/** * \file cipher.c * * \brief Generic cipher wrapper for PolarSSL * * \author Adriaan de Jong * * Copyright (C) 2006-2013, Brainspark B.V. * * This file is part of PolarSSL (http://www.polarssl.org) * Lead Maintainer: Paul Bakker * * 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" #if defined(POLARSSL_GCM_C) #include "polarssl/gcm.h" #endif #include #if defined(POLARSSL_ARC4_C) || defined(POLARSSL_CIPHER_NULL_CIPHER) #define POLARSSL_CIPHER_MODE_STREAM #endif #if defined _MSC_VER && !defined strcasecmp #define strcasecmp _stricmp #endif static const int supported_ciphers[] = { #if defined(POLARSSL_AES_C) POLARSSL_CIPHER_AES_128_ECB, POLARSSL_CIPHER_AES_192_ECB, POLARSSL_CIPHER_AES_256_ECB, POLARSSL_CIPHER_AES_128_CBC, POLARSSL_CIPHER_AES_192_CBC, POLARSSL_CIPHER_AES_256_CBC, #if defined(POLARSSL_CIPHER_MODE_CFB) POLARSSL_CIPHER_AES_128_CFB128, POLARSSL_CIPHER_AES_192_CFB128, POLARSSL_CIPHER_AES_256_CFB128, #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) POLARSSL_CIPHER_AES_128_CTR, POLARSSL_CIPHER_AES_192_CTR, POLARSSL_CIPHER_AES_256_CTR, #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ #if defined(POLARSSL_GCM_C) POLARSSL_CIPHER_AES_128_GCM, POLARSSL_CIPHER_AES_192_GCM, POLARSSL_CIPHER_AES_256_GCM, #endif /* defined(POLARSSL_GCM_C) */ #endif /* defined(POLARSSL_AES_C) */ #if defined(POLARSSL_ARC4_C) POLARSSL_CIPHER_ARC4_128, #endif #if defined(POLARSSL_CAMELLIA_C) POLARSSL_CIPHER_CAMELLIA_128_ECB, POLARSSL_CIPHER_CAMELLIA_192_ECB, POLARSSL_CIPHER_CAMELLIA_256_ECB, POLARSSL_CIPHER_CAMELLIA_128_CBC, POLARSSL_CIPHER_CAMELLIA_192_CBC, POLARSSL_CIPHER_CAMELLIA_256_CBC, #if defined(POLARSSL_CIPHER_MODE_CFB) POLARSSL_CIPHER_CAMELLIA_128_CFB128, POLARSSL_CIPHER_CAMELLIA_192_CFB128, POLARSSL_CIPHER_CAMELLIA_256_CFB128, #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) POLARSSL_CIPHER_CAMELLIA_128_CTR, POLARSSL_CIPHER_CAMELLIA_192_CTR, POLARSSL_CIPHER_CAMELLIA_256_CTR, #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ #endif /* defined(POLARSSL_CAMELLIA_C) */ #if defined(POLARSSL_DES_C) POLARSSL_CIPHER_DES_ECB, POLARSSL_CIPHER_DES_EDE_ECB, POLARSSL_CIPHER_DES_EDE3_ECB, POLARSSL_CIPHER_DES_CBC, POLARSSL_CIPHER_DES_EDE_CBC, POLARSSL_CIPHER_DES_EDE3_CBC, #endif /* defined(POLARSSL_DES_C) */ #if defined(POLARSSL_BLOWFISH_C) POLARSSL_CIPHER_BLOWFISH_ECB, POLARSSL_CIPHER_BLOWFISH_CBC, #if defined(POLARSSL_CIPHER_MODE_CFB) POLARSSL_CIPHER_BLOWFISH_CFB64, #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) POLARSSL_CIPHER_BLOWFISH_CTR, #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ #endif /* defined(POLARSSL_BLOWFISH_C) */ #if defined(POLARSSL_CIPHER_NULL_CIPHER) POLARSSL_CIPHER_NULL, #endif /* defined(POLARSSL_CIPHER_NULL_CIPHER) */ 0 }; const int *cipher_list( void ) { return supported_ciphers; } const cipher_info_t *cipher_info_from_type( const cipher_type_t cipher_type ) { /* Find static cipher information */ switch ( cipher_type ) { #if defined(POLARSSL_AES_C) case POLARSSL_CIPHER_AES_128_ECB: return &aes_128_ecb_info; case POLARSSL_CIPHER_AES_192_ECB: return &aes_192_ecb_info; case POLARSSL_CIPHER_AES_256_ECB: return &aes_256_ecb_info; 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; #if defined(POLARSSL_CIPHER_MODE_CFB) case POLARSSL_CIPHER_AES_128_CFB128: return &aes_128_cfb128_info; case POLARSSL_CIPHER_AES_192_CFB128: return &aes_192_cfb128_info; case POLARSSL_CIPHER_AES_256_CFB128: return &aes_256_cfb128_info; #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) case POLARSSL_CIPHER_AES_128_CTR: return &aes_128_ctr_info; case POLARSSL_CIPHER_AES_192_CTR: return &aes_192_ctr_info; case POLARSSL_CIPHER_AES_256_CTR: return &aes_256_ctr_info; #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ #if defined(POLARSSL_GCM_C) case POLARSSL_CIPHER_AES_128_GCM: return &aes_128_gcm_info; case POLARSSL_CIPHER_AES_192_GCM: return &aes_192_gcm_info; case POLARSSL_CIPHER_AES_256_GCM: return &aes_256_gcm_info; #endif /* defined(POLARSSL_GCM_C) */ #endif #if defined(POLARSSL_CAMELLIA_C) case POLARSSL_CIPHER_CAMELLIA_128_ECB: return &camellia_128_ecb_info; case POLARSSL_CIPHER_CAMELLIA_192_ECB: return &camellia_192_ecb_info; case POLARSSL_CIPHER_CAMELLIA_256_ECB: return &camellia_256_ecb_info; 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; #if