1 /*
2 * Copyright 2018-2024 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 /*
11 * HMAC low level APIs are deprecated for public use, but still ok for internal
12 * use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <stdlib.h>
17 #include <stdarg.h>
18 #include <string.h>
19 #include <openssl/hmac.h>
20 #include <openssl/evp.h>
21 #include <openssl/kdf.h>
22 #include <openssl/core_names.h>
23 #include <openssl/proverr.h>
24 #include "internal/cryptlib.h"
25 #include "internal/numbers.h"
26 #include "crypto/evp.h"
27 #include "prov/provider_ctx.h"
28 #include "prov/providercommon.h"
29 #include "prov/implementations.h"
30 #include "prov/provider_util.h"
31 #include "prov/securitycheck.h"
32 #include "pbkdf2.h"
33
34 /* Constants specified in SP800-132 */
35 #define KDF_PBKDF2_MIN_KEY_LEN_BITS 112
36 #define KDF_PBKDF2_MAX_KEY_LEN_DIGEST_RATIO 0xFFFFFFFF
37 #define KDF_PBKDF2_MIN_ITERATIONS 1000
38 #define KDF_PBKDF2_MIN_SALT_LEN (128 / 8)
39
40 static OSSL_FUNC_kdf_newctx_fn kdf_pbkdf2_new;
41 static OSSL_FUNC_kdf_dupctx_fn kdf_pbkdf2_dup;
42 static OSSL_FUNC_kdf_freectx_fn kdf_pbkdf2_free;
43 static OSSL_FUNC_kdf_reset_fn kdf_pbkdf2_reset;
44 static OSSL_FUNC_kdf_derive_fn kdf_pbkdf2_derive;
45 static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_pbkdf2_settable_ctx_params;
46 static OSSL_FUNC_kdf_set_ctx_params_fn kdf_pbkdf2_set_ctx_params;
47 static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_pbkdf2_gettable_ctx_params;
48 static OSSL_FUNC_kdf_get_ctx_params_fn kdf_pbkdf2_get_ctx_params;
49
50 typedef struct {
51 void *provctx;
52 unsigned char *pass;
53 size_t pass_len;
54 unsigned char *salt;
55 size_t salt_len;
56 uint64_t iter;
57 PROV_DIGEST digest;
58 int lower_bound_checks;
59 OSSL_FIPS_IND_DECLARE
60 } KDF_PBKDF2;
61
62 static int pbkdf2_derive(KDF_PBKDF2 *ctx, const char *pass, size_t passlen,
63 const unsigned char *salt, int saltlen, uint64_t iter,
64 const EVP_MD *digest, unsigned char *key,
65 size_t keylen, int lower_bound_checks);
66
67 static void kdf_pbkdf2_init(KDF_PBKDF2 *ctx);
68
kdf_pbkdf2_new_no_init(void * provctx)69 static void *kdf_pbkdf2_new_no_init(void *provctx)
70 {
71 KDF_PBKDF2 *ctx;
72
73 if (!ossl_prov_is_running())
74 return NULL;
75
76 ctx = OPENSSL_zalloc(sizeof(*ctx));
77 if (ctx == NULL)
78 return NULL;
79 ctx->provctx = provctx;
80 OSSL_FIPS_IND_INIT(ctx);
81 return ctx;
82 }
83
kdf_pbkdf2_new(void * provctx)84 static void *kdf_pbkdf2_new(void *provctx)
85 {
86 KDF_PBKDF2 *ctx = kdf_pbkdf2_new_no_init(provctx);
87
88 if (ctx != NULL)
89 kdf_pbkdf2_init(ctx);
90 return ctx;
91 }
92
kdf_pbkdf2_cleanup(KDF_PBKDF2 * ctx)93 static void kdf_pbkdf2_cleanup(KDF_PBKDF2 *ctx)
94 {
95 ossl_prov_digest_reset(&ctx->digest);
96 #ifdef FIPS_MODULE
97 OPENSSL_clear_free(ctx->salt, ctx->salt_len);
98 #else
99 OPENSSL_free(ctx->salt);
100 #endif
101 OPENSSL_clear_free(ctx->pass, ctx->pass_len);
102 memset(ctx, 0, sizeof(*ctx));
103 }
104
kdf_pbkdf2_free(void * vctx)105 static void kdf_pbkdf2_free(void *vctx)
