1 /*
2 * Copyright 2017-2023 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 OPENSSL_clear_free(ctx->pass, ctx->pass_len);
96 kdf_scrypt_init(ctx);
97 }
98
kdf_scrypt_dup(void * vctx)99 static void *kdf_scrypt_dup(void *vctx)
100 {
101 const KDF_SCRYPT *src = (const KDF_SCRYPT *)vctx;
102 KDF_SCRYPT *dest;
103
104 dest = kdf_scrypt_new_inner(src->libctx);
105 if (dest != NULL) {
106 if (src->sha256 != NULL && !EVP_MD_up_ref(src->sha256))
107 goto err;
108 if (src->propq != NULL) {
109 dest->propq = OPENSSL_strdup(src->propq);
110 if (dest->propq == NULL)
111 goto err;
112 }
113 if (!ossl_prov_memdup(src->salt, src->salt_len,
114 &dest->salt, &dest->salt_len)
115 || !ossl_prov_memdup(src->pass, src->pass_len,
116 &dest->pass , &dest->pass_len))
117 goto err;
118 dest->N = src->N;
119 dest->r = src->r;
120 dest->p = src->p;
121 dest->maxmem_bytes = src->maxmem_bytes;
122 dest->sha256 = src->sha256;
123 }
124 return dest;
125
126 err:
127 kdf_scrypt_free(dest);
128 return NULL;
129 }
130
kdf_scrypt_init(KDF_SCRYPT * ctx)131 static void kdf_scrypt_init(KDF_SCRYPT *ctx)
132 {
133 /* Default values are the most conservative recommendation given in the
134 * original paper of C. Percival. Derivation uses roughly 1 GiB of memory
135 * for this parameter choice (approx. 128 * r * N * p bytes).
136 */
137 ctx->N = 1 << 20;
138 ctx->r = 8;
139 ctx->p = 1;
140 ctx->maxmem_bytes = 1025 * 1024 * 1024;
141 }
142
scrypt_set_membuf(unsigned char ** buffer,size_t * buflen,const OSSL_PARAM * p)143 static int scrypt_set_membuf(unsigned char **buffer, size_t *buflen,
144 const OSSL_PARAM *p)
145 {
146 OPENSSL_clear_free(*buffer, *buflen);
147 *buffer = NULL;
148 *buflen = 0;
149
150 if (p->data_size == 0) {
151 if ((*buffer = OPENSSL_malloc(1)) == NULL)
152 return 0;
153 } else if (p->data != NULL) {
154 if (!OSSL_PARAM_get_octet_string(p, (void **)buffer, 0, buflen))
155 return 0;
156 }
157 return 1;
158 }
159
set_digest(KDF_SCRYPT * ctx)160 static int set_digest(KDF_SCRYPT *ctx)
161 {
162 EVP_MD_free(ctx->sha256);
163 ctx->sha256 = EVP_MD_fetch(ctx->libctx, "sha256", ctx->propq);
164 if (ctx->sha256 == NULL) {
165 OPENSSL_free(ctx);
166 ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_LOAD_SHA256);
167 return 0;
168 }
169 return 1;
170 }
171
set_property_query(KDF_SCRYPT * ctx,const char * propq)172 static int set_property_query(KDF_SCRYPT *ctx, const char *propq)
173 {
174 OPENSSL_free(ctx->propq);
175 ctx->propq = NULL;
176 if (propq != NULL) {
177 ctx->propq = OPENSSL_strdup(propq);
178 if (ctx->propq == NULL)
179 return 0;
180 }
181 return 1;
182 }
183
kdf_scrypt_derive(void * vctx,unsigned char * key,size_t keylen,const OSSL_PARAM params[])184 static int kdf_scrypt_derive(void *vctx, unsigned char *key, size_t keylen,
185 const OSSL_PARAM params[])
186 {
187 KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
188
189 if (!ossl_prov_is_running() || !kdf_scrypt_set_ctx_params(ctx, params))
190 return 0;
191
192 if (ctx->pass == NULL) {
193 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_PASS);
194 return 0;
195 }
196
197 if (ctx->salt == NULL) {
198 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SALT);
199 return 0;
200 }
201
202 if (ctx->sha256 == NULL && !set_digest(ctx))
203 return 0;
204
205 return scrypt_alg((char *)ctx->pass, ctx->pass_len, ctx->salt,
206 ctx->salt_len, ctx->N, ctx->r, ctx->p,
207 ctx->maxmem_bytes, key, keylen, ctx->sha256,
208 ctx->libctx, ctx->propq);
209 }
210
is_power_of_two(uint64_t value)211 static int is_power_of_two(uint64_t value)
212 {
