pkcs5.c

00001 /**
00002  * \file pkcs5.c
00003  *
00004  * \brief PKCS#5 functions
00005  *
00006  * \author Mathias Olsson <mathias@kompetensum.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  * PKCS#5 includes PBKDF2 and more
00027  *
00028  * http://tools.ietf.org/html/rfc2898 (Specification)
00029  * http://tools.ietf.org/html/rfc6070 (Test vectors)
00030  */
00031 
00032 #if !defined(MBEDTLS_CONFIG_FILE)
00033 #include "mbedtls/config.h"
00034 #else
00035 #include MBEDTLS_CONFIG_FILE
00036 #endif
00037 
00038 #if defined(MBEDTLS_PKCS5_C)
00039 
00040 #include "mbedtls/pkcs5.h"
00041 
00042 #if defined(MBEDTLS_ASN1_PARSE_C)
00043 #include "mbedtls/asn1.h"
00044 #include "mbedtls/cipher.h"
00045 #include "mbedtls/oid.h"
00046 #endif /* MBEDTLS_ASN1_PARSE_C */
00047 
00048 #include <string.h>
00049 
00050 #if defined(MBEDTLS_PLATFORM_C)
00051 #include "mbedtls/platform.h"
00052 #else
00053 #include <stdio.h>
00054 #define mbedtls_printf printf
00055 #endif
00056 
00057 #if !defined(MBEDTLS_ASN1_PARSE_C)
00058 int mbedtls_pkcs5_pbes2( const mbedtls_asn1_buf *pbe_params, int mode,
00059                  const unsigned char *pwd,  size_t pwdlen,
00060                  const unsigned char *data, size_t datalen,
00061                  unsigned char *output )
00062 {
00063     ((void) pbe_params);
00064     ((void) mode);
00065     ((void) pwd);
00066     ((void) pwdlen);
00067     ((void) data);
00068     ((void) datalen);
00069     ((void) output);
00070     return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
00071 }
00072 #else
00073 static int pkcs5_parse_pbkdf2_params( const mbedtls_asn1_buf *params,
00074                                       mbedtls_asn1_buf *salt, int *iterations,
00075                                       int *keylen, mbedtls_md_type_t *md_type )
00076 {
00077     int ret;
00078     mbedtls_asn1_buf prf_alg_oid;
00079     unsigned char *p = params->p;
00080     const unsigned char *end = params->p + params->len;
00081 
00082     if( params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) )
00083         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT +
00084                 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
00085     /*
00086      *  PBKDF2-params ::= SEQUENCE {
00087      *    salt              OCTET STRING,
00088      *    iterationCount    INTEGER,
00089      *    keyLength         INTEGER OPTIONAL
00090      *    prf               AlgorithmIdentifier DEFAULT algid-hmacWithSHA1
00091      *  }
00092      *
00093      */
00094     if( ( ret = mbedtls_asn1_get_tag( &p, end, &salt->len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
00095         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret );
00096 
00097     salt->p = p;
00098     p += salt->len;
00099 
00100     if( ( ret = mbedtls_asn1_get_int( &p, end, iterations ) ) != 0 )
00101         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret );
00102 
00103     if( p == end )
00104         return( 0 );
00105 
00106     if( ( ret = mbedtls_asn1_get_int( &p, end, keylen ) ) != 0 )
00107     {
00108         if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
00109             return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret );
00110     }
00111 
00112     if( p == end )
00113         return( 0 );
00114 
00115     if( ( ret = mbedtls_asn1_get_alg_null( &p, end, &prf_alg_oid ) ) != 0 )
00116         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret );
00117 
00118     if( mbedtls_oid_get_md_hmac( &prf_alg_oid, md_type ) != 0 )
