1 /*
2 * Copyright 2017-2021 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 OPENSSL_clear_free(ctx->pass, ctx->pass_len);
92 kdf_scrypt_init(ctx);
93 }
94
kdf_scrypt_init(KDF_SCRYPT * ctx)95 static void kdf_scrypt_init(KDF_SCRYPT *ctx)
96 {
97 /* Default values are the most conservative recommendation given in the
98 * original paper of C. Percival. Derivation uses roughly 1 GiB of memory
99 * for this parameter choice (approx. 128 * r * N * p bytes).
100 */
101 ctx->N = 1 << 20;
102 ctx->r = 8;
103 ctx->p = 1;
104 ctx->maxmem_bytes = 1025 * 1024 * 1024;
105 }
106
scrypt_set_membuf(unsigned char ** buffer,size_t * buflen,const OSSL_PARAM * p)107 static int scrypt_set_membuf(unsigned char **buffer, size_t *buflen,
108 const OSSL_PARAM *p)
109 {
110 OPENSSL_clear_free(*buffer, *buflen);
111 if (p->data_size == 0) {
112 if ((*buffer = OPENSSL_malloc(1)) == NULL) {
113 ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
114 return 0;
115 }
116 } else if (p->data != NULL) {
117 *buffer = NULL;
118 if (!OSSL_PARAM_get_octet_string(p, (void **)buffer, 0, buflen))
119 return 0;
120 }
121 return 1;
122 }
123
set_digest(KDF_SCRYPT * ctx)124 static int set_digest(KDF_SCRYPT *ctx)
125 {
126 EVP_MD_free(ctx->sha256);
127 ctx->sha256 = EVP_MD_fetch(ctx->libctx, "sha256", ctx->propq);
128 if (ctx->sha256 == NULL) {
129 OPENSSL_free(ctx);
130 ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_LOAD_SHA256);
131 return 0;
132 }
133 return 1;
134 }
135
set_property_query(KDF_SCRYPT * ctx,const char * propq)136 static int set_property_query(KDF_SCRYPT *ctx, const char *propq)
137 {
138 OPENSSL_free(ctx->propq);
139 ctx->propq = NULL;
140 if (propq != NULL) {
141 ctx->propq = OPENSSL_strdup(propq);
142 if (ctx->propq == NULL) {
143 ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
144 return 0;
145 }
146 }
147 return 1;
148 }
149
kdf_scrypt_derive(void * vctx,unsigned char * key,size_t keylen,const OSSL_PARAM params[])150 static int kdf_scrypt_derive(void *vctx, unsigned char *key, size_t keylen,
151 const OSSL_PARAM params[])
152 {
153 KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
154
155 if (!ossl_prov_is_running() || !kdf_scrypt_set_ctx_params(ctx, params))
156 return 0;
157
158 if (ctx->pass == NULL) {
159 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_PASS);
160 return 0;
161 }
162
163 if (ctx->salt == NULL) {
164 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SALT);
165 return 0;
166 }
167
168 if (ctx->sha256 == NULL && !set_digest(ctx))
169 return 0;
170
171 return scrypt_alg((char *)ctx->pass, ctx->pass_len, ctx->salt,
172 ctx->salt_len, ctx->N, ctx->r, ctx->p,
173 ctx->maxmem_bytes, key, keylen, ctx->sha256,
174 ctx->libctx, ctx->propq);
175 }
176
is_power_of_two(uint64_t value)177 static int is_power_of_two(uint64_t value)
178 {
179 return (value != 0) && ((value & (value - 1)) == 0);
180 }
181
kdf_scrypt_set_ctx_params(void * vctx,const OSSL_PARAM params[])182 static int kdf_scrypt_set_ctx_params(void *vctx, const OSSL_PARAM params[])
183 {
184 const OSSL_PARAM *p;
185 KDF_SCRYPT *ctx = vctx;
186 uint64_t u64_value;
187
188 if (params == NULL)
189 return 1;
190
191 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL)
192 if (!scrypt_set_membuf(&ctx->pass, &ctx->pass_len, p))
193 return 0;
194
195 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL)
196 if (!scrypt_set_membuf(&ctx->salt, &ctx->salt_len, p))
197 return 0;
198
199 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_N))
200 != NULL) {
201 if (!OSSL_PARAM_get_uint64(p, &u64_value)
202 || u64_value <= 1
203 || !is_power_of_two(u64_value))
204 return 0;
205 ctx->N = u64_value;
206 }
207
208 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_R))
209 != NULL) {
210 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
211 return 0;
212 ctx->r = u64_value;
213 }
214
215 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_P))
216 != NULL) {
217 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
218 return 0;
219 ctx->p = u64_value;
220 }
221
222 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_MAXMEM))
223 != NULL) {
224 if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
225 return 0;
226 ctx->maxmem_bytes = u64_value;
227 }
228
229 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PROPERTIES);
230 if (p != NULL) {
231 if (p->data_type != OSSL_PARAM_UTF8_STRING
232 || !set_property_query(ctx, p->data)