106 {
107 KDF_PBKDF2 *ctx = (KDF_PBKDF2 *)vctx;
108
109 if (ctx != NULL) {
110 kdf_pbkdf2_cleanup(ctx);
111 OPENSSL_free(ctx);
112 }
113 }
114
kdf_pbkdf2_reset(void * vctx)115 static void kdf_pbkdf2_reset(void *vctx)
116 {
117 KDF_PBKDF2 *ctx = (KDF_PBKDF2 *)vctx;
118 void *provctx = ctx->provctx;
119
120 kdf_pbkdf2_cleanup(ctx);
121 ctx->provctx = provctx;
122 kdf_pbkdf2_init(ctx);
123 }
124
kdf_pbkdf2_dup(void * vctx)125 static void *kdf_pbkdf2_dup(void *vctx)
126 {
127 const KDF_PBKDF2 *src = (const KDF_PBKDF2 *)vctx;
128 KDF_PBKDF2 *dest;
129
130 /* We need a new PBKDF2 object but uninitialised since we're filling it */
131 dest = kdf_pbkdf2_new_no_init(src->provctx);
132 if (dest != NULL) {
133 if (!ossl_prov_memdup(src->salt, src->salt_len,
134 &dest->salt, &dest->salt_len)
135 || !ossl_prov_memdup(src->pass, src->pass_len,
136 &dest->pass, &dest->pass_len)
137 || !ossl_prov_digest_copy(&dest->digest, &src->digest))
138 goto err;
139 dest->iter = src->iter;
140 dest->lower_bound_checks = src->lower_bound_checks;
141 OSSL_FIPS_IND_COPY(dest, src)
142 }
143 return dest;
144
145 err:
146 kdf_pbkdf2_free(dest);
147 return NULL;
148 }
149
kdf_pbkdf2_init(KDF_PBKDF2 * ctx)150 static void kdf_pbkdf2_init(KDF_PBKDF2 *ctx)
151 {
152 OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
153 OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);
154
155 params[0] = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
156 SN_sha1, 0);
157 if (!ossl_prov_digest_load_from_params(&ctx->digest, params, provctx))
158 /* This is an error, but there is no way to indicate such directly */
159 ossl_prov_digest_reset(&ctx->digest);
160 ctx->iter = PKCS5_DEFAULT_ITER;
161 ctx->lower_bound_checks = ossl_kdf_pbkdf2_default_checks;
162 }
163
pbkdf2_set_membuf(unsigned char ** buffer,size_t * buflen,const OSSL_PARAM * p)164 static int pbkdf2_set_membuf(unsigned char **buffer, size_t *buflen,
165 const OSSL_PARAM *p)
166 {
167 OPENSSL_clear_free(*buffer, *buflen);
168 *buffer = NULL;
169 *buflen = 0;
170
171 if (p->data_size == 0) {
172 if ((*buffer = OPENSSL_malloc(1)) == NULL)
173 return 0;
174 } else if (p->data != NULL) {
175 if (!OSSL_PARAM_get_octet_string(p, (void **)buffer, 0, buflen))
176 return 0;
177 }
178 return 1;
179 }
180
pbkdf2_lower_bound_check_passed(int saltlen,uint64_t iter,size_t keylen,int * error,const char ** desc)181 static int pbkdf2_lower_bound_check_passed(int saltlen, uint64_t iter,
182 size_t keylen, int *error,
183 const char **desc)
184 {
185 if ((keylen * 8) < KDF_PBKDF2_MIN_KEY_LEN_BITS) {
186 *error = PROV_R_KEY_SIZE_TOO_SMALL;
187 if (desc != NULL)
188 *desc = "Key size";
189 return 0;
190 }
191 if (saltlen < KDF_PBKDF2_MIN_SALT_LEN) {
192 *error = PROV_R_INVALID_SALT_LENGTH;
193 if (desc != NULL)
194 *desc = "Salt size";
195 return 0;
196 }
197 if (iter < KDF_PBKDF2_MIN_ITERATIONS) {
198 *error = PROV_R_INVALID_ITERATION_COUNT;
199 if (desc != NULL)
200 *desc = "Iteration count";
201 return 0;
202 }
203
204 return 1;
