src/libpolarssl/pkcs5.c

   1 /**
   2  * \file pkcs5.c
   3  *
   4  * \brief PKCS#5 functions
   5  *
   6  * \author Mathias Olsson <mathias@kompetensum.com>
   7  *
   8  *  Copyright (C) 2006-2014, Brainspark B.V.
   9  *
  10  *  This file is part of PolarSSL (http://www.polarssl.org)
  11  *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
  12  *
  13  *  All rights reserved.
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License as published by
  17  *  the Free Software Foundation; either version 2 of the License, or
  18  *  (at your option) any later version.
  19  *
  20  *  This program is distributed in the hope that it will be useful,
  21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *  GNU General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License along
  26  *  with this program; if not, write to the Free Software Foundation, Inc.,
  27  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  28  */
  29 /*
  30  * PKCS#5 includes PBKDF2 and more
  31  *
  32  * http://tools.ietf.org/html/rfc2898 (Specification)
  33  * http://tools.ietf.org/html/rfc6070 (Test vectors)
  34  */
  35
  36 #if !defined(POLARSSL_CONFIG_FILE)
  37 #include "config.h"
  38 #else
  39 #include POLARSSL_CONFIG_FILE
  40 #endif
  41
  42 #if defined(POLARSSL_PKCS5_C)
  43
  44 #include "pkcs5.h"
  45 #include "asn1.h"
  46 #include "cipher.h"
  47 #include "oid.h"
  48
  49 #if defined(POLARSSL_PLATFORM_C)
  50 #include "platform.h"
  51 #else
  52 #define polarssl_printf printf
  53 #endif
  54
  55 static int pkcs5_parse_pbkdf2_params( asn1_buf *params,
  56                                       asn1_buf *salt, int *iterations,
  57                                       int *keylen, md_type_t *md_type )
  58 {
  59     int ret;
  60     asn1_buf prf_alg_oid;
  61     unsigned char **p = &params->p;
  62     const unsigned char *end = params->p + params->len;
  63
  64     if( params->tag != ( ASN1_CONSTRUCTED | ASN1_SEQUENCE ) )
  65         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT +
  66                 POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
  67     /*
  68      *  PBKDF2-params ::= SEQUENCE {
  69      *    salt              OCTET STRING,
  70      *    iterationCount    INTEGER,
  71      *    keyLength         INTEGER OPTIONAL
  72      *    prf               AlgorithmIdentifier DEFAULT algid-hmacWithSHA1
  73      *  }
  74      *
  75      */
  76     if( ( ret = asn1_get_tag( p, end, &salt->len, ASN1_OCTET_STRING ) ) != 0 )
  77         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
  78
  79     salt->p = *p;
  80     *p += salt->len;
  81
  82     if( ( ret = asn1_get_int( p, end, iterations ) ) != 0 )
  83         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
  84
  85     if( *p == end )
  86         return( 0 );
  87
  88     if( ( ret = asn1_get_int( p, end, keylen ) ) != 0 )
  89     {
  90         if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
  91             return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
  92     }
  93
  94     if( *p == end )
  95         return( 0 );
  96
  97     if( ( ret = asn1_get_alg_null( p, end, &prf_alg_oid ) ) != 0 )
  98         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
  99
 100     if( !OID_CMP( OID_HMAC_SHA1, &prf_alg_oid ) )