00119         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
00120 
00121     if( p != end )
00122         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT +
00123                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
00124 
00125     return( 0 );
00126 }
00127 
00128 int mbedtls_pkcs5_pbes2( const mbedtls_asn1_buf *pbe_params, int mode,
00129                  const unsigned char *pwd,  size_t pwdlen,
00130                  const unsigned char *data, size_t datalen,
00131                  unsigned char *output )
00132 {
00133     int ret, iterations = 0, keylen = 0;
00134     unsigned char *p, *end;
00135     mbedtls_asn1_buf kdf_alg_oid, enc_scheme_oid, kdf_alg_params, enc_scheme_params;
00136     mbedtls_asn1_buf salt;
00137     mbedtls_md_type_t md_type = MBEDTLS_MD_SHA1;
00138     unsigned char key[32], iv[32];
00139     size_t olen = 0;
00140     const mbedtls_md_info_t *md_info;
00141     const mbedtls_cipher_info_t *cipher_info;
00142     mbedtls_md_context_t md_ctx;
00143     mbedtls_cipher_type_t cipher_alg;
00144     mbedtls_cipher_context_t cipher_ctx;
00145 
00146     p = pbe_params->p;
00147     end = p + pbe_params->len;
00148 
00149     /*
00150      *  PBES2-params ::= SEQUENCE {
00151      *    keyDerivationFunc AlgorithmIdentifier {{PBES2-KDFs}},
00152      *    encryptionScheme AlgorithmIdentifier {{PBES2-Encs}}
00153      *  }
00154      */
00155     if( pbe_params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) )
00156         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT +
00157                 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
00158 
00159     if( ( ret = mbedtls_asn1_get_alg( &p, end, &kdf_alg_oid, &kdf_alg_params ) ) != 0 )
00160         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret );
00161 
00162     // Only PBKDF2 supported at the moment
00163     //
00164     if( MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS5_PBKDF2, &kdf_alg_oid ) != 0 )
00165         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
00166 
00167     if( ( ret = pkcs5_parse_pbkdf2_params( &kdf_alg_params,
00168                                            &salt, &iterations, &keylen,
00169                                            &md_type ) ) != 0 )
00170     {
00171         return( ret );
00172     }
00173 
00174     md_info = mbedtls_md_info_from_type( md_type );
00175     if( md_info == NULL )
00176         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
00177 
00178     if( ( ret = mbedtls_asn1_get_alg( &p, end, &enc_scheme_oid,
00179                               &enc_scheme_params ) ) != 0 )
00180     {
00181         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret );
00182     }
00183 
00184     if( mbedtls_oid_get_cipher_alg( &enc_scheme_oid, &cipher_alg ) != 0 )
00185         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
00186 
00187     cipher_info = mbedtls_cipher_info_from_type( cipher_alg );
00188     if( cipher_info == NULL )
00189         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
00190 
00191     /*
00192      * The value of keylen from pkcs5_parse_pbkdf2_params() is ignored
00193      * since it is optional and we don't know if it was set or not
00194      */
00195     keylen = cipher_info->key_bitlen / 8;
00196 
00197     if( enc_scheme_params.tag != MBEDTLS_ASN1_OCTET_STRING ||
00198         enc_scheme_params.len != cipher_info->iv_size )
00199     {
00200         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT );
00201     }
00202 
00203     mbedtls_md_init( &md_ctx );
