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) 2006-2013, 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 #include "config.h"
  37
  38 #if defined(POLARSSL_PKCS5_C)
  39
  40 #include "pkcs5.h"
  41 #include "asn1.h"
  42 #include "cipher.h"
  43
  44 #define OID_CMP(oid_str, oid_buf) \
  45         ( ( OID_SIZE(oid_str) == (oid_buf)->len ) && \
  46                 memcmp( (oid_str), (oid_buf)->p, (oid_buf)->len) == 0)
  47
  48 static int pkcs5_parse_pbkdf2_params( unsigned char **p,
  49                                       const unsigned char *end,
  50                                       asn1_buf *salt, int *iterations,
  51                                       int *keylen, md_type_t *md_type )
  52 {
  53     int ret;
  54     size_t len = 0;
  55     asn1_buf prf_alg_oid;
  56
  57     /*
  58      *  PBKDF2-params ::= SEQUENCE {
  59      *    salt              OCTET STRING,
  60      *    iterationCount    INTEGER,
  61      *    keyLength         INTEGER OPTIONAL
  62      *    prf               AlgorithmIdentifier DEFAULT algid-hmacWithSHA1
  63      *  }
  64      *
  65      */
  66     if( ( ret = asn1_get_tag( p, end, &len,
  67             ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
  68     {
  69         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
  70     }
  71
  72     end = *p + len;
  73
  74     if( ( ret = asn1_get_tag( p, end, &salt->len, ASN1_OCTET_STRING ) ) != 0 )
  75         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
  76
  77     salt->p = *p;
  78     *p += salt->len;
  79
  80     if( ( ret = asn1_get_int( p, end, iterations ) ) != 0 )
  81         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
  82
  83     if( *p == end )
  84         return( 0 );
  85
  86     if( ( ret = asn1_get_int( p, end, keylen ) ) != 0 )
  87     {
  88         if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
  89             return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
  90     }
  91
  92     if( *p == end )
  93         return( 0 );
  94
  95     if( ( ret = asn1_get_tag( p, end, &prf_alg_oid.len, ASN1_OID ) ) != 0 )
  96         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
  97
  98     if( !OID_CMP( OID_HMAC_SHA1, &prf_alg_oid ) )
  99         return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
 100
 101     *md_type = POLARSSL_MD_SHA1;
 102
 103     if( *p != end )
 104         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT +
 105                 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
 106
 107     return( 0 );
 108 }
 109
 110 int pkcs5_pbes2( asn1_buf *pbe_params, int mode,
 111                  const unsigned char *pwd,  size_t pwdlen,
 112                  const unsigned char *data, size_t datalen,
 113                  unsigned char *output )
 114 {
 115     int ret, iterations = 0, keylen = 0;
 116     unsigned char *p, *end, *end2;
 117     asn1_buf kdf_alg_oid, enc_scheme_oid, salt;
 118     md_type_t md_type = POLARSSL_MD_SHA1;
 119     unsigned char key[32], iv[32];
 120     size_t len = 0, olen = 0;
 121     const md_info_t *md_info;
 122     const cipher_info_t *cipher_info;
 123     md_context_t md_ctx;
 124     cipher_context_t cipher_ctx;
 125
 126     p = pbe_params->p;
 127     end = p + pbe_params->len;
 128
 129     /*
 130      *  PBES2-params ::= SEQUENCE {
 131      *    keyDerivationFunc AlgorithmIdentifier {{PBES2-KDFs}},
 132      *    encryptionScheme AlgorithmIdentifier {{PBES2-Encs}}
 133      *  }
 134      */
 135     if( ( ret = asn1_get_tag( &p, end, &len,
 136             ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
 137     {
 138         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
 139     }
 140
 141     if( ( ret = asn1_get_tag( &p, end, &len,
 142             ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
 143     {
 144         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
 145     }
 146
 147     end2 = p + len;
 148
 149     if( ( ret = asn1_get_tag( &p, end2, &kdf_alg_oid.len, ASN1_OID ) ) != 0 )
 150         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
 151
 152     kdf_alg_oid.p = p;
