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/provider_util.h"
24
25 #ifndef OPENSSL_NO_SCRYPT
26
27 static OSSL_FUNC_kdf_newctx_fn kdf_scrypt_new;
28 static OSSL_FUNC_kdf_dupctx_fn kdf_scrypt_dup;
29 static OSSL_FUNC_kdf_freectx_fn kdf_scrypt_free;
30 static OSSL_FUNC_kdf_reset_fn kdf_scrypt_reset;
31 static OSSL_FUNC_kdf_derive_fn kdf_scrypt_derive;
32 static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_scrypt_settable_ctx_params;
33 static OSSL_FUNC_kdf_set_ctx_params_fn kdf_scrypt_set_ctx_params;
34 static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_scrypt_gettable_ctx_params;
35 static OSSL_FUNC_kdf_get_ctx_params_fn kdf_scrypt_get_ctx_params;
36
37 static int scrypt_alg(const char *pass, size_t passlen,
38 const unsigned char *salt, size_t saltlen,
39 uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
40 unsigned char *key, size_t keylen, EVP_MD *sha256,
41 OSSL_LIB_CTX *libctx, const char *propq);
42
43 typedef struct {
44 OSSL_LIB_CTX *libctx;
45 char *propq;
46 unsigned char *pass;
47 size_t pass_len;
48 unsigned char *salt;
49 size_t salt_len;
50 uint64_t N;
51 uint64_t r, p;
52 uint64_t maxmem_bytes;
53 EVP_MD *sha256;
54 } KDF_SCRYPT;
55
56 static void kdf_scrypt_init(KDF_SCRYPT *ctx);
57
kdf_scrypt_new_inner(OSSL_LIB_CTX * libctx)58 static void *kdf_scrypt_new_inner(OSSL_LIB_CTX *libctx)
59 {
60 KDF_SCRYPT *ctx;
61
62 if (!ossl_prov_is_running())
63 return NULL;
64
65 ctx = OPENSSL_zalloc(sizeof(*ctx));
66 if (ctx == NULL)
67 return NULL;
68 ctx->libctx = libctx;
69 kdf_scrypt_init(ctx);
70 return ctx;
71 }
72
kdf_scrypt_new(void * provctx)73 static void *kdf_scrypt_new(void *provctx)
74 {
75 return kdf_scrypt_new_inner(PROV_LIBCTX_OF(provctx));
76 }
77
kdf_scrypt_free(void * vctx)78 static void kdf_scrypt_free(void *vctx)
79 {
80 KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
81
82 if (ctx != NULL) {
83 OPENSSL_free(ctx->propq);
84 EVP_MD_free(ctx->sha256);
85 kdf_scrypt_reset(ctx);
86 OPENSSL_free(ctx);
87 }
88 }
89
kdf_scrypt_reset(void * vctx)90 static void kdf_scrypt_reset(void *vctx)
91 {
92 KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
93
94 OPENSSL_free(ctx->salt);
95 ctx->salt = NULL;
96 OPENSSL_clear_free(ctx->pass, ctx->pass_len);
97 ctx->pass = NULL;
98 kdf_scrypt_init(ctx);
99 }
100
kdf_scrypt_dup(void * vctx)101 static void *kdf_scrypt_dup(void *vctx)
102 {
103 const KDF_SCRYPT *src = (const KDF_SCRYPT *)vctx;
104 KDF_SCRYPT *dest;
105
106 dest = kdf_scrypt_new_inner(src->libctx);
107 if (dest != NULL) {
108 if (src->sha256 != NULL && !EVP_MD_up_ref(src->sha256))
109 goto err;
110 if (src->propq != NULL) {
111 dest->propq = OPENSSL_strdup(src->propq);
112 if (dest->propq == NULL)
113 goto err;
114 }
115 if (!ossl_prov_memdup(src->salt, src->salt_len,
116 &dest->salt, &dest->salt_len)
117 || !ossl_prov_memdup(src->pass, src->pass_len,
118 &dest->pass , &dest->pass_len))
119 goto err;
120 dest->N = src->N;
121 dest->r = src->r;
122 dest->p = src->p;
123 dest->maxmem_bytes = src->maxmem_bytes;
124 dest->sha256 = src->sha256;
125 }
126 return dest;
127
128 err:
129 kdf_scrypt_free(dest);
130 return NULL;
131 }
132
kdf_scrypt_init(KDF_SCRYPT * ctx)133 static void kdf_scrypt_init(KDF_SCRYPT *ctx)
134 {
135 /* Default values are the most conservative recommendation given in the
136 * original paper of C. Percival. Derivation uses roughly 1 GiB of memory
137 * for this parameter choice (approx. 128 * r * N * p bytes).
