
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copy_len = ilen % block_size;
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if( copy_len == 0 && ctx->operation == MBEDTLS_DECRYPT )
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copy_len = block_size;
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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 != ( ret = ctx->cipher_info->base->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( ret );
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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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#endif /* MBEDTLS_CIPHER_MODE_CBC */
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#if defined(MBEDTLS_CIPHER_MODE_CFB)
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if( ctx->cipher_info->mode == MBEDTLS_MODE_CFB )
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{
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if( 0 != ( ret = ctx->cipher_info->base->cfb_func( ctx->cipher_ctx,
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ctx->operation, ilen, &ctx->unprocessed_len, ctx->iv,
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input, output ) ) )
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{
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return( ret );
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}
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*olen = ilen;
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return( 0 );
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}
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#endif /* MBEDTLS_CIPHER_MODE_CFB */
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#if defined(MBEDTLS_CIPHER_MODE_CTR)
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if( ctx->cipher_info->mode == MBEDTLS_MODE_CTR )
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{
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if( 0 != ( ret = ctx->cipher_info->base->ctr_func( ctx->cipher_ctx,
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ilen, &ctx->unprocessed_len, ctx->iv,
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ctx->unprocessed_data, input, output ) ) )
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{
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return( ret );
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}
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*olen = ilen;
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return( 0 );
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}
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#endif /* MBEDTLS_CIPHER_MODE_CTR */
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#if defined(MBEDTLS_CIPHER_MODE_STREAM)
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if( ctx->cipher_info->mode == MBEDTLS_MODE_STREAM )
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{
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if( 0 != ( ret = ctx->cipher_info->base->stream_func( ctx->cipher_ctx,
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ilen, input, output ) ) )
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{
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return( ret );
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}
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*olen = ilen;
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return( 0 );
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}
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#endif /* MBEDTLS_CIPHER_MODE_STREAM */
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return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
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}
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#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
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#if defined(MBEDTLS_CIPHER_PADDING_PKCS7)
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/*
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* PKCS7 (and PKCS5) padding: fill with ll bytes, with ll = padding_len
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*/
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static void add_pkcs_padding( unsigned char *output, size_t output_len,
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size_t data_len )
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{
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size_t padding_len = output_len - data_len;
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unsigned char i;
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for( i = 0; i < padding_len; i++ )
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output[data_len + i] = (unsigned char) padding_len;
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}
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static int get_pkcs_padding( unsigned char *input, size_t input_len,
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size_t *data_len )
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{
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size_t i, pad_idx;
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unsigned char padding_len, bad = 0;
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if( NULL == input || NULL == data_len )
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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padding_len = input[input_len - 1];
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*data_len = input_len - padding_len;
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/* Avoid logical || since it results in a branch */
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bad |= padding_len > input_len;
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bad |= padding_len == 0;
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/* The number of bytes checked must be independent of padding_len,
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* so pick input_len, which is usually 8 or 16 (one block) */
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pad_idx = input_len - padding_len;
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for( i = 0; i < input_len; i++ )
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bad |= ( input[i] ^ padding_len ) * ( i >= pad_idx );
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return( MBEDTLS_ERR_CIPHER_INVALID_PADDING * ( bad != 0 ) );
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}
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#endif /* MBEDTLS_CIPHER_PADDING_PKCS7 */
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#if defined(MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS)
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/*
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* One and zeros padding: fill with 80 00 ... 00
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*/
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static void add_one_and_zeros_padding( unsigned char *output,
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size_t output_len, size_t data_len )
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{
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size_t padding_len = output_len - data_len;
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unsigned char i = 0;
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output[data_len] = 0x80;
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for( i = 1; i < padding_len; i++ )
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output[data_len + i] = 0x00;
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}
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static int get_one_and_zeros_padding( unsigned char *input, size_t input_len,
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size_t *data_len )
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{
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size_t i;
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unsigned char done = 0, prev_done, bad;
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if( NULL == input || NULL == data_len )
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return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
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bad = 0xFF;
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*data_len = 0;
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for( i = input_len; i > 0; i-- )
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{
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prev_done = done;
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done |= ( input[i-1] != 0 );
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|
*data_len |= ( i - 1 ) * ( done != prev_done );
|
|
bad &= ( input[i-1] ^ 0x80 ) | ( 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 */
|