defined(POLARSSL_CIPHER_MODE_CFB) case POLARSSL_CIPHER_CAMELLIA_128_CFB128: return &camellia_128_cfb128_info; case POLARSSL_CIPHER_CAMELLIA_192_CFB128: return &camellia_192_cfb128_info; case POLARSSL_CIPHER_CAMELLIA_256_CFB128: return &camellia_256_cfb128_info; #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) case POLARSSL_CIPHER_CAMELLIA_128_CTR: return &camellia_128_ctr_info; case POLARSSL_CIPHER_CAMELLIA_192_CTR: return &camellia_192_ctr_info; case POLARSSL_CIPHER_CAMELLIA_256_CTR: return &camellia_256_ctr_info; #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ #endif #if defined(POLARSSL_DES_C) case POLARSSL_CIPHER_DES_ECB: return &des_ecb_info; case POLARSSL_CIPHER_DES_EDE_ECB: return &des_ede_ecb_info; case POLARSSL_CIPHER_DES_EDE3_ECB: return &des_ede3_ecb_info; 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 #if defined(POLARSSL_ARC4_C) case POLARSSL_CIPHER_ARC4_128: return &arc4_128_info; #endif #if defined(POLARSSL_BLOWFISH_C) case POLARSSL_CIPHER_BLOWFISH_ECB: return &blowfish_ecb_info; case POLARSSL_CIPHER_BLOWFISH_CBC: return &blowfish_cbc_info; #if defined(POLARSSL_CIPHER_MODE_CFB) case POLARSSL_CIPHER_BLOWFISH_CFB64: return &blowfish_cfb64_info; #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) case POLARSSL_CIPHER_BLOWFISH_CTR: return &blowfish_ctr_info; #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ #endif #if defined(POLARSSL_CIPHER_NULL_CIPHER) case POLARSSL_CIPHER_NULL: return &null_cipher_info; #endif /* defined(POLARSSL_CIPHER_NULL_CIPHER) */ default: return NULL; } } const cipher_info_t *cipher_info_from_string( const char *cipher_name ) { if( NULL == cipher_name ) return NULL; /* Get the appropriate cipher 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 ); #if defined(POLARSSL_CIPHER_MODE_CFB) if( !strcasecmp( "CAMELLIA-128-CFB128", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_128_CFB128 ); if( !strcasecmp( "CAMELLIA-192-CFB128", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_192_CFB128 ); if( !strcasecmp( "CAMELLIA-256-CFB128", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_256_CFB128 ); #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) if( !strcasecmp( "CAMELLIA-128-CTR", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_128_CTR ); if( !strcasecmp( "CAMELLIA-192-CTR", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_192_CTR ); if( !strcasecmp( "CAMELLIA-256-CTR", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_CAMELLIA_256_CTR ); #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ #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 ); #if defined(POLARSSL_CIPHER_MODE_CFB) if( !strcasecmp( "AES-128-CFB128", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_AES_128_CFB128 ); if( !strcasecmp( "AES-192-CFB128", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_AES_192_CFB128 ); if( !strcasecmp( "AES-256-CFB128", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_AES_256_CFB128 ); #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) if( !strcasecmp( "AES-128-CTR", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_AES_128_CTR ); if( !strcasecmp( "AES-192-CTR", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_AES_192_CTR ); if( !strcasecmp( "AES-256-CTR", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_AES_256_CTR ); #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ #if defined(POLARSSL_GCM_C) if( !strcasecmp( "AES-128-GCM", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_AES_128_GCM ); if( !strcasecmp( "AES-192-GCM", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_AES_192_GCM ); if( !strcasecmp( "AES-256-GCM", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_AES_256_GCM ); #endif #endif /* POLARSSL_AES_C */ #if defined(POLARSSL_ARC4_C) if( !strcasecmp( "ARC4-128", cipher_name ) ) return( cipher_info_from_type( POLARSSL_CIPHER_ARC4_128 ) ); #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 #if defined(POLARSSL_BLOWFISH_C) if( !strcasecmp( "BLOWFISH-CBC", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_BLOWFISH_CBC ); #if defined(POLARSSL_CIPHER_MODE_CFB) if( !strcasecmp( "BLOWFISH-CFB64", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_BLOWFISH_CFB64 ); #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) if( !strcasecmp( "BLOWFISH-CTR", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_BLOWFISH_CTR ); #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ #endif #if defined(POLARSSL_CIPHER_NULL_CIPHER) if( !strcasecmp( "NULL", cipher_name ) ) return cipher_info_from_type( POLARSSL_CIPHER_NULL ); #endif /* defined(POLARSSL_CIPHER_NULL_CIPHER) */ return NULL; } const cipher_info_t *cipher_info_from_values( const cipher_id_t cipher_id, int key_length, const cipher_mode_t mode ) { #if defined(POLARSSL_AES_C) if( cipher_id == POLARSSL_CIPHER_ID_AES ) { if( mode == POLARSSL_MODE_ECB ) { if( key_length == 128 ) return &aes_128_ecb_info; if( key_length == 192 ) return &aes_192_ecb_info; if( key_length == 256 ) return &aes_256_ecb_info; } if( mode == POLARSSL_MODE_CBC ) { if( key_length == 128 ) return &aes_128_cbc_info; if( key_length == 192 ) return &aes_192_cbc_info; if( key_length == 256 ) return &aes_256_cbc_info; } #if defined(POLARSSL_CIPHER_MODE_CFB) if( mode == POLARSSL_MODE_CFB ) { if( key_length == 128 ) return &aes_128_cfb128_info; if( key_length == 192 ) return &aes_192_cfb128_info; if( key_length == 256 ) return &aes_256_cfb128_info; } #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) if( mode == POLARSSL_MODE_CTR ) { if( key_length == 128 ) return &aes_128_ctr_info; if( key_length == 192 ) return &aes_192_ctr_info; if( key_length == 256 ) return &aes_256_ctr_info; } #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ #if defined(POLARSSL_GCM_C) if( mode == POLARSSL_MODE_GCM ) { if( key_length == 128 ) return &aes_128_gcm_info; if( key_length == 192 ) return &aes_192_gcm_info; if( key_length == 256 ) return &aes_256_gcm_info; } #endif /* defined(POLARSSL_GCM_C) */ } #endif #if defined(POLARSSL_CAMELLIA_C) if( cipher_id == POLARSSL_CIPHER_ID_CAMELLIA ) { if( mode == POLARSSL_MODE_ECB ) { if( key_length == 128 ) return &camellia_128_ecb_info; if( key_length == 192 ) return &camellia_192_ecb_info; if( key_length == 256 ) return &camellia_256_ecb_info; } if( mode == POLARSSL_MODE_CBC ) { if( key_length == 128 ) return &camellia_128_cbc_info; if( key_length == 192 ) return &camellia_192_cbc_info; if( key_length == 256 ) return &camellia_256_cbc_info; } #if defined(POLARSSL_CIPHER_MODE_CFB) if( mode == POLARSSL_MODE_CFB ) { if( key_length == 128 ) return &camellia_128_cfb128_info; if( key_length == 192 ) return &camellia_192_cfb128_info; if( key_length == 256 ) return &camellia_256_cfb128_info; } #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) if( mode == POLARSSL_MODE_CTR ) { if( key_length == 128 ) return &camellia_128_ctr_info; if( key_length == 192 ) return &camellia_192_ctr_info; if( key_length == 256 ) return &camellia_256_ctr_info; } #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ } #endif #if defined(POLARSSL_DES_C) if( cipher_id == POLARSSL_CIPHER_ID_DES && key_length == 64 ) { if( mode == POLARSSL_MODE_ECB ) return &des_ecb_info; if( mode == POLARSSL_MODE_CBC ) return &des_cbc_info; } if( cipher_id == POLARSSL_CIPHER_ID_3DES ) { if( mode == POLARSSL_MODE_ECB ) { if( key_length == 128 ) return &des_ede_ecb_info; if( key_length == 192 ) return &des_ede3_ecb_info; } if( mode == POLARSSL_MODE_CBC ) { if( key_length == 128 ) return &des_ede_cbc_info; if( key_length == 192 ) return &des_ede3_cbc_info; } } #endif #if defined(POLARSSL_ARC4_C) if( cipher_id == POLARSSL_CIPHER_ID_ARC4 && key_length == 128 && mode == POLARSSL_MODE_STREAM ) return &arc4_128_info; #endif #if defined(POLARSSL_BLOWFISH_C) if( cipher_id == POLARSSL_CIPHER_ID_BLOWFISH && key_length == 128 ) { if( mode == POLARSSL_MODE_ECB ) return &blowfish_ecb_info; if( mode == POLARSSL_MODE_CBC ) return &blowfish_cbc_info; #if defined(POLARSSL_CIPHER_MODE_CFB) if( mode == POLARSSL_MODE_CFB ) return &blowfish_cfb64_info; #endif /* defined(POLARSSL_CIPHER_MODE_CFB) */ #if defined(POLARSSL_CIPHER_MODE_CTR) if( mode == POLARSSL_MODE_CTR ) return &blowfish_ctr_info; #endif /* defined(POLARSSL_CIPHER_MODE_CTR) */ } #endif #if defined(POLARSSL_CIPHER_NULL_CIPHER) if( cipher_id == POLARSSL_CIPHER_ID_NULL ) return &null_cipher_info; #endif /* defined(POLARSSL_CIPHER_NULL_CIPHER) */ return NULL; } 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; /* * 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 