213 return (value != 0) && ((value & (value - 1)) == 0);
214 }
215
kdf_scrypt_set_ctx_params(void * vctx,const OSSL_PARAM params[])216 static int kdf_scrypt_set_ctx_params(void *vctx, const OSSL_PARAM params[])
217 {
218 const OSSL_PARAM *p;
219 KDF_SCRYPT *ctx = vctx;
220 uint64_t u64_value;
221
222 if (ossl_param_is_empty(params))
223 return 1;
224
225 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL)
226 if (!scrypt_set_membuf(&ctx->pass, &ctx->pass_len, p))
227 return 0;
228
229 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL)
230 if (!scrypt_set_membuf(&ctx->salt, &ctx->salt_len, p))
231 return 0;
232
233 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_N))
234 != NULL) {
235 if (!OSSL_PARAM_get_uint64(p, &u64_value)
236 || u64_value <= 1
237 || !is_power_of_two(u64_value))
238 return 0;
239 ctx->N = u64_value;
240 }
241
242 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_R))
243 != NULL) {
244 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
245 return 0;
246 ctx->r = u64_value;
247 }
248
249 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_P))
250 != NULL) {
251 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
252 return 0;
253 ctx->p = u64_value;
254 }
255
256 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_MAXMEM))
257 != NULL) {
258 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
259 return 0;
260 ctx->maxmem_bytes = u64_value;
261 }
262
263 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PROPERTIES);
264 if (p != NULL) {
265 if (p->data_type != OSSL_PARAM_UTF8_STRING
266 || !set_property_query(ctx, p->data)
267 || !set_digest(ctx))
268 return 0;
269 }
270 return 1;
271 }
272
kdf_scrypt_settable_ctx_params(ossl_unused void * ctx,ossl_unused void * p_ctx)273 static const OSSL_PARAM *kdf_scrypt_settable_ctx_params(ossl_unused void *ctx,
274 ossl_unused void *p_ctx)
275 {
276 static const OSSL_PARAM known_settable_ctx_params[] = {
277 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_PASSWORD, NULL, 0),
278 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
279 OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_N, NULL),
280 OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_R, NULL),
281 OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_P, NULL),
282 OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_MAXMEM, NULL),
283 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
284 OSSL_PARAM_END
285 };
286 return known_settable_ctx_params;
287 }
288
kdf_scrypt_get_ctx_params(void * vctx,OSSL_PARAM params[])289 static int kdf_scrypt_get_ctx_params(void *vctx, OSSL_PARAM params[])
290 {
291 OSSL_PARAM *p;
292
293 if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
294 return OSSL_PARAM_set_size_t(p, SIZE_MAX);
295 return -2;
296 }
297
kdf_scrypt_gettable_ctx_params(ossl_unused void * ctx,ossl_unused void * p_ctx)298 static const OSSL_PARAM *kdf_scrypt_gettable_ctx_params(ossl_unused void *ctx,
299 ossl_unused void *p_ctx)
300 {
301 static const OSSL_PARAM known_gettable_ctx_params[] = {
302 OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
303 OSSL_PARAM_END
304 };
305 return known_gettable_ctx_params;
306 }
307
308 const OSSL_DISPATCH ossl_kdf_scrypt_functions[] = {
309 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_scrypt_new },
310 { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_scrypt_dup },
311 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_scrypt_free },
312 { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_scrypt_reset },
313 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_scrypt_derive },