 153     p += kdf_alg_oid.len;
 154
 155     // Only PBKDF2 supported at the moment
 156     //
 157     if( !OID_CMP( OID_PKCS5_PBKDF2, &kdf_alg_oid ) )
 158         return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
 159
 160     if( ( ret = pkcs5_parse_pbkdf2_params( &p, end2,
 161                                            &salt, &iterations, &keylen,
 162                                            &md_type ) ) != 0 )
 163     {
 164         return( ret );
 165     }
 166
 167     md_info = md_info_from_type( md_type );
 168     if( md_info == NULL )
 169         return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
 170
 171     if( ( ret = asn1_get_tag( &p, end, &len,
 172             ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
 173     {
 174         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
 175     }
 176
 177     end2 = p + len;
 178
 179     if( ( ret = asn1_get_tag( &p, end2, &enc_scheme_oid.len, ASN1_OID ) ) != 0 )
 180         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
 181
 182     enc_scheme_oid.p = p;
 183     p += enc_scheme_oid.len;
 184
 185 #if defined(POLARSSL_DES_C)
 186     // Only DES-CBC and DES-EDE3-CBC supported at the moment
 187     //
 188     if( OID_CMP( OID_DES_EDE3_CBC, &enc_scheme_oid ) )
 189     {
 190         cipher_info = cipher_info_from_type( POLARSSL_CIPHER_DES_EDE3_CBC );
 191     }
 192     else if( OID_CMP( OID_DES_CBC, &enc_scheme_oid ) )
 193     {
 194         cipher_info = cipher_info_from_type( POLARSSL_CIPHER_DES_CBC );
 195     }
 196     else
 197 #endif /* POLARSSL_DES_C */
 198         return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
 199
 200     if( cipher_info == NULL )
 201         return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
 202
 203     keylen = cipher_info->key_length / 8;
 204
 205     if( ( ret = asn1_get_tag( &p, end2, &len, ASN1_OCTET_STRING ) ) != 0 )
 206         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
 207
 208     if( len != cipher_info->iv_size )
 209         return( POLARSSL_ERR_PKCS5_INVALID_FORMAT );
 210
 211     memcpy( iv, p, len );
 212
 213     if( ( ret = md_init_ctx( &md_ctx, md_info ) ) != 0 )
 214         return( ret );
 215
 216     if( ( ret = cipher_init_ctx( &cipher_ctx, cipher_info ) ) != 0 )
 217         return( ret );
 218
 219     if ( ( ret = pkcs5_pbkdf2_hmac( &md_ctx, pwd, pwdlen, salt.p, salt.len,
 220                                     iterations, keylen, key ) ) != 0 )
 221     {
 222         return( ret );
 223     }
 224
 225     if( ( ret = cipher_setkey( &cipher_ctx, key, keylen, mode ) ) != 0 )
 226         return( ret );
 227
 228     if( ( ret = cipher_reset( &cipher_ctx, iv ) ) != 0 )
 229         return( ret );
 230
 231     if( ( ret = cipher_update( &cipher_ctx, data, datalen,
 232                                 output, &olen ) ) != 0 )
 233     {
 234         return( ret );
 235     }
 236
 237     if( ( ret = cipher_finish( &cipher_ctx, output + olen, &olen ) ) != 0 )
 238         return( POLARSSL_ERR_PKCS5_PASSWORD_MISMATCH );
 239
 240     return( 0 );
 241 }
 242
 243 int pkcs5_pbkdf2_hmac( md_context_t *ctx, const unsigned char *password,
 244                        size_t plen, const unsigned char *salt, size_t slen,
 245                        unsigned int iteration_count,
 246                        uint32_t key_length, unsigned char *output )
 247 {
 248     int ret, j;
 249     unsigned int i;
 250     unsigned char md1[POLARSSL_MD_MAX_SIZE];
 251     unsigned char work[POLARSSL_MD_MAX_SIZE];
 252     unsigned char md_size = md_get_size( ctx->md_info );
 253     size_t use_len;
 254     unsigned char *out_p = output;
 255     unsigned char counter[4];
 256
 257     memset( counter, 0, 4 );
 258     counter[3] = 1;
 259
 260     if( iteration_count > 0xFFFFFFFF )
 261         return( POLARSSL_ERR_PKCS5_BAD_INPUT_DATA );
 262
 263     while( key_length )
 264     {
 265         // U1 ends up in work
 266         //
 267         if( ( ret = md_hmac_starts( ctx, password, plen ) ) != 0 )
 268             return( ret );
 269
 270         if( ( ret = md_hmac_update( ctx, salt, slen ) ) != 0 )
 271             return( ret );