 101         return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
 102
 103     *md_type = POLARSSL_MD_SHA1;
 104
 105     if( *p != end )
 106         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT +
 107                 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
 108
 109     return( 0 );
 110 }
 111
 112 int pkcs5_pbes2( asn1_buf *pbe_params, int mode,
 113                  const unsigned char *pwd,  size_t pwdlen,
 114                  const unsigned char *data, size_t datalen,
 115                  unsigned char *output )
 116 {
 117     int ret, iterations = 0, keylen = 0;
 118     unsigned char *p, *end;
 119     asn1_buf kdf_alg_oid, enc_scheme_oid, kdf_alg_params, enc_scheme_params;
 120     asn1_buf salt;
 121     md_type_t md_type = POLARSSL_MD_SHA1;
 122     unsigned char key[32], iv[32];
 123     size_t olen = 0;
 124     const md_info_t *md_info;
 125     const cipher_info_t *cipher_info;
 126     md_context_t md_ctx;
 127     cipher_type_t cipher_alg;
 128     cipher_context_t cipher_ctx;
 129
 130     p = pbe_params->p;
 131     end = p + pbe_params->len;
 132
 133     memset( &md_ctx, 0, sizeof(md_context_t) );
 134     memset( &cipher_ctx, 0, sizeof(cipher_context_t) );
 135
 136     /*
 137      *  PBES2-params ::= SEQUENCE {
 138      *    keyDerivationFunc AlgorithmIdentifier {{PBES2-KDFs}},
 139      *    encryptionScheme AlgorithmIdentifier {{PBES2-Encs}}
 140      *  }
 141      */
 142     if( pbe_params->tag != ( ASN1_CONSTRUCTED | ASN1_SEQUENCE ) )
 143         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT +
 144                 POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
 145
 146     if( ( ret = asn1_get_alg( &p, end, &kdf_alg_oid, &kdf_alg_params ) ) != 0 )
 147         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
 148
 149     // Only PBKDF2 supported at the moment
 150     //
 151     if( !OID_CMP( OID_PKCS5_PBKDF2, &kdf_alg_oid ) )
 152         return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
 153
 154     if( ( ret = pkcs5_parse_pbkdf2_params( &kdf_alg_params,
 155                                            &salt, &iterations, &keylen,
 156                                            &md_type ) ) != 0 )
 157     {
 158         return( ret );
 159     }
 160
 161     md_info = md_info_from_type( md_type );
 162     if( md_info == NULL )
 163         return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
 164
 165     if( ( ret = asn1_get_alg( &p, end, &enc_scheme_oid,
 166                               &enc_scheme_params ) ) != 0 )
 167     {
 168         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
 169     }
 170
 171     if ( oid_get_cipher_alg( &enc_scheme_oid, &cipher_alg ) != 0 )
 172         return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
 173
 174     cipher_info = cipher_info_from_type( cipher_alg );
 175     if( cipher_info == NULL )
 176         return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
 177
 178     keylen = cipher_info->key_length / 8;
 179
 180     if( enc_scheme_params.tag != ASN1_OCTET_STRING ||
 181         enc_scheme_params.len != cipher_info->iv_size )
 182     {
 183         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT );
 184     }
 185
 186     memcpy( iv, enc_scheme_params.p, enc_scheme_params.len );
 187
