1 /*
2 * Copyright 2017-2025 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 #include <stdlib.h>
11 #include <stdarg.h>
12 #include <string.h>
13 #include <openssl/evp.h>
14 #include <openssl/kdf.h>
15 #include <openssl/err.h>
16 #include <openssl/core_names.h>
17 #include <openssl/proverr.h>
18 #include "crypto/evp.h"
19 #include "internal/numbers.h"
20 #include "prov/implementations.h"
21 #include "prov/provider_ctx.h"
22 #include "prov/providercommon.h"
23 #include "prov/implementations.h"
24
25 #ifndef OPENSSL_NO_SCRYPT
26
27 static OSSL_FUNC_kdf_newctx_fn kdf_scrypt_new;
28 static OSSL_FUNC_kdf_freectx_fn kdf_scrypt_free;
29 static OSSL_FUNC_kdf_reset_fn kdf_scrypt_reset;
30 static OSSL_FUNC_kdf_derive_fn kdf_scrypt_derive;
31 static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_scrypt_settable_ctx_params;
32 static OSSL_FUNC_kdf_set_ctx_params_fn kdf_scrypt_set_ctx_params;
33 static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_scrypt_gettable_ctx_params;
34 static OSSL_FUNC_kdf_get_ctx_params_fn kdf_scrypt_get_ctx_params;
35
36 static int scrypt_alg(const char *pass, size_t passlen,
37 const unsigned char *salt, size_t saltlen,
38 uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
39 unsigned char *key, size_t keylen, EVP_MD *sha256,
40 OSSL_LIB_CTX *libctx, const char *propq);
41
42 typedef struct {
43 OSSL_LIB_CTX *libctx;
44 char *propq;
45 unsigned char *pass;
46 size_t pass_len;
47 unsigned char *salt;
48 size_t salt_len;
49 uint64_t N;
50 uint64_t r, p;
51 uint64_t maxmem_bytes;
52 EVP_MD *sha256;
53 } KDF_SCRYPT;
54
55 static void kdf_scrypt_init(KDF_SCRYPT *ctx);
56
kdf_scrypt_new(void * provctx)57 static void *kdf_scrypt_new(void *provctx)
58 {
59 KDF_SCRYPT *ctx;
60
61 if (!ossl_prov_is_running())
62 return NULL;
63
64 ctx = OPENSSL_zalloc(sizeof(*ctx));
65 if (ctx == NULL) {
66 ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
67 return NULL;
68 }
69 ctx->libctx = PROV_LIBCTX_OF(provctx);
70 kdf_scrypt_init(ctx);
71 return ctx;
72 }
73
kdf_scrypt_free(void * vctx)74 static void kdf_scrypt_free(void *vctx)
75 {
76 KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
77
78 if (ctx != NULL) {
79 OPENSSL_free(ctx->propq);
80 EVP_MD_free(ctx->sha256);
81 kdf_scrypt_reset(ctx);
82 OPENSSL_free(ctx);
83 }
84 }
85
kdf_scrypt_reset(void * vctx)86 static void kdf_scrypt_reset(void *vctx)
87 {
88 KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
89
90 OPENSSL_free(ctx->salt);
91 ctx->salt = NULL;
92 OPENSSL_clear_free(ctx->pass, ctx->pass_len);
93 ctx->pass = NULL;
94 kdf_scrypt_init(ctx);
95 }
96
kdf_scrypt_init(KDF_SCRYPT * ctx)97 static void kdf_scrypt_init(KDF_SCRYPT *ctx)
98 {
99 /* Default values are the most conservative recommendation given in the
100 * original paper of C. Percival. Derivation uses roughly 1 GiB of memory
101 * for this parameter choice (approx. 128 * r * N * p bytes).