314 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
315 (void(*)(void))kdf_scrypt_settable_ctx_params },
316 { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_scrypt_set_ctx_params },
317 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
318 (void(*)(void))kdf_scrypt_gettable_ctx_params },
319 { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_scrypt_get_ctx_params },
320 OSSL_DISPATCH_END
321 };
322
323 #define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
salsa208_word_specification(uint32_t inout[16])324 static void salsa208_word_specification(uint32_t inout[16])
325 {
326 int i;
327 uint32_t x[16];
328
329 memcpy(x, inout, sizeof(x));
330 for (i = 8; i > 0; i -= 2) {
331 x[4] ^= R(x[0] + x[12], 7);
332 x[8] ^= R(x[4] + x[0], 9);
333 x[12] ^= R(x[8] + x[4], 13);
334 x[0] ^= R(x[12] + x[8], 18);
335 x[9] ^= R(x[5] + x[1], 7);
336 x[13] ^= R(x[9] + x[5], 9);
337 x[1] ^= R(x[13] + x[9], 13);
338 x[5] ^= R(x[1] + x[13], 18);
339 x[14] ^= R(x[10] + x[6], 7);
340 x[2] ^= R(x[14] + x[10], 9);
341 x[6] ^= R(x[2] + x[14], 13);
342 x[10] ^= R(x[6] + x[2], 18);
343 x[3] ^= R(x[15] + x[11], 7);
344 x[7] ^= R(x[3] + x[15], 9);
345 x[11] ^= R(x[7] + x[3], 13);
346 x[15] ^= R(x[11] + x[7], 18);
347 x[1] ^= R(x[0] + x[3], 7);
348 x[2] ^= R(x[1] + x[0], 9);
349 x[3] ^= R(x[2] + x[1], 13);
350 x[0] ^= R(x[3] + x[2], 18);
351 x[6] ^= R(x[5] + x[4], 7);
352 x[7] ^= R(x[6] + x[5], 9);
353 x[4] ^= R(x[7] + x[6], 13);
354 x[5] ^= R(x[4] + x[7], 18);
355 x[11] ^= R(x[10] + x[9], 7);
356 x[8] ^= R(x[11] + x[10], 9);
357 x[9] ^= R(x[8] + x[11], 13);
358 x[10] ^= R(x[9] + x[8], 18);
359 x[12] ^= R(x[15] + x[14], 7);
360 x[13] ^= R(x[12] + x[15], 9);
361 x[14] ^= R(x[13] + x[12], 13);
362 x[15] ^= R(x[14] + x[13], 18);
363 }
364 for (i = 0; i < 16; ++i)
365 inout[i] += x[i];
366 OPENSSL_cleanse(x, sizeof(x));
367 }
368
scryptBlockMix(uint32_t * B_,uint32_t * B,uint64_t r)369 static void scryptBlockMix(uint32_t *B_, uint32_t *B, uint64_t r)
370 {
371 uint64_t i, j;
372 uint32_t X[16], *pB;
373
374 memcpy(X, B + (r * 2 - 1) * 16, sizeof(X));
375 pB = B;
376 for (i = 0; i < r * 2; i++) {
377 for (j = 0; j < 16; j++)
378 X[j] ^= *pB++;
379 salsa208_word_specification(X);
380 memcpy(B_ + (i / 2 + (i & 1) * r) * 16, X, sizeof(X));
381 }
382 OPENSSL_cleanse(X, sizeof(X));
383 }
384
scryptROMix(unsigned char * B,uint64_t r,uint64_t N,uint32_t * X,uint32_t * T,uint32_t * V)385 static void scryptROMix(unsigned char *B, uint64_t r, uint64_t N,
386 uint32_t *X, uint32_t *T, uint32_t *V)
387 {
388 unsigned char *pB;
389 uint32_t *pV;
390 uint64_t i, k;
391
392 /* Convert from little endian input */
393 for (pV = V, i = 0, pB = B; i < 32 * r; i++, pV++) {
394 *pV = *pB++;
395 *pV |= *pB++ << 8;
396 *pV |= *pB++ << 16;
397 *pV |= (uint32_t)*pB++ << 24;
398 }
399
400 for (i = 1; i < N; i++, pV += 32 * r)
401 scryptBlockMix(pV, pV - 32 * r, r);
402
403 scryptBlockMix(X, V + (N - 1) * 32 * r, r);
404
405 for (i = 0; i < N; i++) {
406 uint32_t j;
407 j = X[16 * (2 * r - 1)] % N;
408 pV = V + 32 * r * j;
409 for (k = 0; k < 32 * r; k++)
410 T[k] = X[k] ^ *pV++;
411 scryptBlockMix(X, T, r);
412 }
413 /* Convert output to little endian */
414 for (i = 0, pB = B; i < 32 * r; i++) {
415 uint32_t xtmp = X[i];
416 *pB++ = xtmp & 0xff;
417 *pB++ = (xtmp >> 8) & 0xff;
418 *pB++ = (xtmp >> 16) & 0xff;
419 *pB++ = (xtmp >> 24) & 0xff;
420 }
421 }
422
423 #ifndef SIZE_MAX
424 # define SIZE_MAX ((size_t)-1)
425 #endif
426
427 /*
428 * Maximum power of two that will fit in uint64_t: this should work on
429 * most (all?) platforms.