138 */
139 ctx->N = 1 << 20;
140 ctx->r = 8;
141 ctx->p = 1;
142 ctx->maxmem_bytes = 1025 * 1024 * 1024;
143 }
144
scrypt_set_membuf(unsigned char ** buffer,size_t * buflen,const OSSL_PARAM * p)145 static int scrypt_set_membuf(unsigned char **buffer, size_t *buflen,
146 const OSSL_PARAM *p)
147 {
148 OPENSSL_clear_free(*buffer, *buflen);
149 *buffer = NULL;
150 *buflen = 0;
151
152 if (p->data_size == 0) {
153 if ((*buffer = OPENSSL_malloc(1)) == NULL)
154 return 0;
155 } else if (p->data != NULL) {
156 if (!OSSL_PARAM_get_octet_string(p, (void **)buffer, 0, buflen))
157 return 0;
158 }
159 return 1;
160 }
161
set_digest(KDF_SCRYPT * ctx)162 static int set_digest(KDF_SCRYPT *ctx)
163 {
164 EVP_MD_free(ctx->sha256);
165 ctx->sha256 = EVP_MD_fetch(ctx->libctx, "sha256", ctx->propq);
166 if (ctx->sha256 == NULL) {
167 ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_LOAD_SHA256);
168 return 0;
169 }
170 return 1;
171 }
172
set_property_query(KDF_SCRYPT * ctx,const char * propq)173 static int set_property_query(KDF_SCRYPT *ctx, const char *propq)
174 {
175 OPENSSL_free(ctx->propq);
176 ctx->propq = NULL;
177 if (propq != NULL) {
178 ctx->propq = OPENSSL_strdup(propq);
179 if (ctx->propq == NULL)
180 return 0;
181 }
182 return 1;
183 }
184
kdf_scrypt_derive(void * vctx,unsigned char * key,size_t keylen,const OSSL_PARAM params[])185 static int kdf_scrypt_derive(void *vctx, unsigned char *key, size_t keylen,
186 const OSSL_PARAM params[])
187 {
188 KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
189
190 if (!ossl_prov_is_running() || !kdf_scrypt_set_ctx_params(ctx, params))
191 return 0;
192
193 if (ctx->pass == NULL) {
194 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_PASS);
195 return 0;
196 }
197
198 if (ctx->salt == NULL) {
199 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SALT);
200 return 0;
201 }
202
203 if (ctx->sha256 == NULL && !set_digest(ctx))
204 return 0;
205
206 return scrypt_alg((char *)ctx->pass, ctx->pass_len, ctx->salt,
207 ctx->salt_len, ctx->N, ctx->r, ctx->p,
208 ctx->maxmem_bytes, key, keylen, ctx->sha256,
209 ctx->libctx, ctx->propq);
210 }
211
is_power_of_two(uint64_t value)212 static int is_power_of_two(uint64_t value)
213 {
214 return (value != 0) && ((value & (value - 1)) == 0);
215 }
216
kdf_scrypt_set_ctx_params(void * vctx,const OSSL_PARAM params[])217 static int kdf_scrypt_set_ctx_params(void *vctx, const OSSL_PARAM params[])
218 {
219 const OSSL_PARAM *p;
220 KDF_SCRYPT *ctx = vctx;
221 uint64_t u64_value;
222
223 if (ossl_param_is_empty(params))
224 return 1;
225
226 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL)
227 if (!scrypt_set_membuf(&ctx->pass, &ctx->pass_len, p))
228 return 0;
229
230 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL)
231 if (!scrypt_set_membuf(&ctx->salt, &ctx->salt_len, p))
232 return 0;
233
234 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_N))
235 != NULL) {
236 if (!OSSL_PARAM_get_uint64(p, &u64_value)
237 || u64_value <= 1
238 || !is_power_of_two(u64_value))
239 return 0;
240 ctx->N = u64_value;
241 }
242
243 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_R))