102 */
103 ctx->N = 1 << 20;
104 ctx->r = 8;
105 ctx->p = 1;
106 ctx->maxmem_bytes = 1025 * 1024 * 1024;
107 }
108
scrypt_set_membuf(unsigned char ** buffer,size_t * buflen,const OSSL_PARAM * p)109 static int scrypt_set_membuf(unsigned char **buffer, size_t *buflen,
110 const OSSL_PARAM *p)
111 {
112 OPENSSL_clear_free(*buffer, *buflen);
113 *buffer = NULL;
114 *buflen = 0;
115
116 if (p->data_size == 0) {
117 if ((*buffer = OPENSSL_malloc(1)) == NULL) {
118 ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
119 return 0;
120 }
121 } else if (p->data != NULL) {
122 if (!OSSL_PARAM_get_octet_string(p, (void **)buffer, 0, buflen))
123 return 0;
124 }
125 return 1;
126 }
127
set_digest(KDF_SCRYPT * ctx)128 static int set_digest(KDF_SCRYPT *ctx)
129 {
130 EVP_MD_free(ctx->sha256);
131 ctx->sha256 = EVP_MD_fetch(ctx->libctx, "sha256", ctx->propq);
132 if (ctx->sha256 == NULL) {
133 ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_LOAD_SHA256);
134 return 0;
135 }
136 return 1;
137 }
138
set_property_query(KDF_SCRYPT * ctx,const char * propq)139 static int set_property_query(KDF_SCRYPT *ctx, const char *propq)
140 {
141 OPENSSL_free(ctx->propq);
142 ctx->propq = NULL;
143 if (propq != NULL) {
144 ctx->propq = OPENSSL_strdup(propq);
145 if (ctx->propq == NULL) {
146 ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
147 return 0;
148 }
149 }
150 return 1;
151 }
152
kdf_scrypt_derive(void * vctx,unsigned char * key,size_t keylen,const OSSL_PARAM params[])153 static int kdf_scrypt_derive(void *vctx, unsigned char *key, size_t keylen,
154 const OSSL_PARAM params[])
155 {
156 KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
157
158 if (!ossl_prov_is_running() || !kdf_scrypt_set_ctx_params(ctx, params))
159 return 0;
160
161 if (ctx->pass == NULL) {
162 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_PASS);
163 return 0;
164 }
165
166 if (ctx->salt == NULL) {
167 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SALT);
168 return 0;
169 }
170
171 if (ctx->sha256 == NULL && !set_digest(ctx))
172 return 0;
173
174 return scrypt_alg((char *)ctx->pass, ctx->pass_len, ctx->salt,
175 ctx->salt_len, ctx->N, ctx->r, ctx->p,
176 ctx->maxmem_bytes, key, keylen, ctx->sha256,
177 ctx->libctx, ctx->propq);
178 }
179
is_power_of_two(uint64_t value)180 static int is_power_of_two(uint64_t value)
181 {
182 return (value != 0) && ((value & (value - 1)) == 0);
183 }
184
kdf_scrypt_set_ctx_params(void * vctx,const OSSL_PARAM params[])185 static int kdf_scrypt_set_ctx_params(void *vctx, const OSSL_PARAM params[])
186 {
187 const OSSL_PARAM *p;
188 KDF_SCRYPT *ctx = vctx;
189 uint64_t u64_value;
190
191 if (params == NULL)
192 return 1;
193
194 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL)
195 if (!scrypt_set_membuf(&ctx->pass, &ctx->pass_len, p))
196 return 0;
197
198 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL)
199 if (!scrypt_set_membuf(&ctx->salt, &ctx->salt_len, p))
200 return 0;
201
202 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_N))
203 != NULL) {
204 if (!OSSL_PARAM_get_uint64(p, &u64_value)
205 || u64_value <= 1
206 || !is_power_of_two(u64_value))