 188     if( ( ret = md_init_ctx( &md_ctx, md_info ) ) != 0 )
 189         goto exit;
 190
 191     if ( ( ret = pkcs5_pbkdf2_hmac( &md_ctx, pwd, pwdlen, salt.p, salt.len,
 192                                     iterations, keylen, key ) ) != 0 )
 193     {
 194         goto exit;
 195     }
 196
 197     if( ( ret = cipher_init_ctx( &cipher_ctx, cipher_info ) ) != 0 )
 198         goto exit;
 199
 200     if( ( ret = cipher_setkey( &cipher_ctx, key, 8 * keylen, mode ) ) != 0 )
 201         goto exit;
 202
 203     if( ( ret = cipher_set_iv( &cipher_ctx, iv, enc_scheme_params.len ) ) != 0 )
 204         goto exit;
 205
 206     if( ( ret = cipher_reset( &cipher_ctx ) ) != 0 )
 207         goto exit;
 208
 209     if( ( ret = cipher_update( &cipher_ctx, data, datalen,
 210                                 output, &olen ) ) != 0 )
 211     {
 212         goto exit;
 213     }
 214
 215     if( ( ret = cipher_finish( &cipher_ctx, output + olen, &olen ) ) != 0 )
 216         ret = POLARSSL_ERR_PKCS5_PASSWORD_MISMATCH;
 217
 218 exit:
 219     md_free_ctx( &md_ctx );
 220     cipher_free_ctx( &cipher_ctx );
 221
 222     return( ret );
 223 }
 224
 225 int pkcs5_pbkdf2_hmac( md_context_t *ctx, const unsigned char *password,
 226                        size_t plen, const unsigned char *salt, size_t slen,
 227                        unsigned int iteration_count,
 228                        uint32_t key_length, unsigned char *output )
 229 {
 230     int ret, j;
 231     unsigned int i;
 232     unsigned char md1[POLARSSL_MD_MAX_SIZE];
 233     unsigned char work[POLARSSL_MD_MAX_SIZE];
 234     unsigned char md_size = md_get_size( ctx->md_info );
 235     size_t use_len;
 236     unsigned char *out_p = output;
 237     unsigned char counter[4];
 238
 239     memset( counter, 0, 4 );
 240     counter[3] = 1;
 241
 242     if( iteration_count > 0xFFFFFFFF )
 243         return( POLARSSL_ERR_PKCS5_BAD_INPUT_DATA );
 244
 245     while( key_length )
 246     {
 247         // U1 ends up in work
 248         //
 249         if( ( ret = md_hmac_starts( ctx, password, plen ) ) != 0 )
 250             return( ret );
 251
 252         if( ( ret = md_hmac_update( ctx, salt, slen ) ) != 0 )
 253             return( ret );
 254
 255         if( ( ret = md_hmac_update( ctx, counter, 4 ) ) != 0 )
 256             return( ret );
 257
 258         if( ( ret = md_hmac_finish( ctx, work ) ) != 0 )
 259             return( ret );
 260
 261         memcpy( md1, work, md_size );
 262
 263         for ( i = 1; i < iteration_count; i++ )
 264         {
 265             // U2 ends up in md1
 266             //
 267             if( ( ret = md_hmac_starts( ctx, password, plen ) ) != 0 )
 268                 return( ret );
 269
 270             if( ( ret = md_hmac_update( ctx, md1, md_size ) ) != 0 )
 271                 return( ret );
 272
 273             if( ( ret = md_hmac_finish( ctx, md1 ) ) != 0 )
 274                 return( ret );
 275
 276             // U1 xor U2
 277             //
 278             for( j = 0; j < md_size; j++ )
 279                 work[j] ^= md1[j];
 280         }
 281
 282         use_len = ( key_length < md_size ) ? key_length : md_size;
 283         memcpy( out_p, work, use_len );
 284
 285         key_length -= (uint32_t) use_len;
 286         out_p += use_len;
 287
 288         for( i = 4; i > 0; i-- )