430 */
431
432 #define LOG2_UINT64_MAX (sizeof(uint64_t) * 8 - 1)
433
434 /*
435 * Maximum value of p * r:
436 * p <= ((2^32-1) * hLen) / MFLen =>
437 * p <= ((2^32-1) * 32) / (128 * r) =>
438 * p * r <= (2^30-1)
439 */
440
441 #define SCRYPT_PR_MAX ((1 << 30) - 1)
442
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)443 static int scrypt_alg(const char *pass, size_t passlen,
444 const unsigned char *salt, size_t saltlen,
445 uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
446 unsigned char *key, size_t keylen, EVP_MD *sha256,
447 OSSL_LIB_CTX *libctx, const char *propq)
448 {
449 int rv = 0;
450 unsigned char *B;
451 uint32_t *X, *V, *T;
452 uint64_t i, Blen, Vlen;
453
454 /* Sanity check parameters */
455 /* initial check, r,p must be non zero, N >= 2 and a power of 2 */
456 if (r == 0 || p == 0 || N < 2 || (N & (N - 1)))
457 return 0;
458 /* Check p * r < SCRYPT_PR_MAX avoiding overflow */
459 if (p > SCRYPT_PR_MAX / r) {
460 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
461 return 0;
462 }
463
464 /*
465 * Need to check N: if 2^(128 * r / 8) overflows limit this is
466 * automatically satisfied since N <= UINT64_MAX.
467 */
468
469 if (16 * r <= LOG2_UINT64_MAX) {
470 if (N >= (((uint64_t)1) << (16 * r))) {
471 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
472 return 0;
473 }
474 }
475
476 /* Memory checks: check total allocated buffer size fits in uint64_t */
477
478 /*
479 * B size in section 5 step 1.S
480 * Note: we know p * 128 * r < UINT64_MAX because we already checked
481 * p * r < SCRYPT_PR_MAX
482 */
483 Blen = p * 128 * r;
484 /*
485 * Yet we pass it as integer to PKCS5_PBKDF2_HMAC... [This would
486 * have to be revised when/if PKCS5_PBKDF2_HMAC accepts size_t.]
487 */
488 if (Blen > INT_MAX) {
489 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
490 return 0;
491 }
492
493 /*
494 * Check 32 * r * (N + 2) * sizeof(uint32_t) fits in uint64_t
495 * This is combined size V, X and T (section 4)
496 */
497 i = UINT64_MAX / (32 * sizeof(uint32_t));
498 if (N + 2 > i / r) {
499 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
500 return 0;
501 }
502 Vlen = 32 * r * (N + 2) * sizeof(uint32_t);
503
504 /* check total allocated size fits in uint64_t */
505 if (Blen > UINT64_MAX - Vlen) {
506 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
507 return 0;
508 }
509
510 /* Check that the maximum memory doesn't exceed a size_t limits */
511 if (maxmem > SIZE_MAX)
512 maxmem = SIZE_MAX;
513
514 if (Blen + Vlen > maxmem) {
515 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
516 return 0;
517 }
518
519 /* If no key return to indicate parameters are OK */
520 if (key == NULL)
521 return 1;
522
523 B = OPENSSL_malloc((size_t)(Blen + Vlen));
524 if (B == NULL)
525 return 0;
526 X = (uint32_t *)(B + Blen);
527 T = X + 32 * r;
528 V = T + 32 * r;
529 if (ossl_pkcs5_pbkdf2_hmac_ex(pass, passlen, salt, saltlen, 1, sha256,
530 (int)Blen, B, libctx, propq) == 0)
531 goto err;
532
533 for (i = 0; i < p; i++)
534 scryptROMix(B + 128 * r * i, r, N, X, T, V);
535
536 if (ossl_pkcs5_pbkdf2_hmac_ex(pass, passlen, B, (int)Blen, 1, sha256,
537 keylen, key, libctx, propq) == 0)
538 goto err;
539 rv = 1;
540 err:
541 if (rv == 0)
542 ERR_raise(ERR_LIB_EVP, EVP_R_PBKDF2_ERROR);
543
544 OPENSSL_clear_free(B, (size_t)(Blen + Vlen));
545 return rv;
546 }
547
548 #endif
549
