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 OR GPL-2.0-or-later
10 */
11 /*
12 * PKCS#5 includes PBKDF2 and more
13 *
14 * http://tools.ietf.org/html/rfc2898 (Specification)
15 * http://tools.ietf.org/html/rfc6070 (Test vectors)
16 */
17
18 #include "common.h"
19
20 #if defined(MBEDTLS_PKCS5_C)
21
22 #include "mbedtls/pkcs5.h"
23 #include "mbedtls/error.h"
24
25 #if defined(MBEDTLS_ASN1_PARSE_C)
26 #include "mbedtls/asn1.h"
27 #include "mbedtls/cipher.h"
28 #include "mbedtls/oid.h"
29 #endif /* MBEDTLS_ASN1_PARSE_C */
30
31 #include <string.h>
32
33 #include "mbedtls/platform.h"
34
35
36 #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)37 static int pkcs5_parse_pbkdf2_params(const mbedtls_asn1_buf *params,
38 mbedtls_asn1_buf *salt, int *iterations,
39 int *keylen, mbedtls_md_type_t *md_type)
40 {
41 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
42 mbedtls_asn1_buf prf_alg_oid;
43 unsigned char *p = params->p;
44 const unsigned char *end = params->p + params->len;
45
46 if (params->tag != (MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) {
47 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT,
48 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
49 }
50 /*
51 * PBKDF2-params ::= SEQUENCE {
52 * salt OCTET STRING,
53 * iterationCount INTEGER,
54 * keyLength INTEGER OPTIONAL
55 * prf AlgorithmIdentifier DEFAULT algid-hmacWithSHA1
56 * }
57 *
58 */
59 if ((ret = mbedtls_asn1_get_tag(&p, end, &salt->len,
60 MBEDTLS_ASN1_OCTET_STRING)) != 0) {
61 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);
62 }
63
64 salt->p = p;
65 p += salt->len;
66
67 if ((ret = mbedtls_asn1_get_int(&p, end, iterations)) != 0) {
68 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);
69 }
70
71 if (p == end) {
72 return 0;
73 }
74
75 if ((ret = mbedtls_asn1_get_int(&p, end, keylen)) != 0) {
76 if (ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
77 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);
78 }
79 }
80
81 if (p == end) {
82 return 0;
83 }
84
85 if ((ret = mbedtls_asn1_get_alg_null(&p, end, &prf_alg_oid)) != 0) {
86 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);
87 }
88
89 if (mbedtls_oid_get_md_hmac(&prf_alg_oid, md_type) != 0) {
90 return MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE;
91 }
92
93 if (p != end) {
94 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT,
95 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
96 }
97
98 return 0;
99 }
100
101 #if !defined(MBEDTLS_CIPHER_PADDING_PKCS7)
102 int mbedtls_pkcs5_pbes2_ext(const mbedtls_asn1_buf *pbe_params, int mode,
103 const unsigned char *pwd, size_t pwdlen,
104 const unsigned char *data, size_t datalen,
105 unsigned char *output, size_t output_size,
106 size_t *output_len);
107 #endif
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 size_t output_len = 0;
115
116 /* We assume caller of the function is providing a big enough output buffer
117 * so we pass output_size as SIZE_MAX to pass checks, However, no guarantees
118 * for the output size actually being correct.