205 }
206
207 #ifdef FIPS_MODULE
fips_lower_bound_check_passed(KDF_PBKDF2 * ctx,size_t keylen)208 static int fips_lower_bound_check_passed(KDF_PBKDF2 *ctx, size_t keylen)
209 {
210 OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
211 int error = 0;
212 const char *desc = NULL;
213 int approved = pbkdf2_lower_bound_check_passed(ctx->salt_len, ctx->iter,
214 keylen, &error, &desc);
215
216 if (!approved) {
217 if (!OSSL_FIPS_IND_ON_UNAPPROVED(ctx, OSSL_FIPS_IND_SETTABLE0, libctx,
218 "PBKDF2", desc,
219 ossl_fips_config_pbkdf2_lower_bound_check)) {
220 ERR_raise(ERR_LIB_PROV, error);
221 return 0;
222 }
223 }
224 return 1;
225 }
226 #endif
227
kdf_pbkdf2_derive(void * vctx,unsigned char * key,size_t keylen,const OSSL_PARAM params[])228 static int kdf_pbkdf2_derive(void *vctx, unsigned char *key, size_t keylen,
229 const OSSL_PARAM params[])
230 {
231 KDF_PBKDF2 *ctx = (KDF_PBKDF2 *)vctx;
232 const EVP_MD *md;
233
234 if (!ossl_prov_is_running() || !kdf_pbkdf2_set_ctx_params(ctx, params))
235 return 0;
236
237 if (ctx->pass == NULL) {
238 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_PASS);
239 return 0;
240 }
241
242 if (ctx->salt == NULL) {
243 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SALT);
244 return 0;
245 }
246
247 md = ossl_prov_digest_md(&ctx->digest);
248 return pbkdf2_derive(ctx, (char *)ctx->pass, ctx->pass_len,
249 ctx->salt, ctx->salt_len, ctx->iter,
250 md, key, keylen, ctx->lower_bound_checks);
251 }
252
kdf_pbkdf2_set_ctx_params(void * vctx,const OSSL_PARAM params[])253 static int kdf_pbkdf2_set_ctx_params(void *vctx, const OSSL_PARAM params[])
254 {
255 const OSSL_PARAM *p;
256 KDF_PBKDF2 *ctx = vctx;
257 OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);
258 int pkcs5;
259 uint64_t iter, min_iter;
260 const EVP_MD *md;
261
262 if (ossl_param_is_empty(params))
263 return 1;
264
265 if (OSSL_PARAM_locate_const(params, OSSL_ALG_PARAM_DIGEST) != NULL) {
266 if (!ossl_prov_digest_load_from_params(&ctx->digest, params, provctx))
267 return 0;
268 md = ossl_prov_digest_md(&ctx->digest);
269 if (EVP_MD_xof(md)) {
270 ERR_raise(ERR_LIB_PROV, PROV_R_XOF_DIGESTS_NOT_ALLOWED);
271 return 0;
272 }
273 }
274
275 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PKCS5)) != NULL) {
276 if (!OSSL_PARAM_get_int(p, &pkcs5))
277 return 0;
278 ctx->lower_bound_checks = pkcs5 == 0;
279 #ifdef FIPS_MODULE
280 ossl_FIPS_IND_set_settable(OSSL_FIPS_IND_GET(ctx),
281 OSSL_FIPS_IND_SETTABLE0,
282 ctx->lower_bound_checks);
283 #endif
284 }
285
286 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL)
287 if (!pbkdf2_set_membuf(&ctx->pass, &ctx->pass_len, p))
288 return 0;
289
290 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL) {
291 if (ctx->lower_bound_checks != 0
292 && p->data_size < KDF_PBKDF2_MIN_SALT_LEN) {
293 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SALT_LENGTH);
294 return 0;
295 }
296 if (!pbkdf2_set_membuf(&ctx->salt, &ctx->salt_len, p))
297 return 0;
298 }
299
