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1 /**
2  * \file pkcs5.c
3  *
4  * \brief PKCS#5 functions
5  *
6  * \author Mathias Olsson <mathias@kompetensum.com>
7  *
8  *  Copyright The Mbed TLS Contributors
9  *  SPDX-License-Identifier: Apache-2.0
10  *
11  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
12  *  not use this file except in compliance with the License.
13  *  You may obtain a copy of the License at
14  *
15  *  http://www.apache.org/licenses/LICENSE-2.0
16  *
17  *  Unless required by applicable law or agreed to in writing, software
18  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
19  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20  *  See the License for the specific language governing permissions and
21  *  limitations under the License.
22  */
23 /*
24  * PKCS#5 includes PBKDF2 and more
25  *
26  * http://tools.ietf.org/html/rfc2898 (Specification)
27  * http://tools.ietf.org/html/rfc6070 (Test vectors)
28  */
29 
30 #include "common.h"
31 
32 #if defined(MBEDTLS_PKCS5_C)
33 #include "mbedtls/hw_tee_tag.h"
34 #include "mbedtls/pkcs5.h"
35 #include "mbedtls/error.h"
36 
37 #if defined(MBEDTLS_ASN1_PARSE_C)
38 #include "mbedtls/asn1.h"
39 #include "mbedtls/cipher.h"
40 #include "mbedtls/oid.h"
41 #endif /* MBEDTLS_ASN1_PARSE_C */
42 
43 #include <string.h>
44 
45 #if defined(MBEDTLS_PLATFORM_C)
46 #include "mbedtls/platform.h"
47 #else
48 #include <stdio.h>
49 #define mbedtls_printf printf
50 #endif
51 
52 #if defined(MBEDTLS_ASN1_PARSE_C)
pkcs5_parse_pbkdf2_params(const mbedtls_asn1_buf * params,mbedtls_asn1_buf * salt,int * iterations,int * keylen,mbedtls_md_type_t * md_type)53 static int pkcs5_parse_pbkdf2_params( const mbedtls_asn1_buf *params,
54                                       mbedtls_asn1_buf *salt, int *iterations,
55                                       int *keylen, mbedtls_md_type_t *md_type )
56 {
57     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
58     mbedtls_asn1_buf prf_alg_oid;
59     unsigned char *p = params->p;
60     const unsigned char *end = params->p + params->len;
61 
62     if( params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) )
63         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS5_INVALID_FORMAT,
64                 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) );
65     /*
66      *  PBKDF2-params ::= SEQUENCE {
67      *    salt              OCTET STRING,
68      *    iterationCount    INTEGER,
69      *    keyLength         INTEGER OPTIONAL
70      *    prf               AlgorithmIdentifier DEFAULT algid-hmacWithSHA1
71      *  }
72      *
73      */
74     if( ( ret = mbedtls_asn1_get_tag( &p, end, &salt->len,
75                                       MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
76         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret ) );
77 
78     salt->p = p;
79     p += salt->len;
80 
81     if( ( ret = mbedtls_asn1_get_int( &p, end, iterations ) ) != 0 )
82         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret ) );
83 
84     if( p == end )
85         return( 0 );
86 
87     if( ( ret = mbedtls_asn1_get_int( &p, end, keylen ) ) != 0 )
88     {
89         if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
90             return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret ) );
91     }
92 
93     if( p == end )
94         return( 0 );
95 
96     if( ( ret = mbedtls_asn1_get_alg_null( &p, end, &prf_alg_oid ) ) != 0 )
97         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret ) );
98 
99     if( mbedtls_oid_get_md_hmac( &prf_alg_oid, md_type ) != 0 )
100         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
101 
102     if( p != end )
103         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS5_INVALID_FORMAT,