119 */
120 return mbedtls_pkcs5_pbes2_ext(pbe_params, mode, pwd, pwdlen, data,
121 datalen, output, SIZE_MAX, &output_len);
122 }
123
mbedtls_pkcs5_pbes2_ext(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,size_t output_size,size_t * output_len)124 int mbedtls_pkcs5_pbes2_ext(const mbedtls_asn1_buf *pbe_params, int mode,
125 const unsigned char *pwd, size_t pwdlen,
126 const unsigned char *data, size_t datalen,
127 unsigned char *output, size_t output_size,
128 size_t *output_len)
129 {
130 int ret, iterations = 0, keylen = 0;
131 unsigned char *p, *end;
132 mbedtls_asn1_buf kdf_alg_oid, enc_scheme_oid, kdf_alg_params, enc_scheme_params;
133 mbedtls_asn1_buf salt;
134 mbedtls_md_type_t md_type = MBEDTLS_MD_SHA1;
135 unsigned char key[32], iv[32];
136 const mbedtls_md_info_t *md_info;
137 const mbedtls_cipher_info_t *cipher_info;
138 mbedtls_md_context_t md_ctx;
139 mbedtls_cipher_type_t cipher_alg;
140 mbedtls_cipher_context_t cipher_ctx;
141 unsigned int padlen = 0;
142
143 p = pbe_params->p;
144 end = p + pbe_params->len;
145
146 /*
147 * PBES2-params ::= SEQUENCE {
148 * keyDerivationFunc AlgorithmIdentifier {{PBES2-KDFs}},
149 * encryptionScheme AlgorithmIdentifier {{PBES2-Encs}}
150 * }
151 */
152 if (pbe_params->tag != (MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) {
153 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT,
154 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
155 }
156
157 if ((ret = mbedtls_asn1_get_alg(&p, end, &kdf_alg_oid,
158 &kdf_alg_params)) != 0) {
159 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);
160 }
161
162 // Only PBKDF2 supported at the moment
163 //
164 if (MBEDTLS_OID_CMP(MBEDTLS_OID_PKCS5_PBKDF2, &kdf_alg_oid) != 0) {
165 return MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE;
166 }
167
168 if ((ret = pkcs5_parse_pbkdf2_params(&kdf_alg_params,
169 &salt, &iterations, &keylen,
170 &md_type)) != 0) {
171 return ret;
172 }
173
174 md_info = mbedtls_md_info_from_type(md_type);
175 if (md_info == NULL) {
176 return MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE;
177 }
178
179 if ((ret = mbedtls_asn1_get_alg(&p, end, &enc_scheme_oid,
180 &enc_scheme_params)) != 0) {
181 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);
182 }
183
184 if (mbedtls_oid_get_cipher_alg(&enc_scheme_oid, &cipher_alg) != 0) {
185 return MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE;
186 }
187
188 cipher_info = mbedtls_cipher_info_from_type(cipher_alg);
189 if (cipher_info == NULL) {
190 return MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE;
191 }
192
193 /*
194 * The value of keylen from pkcs5_parse_pbkdf2_params() is ignored
195 * since it is optional and we don't know if it was set or not
196 */
197 keylen = cipher_info->key_bitlen / 8;
198
199 if (enc_scheme_params.tag != MBEDTLS_ASN1_OCTET_STRING ||
200 enc_scheme_params.len != cipher_info->iv_size) {
201 return MBEDTLS_ERR_PKCS5_INVALID_FORMAT;
202 }
203
204 if (mode == MBEDTLS_PKCS5_DECRYPT) {
205 if (output_size < datalen) {
206 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
207 }
208 }
209
210 if (mode == MBEDTLS_PKCS5_ENCRYPT) {
211 padlen = cipher_info->block_size - (datalen % cipher_info->block_size);
212 if (output_size < (datalen + padlen)) {
213 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
214 }
215 }
216
217 mbedtls_md_init(&md_ctx);
218
219 mbedtls_cipher_init(&cipher_ctx);
220
221 memcpy(iv, enc_scheme_params.p, enc_scheme_params.len);
222
223 if ((ret = mbedtls_md_setup(&md_ctx, md_info, 1)) != 0) {
224 goto exit;
225 }
226
227 if ((ret = mbedtls_pkcs5_pbkdf2_hmac(&md_ctx, pwd, pwdlen, salt.p, salt.len,
228 iterations, keylen, key)) != 0) {
229 goto exit;
230 }
231
232 if ((ret = mbedtls_cipher_setup(&cipher_ctx, cipher_info)) != 0) {
233 goto exit;
234 }
235
236 if ((ret = mbedtls_cipher_setkey(&cipher_ctx, key, 8 * keylen,
237 (mbedtls_operation_t) mode)) != 0) {
238 goto exit;
239 }
240
241 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
242 /* PKCS5 uses CBC with PKCS7 padding (which is the same as
243 * "PKCS5 padding" except that it's typically only called PKCS5
244 * with 64-bit-block ciphers).
245 */
246 mbedtls_cipher_padding_t padding = MBEDTLS_PADDING_PKCS7;
247 #if !defined(MBEDTLS_CIPHER_PADDING_PKCS7)
248 /* For historical reasons, when decrypting, this function works when
249 * decrypting even when support for PKCS7 padding is disabled. In this
250 * case, it ignores the padding, and so will never report a
251 * password mismatch.