244 != NULL) {
245 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
246 return 0;
247 ctx->r = u64_value;
248 }
249
250 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_P))
251 != NULL) {
252 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
253 return 0;
254 ctx->p = u64_value;
255 }
256
257 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_MAXMEM))
258 != NULL) {
259 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
260 return 0;
261 ctx->maxmem_bytes = u64_value;
262 }
263
264 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PROPERTIES);
265 if (p != NULL) {
266 if (p->data_type != OSSL_PARAM_UTF8_STRING
267 || !set_property_query(ctx, p->data)
268 || !set_digest(ctx))
269 return 0;
270 }
271 return 1;
272 }
273
kdf_scrypt_settable_ctx_params(ossl_unused void * ctx,ossl_unused void * p_ctx)274 static const OSSL_PARAM *kdf_scrypt_settable_ctx_params(ossl_unused void *ctx,
275 ossl_unused void *p_ctx)
276 {
277 static const OSSL_PARAM known_settable_ctx_params[] = {
278 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_PASSWORD, NULL, 0),
279 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
280 OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_N, NULL),
281 OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_R, NULL),
282 OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_P, NULL),
283 OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_MAXMEM, NULL),
284 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
285 OSSL_PARAM_END
286 };
287 return known_settable_ctx_params;
288 }
289
kdf_scrypt_get_ctx_params(void * vctx,OSSL_PARAM params[])290 static int kdf_scrypt_get_ctx_params(void *vctx, OSSL_PARAM params[])
291 {
292 OSSL_PARAM *p;
293
294 if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
295 return OSSL_PARAM_set_size_t(p, SIZE_MAX);
296 return -2;
297 }
298
kdf_scrypt_gettable_ctx_params(ossl_unused void * ctx,ossl_unused void * p_ctx)299 static const OSSL_PARAM *kdf_scrypt_gettable_ctx_params(ossl_unused void *ctx,
300 ossl_unused void *p_ctx)
301 {
302 static const OSSL_PARAM known_gettable_ctx_params[] = {
303 OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
304 OSSL_PARAM_END
305 };
306 return known_gettable_ctx_params;
307 }
308
309 const OSSL_DISPATCH ossl_kdf_scrypt_functions[] = {
310 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_scrypt_new },
311 { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_scrypt_dup },
312 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_scrypt_free },
313 { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_scrypt_reset },
314 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_scrypt_derive },
315 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
316 (void(*)(void))kdf_scrypt_settable_ctx_params },
317 { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_scrypt_set_ctx_params },
318 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
319 (void(*)(void))kdf_scrypt_gettable_ctx_params },
320 { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_scrypt_get_ctx_params },
321 OSSL_DISPATCH_END
322 };
323