104                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
105 
106     return( 0 );
107 }
108 
mbedtls_pkcs5_pbes2(const mbedtls_asn1_buf * pbe_params,int mode,const unsigned char * pwd,size_t pwdlen,const unsigned char * data,size_t datalen,unsigned char * output)109 int mbedtls_pkcs5_pbes2( const mbedtls_asn1_buf *pbe_params, int mode,
110                  const unsigned char *pwd,  size_t pwdlen,
111                  const unsigned char *data, size_t datalen,
112                  unsigned char *output )
113 {
114     int ret, iterations = 0, keylen = 0;
115     unsigned char *p, *end;
116     mbedtls_asn1_buf kdf_alg_oid, enc_scheme_oid, kdf_alg_params, enc_scheme_params;
117     mbedtls_asn1_buf salt;
118     mbedtls_md_type_t md_type = MBEDTLS_MD_SHA1;
119     unsigned char key[32], iv[32];
120     size_t olen = 0;
121     const mbedtls_md_info_t *md_info;
122     const mbedtls_cipher_info_t *cipher_info;
123     mbedtls_md_context_t md_ctx;
124     mbedtls_cipher_type_t cipher_alg;
125     mbedtls_cipher_context_t cipher_ctx;
126 
127     p = pbe_params->p;
128     end = p + pbe_params->len;
129 
130     /*
131      *  PBES2-params ::= SEQUENCE {
132      *    keyDerivationFunc AlgorithmIdentifier {{PBES2-KDFs}},
133      *    encryptionScheme AlgorithmIdentifier {{PBES2-Encs}}
134      *  }
135      */
136     if( pbe_params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) )
137         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS5_INVALID_FORMAT,
138                 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) );
139 
140     if( ( ret = mbedtls_asn1_get_alg( &p, end, &kdf_alg_oid,
141                                       &kdf_alg_params ) ) != 0 )
142         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret ) );
143 
144     // Only PBKDF2 supported at the moment
145     //
146     if( MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS5_PBKDF2, &kdf_alg_oid ) != 0 )
147         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
148 
149     if( ( ret = pkcs5_parse_pbkdf2_params( &kdf_alg_params,
150                                            &salt, &iterations, &keylen,
151                                            &md_type ) ) != 0 )
152     {
153         return( ret );
154     }
155 
156     md_info = mbedtls_md_info_from_type( md_type );
157     if( md_info == NULL )
158         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
159 
160     if( ( ret = mbedtls_asn1_get_alg( &p, end, &enc_scheme_oid,
161                               &enc_scheme_params ) ) != 0 )
162     {
163         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret ) );
164     }
165 
166     if( mbedtls_oid_get_cipher_alg( &enc_scheme_oid, &cipher_alg ) != 0 )
167         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
168 
169     cipher_info = mbedtls_cipher_info_from_type( cipher_alg );
170     if( cipher_info == NULL )
171         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
172 
173     /*
174      * The value of keylen from pkcs5_parse_pbkdf2_params() is ignored
175      * since it is optional and we don't know if it was set or not
176      */
177     keylen = cipher_info->key_bitlen / 8;
178 
179     if( enc_scheme_params.tag != MBEDTLS_ASN1_OCTET_STRING ||
180         enc_scheme_params.len != cipher_info->iv_size )
181     {
182         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT );
183     }
184 
185     mbedtls_md_init( &md_ctx );
186     mbedtls_cipher_init( &cipher_ctx );
187 
188     memcpy( iv, enc_scheme_params.p, enc_scheme_params.len );
189 
190     if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 )
191         goto exit;
192 
