md.c

00001 /**
00002  * \file mbedtls_md.c
00003  *
00004  * \brief Generic message digest wrapper for mbed TLS
00005  *
00006  * \author Adriaan de Jong <dejong@fox-it.com>
00007  *
00008  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
00009  *  SPDX-License-Identifier: Apache-2.0
00010  *
00011  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00012  *  not use this file except in compliance with the License.
00013  *  You may obtain a copy of the License at
00014  *
00015  *  http://www.apache.org/licenses/LICENSE-2.0
00016  *
00017  *  Unless required by applicable law or agreed to in writing, software
00018  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00019  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00020  *  See the License for the specific language governing permissions and
00021  *  limitations under the License.
00022  *
00023  *  This file is part of mbed TLS (https://tls.mbed.org)
00024  */
00025 
00026 #if !defined(MBEDTLS_CONFIG_FILE)
00027 #include "mbedtls/config.h"
00028 #else
00029 #include MBEDTLS_CONFIG_FILE
00030 #endif
00031 
00032 #if defined(MBEDTLS_MD_C)
00033 
00034 #include "mbedtls/md.h"
00035 #include "mbedtls/md_internal.h"
00036 
00037 #if defined(MBEDTLS_PLATFORM_C)
00038 #include "mbedtls/platform.h"
00039 #else
00040 #include <stdlib.h>
00041 #define mbedtls_calloc    calloc
00042 #define mbedtls_free       free
00043 #endif
00044 
00045 #include <string.h>
00046 
00047 #if defined(MBEDTLS_FS_IO)
00048 #include <stdio.h>
00049 #endif
00050 
00051 /* Implementation that should never be optimized out by the compiler */
00052 static void mbedtls_zeroize( void *v, size_t n ) {
00053     volatile unsigned char *p = v; while( n-- ) *p++ = 0;
00054 }
00055 
00056 /*
00057  * Reminder: update profiles in x509_crt.c when adding a new hash!
00058  */
00059 static const int supported_digests[] = {
00060 
00061 #if defined(MBEDTLS_SHA512_C)
00062         MBEDTLS_MD_SHA512,
00063         MBEDTLS_MD_SHA384,
00064 #endif
00065 
00066 #if defined(MBEDTLS_SHA256_C)
00067         MBEDTLS_MD_SHA256,
00068         MBEDTLS_MD_SHA224,
00069 #endif
00070 
00071 #if defined(MBEDTLS_SHA1_C)
00072         MBEDTLS_MD_SHA1,
00073 #endif
00074 
00075 #if defined(MBEDTLS_RIPEMD160_C)
00076         MBEDTLS_MD_RIPEMD160,
00077 #endif
00078 
00079 #if defined(MBEDTLS_MD5_C)
00080         MBEDTLS_MD_MD5,
00081 #endif
00082 
00083 #if defined(MBEDTLS_MD4_C)
00084         MBEDTLS_MD_MD4,
00085 #endif
00086 
00087 #if defined(MBEDTLS_MD2_C)
00088         MBEDTLS_MD_MD2,
00089 #endif
00090 
00091         MBEDTLS_MD_NONE
00092 };
00093 
00094 const int *mbedtls_md_list( void )
00095 {
00096     return( supported_digests );
00097 }
00098 
00099 const mbedtls_md_info_t *mbedtls_md_info_from_string( const char *md_name )
00100 {
00101     if( NULL == md_name )
00102         return( NULL );
00103 
00104     /* Get the appropriate digest information */
00105 #if defined(MBEDTLS_MD2_C)
00106     if( !strcmp( "MD2", md_name ) )
00107         return mbedtls_md_info_from_type( MBEDTLS_MD_MD2 );
00108 #endif
00109 #if defined(MBEDTLS_MD4_C)
00110     if( !strcmp( "MD4", md_name ) )
00111         return mbedtls_md_info_from_type( MBEDTLS_MD_MD4 );
00112 #endif
00113 #if defined(MBEDTLS_MD5_C)
00114     if( !strcmp( "MD5", md_name ) )
00115         return mbedtls_md_info_from_type( MBEDTLS_MD_MD5 );
00116 #endif
00117 #if defined(MBEDTLS_RIPEMD160_C)
00118     if( !strcmp( "RIPEMD160", md_name ) )
00119         return mbedtls_md_info_from_type( MBEDTLS_MD_RIPEMD160 );
00120 #endif
00121 #if defined(MBEDTLS_SHA1_C)
00122     if( !strcmp( "SHA1", md_name ) || !strcmp( "SHA", md_name ) )
00123         return mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 );
00124 #endif
00125 #if defined(MBEDTLS_SHA256_C)
00126     if( !strcmp( "SHA224", md_name ) )
00127         return mbedtls_md_info_from_type( MBEDTLS_MD_SHA224 );
00128     if( !strcmp( "SHA256", md_name ) )
00129         return mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 );