 289             if( ++counter[i - 1] != 0 )
 290                 break;
 291     }
 292
 293     return( 0 );
 294 }
 295
 296 #if defined(POLARSSL_SELF_TEST)
 297
 298 #include <stdio.h>
 299
 300 #define MAX_TESTS   6
 301
 302 size_t plen[MAX_TESTS] =
 303     { 8, 8, 8, 8, 24, 9 };
 304
 305 unsigned char password[MAX_TESTS][32] =
 306 {
 307     "password",
 308     "password",
 309     "password",
 310     "password",
 311     "passwordPASSWORDpassword",
 312     "pass\0word",
 313 };
 314
 315 size_t slen[MAX_TESTS] =
 316     { 4, 4, 4, 4, 36, 5 };
 317
 318 unsigned char salt[MAX_TESTS][40] =
 319 {
 320     "salt",
 321     "salt",
 322     "salt",
 323     "salt",
 324     "saltSALTsaltSALTsaltSALTsaltSALTsalt",
 325     "sa\0lt",
 326 };
 327
 328 uint32_t it_cnt[MAX_TESTS] =
 329     { 1, 2, 4096, 16777216, 4096, 4096 };
 330
 331 uint32_t key_len[MAX_TESTS] =
 332     { 20, 20, 20, 20, 25, 16 };
 333
 334
 335 unsigned char result_key[MAX_TESTS][32] =
 336 {
 337     { 0x0c, 0x60, 0xc8, 0x0f, 0x96, 0x1f, 0x0e, 0x71,
 338       0xf3, 0xa9, 0xb5, 0x24, 0xaf, 0x60, 0x12, 0x06,
 339       0x2f, 0xe0, 0x37, 0xa6 },
 340     { 0xea, 0x6c, 0x01, 0x4d, 0xc7, 0x2d, 0x6f, 0x8c,
 341       0xcd, 0x1e, 0xd9, 0x2a, 0xce, 0x1d, 0x41, 0xf0,
 342       0xd8, 0xde, 0x89, 0x57 },
 343     { 0x4b, 0x00, 0x79, 0x01, 0xb7, 0x65, 0x48, 0x9a,
 344       0xbe, 0xad, 0x49, 0xd9, 0x26, 0xf7, 0x21, 0xd0,
 345       0x65, 0xa4, 0x29, 0xc1 },
 346     { 0xee, 0xfe, 0x3d, 0x61, 0xcd, 0x4d, 0xa4, 0xe4,
 347       0xe9, 0x94, 0x5b, 0x3d, 0x6b, 0xa2, 0x15, 0x8c,
 348       0x26, 0x34, 0xe9, 0x84 },
 349     { 0x3d, 0x2e, 0xec, 0x4f, 0xe4, 0x1c, 0x84, 0x9b,
 350       0x80, 0xc8, 0xd8, 0x36, 0x62, 0xc0, 0xe4, 0x4a,
 351       0x8b, 0x29, 0x1a, 0x96, 0x4c, 0xf2, 0xf0, 0x70,
 352       0x38 },
 353     { 0x56, 0xfa, 0x6a, 0xa7, 0x55, 0x48, 0x09, 0x9d,
 354       0xcc, 0x37, 0xd7, 0xf0, 0x34, 0x25, 0xe0, 0xc3 },
 355 };
 356
 357 int pkcs5_self_test( int verbose )
 358 {
 359     md_context_t sha1_ctx;
 360     const md_info_t *info_sha1;
 361     int ret, i;
 362     unsigned char key[64];
 363
 364     info_sha1 = md_info_from_type( POLARSSL_MD_SHA1 );
 365     if( info_sha1 == NULL )
 366         return( 1 );
 367
 368     if( ( ret = md_init_ctx( &sha1_ctx, info_sha1 ) ) != 0 )
 369         return( 1 );
 370
 371     if( verbose != 0 )
 372         polarssl_printf( "  PBKDF2 note: test #3 may be slow!\n" );
 373
 374     for( i = 0; i < MAX_TESTS; i++ )
 375     {
 376         if( verbose != 0 )
 377             polarssl_printf( "  PBKDF2 (SHA1) #%d: ", i );
 378
 379         ret = pkcs5_pbkdf2_hmac( &sha1_ctx, password[i], plen[i], salt[i],
 380                                   slen[i], it_cnt[i], key_len[i], key );
 381         if( ret != 0 ||
 382             memcmp( result_key[i], key, key_len[i] ) != 0 )
 383         {
 384             if( verbose != 0 )
 385                 polarssl_printf( "failed\n" );
 386
 387             return( 1 );
 388         }
 389
 390         if( verbose != 0 )
 391             polarssl_printf( "passed\n" );
 392     }
 393
 394     polarssl_printf( "\n" );
 395
 396     if( ( ret = md_free_ctx( &sha1_ctx ) ) != 0 )
 397         return( 1 );
 398
 399     return( 0 );
 400 }
 401
 402 #endif /* POLARSSL_SELF_TEST */
 403
 404 #endif /* POLARSSL_PKCS5_C */