00204     mbedtls_cipher_init( &cipher_ctx );
00205 
00206     memcpy( iv, enc_scheme_params.p, enc_scheme_params.len );
00207 
00208     if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 )
00209         goto exit;
00210 
00211     if( ( ret = mbedtls_pkcs5_pbkdf2_hmac( &md_ctx, pwd, pwdlen, salt.p, salt.len,
00212                                    iterations, keylen, key ) ) != 0 )
00213     {
00214         goto exit;
00215     }
00216 
00217     if( ( ret = mbedtls_cipher_setup( &cipher_ctx, cipher_info ) ) != 0 )
00218         goto exit;
00219 
00220     if( ( ret = mbedtls_cipher_setkey( &cipher_ctx, key, 8 * keylen, (mbedtls_operation_t) mode ) ) != 0 )
00221         goto exit;
00222 
00223     if( ( ret = mbedtls_cipher_crypt( &cipher_ctx, iv, enc_scheme_params.len,
00224                               data, datalen, output, &olen ) ) != 0 )
00225         ret = MBEDTLS_ERR_PKCS5_PASSWORD_MISMATCH;
00226 
00227 exit:
00228     mbedtls_md_free( &md_ctx );
00229     mbedtls_cipher_free( &cipher_ctx );
00230 
00231     return( ret );
00232 }
00233 #endif /* MBEDTLS_ASN1_PARSE_C */
00234 
00235 int mbedtls_pkcs5_pbkdf2_hmac( mbedtls_md_context_t *ctx, const unsigned char *password,
00236                        size_t plen, const unsigned char *salt, size_t slen,
00237                        unsigned int iteration_count,
00238                        uint32_t key_length, unsigned char *output )
00239 {
00240     int ret, j;
00241     unsigned int i;
00242     unsigned char md1[MBEDTLS_MD_MAX_SIZE];
00243     unsigned char work[MBEDTLS_MD_MAX_SIZE];
00244     unsigned char md_size = mbedtls_md_get_size( ctx->md_info );
00245     size_t use_len;
00246     unsigned char *out_p = output;
00247     unsigned char counter[4];
00248 
00249     memset( counter, 0, 4 );
00250     counter[3] = 1;
00251 
00252     if( iteration_count > 0xFFFFFFFF )
00253         return( MBEDTLS_ERR_PKCS5_BAD_INPUT_DATA );
00254 
00255     while( key_length )
00256     {
00257         // U1 ends up in work
00258         //
00259         if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 )
00260             return( ret );
00261 
00262         if( ( ret = mbedtls_md_hmac_update( ctx, salt, slen ) ) != 0 )
00263             return( ret );
00264 
00265         if( ( ret = mbedtls_md_hmac_update( ctx, counter, 4 ) ) != 0 )
00266             return( ret );
00267 
00268         if( ( ret = mbedtls_md_hmac_finish( ctx, work ) ) != 0 )
00269             return( ret );
00270 
00271         memcpy( md1, work, md_size );
00272 
00273         for( i = 1; i < iteration_count; i++ )
00274         {
00275             // U2 ends up in md1
00276             //
00277             if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 )
00278                 return( ret );
00279 
00280             if( ( ret = mbedtls_md_hmac_update( ctx, md1, md_size ) ) != 0 )
00281                 return( ret );
00282 
00283             if( ( ret = mbedtls_md_hmac_finish( ctx, md1 ) ) != 0 )
00284                 return( ret );
00285 
00286             // U1 xor U2
00287             //
00288             for( j = 0; j < md_size; j++ )
00289                 work[j] ^= md1[j];
00290         }
00291 
00292         use_len = ( key_length < md_size ) ? key_length : md_size;
00293         memcpy( out_p, work, use_len );
00294 
00295         key_length -= (uint32_t) use_len;
00296         out_p += use_len;
00297 
00298         for( i = 4; i > 0; i-- )
00299             if( ++counter[i - 1] != 0 )
00300                 break;
00301     }
00302 
00303     return( 0 );
00304 }