324 #define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
salsa208_word_specification(uint32_t inout[16])325 static void salsa208_word_specification(uint32_t inout[16])
326 {
327 int i;
328 uint32_t x[16];
329
330 memcpy(x, inout, sizeof(x));
331 for (i = 8; i > 0; i -= 2) {
332 x[4] ^= R(x[0] + x[12], 7);
333 x[8] ^= R(x[4] + x[0], 9);
334 x[12] ^= R(x[8] + x[4], 13);
335 x[0] ^= R(x[12] + x[8], 18);
336 x[9] ^= R(x[5] + x[1], 7);
337 x[13] ^= R(x[9] + x[5], 9);
338 x[1] ^= R(x[13] + x[9], 13);
339 x[5] ^= R(x[1] + x[13], 18);
340 x[14] ^= R(x[10] + x[6], 7);
341 x[2] ^= R(x[14] + x[10], 9);
342 x[6] ^= R(x[2] + x[14], 13);
343 x[10] ^= R(x[6] + x[2], 18);
344 x[3] ^= R(x[15] + x[11], 7);
345 x[7] ^= R(x[3] + x[15], 9);
346 x[11] ^= R(x[7] + x[3], 13);
347 x[15] ^= R(x[11] + x[7], 18);
348 x[1] ^= R(x[0] + x[3], 7);
349 x[2] ^= R(x[1] + x[0], 9);
350 x[3] ^= R(x[2] + x[1], 13);
351 x[0] ^= R(x[3] + x[2], 18);
352 x[6] ^= R(x[5] + x[4], 7);
353 x[7] ^= R(x[6] + x[5], 9);
354 x[4] ^= R(x[7] + x[6], 13);
355 x[5] ^= R(x[4] + x[7], 18);
356 x[11] ^= R(x[10] + x[9], 7);
357 x[8] ^= R(x[11] + x[10], 9);
358 x[9] ^= R(x[8] + x[11], 13);
359 x[10] ^= R(x[9] + x[8], 18);
360 x[12] ^= R(x[15] + x[14], 7);
361 x[13] ^= R(x[12] + x[15], 9);
362 x[14] ^= R(x[13] + x[12], 13);
363 x[15] ^= R(x[14] + x[13], 18);
364 }
365 for (i = 0; i < 16; ++i)
366 inout[i] += x[i];
367 OPENSSL_cleanse(x, sizeof(x));
368 }
369
scryptBlockMix(uint32_t * B_,uint32_t * B,uint64_t r)370 static void scryptBlockMix(uint32_t *B_, uint32_t *B, uint64_t r)
371 {
372 uint64_t i, j;
373 uint32_t X[16], *pB;
374
375 memcpy(X, B + (r * 2 - 1) * 16, sizeof(X));
376 pB = B;
377 for (i = 0; i < r * 2; i++) {
378 for (j = 0; j < 16; j++)
379 X[j] ^= *pB++;
380 salsa208_word_specification(X);
381 memcpy(B_ + (i / 2 + (i & 1) * r) * 16, X, sizeof(X));
382 }
383 OPENSSL_cleanse(X, sizeof(X));
384 }
385
scryptROMix(unsigned char * B,uint64_t r,uint64_t N,uint32_t * X,uint32_t * T,uint32_t * V)386 static void scryptROMix(unsigned char *B, uint64_t r, uint64_t N,
387 uint32_t *X, uint32_t *T, uint32_t *V)
388 {
389 unsigned char *pB;
390 uint32_t *pV;
391 uint64_t i, k;
392
393 /* Convert from little endian input */
394 for (pV = V, i = 0, pB = B; i < 32 * r; i++, pV++) {
395 *pV = *pB++;
396 *pV |= *pB++ << 8;
397 *pV |= *pB++ << 16;
398 *pV |= (uint32_t)*pB++ << 24;
399 }
400
401 for (i = 1; i < N; i++, pV += 32 * r)
402 scryptBlockMix(pV, pV - 32 * r, r);
403
404 scryptBlockMix(X, V + (N - 1) * 32 * r, r);
405
406 for (i = 0; i < N; i++) {
407 uint32_t j;
408 j = X[16 * (2 * r - 1)] % N;
409 pV = V + 32 * r * j;
410 for (k = 0; k < 32 * r; k++)
411 T[k] = X[k] ^ *pV++;
412 scryptBlockMix(X, T, r);
413 }
414 /* Convert output to little endian */
415 for (i = 0, pB = B; i < 32 * r; i++) {
416 uint32_t xtmp = X[i];
417 *pB++ = xtmp & 0xff;
418 *pB++ = (xtmp >> 8) & 0xff;
419 *pB++ = (xtmp >> 16) & 0xff;
420 *pB++ = (xtmp >> 24) & 0xff;
421 }
422 }
423
424 #ifndef SIZE_MAX
425 # define SIZE_MAX ((size_t)-1)
426 #endif
427
428 /*
429 * Maximum power of two that will fit in uint64_t: this should work on
430 * most (all?) platforms.