00130 #endif
00131 #if defined(MBEDTLS_SHA512_C)
00132     if( !strcmp( "SHA384", md_name ) )
00133         return mbedtls_md_info_from_type( MBEDTLS_MD_SHA384 );
00134     if( !strcmp( "SHA512", md_name ) )
00135         return mbedtls_md_info_from_type( MBEDTLS_MD_SHA512 );
00136 #endif
00137     return( NULL );
00138 }
00139 
00140 const mbedtls_md_info_t *mbedtls_md_info_from_type( mbedtls_md_type_t md_type )
00141 {
00142     switch( md_type )
00143     {
00144 #if defined(MBEDTLS_MD2_C)
00145         case MBEDTLS_MD_MD2:
00146             return( &mbedtls_md2_info );
00147 #endif
00148 #if defined(MBEDTLS_MD4_C)
00149         case MBEDTLS_MD_MD4:
00150             return( &mbedtls_md4_info );
00151 #endif
00152 #if defined(MBEDTLS_MD5_C)
00153         case MBEDTLS_MD_MD5:
00154             return( &mbedtls_md5_info );
00155 #endif
00156 #if defined(MBEDTLS_RIPEMD160_C)
00157         case MBEDTLS_MD_RIPEMD160:
00158             return( &mbedtls_ripemd160_info );
00159 #endif
00160 #if defined(MBEDTLS_SHA1_C)
00161         case MBEDTLS_MD_SHA1:
00162             return( &mbedtls_sha1_info );
00163 #endif
00164 #if defined(MBEDTLS_SHA256_C)
00165         case MBEDTLS_MD_SHA224:
00166             return( &mbedtls_sha224_info );
00167         case MBEDTLS_MD_SHA256:
00168             return( &mbedtls_sha256_info );
00169 #endif
00170 #if defined(MBEDTLS_SHA512_C)
00171         case MBEDTLS_MD_SHA384:
00172             return( &mbedtls_sha384_info );
00173         case MBEDTLS_MD_SHA512:
00174             return( &mbedtls_sha512_info );
00175 #endif
00176         default:
00177             return( NULL );
00178     }
00179 }
00180 
00181 void mbedtls_md_init( mbedtls_md_context_t *ctx )
00182 {
00183     memset( ctx, 0, sizeof( mbedtls_md_context_t ) );
00184 }
00185 
00186 void mbedtls_md_free( mbedtls_md_context_t *ctx )
00187 {
00188     if( ctx == NULL || ctx->md_info == NULL )
00189         return;
00190 
00191     if( ctx->md_ctx != NULL )
00192         ctx->md_info->ctx_free_func( ctx->md_ctx );
00193 
00194     if( ctx->hmac_ctx != NULL )
00195     {
00196         mbedtls_zeroize( ctx->hmac_ctx, 2 * ctx->md_info->block_size );
00197         mbedtls_free( ctx->hmac_ctx );
00198     }
00199 
00200     mbedtls_zeroize( ctx, sizeof( mbedtls_md_context_t ) );
00201 }
00202 
00203 int mbedtls_md_clone( mbedtls_md_context_t *dst,
00204                       const mbedtls_md_context_t *src )
00205 {
00206     if( dst == NULL || dst->md_info == NULL ||
00207         src == NULL || src->md_info == NULL ||
00208         dst->md_info != src->md_info )
00209     {
00210         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00211     }
00212 
00213     dst->md_info->clone_func( dst->md_ctx, src->md_ctx );
00214 
00215     return( 0 );
00216 }
00217 
00218 #if ! defined(MBEDTLS_DEPRECATED_REMOVED)
00219 int mbedtls_md_init_ctx( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info )
00220 {
00221     return mbedtls_md_setup( ctx, md_info, 1 );
00222 }
00223 #endif
00224 
00225 int mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info, int hmac )
00226 {
00227     if( md_info == NULL || ctx == NULL )
00228         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00229 
00230     if( ( ctx->md_ctx = md_info->ctx_alloc_func() ) == NULL )
00231         return( MBEDTLS_ERR_MD_ALLOC_FAILED );
00232 
00233     if( hmac != 0 )
00234     {
00235         ctx->hmac_ctx = mbedtls_calloc( 2, md_info->block_size );
00236         if( ctx->hmac_ctx == NULL )
00237         {
00238             md_info->ctx_free_func( ctx->md_ctx );
00239             return( MBEDTLS_ERR_MD_ALLOC_FAILED );
00240         }
00241     }
00242 
00243     ctx->md_info = md_info;
00244 
00245     return( 0 );
00246 }
00247 
00248 int mbedtls_md_starts( mbedtls_md_context_t *ctx )
00249 {
00250     if( ctx == NULL || ctx->md_info == NULL )
00251         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00252 
