Hannes Tschofenig
/
aes-gcm-test-program
Example program to test AES-GCM functionality. Used for a workshop
SSL/library/cipher.c
- Committer:
- HannesTschofenig
- Date:
- 2018-09-27
- Revision:
- 0:796d0f61a05b
File content as of revision 0:796d0f61a05b:
/** * \file cipher.c * * \brief Generic cipher wrapper for PolarSSL * * \author Adriaan de Jong <dejong@fox-it.com> * * Copyright (C) 2006-2014, Brainspark B.V. * * This file is part of PolarSSL (http://www.polarssl.org) * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #if !defined(POLARSSL_CONFIG_FILE) #include "polarssl/config.h" #else #include POLARSSL_CONFIG_FILE #endif #if defined(POLARSSL_CIPHER_C) #include "polarssl/cipher.h" #include "polarssl/cipher_wrap.h" #if defined(POLARSSL_GCM_C) #include "polarssl/gcm.h" #endif #include <stdlib.h> #if defined(POLARSSL_ARC4_C) || defined(POLARSSL_CIPHER_NULL_CIPHER) #define POLARSSL_CIPHER_MODE_STREAM #endif #if defined(_MSC_VER) && !defined strcasecmp && !defined(EFIX64) && \ !defined(EFI32) #define strcasecmp _stricmp #endif static int supported_init = 0; const int *cipher_list( void ) { const cipher_definition_t *def; int *type; if( ! supported_init ) { def = cipher_definitions; type = supported_ciphers; while( def->type != 0 ) *type++ = (*def++).type; *type = 0; supported_init = 1; } return supported_ciphers; } const cipher_info_t *cipher_info_from_type( const cipher_type_t cipher_type ) { const cipher_definition_t *def; for( def = cipher_definitions; def->info != NULL; def++ ) if( def->type == cipher_type ) return( def->info ); return NULL; } const cipher_info_t *cipher_info_from_string( const char *cipher_name ) { const cipher_definition_t *def; if( NULL == cipher_name ) return NULL; for( def = cipher_definitions; def->info != NULL; def++ ) if( ! strcasecmp( def->info->name, cipher_name ) ) return( def->info ); return NULL; } const cipher_info_t *cipher_info_from_values( const cipher_id_t cipher_id, int key_length, const cipher_mode_t mode ) { const cipher_definition_t *def; for( def = cipher_definitions; def->info != NULL; def++ ) if( def->info->base->cipher == cipher_id && def->info->key_length == (unsigned) key_length && def->info->mode == mode ) return( def->info ); return NULL; } int cipher_init_ctx( cipher_context_t *ctx, const cipher_info_t *cipher_info ) { if( NULL == cipher_info || NULL == ctx ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; memset( ctx, 0, sizeof( cipher_context_t ) ); if( NULL == ( ctx->cipher_ctx = cipher_info->base->ctx_alloc_func() ) ) return POLARSSL_ERR_CIPHER_ALLOC_FAILED; ctx->cipher_info = cipher_info; #if defined(POLARSSL_CIPHER_MODE_WITH_PADDING) /* * Ignore possible errors caused by a cipher mode that doesn't use padding */ #if defined(POLARSSL_CIPHER_PADDING_PKCS7) (void) cipher_set_padding_mode( ctx, POLARSSL_PADDING_PKCS7 ); #else (void) cipher_set_padding_mode( ctx, POLARSSL_PADDING_NONE ); #endif #endif /* POLARSSL_CIPHER_MODE_WITH_PADDING */ return 0; } 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; if( (int) ctx->cipher_info->key_length != key_length ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; ctx->key_length = key_length; ctx->operation = operation; /* * For CFB and CTR mode always use the encryption key schedule */ if( POLARSSL_ENCRYPT == operation || POLARSSL_MODE_CFB == ctx->cipher_info->mode || POLARSSL_MODE_CTR == ctx->cipher_info->mode ) { return ctx->cipher_info->base->setkey_enc_func( ctx->cipher_ctx, key, ctx->key_length ); } if( POLARSSL_DECRYPT == operation ) return ctx->cipher_info->base->setkey_dec_func( ctx->cipher_ctx, key, ctx->key_length ); return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; } int cipher_set_iv( cipher_context_t *ctx, const unsigned char *iv, size_t iv_len ) { size_t actual_iv_size; if( NULL == ctx || NULL == ctx->cipher_info || NULL == iv ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; /* avoid buffer overflow in ctx->iv */ if( iv_len > POLARSSL_MAX_IV_LENGTH ) return POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE; if( ctx->cipher_info->accepts_variable_iv_size ) actual_iv_size = iv_len; else { actual_iv_size = ctx->cipher_info->iv_size; /* avoid reading past the end of input buffer */ if( actual_iv_size > iv_len ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; } memcpy( ctx->iv, iv, actual_iv_size ); ctx->iv_size = actual_iv_size; return 0; } int cipher_reset( cipher_context_t *ctx ) { if( NULL == ctx || NULL == ctx->cipher_info ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; ctx->unprocessed_len = 0; return 0; } #if defined(POLARSSL_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( (gcm_context *) 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; if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen ) { return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; } *olen = 0; if( ctx->cipher_info->mode == POLARSSL_MODE_ECB ) { if( ilen != cipher_get_block_size( ctx ) ) return POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED; *olen = ilen; if( 0 != ( ret = ctx->cipher_info->base->ecb_func( ctx->cipher_ctx, ctx->operation, input, output ) ) ) { return ret; } return 0; } #if defined(POLARSSL_GCM_C) if( ctx->cipher_info->mode == POLARSSL_MODE_GCM ) { *olen = ilen; return gcm_update( (gcm_context *) ctx->cipher_ctx, ilen, input, output ); } #endif if( input == output && ( ctx->unprocessed_len != 0 || ilen % cipher_get_block_size( ctx ) ) ) { return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; } #if defined(POLARSSL_CIPHER_MODE_CBC) if( ctx->cipher_info->mode == POLARSSL_MODE_CBC ) { size_t copy_len = 0; /* * If there is not enough data for a full block, cache it. */ if( ( ctx->operation == POLARSSL_DECRYPT && ilen + ctx->unprocessed_len <= cipher_get_block_size( ctx ) ) || ( ctx->operation == POLARSSL_ENCRYPT && ilen + ctx->unprocessed_len < cipher_get_block_size( ctx ) ) ) { memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input, ilen ); ctx->unprocessed_len += ilen; return 0; } /* * Process cached data first */ if( ctx->unprocessed_len != 0 ) { copy_len = cipher_get_block_size( ctx ) - ctx->unprocessed_len; memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input, copy_len ); if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx, ctx->operation, cipher_get_block_size( ctx ), ctx->iv, ctx->unprocessed_data, output ) ) ) { return ret; } *olen += cipher_get_block_size( ctx ); output += cipher_get_block_size( ctx ); ctx->unprocessed_len = 0; input += copy_len; ilen -= copy_len; } /* * Cache final, incomplete block */ if( 0 != ilen ) { copy_len = ilen % cipher_get_block_size( ctx ); if( copy_len == 0 && ctx->operation == POLARSSL_DECRYPT ) copy_len = cipher_get_block_size(ctx); memcpy( ctx->unprocessed_data, &( input[ilen - copy_len] ), copy_len ); ctx->unprocessed_len += copy_len; ilen -= copy_len; } /* * Process remaining full blocks */ if( ilen ) { if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx, ctx->operation, ilen, ctx->iv, input, output ) ) ) { return ret; } *olen += ilen; } return 0; } #endif /* POLARSSL_CIPHER_MODE_CBC */ #if defined(POLARSSL_CIPHER_MODE_CFB) if( ctx->cipher_info->mode == POLARSSL_MODE_CFB ) { if( 0 != ( ret = ctx->cipher_info->base->cfb_func( ctx->cipher_ctx, ctx->operation, ilen, &ctx->unprocessed_len, ctx->iv, input, output ) ) ) { return ret; } *olen = ilen; return 0; } #endif /* POLARSSL_CIPHER_MODE_CFB */ #if defined(POLARSSL_CIPHER_MODE_CTR) if( ctx->cipher_info->mode == POLARSSL_MODE_CTR ) { if( 0 != ( ret = ctx->cipher_info->base->ctr_func( ctx->cipher_ctx, ilen, &ctx->unprocessed_len, ctx->iv, ctx->unprocessed_data, input, output ) ) ) { return ret; } *olen = ilen; return 0; } #endif /* POLARSSL_CIPHER_MODE_CTR */ #if defined(POLARSSL_CIPHER_MODE_STREAM) if( ctx->cipher_info->mode == POLARSSL_MODE_STREAM ) { if( 0 != ( ret = ctx->cipher_info->base->stream_func( ctx->cipher_ctx, ilen, input, output ) ) ) { return ret; } *olen = ilen; return 0; } #endif /* POLARSSL_CIPHER_MODE_STREAM */ return POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE; } #if