300 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_ITER)) != NULL) {
301 if (!OSSL_PARAM_get_uint64(p, &iter))
302 return 0;
303 min_iter = ctx->lower_bound_checks != 0 ? KDF_PBKDF2_MIN_ITERATIONS : 1;
304 if (iter < min_iter) {
305 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_ITERATION_COUNT);
306 return 0;
307 }
308 ctx->iter = iter;
309 }
310 return 1;
311 }
312
kdf_pbkdf2_settable_ctx_params(ossl_unused void * ctx,ossl_unused void * p_ctx)313 static const OSSL_PARAM *kdf_pbkdf2_settable_ctx_params(ossl_unused void *ctx,
314 ossl_unused void *p_ctx)
315 {
316 static const OSSL_PARAM known_settable_ctx_params[] = {
317 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
318 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
319 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_PASSWORD, NULL, 0),
320 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
321 OSSL_PARAM_uint64(OSSL_KDF_PARAM_ITER, NULL),
322 OSSL_PARAM_int(OSSL_KDF_PARAM_PKCS5, NULL),
323 OSSL_PARAM_END
324 };
325 return known_settable_ctx_params;
326 }
327
kdf_pbkdf2_get_ctx_params(void * vctx,OSSL_PARAM params[])328 static int kdf_pbkdf2_get_ctx_params(void *vctx, OSSL_PARAM params[])
329 {
330 OSSL_PARAM *p;
331
332 if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
333 if (!OSSL_PARAM_set_size_t(p, SIZE_MAX))
334 return 0;
335
336 if (!OSSL_FIPS_IND_GET_CTX_PARAM((KDF_PBKDF2 *) vctx, params))
337 return 0;
338 return 1;
339 }
340
kdf_pbkdf2_gettable_ctx_params(ossl_unused void * ctx,ossl_unused void * p_ctx)341 static const OSSL_PARAM *kdf_pbkdf2_gettable_ctx_params(ossl_unused void *ctx,
342 ossl_unused void *p_ctx)
343 {
344 static const OSSL_PARAM known_gettable_ctx_params[] = {
345 OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
346 OSSL_FIPS_IND_GETTABLE_CTX_PARAM()
347 OSSL_PARAM_END
348 };
349 return known_gettable_ctx_params;
350 }
351
352 const OSSL_DISPATCH ossl_kdf_pbkdf2_functions[] = {
353 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_pbkdf2_new },
354 { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_pbkdf2_dup },
355 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_pbkdf2_free },
356 { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_pbkdf2_reset },
357 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_pbkdf2_derive },
358 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
359 (void(*)(void))kdf_pbkdf2_settable_ctx_params },
360 { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_pbkdf2_set_ctx_params },
361 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
362 (void(*)(void))kdf_pbkdf2_gettable_ctx_params },
363 { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_pbkdf2_get_ctx_params },
364 OSSL_DISPATCH_END
365 };
366
367 /*
368 * This is an implementation of PKCS#5 v2.0 password based encryption key
369 * derivation function PBKDF2. SHA1 version verified against test vectors
370 * posted by Peter Gutmann to the PKCS-TNG mailing list.
371 *
372 * The constraints specified by SP800-132 have been added i.e.