207 return 0;
208 ctx->N = u64_value;
209 }
210
211 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_R))
212 != NULL) {
213 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
214 return 0;
215 ctx->r = u64_value;
216 }
217
218 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_P))
219 != NULL) {
220 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
221 return 0;
222 ctx->p = u64_value;
223 }
224
225 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_MAXMEM))
226 != NULL) {
227 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
228 return 0;
229 ctx->maxmem_bytes = u64_value;
230 }
231
232 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PROPERTIES);
233 if (p != NULL) {
234 if (p->data_type != OSSL_PARAM_UTF8_STRING
235 || !set_property_query(ctx, p->data)
236 || !set_digest(ctx))
237 return 0;
238 }
239 return 1;
240 }
241
kdf_scrypt_settable_ctx_params(ossl_unused void * ctx,ossl_unused void * p_ctx)242 static const OSSL_PARAM *kdf_scrypt_settable_ctx_params(ossl_unused void *ctx,
243 ossl_unused void *p_ctx)
244 {
245 static const OSSL_PARAM known_settable_ctx_params[] = {
246 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_PASSWORD, NULL, 0),
247 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
248 OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_N, NULL),
249 OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_R, NULL),
250 OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_P, NULL),
251 OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_MAXMEM, NULL),
252 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
253 OSSL_PARAM_END
254 };
255 return known_settable_ctx_params;
256 }
257
kdf_scrypt_get_ctx_params(void * vctx,OSSL_PARAM params[])258 static int kdf_scrypt_get_ctx_params(void *vctx, OSSL_PARAM params[])
259 {
260 OSSL_PARAM *p;
261
262 if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
263 return OSSL_PARAM_set_size_t(p, SIZE_MAX);
264 return -2;
265 }
266
kdf_scrypt_gettable_ctx_params(ossl_unused void * ctx,ossl_unused void * p_ctx)267 static const OSSL_PARAM *kdf_scrypt_gettable_ctx_params(ossl_unused void *ctx,
268 ossl_unused void *p_ctx)
269 {
270 static const OSSL_PARAM known_gettable_ctx_params[] = {
271 OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
272 OSSL_PARAM_END
273 };
274 return known_gettable_ctx_params;
275 }
276
277 const OSSL_DISPATCH ossl_kdf_scrypt_functions[] = {
278 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_scrypt_new },
279 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_scrypt_free },
280 { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_scrypt_reset },
281 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_scrypt_derive },
282 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
283 (void(*)(void))kdf_scrypt_settable_ctx_params },
284 { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_scrypt_set_ctx_params },
285 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
286 (void(*)(void))kdf_scrypt_gettable_ctx_params },
287 { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_scrypt_get_ctx_params },
288 { 0, NULL }
289 };
290