252 */
253 if (mode == MBEDTLS_DECRYPT) {
254 padding = MBEDTLS_PADDING_NONE;
255 }
256 #endif
257 if ((ret = mbedtls_cipher_set_padding_mode(&cipher_ctx, padding)) != 0) {
258 goto exit;
259 }
260 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
261 if ((ret = mbedtls_cipher_crypt(&cipher_ctx, iv, enc_scheme_params.len,
262 data, datalen, output, output_len)) != 0) {
263 ret = MBEDTLS_ERR_PKCS5_PASSWORD_MISMATCH;
264 }
265
266 exit:
267 mbedtls_md_free(&md_ctx);
268 mbedtls_cipher_free(&cipher_ctx);
269
270 return ret;
271 }
272 #endif /* MBEDTLS_ASN1_PARSE_C */
273
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)274 int mbedtls_pkcs5_pbkdf2_hmac(mbedtls_md_context_t *ctx,
275 const unsigned char *password,
276 size_t plen, const unsigned char *salt, size_t slen,
277 unsigned int iteration_count,
278 uint32_t key_length, unsigned char *output)
279 {
280 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
281 int j;
282 unsigned int i;
283 unsigned char md1[MBEDTLS_MD_MAX_SIZE];
284 unsigned char work[MBEDTLS_MD_MAX_SIZE];
285 unsigned char md_size = mbedtls_md_get_size(ctx->md_info);
286 size_t use_len;
287 unsigned char *out_p = output;
288 unsigned char counter[4];
289
290 memset(counter, 0, 4);
291 counter[3] = 1;
292
293 #if UINT_MAX > 0xFFFFFFFF
294 if (iteration_count > 0xFFFFFFFF) {
295 return MBEDTLS_ERR_PKCS5_BAD_INPUT_DATA;
296 }
297 #endif
298
299 if ((ret = mbedtls_md_hmac_starts(ctx, password, plen)) != 0) {
300 return ret;
301 }
302 while (key_length) {
303 // U1 ends up in work
304 //
305 if ((ret = mbedtls_md_hmac_update(ctx, salt, slen)) != 0) {
306 goto cleanup;
307 }
308
309 if ((ret = mbedtls_md_hmac_update(ctx, counter, 4)) != 0) {
310 goto cleanup;
311 }
312
313 if ((ret = mbedtls_md_hmac_finish(ctx, work)) != 0) {
314 goto cleanup;
315 }
316
317 if ((ret = mbedtls_md_hmac_reset(ctx)) != 0) {
318 goto cleanup;
319 }
320
321 memcpy(md1, work, md_size);
322
323 for (i = 1; i < iteration_count; i++) {
324 // U2 ends up in md1
325 //
326 if ((ret = mbedtls_md_hmac_update(ctx, md1, md_size)) != 0) {
327 goto cleanup;
328 }
329
330 if ((ret = mbedtls_md_hmac_finish(ctx, md1)) != 0) {
331 goto cleanup;
332 }
333
334 if ((ret = mbedtls_md_hmac_reset(ctx)) != 0) {
335 goto cleanup;
336 }
337
338 // U1 xor U2
339 //
340 for (j = 0; j < md_size; j++) {
341 work[j] ^= md1[j];
342 }
343 }
344
345 use_len = (key_length < md_size) ? key_length : md_size;
346 memcpy(out_p, work, use_len);
347
348 key_length -= (uint32_t) use_len;
349 out_p += use_len;
350
351 for (i = 4; i > 0; i--) {
352 if (++counter[i - 1] != 0) {
353 break;
354 }
355 }
356 }
357
358 cleanup:
359 /* Zeroise buffers to clear sensitive data from memory. */
360 mbedtls_platform_zeroize(work, MBEDTLS_MD_MAX_SIZE);
361 mbedtls_platform_zeroize(md1, MBEDTLS_MD_MAX_SIZE);
362
363 return ret;
364 }
365
366 #if defined(MBEDTLS_SELF_TEST)
367
368 #if !defined(MBEDTLS_SHA1_C)
mbedtls_pkcs5_self_test(int verbose)369 int mbedtls_pkcs5_self_test(int verbose)