193     if( ( ret = mbedtls_pkcs5_pbkdf2_hmac( &md_ctx, pwd, pwdlen, salt.p, salt.len,
194                                    iterations, keylen, key ) ) != 0 )
195     {
196         goto exit;
197     }
198 
199     if( ( ret = mbedtls_cipher_setup( &cipher_ctx, cipher_info ) ) != 0 )
200         goto exit;
201 
202     if( ( ret = mbedtls_cipher_setkey( &cipher_ctx, key, 8 * keylen,
203                                        (mbedtls_operation_t) mode ) ) != 0 )
204         goto exit;
205 
206     if( ( ret = mbedtls_cipher_crypt( &cipher_ctx, iv, enc_scheme_params.len,
207                               data, datalen, output, &olen ) ) != 0 )
208         ret = MBEDTLS_ERR_PKCS5_PASSWORD_MISMATCH;
209 
210 exit:
211     mbedtls_md_free( &md_ctx );
212     mbedtls_cipher_free( &cipher_ctx );
213 
214     return( ret );
215 }
216 #endif /* MBEDTLS_ASN1_PARSE_C */
217 
218 #if !defined(MBEDTLS_PBKDF2_HMAC_ALT)
219 FLA_TAG STROBF_TAG
mbedtls_pkcs5_pbkdf2_hmac(mbedtls_md_context_t * ctx,const unsigned char * password,size_t plen,const unsigned char * salt,size_t slen,unsigned int iteration_count,uint32_t key_length,unsigned char * output)220 int mbedtls_pkcs5_pbkdf2_hmac( mbedtls_md_context_t *ctx,
221                        const unsigned char *password,
222                        size_t plen, const unsigned char *salt, size_t slen,
223                        unsigned int iteration_count,
224                        uint32_t key_length, unsigned char *output )
225 {
226     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
227     int j;
228     unsigned int i;
229     unsigned char md1[MBEDTLS_MD_MAX_SIZE];
230     unsigned char work[MBEDTLS_MD_MAX_SIZE];
231     unsigned char md_size = mbedtls_md_get_size( ctx->md_info );
232     size_t use_len;
233     unsigned char *out_p = output;
234     unsigned char counter[4];
235 
236     memset( counter, 0, 4 );
237     counter[3] = 1;
238 
239 #if UINT_MAX > 0xFFFFFFFF
240     if( iteration_count > 0xFFFFFFFF )
241         return( MBEDTLS_ERR_PKCS5_BAD_INPUT_DATA );
242 #endif
243 
244     if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 )
245         return( ret );
246     while( key_length )
247     {
248         // U1 ends up in work
249         //
250         if( ( ret = mbedtls_md_hmac_update( ctx, salt, slen ) ) != 0 )
251             goto cleanup;
252 
253         if( ( ret = mbedtls_md_hmac_update( ctx, counter, 4 ) ) != 0 )
254             goto cleanup;
255 
256         if( ( ret = mbedtls_md_hmac_finish( ctx, work ) ) != 0 )
257             goto cleanup;
258 
259         if( ( ret = mbedtls_md_hmac_reset( ctx ) ) != 0 )
260             goto cleanup;
261 
262         memcpy( md1, work, md_size );
263 
264         for( i = 1; i < iteration_count; i++ )
265         {
266             // U2 ends up in md1
267             //
268             if( ( ret = mbedtls_md_hmac_update( ctx, md1, md_size ) ) != 0 )
269                 goto cleanup;
270 
271             if( ( ret = mbedtls_md_hmac_finish( ctx, md1 ) ) != 0 )
272                 goto cleanup;
273 
274             if( ( ret = mbedtls_md_hmac_reset( ctx ) ) != 0 )
275                 goto cleanup;
276 
277             // U1 xor U2
278             //
279             for( j = 0; j < md_size; j++ )
280                 work[j] ^= md1[j];
281         }
282 
283         use_len = ( key_length < md_size ) ? key_length : md_size;
284         memcpy( out_p, work, use_len );
285 
286         key_length -= (uint32_t) use_len;
287         out_p += use_len;
288 
289         for( i = 4; i > 0; i-- )
290             if( ++counter[i - 1] != 0 )
291                 break;
292     }
293 
294 cleanup:
295     /* Zeroise buffers to clear sensitive data from memory. */
296     mbedtls_platform_zeroize( work, MBEDTLS_MD_MAX_SIZE );