return 0; } int cipher_free_ctx( cipher_context_t *ctx ) { if( ctx == NULL || ctx->cipher_info == NULL ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; ctx->cipher_info->base->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 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; if( ctx->cipher_info->accepts_variable_iv_size ) actual_iv_size = iv_len; else actual_iv_size = ctx->cipher_info->iv_size; 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_CIPHER_MODE_AEAD) 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 defined(POLARSSL_GCM_C) if( POLARSSL_MODE_GCM == ctx->cipher_info->mode ) { return gcm_starts( ctx->cipher_ctx, ctx->operation, ctx->iv, ctx->iv_size, ad, ad_len ); } #endif return 0; } #endif /* POLARSSL_CIPHER_MODE_AEAD */ int cipher_update( cipher_context_t *ctx, const unsigned char *input, size_t ilen, unsigned char *output, size_t *olen ) { int ret; size_t copy_len = 0; *olen = 0; if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen ) { return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; } 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( 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( 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 != ( 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; } #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 #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 #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 return POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE; } #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 = 0; 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 ) { unsigned int i, padding_len = 0; if( NULL == input || NULL == data_len ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; padding_len = input[input_len - 1]; if( padding_len > input_len || padding_len == 0 ) return POLARSSL_ERR_CIPHER_INVALID_PADDING; for( i = input_len - padding_len; i < input_len; i++ ) if( input[i] != padding_len ) return POLARSSL_ERR_CIPHER_INVALID_PADDING; *data_len = input_len - padding_len; return 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 ) { unsigned char *p = input + input_len - 1; if( NULL == input || NULL == data_len ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; while( *p == 0x00 && p > input ) --p; if( *p != 0x80 ) return POLARSSL_ERR_CIPHER_INVALID_PADDING; *data_len = p - input; return 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 ) { unsigned int i, padding_len = 0; if( NULL == input || NULL == data_len ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; padding_len = input[input_len - 1]; if( padding_len > input_len || padding_len == 0 ) return POLARSSL_ERR_CIPHER_INVALID_PADDING; for( i = input_len - padding_len; i < input_len - 1; i++ ) if( input[i] != 0x00 ) return POLARSSL_ERR_CIPHER_INVALID_PADDING; *data_len = input_len - padding_len; return 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 ) { unsigned char 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 ) { unsigned char *p = input + input_len - 1; if( NULL == input || NULL == data_len ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; while( *p == 0x00 && p > input ) --p; *data_len = *p == 0x00 ? 0 : p - input + 1; 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; } int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen ) { int ret = 0; 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( POLARSSL_MODE_CBC == ctx->cipher_info->mode ) { 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; } return POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE; } 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; } #if defined(POLARSSL_CIPHER_MODE_AEAD) 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 defined(POLARSSL_GCM_C) if( POLARSSL_MODE_GCM == ctx->cipher_info->mode ) return gcm_finish( ctx->cipher_ctx, tag, tag_len ); #endif 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 defined(POLARSSL_GCM_C) 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( 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_GCM_AUTH_FAILED ); return( 0 ); } #endif return( 0 ); } #endif /* POLARSSL_CIPHER_MODE_AEAD */ #if defined(POLARSSL_SELF_TEST) #include #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