370 {
371 if (verbose != 0) {
372 mbedtls_printf(" PBKDF2 (SHA1): skipped\n\n");
373 }
374
375 return 0;
376 }
377 #else
378
379 #define MAX_TESTS 6
380
381 static const size_t plen_test_data[MAX_TESTS] =
382 { 8, 8, 8, 24, 9 };
383
384 static const unsigned char password_test_data[MAX_TESTS][32] =
385 {
386 "password",
387 "password",
388 "password",
389 "passwordPASSWORDpassword",
390 "pass\0word",
391 };
392
393 static const size_t slen_test_data[MAX_TESTS] =
394 { 4, 4, 4, 36, 5 };
395
396 static const unsigned char salt_test_data[MAX_TESTS][40] =
397 {
398 "salt",
399 "salt",
400 "salt",
401 "saltSALTsaltSALTsaltSALTsaltSALTsalt",
402 "sa\0lt",
403 };
404
405 static const uint32_t it_cnt_test_data[MAX_TESTS] =
406 { 1, 2, 4096, 4096, 4096 };
407
408 static const uint32_t key_len_test_data[MAX_TESTS] =
409 { 20, 20, 20, 25, 16 };
410
411 static const unsigned char result_key_test_data[MAX_TESTS][32] =
412 {
413 { 0x0c, 0x60, 0xc8, 0x0f, 0x96, 0x1f, 0x0e, 0x71,
414 0xf3, 0xa9, 0xb5, 0x24, 0xaf, 0x60, 0x12, 0x06,
415 0x2f, 0xe0, 0x37, 0xa6 },
416 { 0xea, 0x6c, 0x01, 0x4d, 0xc7, 0x2d, 0x6f, 0x8c,
417 0xcd, 0x1e, 0xd9, 0x2a, 0xce, 0x1d, 0x41, 0xf0,
418 0xd8, 0xde, 0x89, 0x57 },
419 { 0x4b, 0x00, 0x79, 0x01, 0xb7, 0x65, 0x48, 0x9a,
420 0xbe, 0xad, 0x49, 0xd9, 0x26, 0xf7, 0x21, 0xd0,
421 0x65, 0xa4, 0x29, 0xc1 },
422 { 0x3d, 0x2e, 0xec, 0x4f, 0xe4, 0x1c, 0x84, 0x9b,
423 0x80, 0xc8, 0xd8, 0x36, 0x62, 0xc0, 0xe4, 0x4a,
424 0x8b, 0x29, 0x1a, 0x96, 0x4c, 0xf2, 0xf0, 0x70,
425 0x38 },
426 { 0x56, 0xfa, 0x6a, 0xa7, 0x55, 0x48, 0x09, 0x9d,
427 0xcc, 0x37, 0xd7, 0xf0, 0x34, 0x25, 0xe0, 0xc3 },
428 };
429
mbedtls_pkcs5_self_test(int verbose)430 int mbedtls_pkcs5_self_test(int verbose)
431 {
432 mbedtls_md_context_t sha1_ctx;
433 const mbedtls_md_info_t *info_sha1;
434 int ret, i;
435 unsigned char key[64];
436
437 mbedtls_md_init(&sha1_ctx);
438
439 info_sha1 = mbedtls_md_info_from_type(MBEDTLS_MD_SHA1);
440 if (info_sha1 == NULL) {
441 ret = 1;
442 goto exit;
443 }
444
445 if ((ret = mbedtls_md_setup(&sha1_ctx, info_sha1, 1)) != 0) {
446 ret = 1;
447 goto exit;
448 }
449
450 for (i = 0; i < MAX_TESTS; i++) {
451 if (verbose != 0) {
452 mbedtls_printf(" PBKDF2 (SHA1) #%d: ", i);
453 }
454
455 ret = mbedtls_pkcs5_pbkdf2_hmac(&sha1_ctx, password_test_data[i],
456 plen_test_data[i], salt_test_data[i],
457 slen_test_data[i], it_cnt_test_data[i],
458 key_len_test_data[i], key);
459 if (ret != 0 ||
460 memcmp(result_key_test_data[i], key, key_len_test_data[i]) != 0) {
461 if (verbose != 0) {
462 mbedtls_printf("failed\n");
463 }
464
465 ret = 1;
466 goto exit;
467 }
468
469 if (verbose != 0) {
470 mbedtls_printf("passed\n");
471 }
472 }
473
474 if (verbose != 0) {
475 mbedtls_printf("\n");
476 }
477
478 exit:
479 mbedtls_md_free(&sha1_ctx);
480
481 return ret;
482 }
483 #endif /* MBEDTLS_SHA1_C */
484
485 #endif /* MBEDTLS_SELF_TEST */
486
487 #endif /* MBEDTLS_PKCS5_C */
488