 272
 273         if( ( ret = md_hmac_update( ctx, counter, 4 ) ) != 0 )
 274             return( ret );
 275
 276         if( ( ret = md_hmac_finish( ctx, work ) ) != 0 )
 277             return( ret );
 278
 279         memcpy( md1, work, md_size );
 280
 281         for ( i = 1; i < iteration_count; i++ )
 282         {
 283             // U2 ends up in md1
 284             //
 285             if( ( ret = md_hmac_starts( ctx, password, plen ) ) != 0 )
 286                 return( ret );
 287
 288             if( ( ret = md_hmac_update( ctx, md1, md_size ) ) != 0 )
 289                 return( ret );
 290
 291             if( ( ret = md_hmac_finish( ctx, md1 ) ) != 0 )
 292                 return( ret );
 293
 294             // U1 xor U2
 295             //
 296             for( j = 0; j < md_size; j++ )
 297                 work[j] ^= md1[j];
 298         }
 299
 300         use_len = ( key_length < md_size ) ? key_length : md_size;
 301         memcpy( out_p, work, use_len );
 302
 303         key_length -= use_len;
 304         out_p += use_len;
 305
 306         for( i = 4; i > 0; i-- )
 307             if( ++counter[i - 1] != 0 )
 308                 break;
 309     }
 310
 311     return( 0 );
 312 }
 313
 314 #if defined(POLARSSL_SELF_TEST)
 315
 316 #include <stdio.h>
 317
 318 #define MAX_TESTS   6
 319
 320 size_t plen[MAX_TESTS] =
 321     { 8, 8, 8, 8, 24, 9 };
 322
 323 unsigned char password[MAX_TESTS][32] =
 324 {
 325     "password",
 326     "password",
 327     "password",
 328     "password",
 329     "passwordPASSWORDpassword",
 330     "pass\0word",
 331 };
 332
 333 size_t slen[MAX_TESTS] =
 334     { 4, 4, 4, 4, 36, 5 };
 335
 336 unsigned char salt[MAX_TESTS][40] =
 337 {
 338     "salt",
 339     "salt",
 340     "salt",
 341     "salt",
 342     "saltSALTsaltSALTsaltSALTsaltSALTsalt",
 343     "sa\0lt",
 344 };
 345
 346 uint32_t it_cnt[MAX_TESTS] =
 347     { 1, 2, 4096, 16777216, 4096, 4096 };
 348
 349 uint32_t key_len[MAX_TESTS] =
 350     { 20, 20, 20, 20, 25, 16 };
 351
 352
 353 unsigned char result_key[MAX_TESTS][32] =
 354 {
 355     { 0x0c, 0x60, 0xc8, 0x0f, 0x96, 0x1f, 0x0e, 0x71,
 356       0xf3, 0xa9, 0xb5, 0x24, 0xaf, 0x60, 0x12, 0x06,
 357       0x2f, 0xe0, 0x37, 0xa6 },
 358     { 0xea, 0x6c, 0x01, 0x4d, 0xc7, 0x2d, 0x6f, 0x8c,
 359       0xcd, 0x1e, 0xd9, 0x2a, 0xce, 0x1d, 0x41, 0xf0,
 360       0xd8, 0xde, 0x89, 0x57 },
 361     { 0x4b, 0x00, 0x79, 0x01, 0xb7, 0x65, 0x48, 0x9a,
 362       0xbe, 0xad, 0x49, 0xd9, 0x26, 0xf7, 0x21, 0xd0,
 363       0x65, 0xa4, 0x29, 0xc1 },
 364     { 0xee, 0xfe, 0x3d, 0x61, 0xcd, 0x4d, 0xa4, 0xe4,
 365       0xe9, 0x94, 0x5b, 0x3d, 0x6b, 0xa2, 0x15, 0x8c,
 366       0x26, 0x34, 0xe9, 0x84 },
 367     { 0x3d, 0x2e, 0xec, 0x4f, 0xe4, 0x1c, 0x84, 0x9b,
 368       0x80, 0xc8, 0xd8, 0x36, 0x62, 0xc0, 0xe4, 0x4a,
 369       0x8b, 0x29, 0x1a, 0x96, 0x4c, 0xf2, 0xf0, 0x70,
 370       0x38 },
 371     { 0x56, 0xfa, 0x6a, 0xa7, 0x55, 0x48, 0x09, 0x9d,
 372       0xcc, 0x37, 0xd7, 0xf0, 0x34, 0x25, 0xe0, 0xc3 },
 373 };
 374
 375 int pkcs5_self_test( int verbose )
 376 {
 377     md_context_t sha1_ctx;
 378     const md_info_t *info_sha1;
 379     int ret, i;
 380     unsigned char key[64];
 381
 382     info_sha1 = md_info_from_type( POLARSSL_MD_SHA1 );
 383     if( info_sha1 == NULL )
 384         return( 1 );
 385
 386     if( ( ret = md_init_ctx( &sha1_ctx, info_sha1 ) ) != 0 )
 387         return( 1 );
 388
 389     for( i = 0; i < MAX_TESTS; i++ )
 390     {
 391         printf( "  PBKDF2 (SHA1) #%d: ", i );
 392
 393         ret = pkcs5_pbkdf2_hmac( &sha1_ctx, password[i], plen[i], salt[i],
 394                                   slen[i], it_cnt[i], key_len[i], key );
 395         if( ret != 0 ||
 396             memcmp( result_key[i], key, key_len[i] ) != 0 )
 397         {
 398             if( verbose != 0 )
 399                 printf( "failed\n" );
 400
 401             return( 1 );
 402         }
 403
 404         if( verbose != 0 )
 405             printf( "passed\n" );
 406     }
 407
 408     printf( "\n" );
 409
 410     return( 0 );
 411 }
 412
 413 #endif /* POLARSSL_SELF_TEST */
 414
 415 #endif /* POLARSSL_PKCS5_C */