431 */
432
433 #define LOG2_UINT64_MAX (sizeof(uint64_t) * 8 - 1)
434
435 /*
436 * Maximum value of p * r:
437 * p <= ((2^32-1) * hLen) / MFLen =>
438 * p <= ((2^32-1) * 32) / (128 * r) =>
439 * p * r <= (2^30-1)
440 */
441
442 #define SCRYPT_PR_MAX ((1 << 30) - 1)
443
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)444 static int scrypt_alg(const char *pass, size_t passlen,
445 const unsigned char *salt, size_t saltlen,
446 uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
447 unsigned char *key, size_t keylen, EVP_MD *sha256,
448 OSSL_LIB_CTX *libctx, const char *propq)
449 {
450 int rv = 0;
451 unsigned char *B;
452 uint32_t *X, *V, *T;
453 uint64_t i, Blen, Vlen;
454
455 /* Sanity check parameters */
456 /* initial check, r,p must be non zero, N >= 2 and a power of 2 */
457 if (r == 0 || p == 0 || N < 2 || (N & (N - 1)))
458 return 0;
459 /* Check p * r < SCRYPT_PR_MAX avoiding overflow */
460 if (p > SCRYPT_PR_MAX / r) {
461 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
462 return 0;
463 }
464
465 /*
466 * Need to check N: if 2^(128 * r / 8) overflows limit this is
467 * automatically satisfied since N <= UINT64_MAX.
468 */
469
470 if (16 * r <= LOG2_UINT64_MAX) {
471 if (N >= (((uint64_t)1) << (16 * r))) {
472 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
473 return 0;
474 }
475 }
476
477 /* Memory checks: check total allocated buffer size fits in uint64_t */
478
479 /*
480 * B size in section 5 step 1.S
481 * Note: we know p * 128 * r < UINT64_MAX because we already checked
482 * p * r < SCRYPT_PR_MAX
483 */
484 Blen = p * 128 * r;
485 /*
486 * Yet we pass it as integer to PKCS5_PBKDF2_HMAC... [This would
487 * have to be revised when/if PKCS5_PBKDF2_HMAC accepts size_t.]
488 */
489 if (Blen > INT_MAX) {
490 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
491 return 0;
492 }
493
494 /*
495 * Check 32 * r * (N + 2) * sizeof(uint32_t) fits in uint64_t
496 * This is combined size V, X and T (section 4)
497 */
498 i = UINT64_MAX / (32 * sizeof(uint32_t));
499 if (N + 2 > i / r) {
500 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
501 return 0;
502 }
503 Vlen = 32 * r * (N + 2) * sizeof(uint32_t);
504
505 /* check total allocated size fits in uint64_t */
506 if (Blen > UINT64_MAX - Vlen) {
507 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
508 return 0;
509 }
510
511 /* Check that the maximum memory doesn't exceed a size_t limits */
512 if (maxmem > SIZE_MAX)
513 maxmem = SIZE_MAX;
514
515 if (Blen + Vlen > maxmem) {
516 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
517 return 0;
518 }
519
520 /* If no key return to indicate parameters are OK */
521 if (key == NULL)
522 return 1;
523
524 B = OPENSSL_malloc((size_t)(Blen + Vlen));
525 if (B == NULL)
526 return 0;
527 X = (uint32_t *)(B + Blen);
528 T = X + 32 * r;
529 V = T + 32 * r;
530 if (ossl_pkcs5_pbkdf2_hmac_ex(pass, passlen, salt, saltlen, 1, sha256,
531 (int)Blen, B, libctx, propq) == 0)
532 goto err;
533
534 for (i = 0; i < p; i++)
535 scryptROMix(B + 128 * r * i, r, N, X, T, V);
536
537 if (ossl_pkcs5_pbkdf2_hmac_ex(pass, passlen, B, (int)Blen, 1, sha256,
538 keylen, key, libctx, propq) == 0)
539 goto err;
540 rv = 1;
541 err:
542 if (rv == 0)
543 ERR_raise(ERR_LIB_EVP, EVP_R_PBKDF2_ERROR);
544
545 OPENSSL_clear_free(B, (size_t)(Blen + Vlen));
546 return rv;
547 }
548
549 #endif
550