defined(POLARSSL_CIPHER_MODE_WITH_PADDING) #if defined(POLARSSL_CIPHER_PADDING_PKCS7) /* * PKCS7 (and PKCS5) padding: fill with ll bytes, with ll = padding_len */ static void add_pkcs_padding( unsigned char *output, size_t output_len, size_t data_len ) { size_t padding_len = output_len - data_len; unsigned char i; for( i = 0; i < padding_len; i++ ) output[data_len + i] = (unsigned char) padding_len; } static int get_pkcs_padding( unsigned char *input, size_t input_len, size_t *data_len ) { size_t i, pad_idx; unsigned char padding_len, bad = 0; if( NULL == input || NULL == data_len ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; padding_len = input[input_len - 1]; *data_len = input_len - padding_len; /* Avoid logical || since it results in a branch */ bad |= padding_len > input_len; bad |= padding_len == 0; /* The number of bytes checked must be independent of padding_len, * so pick input_len, which is usually 8 or 16 (one block) */ pad_idx = input_len - padding_len; for( i = 0; i < input_len; i++ ) bad |= ( input[i] ^ padding_len ) * ( i >= pad_idx ); return POLARSSL_ERR_CIPHER_INVALID_PADDING * (bad != 0); } #endif /* POLARSSL_CIPHER_PADDING_PKCS7 */ #if defined(POLARSSL_CIPHER_PADDING_ONE_AND_ZEROS) /* * One and zeros padding: fill with 80 00 ... 00 */ static void add_one_and_zeros_padding( unsigned char *output, size_t output_len, size_t data_len ) { size_t padding_len = output_len - data_len; unsigned char i = 0; output[data_len] = 0x80; for( i = 1; i < padding_len; i++ ) output[data_len + i] = 0x00; } static int get_one_and_zeros_padding( unsigned char *input, size_t input_len, size_t *data_len ) { size_t i; unsigned char done = 0, prev_done, bad; if( NULL == input || NULL == data_len ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; bad = 0xFF; *data_len = 0; for( i = input_len; i > 0; i-- ) { prev_done = done; done |= ( input[i-1] != 0 ); *data_len |= ( i - 1 ) * ( done != prev_done ); bad &= ( input[i-1] ^ 0x80 ) | ( done == prev_done ); } return POLARSSL_ERR_CIPHER_INVALID_PADDING * (bad != 0); } #endif /* POLARSSL_CIPHER_PADDING_ONE_AND_ZEROS */ #if defined(POLARSSL_CIPHER_PADDING_ZEROS_AND_LEN) /* * Zeros and len padding: fill with 00 ... 00 ll, where ll is padding length */ static void add_zeros_and_len_padding( unsigned char *output, size_t output_len, size_t data_len ) { size_t padding_len = output_len - data_len; unsigned char i = 0; for( i = 1; i < padding_len; i++ ) output[data_len + i - 1] = 0x00; output[output_len - 1] = (unsigned char) padding_len; } static int get_zeros_and_len_padding( unsigned char *input, size_t input_len, size_t *data_len ) { size_t i, pad_idx; unsigned char padding_len, bad = 0; if( NULL == input || NULL == data_len ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; padding_len = input[input_len - 1]; *data_len = input_len - padding_len; /* Avoid logical || since it results in a branch */ bad |= padding_len > input_len; bad |= padding_len == 0; /* The number of bytes checked must be independent of padding_len */ pad_idx = input_len - padding_len; for( i = 0; i < input_len - 1; i++ ) bad |= input[i] * ( i >= pad_idx ); return POLARSSL_ERR_CIPHER_INVALID_PADDING * (bad != 0); } #endif /* POLARSSL_CIPHER_PADDING_ZEROS_AND_LEN */ #if defined(POLARSSL_CIPHER_PADDING_ZEROS) /* * Zero padding: fill with 00 ... 00 */ static void add_zeros_padding( unsigned char *output, size_t output_len, size_t data_len ) { size_t i; for( i = data_len; i < output_len; i++ ) output[i] = 0x00; } static int get_zeros_padding( unsigned char *input, size_t input_len, size_t *data_len ) { size_t i; unsigned char done = 0, prev_done; if( NULL == input || NULL == data_len ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; *data_len = 0; for( i = input_len; i > 0; i-- ) { prev_done = done; done |= ( input[i-1] != 0 ); *data_len |= i * ( done != prev_done ); } return 0; } #endif /* POLARSSL_CIPHER_PADDING_ZEROS */ /* * No padding: don't pad :) * * There is no add_padding function (check for NULL in cipher_finish) * but