00253     return( ctx->md_info->starts_func( ctx->md_ctx ) );
00254 }
00255 
00256 int mbedtls_md_update( mbedtls_md_context_t *ctx, const unsigned char *input, size_t ilen )
00257 {
00258     if( ctx == NULL || ctx->md_info == NULL )
00259         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00260 
00261     return( ctx->md_info->update_func( ctx->md_ctx, input, ilen ) );
00262 }
00263 
00264 int mbedtls_md_finish( mbedtls_md_context_t *ctx, unsigned char *output )
00265 {
00266     if( ctx == NULL || ctx->md_info == NULL )
00267         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00268 
00269     return( ctx->md_info->finish_func( ctx->md_ctx, output ) );
00270 }
00271 
00272 int mbedtls_md( const mbedtls_md_info_t *md_info, const unsigned char *input, size_t ilen,
00273             unsigned char *output )
00274 {
00275     if( md_info == NULL )
00276         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00277 
00278     return( md_info->digest_func( input, ilen, output ) );
00279 }
00280 
00281 #if defined(MBEDTLS_FS_IO)
00282 int mbedtls_md_file( const mbedtls_md_info_t *md_info, const char *path, unsigned char *output )
00283 {
00284     int ret;
00285     FILE *f;
00286     size_t n;
00287     mbedtls_md_context_t ctx;
00288     unsigned char buf[1024];
00289 
00290     if( md_info == NULL )
00291         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00292 
00293     if( ( f = fopen( path, "rb" ) ) == NULL )
00294         return( MBEDTLS_ERR_MD_FILE_IO_ERROR );
00295 
00296     mbedtls_md_init( &ctx );
00297 
00298     if( ( ret = mbedtls_md_setup( &ctx, md_info, 0 ) ) != 0 )
00299         goto cleanup;
00300 
00301     if( ( ret = md_info->starts_func( ctx.md_ctx ) ) != 0 )
00302         goto cleanup;
00303 
00304     while( ( n = fread( buf, 1, sizeof( buf ), f ) ) > 0 )
00305         if( ( ret = md_info->update_func( ctx.md_ctx, buf, n ) ) != 0 )
00306             goto cleanup;
00307 
00308     if( ferror( f ) != 0 )
00309         ret = MBEDTLS_ERR_MD_FILE_IO_ERROR;
00310     else
00311         ret = md_info->finish_func( ctx.md_ctx, output );
00312 
00313 cleanup:
00314     mbedtls_zeroize( buf, sizeof( buf ) );
00315     fclose( f );
00316     mbedtls_md_free( &ctx );
00317 
00318     return( ret );
00319 }
00320 #endif /* MBEDTLS_FS_IO */
00321 
00322 int mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const unsigned char *key, size_t keylen )
00323 {
00324     int ret;
00325     unsigned char sum[MBEDTLS_MD_MAX_SIZE];
00326     unsigned char *ipad, *opad;
00327     size_t i;
00328 
00329     if( ctx == NULL || ctx->md_info == NULL || ctx->hmac_ctx == NULL )
00330         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00331 
00332     if( keylen > (size_t) ctx->md_info->block_size )
00333     {
00334         if( ( ret = ctx->md_info->starts_func( ctx->md_ctx ) ) != 0 )
00335             goto cleanup;
00336         if( ( ret = ctx->md_info->update_func( ctx->md_ctx, key, keylen ) ) != 0 )
00337             goto cleanup;
00338         if( ( ret = ctx->md_info->finish_func( ctx->md_ctx, sum ) ) != 0 )
00339             goto cleanup;
00340 
00341         keylen = ctx->md_info->size;
00342         key = sum;
00343     }
00344 
00345     ipad = (unsigned char *) ctx->hmac_ctx;
00346     opad = (unsigned char *) ctx->hmac_ctx + ctx->md_info->block_size;
00347 
00348     memset( ipad, 0x36, ctx->md_info->block_size );
00349     memset( opad, 0x5C, ctx->md_info->block_size );
00350 
00351     for( i = 0; i < keylen; i++ )
00352     {
00353         ipad[i] = (unsigned char)( ipad[i] ^ key[i] );
00354         opad[i] = (unsigned char)( opad[i] ^ key[i] );
00355     }
00356 
00357     if( ( ret = ctx->md_info->starts_func( ctx->md_ctx ) ) != 0 )
00358         goto cleanup;
00359     if( ( ret = ctx->md_info->update_func( ctx->md_ctx, ipad,
00360                                            ctx->md_info->block_size ) ) != 0 )
00361         goto cleanup;
00362 
00363 cleanup:
00364     mbedtls_zeroize( sum, sizeof( sum ) );