291 #define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
salsa208_word_specification(uint32_t inout[16])292 static void salsa208_word_specification(uint32_t inout[16])
293 {
294 int i;
295 uint32_t x[16];
296
297 memcpy(x, inout, sizeof(x));
298 for (i = 8; i > 0; i -= 2) {
299 x[4] ^= R(x[0] + x[12], 7);
300 x[8] ^= R(x[4] + x[0], 9);
301 x[12] ^= R(x[8] + x[4], 13);
302 x[0] ^= R(x[12] + x[8], 18);
303 x[9] ^= R(x[5] + x[1], 7);
304 x[13] ^= R(x[9] + x[5], 9);
305 x[1] ^= R(x[13] + x[9], 13);
306 x[5] ^= R(x[1] + x[13], 18);
307 x[14] ^= R(x[10] + x[6], 7);
308 x[2] ^= R(x[14] + x[10], 9);
309 x[6] ^= R(x[2] + x[14], 13);
310 x[10] ^= R(x[6] + x[2], 18);
311 x[3] ^= R(x[15] + x[11], 7);
312 x[7] ^= R(x[3] + x[15], 9);
313 x[11] ^= R(x[7] + x[3], 13);
314 x[15] ^= R(x[11] + x[7], 18);
315 x[1] ^= R(x[0] + x[3], 7);
316 x[2] ^= R(x[1] + x[0], 9);
317 x[3] ^= R(x[2] + x[1], 13);
318 x[0] ^= R(x[3] + x[2], 18);
319 x[6] ^= R(x[5] + x[4], 7);
320 x[7] ^= R(x[6] + x[5], 9);
321 x[4] ^= R(x[7] + x[6], 13);
322 x[5] ^= R(x[4] + x[7], 18);
323 x[11] ^= R(x[10] + x[9], 7);
324 x[8] ^= R(x[11] + x[10], 9);
325 x[9] ^= R(x[8] + x[11], 13);
326 x[10] ^= R(x[9] + x[8], 18);
327 x[12] ^= R(x[15] + x[14], 7);
328 x[13] ^= R(x[12] + x[15], 9);
329 x[14] ^= R(x[13] + x[12], 13);
330 x[15] ^= R(x[14] + x[13], 18);
331 }
332 for (i = 0; i < 16; ++i)
333 inout[i] += x[i];
334 OPENSSL_cleanse(x, sizeof(x));
335 }
336
scryptBlockMix(uint32_t * B_,uint32_t * B,uint64_t r)337 static void scryptBlockMix(uint32_t *B_, uint32_t *B, uint64_t r)
338 {
339 uint64_t i, j;
340 uint32_t X[16], *pB;
341
342 memcpy(X, B + (r * 2 - 1) * 16, sizeof(X));
343 pB = B;
344 for (i = 0; i < r * 2; i++) {
345 for (j = 0; j < 16; j++)
346 X[j] ^= *pB++;
347 salsa208_word_specification(X);
348 memcpy(B_ + (i / 2 + (i & 1) * r) * 16, X, sizeof(X));
349 }
350 OPENSSL_cleanse(X, sizeof(X));
351 }
352
scryptROMix(unsigned char * B,uint64_t r,uint64_t N,uint32_t * X,uint32_t * T,uint32_t * V)353 static void scryptROMix(unsigned char *B, uint64_t r, uint64_t N,
354 uint32_t *X, uint32_t *T, uint32_t *V)
355 {
356 unsigned char *pB;
357 uint32_t *pV;
358 uint64_t i, k;
359
360 /* Convert from little endian input */
361 for (pV = V, i = 0, pB = B; i < 32 * r; i++, pV++) {
362 *pV = *pB++;
363 *pV |= *pB++ << 8;
364 *pV |= *pB++ << 16;
365 *pV |= (uint32_t)*pB++ << 24;
366 }
367
368 for (i = 1; i < N; i++, pV += 32 * r)
369 scryptBlockMix(pV, pV - 32 * r, r);
370
371 scryptBlockMix(X, V + (N - 1) * 32 * r, r);
372
373 for (i = 0; i < N; i++) {
374 uint32_t j;
375 j = X[16 * (2 * r - 1)] % N;
376 pV = V + 32 * r * j;
377 for (k = 0; k < 32 * r; k++)
378 T[k] = X[k] ^ *pV++;
379 scryptBlockMix(X, T, r);
380 }
381 /* Convert output to little endian */
382 for (i = 0, pB = B; i < 32 * r; i++) {
383 uint32_t xtmp = X[i];
384 *pB++ = xtmp & 0xff;
385 *pB++ = (xtmp >> 8) & 0xff;
386 *pB++ = (xtmp >> 16) & 0xff;
387 *pB++ = (xtmp >> 24) & 0xff;
388 }
389 }
390
391 #ifndef SIZE_MAX
392 # define SIZE_MAX ((size_t)-1)
393 #endif
394
395 /*
396 * Maximum power of two that will fit in uint64_t: this should work on
397 * most (all?) platforms.