297     mbedtls_platform_zeroize( md1, MBEDTLS_MD_MAX_SIZE );
298 
299     return( ret );
300 }
301 #endif /* !MBEDTLS_PBKDF2_HMAC_ALT */
302 #if defined(MBEDTLS_SELF_TEST)
303 
304 #if !defined(MBEDTLS_SHA1_C)
mbedtls_pkcs5_self_test(int verbose)305 int mbedtls_pkcs5_self_test( int verbose )
306 {
307     if( verbose != 0 )
308         mbedtls_printf( "  PBKDF2 (SHA1): skipped\n\n" );
309 
310     return( 0 );
311 }
312 #else
313 
314 #define MAX_TESTS   6
315 
316 static const size_t plen_test_data[MAX_TESTS] =
317     { 8, 8, 8, 24, 9 };
318 
319 static const unsigned char password_test_data[MAX_TESTS][32] =
320 {
321     "password",
322     "password",
323     "password",
324     "passwordPASSWORDpassword",
325     "pass\0word",
326 };
327 
328 static const size_t slen_test_data[MAX_TESTS] =
329     { 4, 4, 4, 36, 5 };
330 
331 static const unsigned char salt_test_data[MAX_TESTS][40] =
332 {
333     "salt",
334     "salt",
335     "salt",
336     "saltSALTsaltSALTsaltSALTsaltSALTsalt",
337     "sa\0lt",
338 };
339 
340 static const uint32_t it_cnt_test_data[MAX_TESTS] =
341     { 1, 2, 4096, 4096, 4096 };
342 
343 static const uint32_t key_len_test_data[MAX_TESTS] =
344     { 20, 20, 20, 25, 16 };
345 
346 static const unsigned char result_key_test_data[MAX_TESTS][32] =
347 {
348     { 0x0c, 0x60, 0xc8, 0x0f, 0x96, 0x1f, 0x0e, 0x71,
349       0xf3, 0xa9, 0xb5, 0x24, 0xaf, 0x60, 0x12, 0x06,
350       0x2f, 0xe0, 0x37, 0xa6 },
351     { 0xea, 0x6c, 0x01, 0x4d, 0xc7, 0x2d, 0x6f, 0x8c,
352       0xcd, 0x1e, 0xd9, 0x2a, 0xce, 0x1d, 0x41, 0xf0,
353       0xd8, 0xde, 0x89, 0x57 },
354     { 0x4b, 0x00, 0x79, 0x01, 0xb7, 0x65, 0x48, 0x9a,
355       0xbe, 0xad, 0x49, 0xd9, 0x26, 0xf7, 0x21, 0xd0,
356       0x65, 0xa4, 0x29, 0xc1 },
357     { 0x3d, 0x2e, 0xec, 0x4f, 0xe4, 0x1c, 0x84, 0x9b,
358       0x80, 0xc8, 0xd8, 0x36, 0x62, 0xc0, 0xe4, 0x4a,
359       0x8b, 0x29, 0x1a, 0x96, 0x4c, 0xf2, 0xf0, 0x70,
360       0x38 },
361     { 0x56, 0xfa, 0x6a, 0xa7, 0x55, 0x48, 0x09, 0x9d,
362       0xcc, 0x37, 0xd7, 0xf0, 0x34, 0x25, 0xe0, 0xc3 },
363 };
364 
mbedtls_pkcs5_self_test(int verbose)365 int mbedtls_pkcs5_self_test( int verbose )
366 {
367     mbedtls_md_context_t sha1_ctx;
368     const mbedtls_md_info_t *info_sha1;
369     int ret, i;
370     unsigned char key[64];
371 
372     mbedtls_md_init( &sha1_ctx );
373 
374     info_sha1 = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 );
375     if( info_sha1 == NULL )
376     {
377         ret = 1;
378         goto exit;
379     }
380 
381     if( ( ret = mbedtls_md_setup( &sha1_ctx, info_sha1, 1 ) ) != 0 )
382     {
383         ret = 1;
384         goto exit;
385     }
386 
387     for( i = 0; i < MAX_TESTS; i++ )
388     {
389         if( verbose != 0 )
390             mbedtls_printf( "  PBKDF2 (SHA1) #%d: ", i );
391 
392         ret = mbedtls_pkcs5_pbkdf2_hmac( &sha1_ctx, password_test_data[i],
393                                          plen_test_data[i], salt_test_data[i],
394                                          slen_test_data[i], it_cnt_test_data[i],
395                                          key_len_test_data[i], key );
396         if( ret != 0 ||
397             memcmp( result_key_test_data[i], key, key_len_test_data[i] ) != 0 )
398         {
399             if( verbose != 0 )
400                 mbedtls_printf( "failed\n" );
401 
402             ret = 1;
403             goto exit;
404         }
405 
406         if( verbose != 0 )
407             mbedtls_printf( "passed\n" );
408     }
409 
410     if( verbose != 0 )
411         mbedtls_printf( "\n" );
412 
413 exit:
414     mbedtls_md_free( &sha1_ctx );
415 
416     return( ret );
417 }
418 #endif /* MBEDTLS_SHA1_C */
419 
420 #endif /* MBEDTLS_SELF_TEST */
421 
422 #endif /* MBEDTLS_PKCS5_C */
423