00365 
00366     return( ret );
00367 }
00368 
00369 int mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const unsigned char *input, size_t ilen )
00370 {
00371     if( ctx == NULL || ctx->md_info == NULL || ctx->hmac_ctx == NULL )
00372         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00373 
00374     return( ctx->md_info->update_func( ctx->md_ctx, input, ilen ) );
00375 }
00376 
00377 int mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, unsigned char *output )
00378 {
00379     int ret;
00380     unsigned char tmp[MBEDTLS_MD_MAX_SIZE];
00381     unsigned char *opad;
00382 
00383     if( ctx == NULL || ctx->md_info == NULL || ctx->hmac_ctx == NULL )
00384         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00385 
00386     opad = (unsigned char *) ctx->hmac_ctx + ctx->md_info->block_size;
00387 
00388     if( ( ret = ctx->md_info->finish_func( ctx->md_ctx, tmp ) ) != 0 )
00389         return( ret );
00390     if( ( ret = ctx->md_info->starts_func( ctx->md_ctx ) ) != 0 )
00391         return( ret );
00392     if( ( ret = ctx->md_info->update_func( ctx->md_ctx, opad,
00393                                            ctx->md_info->block_size ) ) != 0 )
00394         return( ret );
00395     if( ( ret = ctx->md_info->update_func( ctx->md_ctx, tmp,
00396                                            ctx->md_info->size ) ) != 0 )
00397         return( ret );
00398     return( ctx->md_info->finish_func( ctx->md_ctx, output ) );
00399 }
00400 
00401 int mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx )
00402 {
00403     int ret;
00404     unsigned char *ipad;
00405 
00406     if( ctx == NULL || ctx->md_info == NULL || ctx->hmac_ctx == NULL )
00407         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00408 
00409     ipad = (unsigned char *) ctx->hmac_ctx;
00410 
00411     if( ( ret = ctx->md_info->starts_func( ctx->md_ctx ) ) != 0 )
00412         return( ret );
00413     return( ctx->md_info->update_func( ctx->md_ctx, ipad,
00414                                        ctx->md_info->block_size ) );
00415 }
00416 
00417 int mbedtls_md_hmac( const mbedtls_md_info_t *md_info,
00418                      const unsigned char *key, size_t keylen,
00419                      const unsigned char *input, size_t ilen,
00420                      unsigned char *output )
00421 {
00422     mbedtls_md_context_t ctx;
00423     int ret;
00424 
00425     if( md_info == NULL )
00426         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00427 
00428     mbedtls_md_init( &ctx );
00429 
00430     if( ( ret = mbedtls_md_setup( &ctx, md_info, 1 ) ) != 0 )
00431         goto cleanup;
00432 
00433     if( ( ret = mbedtls_md_hmac_starts( &ctx, key, keylen ) ) != 0 )
00434         goto cleanup;
00435     if( ( ret = mbedtls_md_hmac_update( &ctx, input, ilen ) ) != 0 )
00436         goto cleanup;
00437     if( ( ret = mbedtls_md_hmac_finish( &ctx, output ) ) != 0 )
00438         goto cleanup;
00439 
00440 cleanup:
00441     mbedtls_md_free( &ctx );
00442 
00443     return( ret );
00444 }
00445 
00446 int mbedtls_md_process( mbedtls_md_context_t *ctx, const unsigned char *data )
00447 {
00448     if( ctx == NULL || ctx->md_info == NULL )
00449         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
00450 
00451     return( ctx->md_info->process_func( ctx->md_ctx, data ) );
00452 }
00453 
00454 unsigned char mbedtls_md_get_size( const mbedtls_md_info_t *md_info )
00455 {
00456     if( md_info == NULL )
00457         return( 0 );
00458 
00459     return md_info->size;
00460 }
00461 
00462 mbedtls_md_type_t mbedtls_md_get_type( const mbedtls_md_info_t *md_info )
00463 {
00464     if( md_info == NULL )
00465         return( MBEDTLS_MD_NONE );
00466 
00467     return md_info->type;
00468 }
00469 
00470 const char *mbedtls_md_get_name( const mbedtls_md_info_t *md_info )
00471 {
00472     if( md_info == NULL )
00473         return( NULL );
00474 
00475     return md_info->name;
00476 }
00477 
00478 #endif /* MBEDTLS_MD_C */