398 */
399
400 #define LOG2_UINT64_MAX (sizeof(uint64_t) * 8 - 1)
401
402 /*
403 * Maximum value of p * r:
404 * p <= ((2^32-1) * hLen) / MFLen =>
405 * p <= ((2^32-1) * 32) / (128 * r) =>
406 * p * r <= (2^30-1)
407 */
408
409 #define SCRYPT_PR_MAX ((1 << 30) - 1)
410
scrypt_alg(const char * pass,size_t passlen,const unsigned char * salt,size_t saltlen,uint64_t N,uint64_t r,uint64_t p,uint64_t maxmem,unsigned char * key,size_t keylen,EVP_MD * sha256,OSSL_LIB_CTX * libctx,const char * propq)411 static int scrypt_alg(const char *pass, size_t passlen,
412 const unsigned char *salt, size_t saltlen,
413 uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
414 unsigned char *key, size_t keylen, EVP_MD *sha256,
415 OSSL_LIB_CTX *libctx, const char *propq)
416 {
417 int rv = 0;
418 unsigned char *B;
419 uint32_t *X, *V, *T;
420 uint64_t i, Blen, Vlen;
421
422 /* Sanity check parameters */
423 /* initial check, r,p must be non zero, N >= 2 and a power of 2 */
424 if (r == 0 || p == 0 || N < 2 || (N & (N - 1)))
425 return 0;
426 /* Check p * r < SCRYPT_PR_MAX avoiding overflow */
427 if (p > SCRYPT_PR_MAX / r) {
428 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
429 return 0;
430 }
431
432 /*
433 * Need to check N: if 2^(128 * r / 8) overflows limit this is
434 * automatically satisfied since N <= UINT64_MAX.
435 */
436
437 if (16 * r <= LOG2_UINT64_MAX) {
438 if (N >= (((uint64_t)1) << (16 * r))) {
439 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
440 return 0;
441 }
442 }
443
444 /* Memory checks: check total allocated buffer size fits in uint64_t */
445
446 /*
447 * B size in section 5 step 1.S
448 * Note: we know p * 128 * r < UINT64_MAX because we already checked
449 * p * r < SCRYPT_PR_MAX
450 */
451 Blen = p * 128 * r;
452 /*
453 * Yet we pass it as integer to PKCS5_PBKDF2_HMAC... [This would
454 * have to be revised when/if PKCS5_PBKDF2_HMAC accepts size_t.]
455 */
456 if (Blen > INT_MAX) {
457 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
458 return 0;
459 }
460
461 /*
462 * Check 32 * r * (N + 2) * sizeof(uint32_t) fits in uint64_t
463 * This is combined size V, X and T (section 4)
464 */
465 i = UINT64_MAX / (32 * sizeof(uint32_t));
466 if (N + 2 > i / r) {
467 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
468 return 0;
469 }
470 Vlen = 32 * r * (N + 2) * sizeof(uint32_t);
471
472 /* check total allocated size fits in uint64_t */
473 if (Blen > UINT64_MAX - Vlen) {
474 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
475 return 0;
476 }
477
478 /* Check that the maximum memory doesn't exceed a size_t limits */
479 if (maxmem > SIZE_MAX)
480 maxmem = SIZE_MAX;
481
482 if (Blen + Vlen > maxmem) {
483 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
484 return 0;
485 }
486
487 /* If no key return to indicate parameters are OK */
488 if (key == NULL)
489 return 1;
490
491 B = OPENSSL_malloc((size_t)(Blen + Vlen));
492 if (B == NULL) {
493 ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
494 return 0;
495 }
496 X = (uint32_t *)(B + Blen);
497 T = X + 32 * r;
498 V = T + 32 * r;
499 if (ossl_pkcs5_pbkdf2_hmac_ex(pass, passlen, salt, saltlen, 1, sha256,
500 (int)Blen, B, libctx, propq) == 0)
501 goto err;
502
503 for (i = 0; i < p; i++)
504 scryptROMix(B + 128 * r * i, r, N, X, T, V);
505
506 if (ossl_pkcs5_pbkdf2_hmac_ex(pass, passlen, B, (int)Blen, 1, sha256,
507 keylen, key, libctx, propq) == 0)
508 goto err;
509 rv = 1;
510 err:
511 if (rv == 0)
512 ERR_raise(ERR_LIB_EVP, EVP_R_PBKDF2_ERROR);
513
514 OPENSSL_clear_free(B, (size_t)(Blen + Vlen));
515 return rv;
516 }
517
518 #endif
519