a trivial get_padding function */ static int get_no_padding( unsigned char *input, size_t input_len, size_t *data_len ) { if( NULL == input || NULL == data_len ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; *data_len = input_len; return 0; } #endif /* POLARSSL_CIPHER_MODE_WITH_PADDING */ int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen ) { if( NULL == ctx || NULL == ctx->cipher_info || NULL == olen ) return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; *olen = 0; if( POLARSSL_MODE_CFB == ctx->cipher_info->mode || POLARSSL_MODE_CTR == ctx->cipher_info->mode || POLARSSL_MODE_GCM == ctx->cipher_info->mode || POLARSSL_MODE_STREAM == ctx->cipher_info->mode ) { return 0; } if( POLARSSL_MODE_ECB == ctx->cipher_info->mode ) { if( ctx->unprocessed_len != 0 ) return POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED; return 0; } #if defined(POLARSSL_CIPHER_MODE_CBC) if( POLARSSL_MODE_CBC == ctx->cipher_info->mode ) { int ret = 0; if( POLARSSL_ENCRYPT == ctx->operation ) { /* check for 'no padding' mode */ if( NULL == ctx->add_padding ) { if( 0 != ctx->unprocessed_len ) return POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED; return 0; } ctx->add_padding( ctx->unprocessed_data, cipher_get_iv_size( ctx ), ctx->unprocessed_len ); } else if ( cipher_get_block_size( ctx ) != ctx->unprocessed_len ) { /* * For decrypt operations, expect a full block, * or an empty block if no padding */ if( NULL == ctx->add_padding && 0 == ctx->unprocessed_len ) return 0; return POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED; } /* cipher block */ if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx, ctx->operation, cipher_get_block_size( ctx ), ctx->iv, ctx->unprocessed_data, output ) ) ) { return ret; } /* Set output size for decryption */ if( POLARSSL_DECRYPT == ctx->operation ) return ctx->get_padding( output, cipher_get_block_size( ctx ), olen ); /* Set output size for encryption */ *olen = cipher_get_block_size( ctx ); return 0; } #else ((void) output); #endif /* POLARSSL_CIPHER_MODE_CBC */ return POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE; } #if defined(POLARSSL_CIPHER_MODE_WITH_PADDING) int cipher_set_padding_mode( cipher_context_t *ctx, cipher_padding_t mode ) { if( NULL == ctx || POLARSSL_MODE_CBC != ctx->cipher_info->mode ) { return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; } switch( mode ) { #if defined(POLARSSL_CIPHER_PADDING_PKCS7) case POLARSSL_PADDING_PKCS7: ctx->add_padding = add_pkcs_padding; ctx->get_padding = get_pkcs_padding; break; #endif #if defined(POLARSSL_CIPHER_PADDING_ONE_AND_ZEROS) case POLARSSL_PADDING_ONE_AND_ZEROS: ctx->add_padding = add_one_and_zeros_padding; ctx->get_padding = get_one_and_zeros_padding; break; #endif #if defined(POLARSSL_CIPHER_PADDING_ZEROS_AND_LEN) case POLARSSL_PADDING_ZEROS_AND_LEN: ctx->add_padding = add_zeros_and_len_padding; ctx->get_padding = get_zeros_and_len_padding; break; #endif #if defined(POLARSSL_CIPHER_PADDING_ZEROS) case POLARSSL_PADDING_ZEROS: ctx->add_padding = add_zeros_padding; ctx->get_padding = get_zeros_padding; break; #endif case POLARSSL_PADDING_NONE: ctx->add_padding = NULL; ctx->get_padding = get_no_padding; break; default: return POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE; } return 0; } #endif /* POLARSSL_CIPHER_MODE_WITH_PADDING */ #if defined(POLARSSL_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( (gcm_context *) 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( (gcm_context *) ctx->cipher_ctx, check_tag, tag_len ) ) ) { return( ret ); } /* Check the tag in "constant-time" */ for( diff = 0, i = 0; i < tag_len; i++ ) diff |= tag[i] ^ check_tag[i]; if( diff != 0 ) return( POLARSSL_ERR_CIPHER_AUTH_FAILED ); return( 0 ); } #endif /* POLARSSL_GCM_C */ return( 0 ); } #endif /* POLARSSL_CIPHER_MODE_AEAD */ #if defined(POLARSSL_SELF_TEST) /* * Checkup routine */ int cipher_self_test( int verbose ) { ((void) verbose); return( 0 ); } #endif /* POLARSSL_SELF_TEST */ #endif /* POLARSSL_CIPHER_C */