373 * - Check the range of the key length.
374 * - Minimum iteration count of 1000.
375 * - Randomly-generated portion of the salt shall be at least 128 bits.
376 */
pbkdf2_derive(KDF_PBKDF2 * ctx,const char * pass,size_t passlen,const unsigned char * salt,int saltlen,uint64_t iter,const EVP_MD * digest,unsigned char * key,size_t keylen,int lower_bound_checks)377 static int pbkdf2_derive(KDF_PBKDF2 *ctx, const char *pass, size_t passlen,
378 const unsigned char *salt, int saltlen, uint64_t iter,
379 const EVP_MD *digest, unsigned char *key,
380 size_t keylen, int lower_bound_checks)
381 {
382 int ret = 0;
383 unsigned char digtmp[EVP_MAX_MD_SIZE], *p, itmp[4];
384 int cplen, k, tkeylen, mdlen;
385 uint64_t j;
386 unsigned long i = 1;
387 HMAC_CTX *hctx_tpl = NULL, *hctx = NULL;
388
389 mdlen = EVP_MD_get_size(digest);
390 if (mdlen <= 0)
391 return 0;
392
393 /*
394 * This check should always be done because keylen / mdlen >= (2^32 - 1)
395 * results in an overflow of the loop counter 'i'.
396 */
397 if ((keylen / mdlen) >= KDF_PBKDF2_MAX_KEY_LEN_DIGEST_RATIO) {
398 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
399 return 0;
400 }
401
402 #ifdef FIPS_MODULE
403 if (!fips_lower_bound_check_passed(ctx, keylen))
404 return 0;
405 #else
406 if (lower_bound_checks) {
407 int error = 0;
408 int passed = pbkdf2_lower_bound_check_passed(saltlen, iter, keylen,
409 &error, NULL);
410
411 if (!passed) {
412 ERR_raise(ERR_LIB_PROV, error);
413 return 0;
414 }
415 }
416 #endif
417
418 hctx_tpl = HMAC_CTX_new();
419 if (hctx_tpl == NULL)
420 return 0;
421 p = key;
422 tkeylen = keylen;
423 if (!HMAC_Init_ex(hctx_tpl, pass, passlen, digest, NULL))
424 goto err;
425 hctx = HMAC_CTX_new();
426 if (hctx == NULL)
427 goto err;
428 while (tkeylen) {
429 if (tkeylen > mdlen)
430 cplen = mdlen;
431 else
432 cplen = tkeylen;
433 /*
434 * We are unlikely to ever use more than 256 blocks (5120 bits!) but
435 * just in case...
436 */
437 itmp[0] = (unsigned char)((i >> 24) & 0xff);
438 itmp[1] = (unsigned char)((i >> 16) & 0xff);
439 itmp[2] = (unsigned char)((i >> 8) & 0xff);
440 itmp[3] = (unsigned char)(i & 0xff);
441 if (!HMAC_CTX_copy(hctx, hctx_tpl))
442 goto err;
443 if (!HMAC_Update(hctx, salt, saltlen)
444 || !HMAC_Update(hctx, itmp, 4)
445 || !HMAC_Final(hctx, digtmp, NULL))
446 goto err;
447 memcpy(p, digtmp, cplen);
448 for (j = 1; j < iter; j++) {
449 if (!HMAC_CTX_copy(hctx, hctx_tpl))
450 goto err;
451 if (!HMAC_Update(hctx, digtmp, mdlen)
452 || !HMAC_Final(hctx, digtmp, NULL))
453 goto err;
454 for (k = 0; k < cplen; k++)
455 p[k] ^= digtmp[k];
456 }
457 tkeylen -= cplen;
458 i++;
459 p += cplen;
460 }
461 ret = 1;
462
463 err:
464 HMAC_CTX_free(hctx);
465 HMAC_CTX_free(hctx_tpl);
466 return ret;
467 }
468