00305 
00306 #if defined(MBEDTLS_SELF_TEST)
00307 
00308 #if !defined(MBEDTLS_SHA1_C)
00309 int mbedtls_pkcs5_self_test( int verbose )
00310 {
00311     if( verbose != 0 )
00312         mbedtls_printf( "  PBKDF2 (SHA1): skipped\n\n" );
00313 
00314     return( 0 );
00315 }
00316 #else
00317 
00318 #define MAX_TESTS   6
00319 
00320 static const size_t plen[MAX_TESTS] =
00321     { 8, 8, 8, 24, 9 };
00322 
00323 static const unsigned char password[MAX_TESTS][32] =
00324 {
00325     "password",
00326     "password",
00327     "password",
00328     "passwordPASSWORDpassword",
00329     "pass\0word",
00330 };
00331 
00332 static const size_t slen[MAX_TESTS] =
00333     { 4, 4, 4, 36, 5 };
00334 
00335 static const unsigned char salt[MAX_TESTS][40] =
00336 {
00337     "salt",
00338     "salt",
00339     "salt",
00340     "saltSALTsaltSALTsaltSALTsaltSALTsalt",
00341     "sa\0lt",
00342 };
00343 
00344 static const uint32_t it_cnt[MAX_TESTS] =
00345     { 1, 2, 4096, 4096, 4096 };
00346 
00347 static const uint32_t key_len[MAX_TESTS] =
00348     { 20, 20, 20, 25, 16 };
00349 
00350 static const unsigned char result_key[MAX_TESTS][32] =
00351 {
00352     { 0x0c, 0x60, 0xc8, 0x0f, 0x96, 0x1f, 0x0e, 0x71,
00353       0xf3, 0xa9, 0xb5, 0x24, 0xaf, 0x60, 0x12, 0x06,
00354       0x2f, 0xe0, 0x37, 0xa6 },
00355     { 0xea, 0x6c, 0x01, 0x4d, 0xc7, 0x2d, 0x6f, 0x8c,
00356       0xcd, 0x1e, 0xd9, 0x2a, 0xce, 0x1d, 0x41, 0xf0,
00357       0xd8, 0xde, 0x89, 0x57 },
00358     { 0x4b, 0x00, 0x79, 0x01, 0xb7, 0x65, 0x48, 0x9a,
00359       0xbe, 0xad, 0x49, 0xd9, 0x26, 0xf7, 0x21, 0xd0,
00360       0x65, 0xa4, 0x29, 0xc1 },
00361     { 0x3d, 0x2e, 0xec, 0x4f, 0xe4, 0x1c, 0x84, 0x9b,
00362       0x80, 0xc8, 0xd8, 0x36, 0x62, 0xc0, 0xe4, 0x4a,
00363       0x8b, 0x29, 0x1a, 0x96, 0x4c, 0xf2, 0xf0, 0x70,
00364       0x38 },
00365     { 0x56, 0xfa, 0x6a, 0xa7, 0x55, 0x48, 0x09, 0x9d,
00366       0xcc, 0x37, 0xd7, 0xf0, 0x34, 0x25, 0xe0, 0xc3 },
00367 };
00368 
00369 int mbedtls_pkcs5_self_test( int verbose )
00370 {
00371     mbedtls_md_context_t sha1_ctx;
00372     const mbedtls_md_info_t *info_sha1;
00373     int ret, i;
00374     unsigned char key[64];
00375 
00376     mbedtls_md_init( &sha1_ctx );
00377 
00378     info_sha1 = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 );
00379     if( info_sha1 == NULL )
00380     {
00381         ret = 1;
00382         goto exit;
00383     }
00384 
00385     if( ( ret = mbedtls_md_setup( &sha1_ctx, info_sha1, 1 ) ) != 0 )
00386     {
00387         ret = 1;
00388         goto exit;
00389     }
00390 
00391     for( i = 0; i < MAX_TESTS; i++ )
00392     {
00393         if( verbose != 0 )
00394             mbedtls_printf( "  PBKDF2 (SHA1) #%d: ", i );
00395 
00396         ret = mbedtls_pkcs5_pbkdf2_hmac( &sha1_ctx, password[i], plen[i], salt[i],
00397                                   slen[i], it_cnt[i], key_len[i], key );
00398         if( ret != 0 ||
00399             memcmp( result_key[i], key, key_len[i] ) != 0 )
00400         {
00401             if( verbose != 0 )
00402                 mbedtls_printf( "failed\n" );
00403 
00404             ret = 1;
00405             goto exit;
00406         }
00407 
00408         if( verbose != 0 )
00409             mbedtls_printf( "passed\n" );
00410     }
00411 
00412     if( verbose != 0 )
00413         mbedtls_printf( "\n" );
00414 
00415 exit:
00416     mbedtls_md_free( &sha1_ctx );
00417 
00418     return( ret );
00419 }
00420 #endif /* MBEDTLS_SHA1_C */
00421 
00422 #endif /* MBEDTLS_SELF_TEST */
00423 
00424 #endif /* MBEDTLS_PKCS5_C */