233 || !set_digest(ctx))
234 return 0;
235 }
236 return 1;
237 }
238
kdf_scrypt_settable_ctx_params(ossl_unused void * ctx,ossl_unused void * p_ctx)239 static const OSSL_PARAM *kdf_scrypt_settable_ctx_params(ossl_unused void *ctx,
240 ossl_unused void *p_ctx)
241 {
242 static const OSSL_PARAM known_settable_ctx_params[] = {
243 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_PASSWORD, NULL, 0),
244 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
245 OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_N, NULL),
246 OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_R, NULL),
247 OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_P, NULL),
248 OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_MAXMEM, NULL),
249 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
250 OSSL_PARAM_END
251 };
252 return known_settable_ctx_params;
253 }
254
kdf_scrypt_get_ctx_params(void * vctx,OSSL_PARAM params[])255 static int kdf_scrypt_get_ctx_params(void *vctx, OSSL_PARAM params[])
256 {
257 OSSL_PARAM *p;
258
259 if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
260 return OSSL_PARAM_set_size_t(p, SIZE_MAX);
261 return -2;
262 }
263
kdf_scrypt_gettable_ctx_params(ossl_unused void * ctx,ossl_unused void * p_ctx)264 static const OSSL_PARAM *kdf_scrypt_gettable_ctx_params(ossl_unused void *ctx,
265 ossl_unused void *p_ctx)
266 {
267 static const OSSL_PARAM known_gettable_ctx_params[] = {
268 OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
269 OSSL_PARAM_END
270 };
271 return known_gettable_ctx_params;
272 }
273
274 const OSSL_DISPATCH ossl_kdf_scrypt_functions[] = {
275 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_scrypt_new },
276 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_scrypt_free },
277 { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_scrypt_reset },
278 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_scrypt_derive },
279 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
280 (void(*)(void))kdf_scrypt_settable_ctx_params },
281 { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_scrypt_set_ctx_params },
282 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
283 (void(*)(void))kdf_scrypt_gettable_ctx_params },
284 { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_scrypt_get_ctx_params },
285 { 0, NULL }
286 };
287
288 #define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
salsa208_word_specification(uint32_t inout[16])289 static void salsa208_word_specification(uint32_t inout[16])
290 {
291 int i;
292 uint32_t x[16];
293
294 memcpy(x, inout, sizeof(x));
295 for (i = 8; i > 0; i -= 2) {
296 x[4] ^= R(x[0] + x[12], 7);
297 x[8] ^= R(x[4] + x[0], 9);
298 x[12] ^= R(x[8] + x[4], 13);
299 x[0] ^= R(x[12] + x[8], 18);
300 x[9] ^= R(x[5] + x[1], 7);
301 x[13] ^= R(x[9] + x[5], 9);
302 x[1] ^= R(x[13] + x[9], 13);
303 x[5] ^= R(x[1] + x[13], 18);
304 x[14] ^= R(x[10] + x[6], 7);
305 x[2] ^= R(x[14] + x[10], 9);
306 x[6] ^= R(x[2] + x[14], 13);
307 x[10] ^= R(x[6] + x[2], 18);
308 x[3] ^= R(x[15] + x[11], 7);
309 x[7] ^= R(x[3] + x[15], 9);
310 x[11] ^= R(x[7] + x[3], 13);
311 x[15] ^= R(x[11] + x[7], 18);
312 x[1] ^= R(x[0] + x[3], 7);
313 x[2] ^= R(x[1] + x[0], 9);
314 x[3] ^= R(x[2] + x[1], 13);
315 x[0] ^= R(x[3] + x[2], 18);
316 x[6] ^= R(x[5] + x[4], 7);
317 x[7] ^= R(x[6] + x[5], 9);
318 x[4] ^= R(x[7] + x[6], 13);
319 x[5] ^= R(x[4] + x[7], 18);
320 x[11] ^= R(x[10] + x[9], 7);
321 x[8] ^= R(x[11] + x[10], 9);
322 x[9] ^= R(x[8] + x[11], 13);
323 x[10] ^= R(x[9] + x[8], 18);
324 x[12] ^= R(x[15] + x[14], 7);
325 x[13] ^= R(x[12] + x[15], 9);
326 x[14] ^= R(x[13] + x[12], 13);
327 x[15] ^= R(x[14] + x[13], 18);
328 }
329 for (i = 0; i < 16; ++i)
330 inout[i] += x[i];
331 OPENSSL_cleanse(x, sizeof(x));
332 }
333
scryptBlockMix(uint32_t * B_,uint32_t * B,uint64_t r)334 static void scryptBlockMix(uint32_t *B_, uint32_t *B, uint64_t r)
335 {
336 uint64_t i, j;
337 uint32_t X[16], *pB;
338
339 memcpy(X, B + (r * 2 - 1) * 16, sizeof(X));
340 pB = B;
341 for (i = 0; i < r * 2; i++) {
342 for (j = 0; j < 16; j++)
343 X[j] ^= *pB++;
344 salsa208_word_specification(X);
345 memcpy(B_ + (i / 2 + (i & 1) * r) * 16, X, sizeof(X));
346 }
347 OPENSSL_cleanse(X, sizeof(X));
348 }
349
scryptROMix(unsigned char * B,uint64_t r,uint64_t N,uint32_t * X,uint32_t * T,uint32_t * V)350 static void scryptROMix(unsigned char *B, uint64_t r, uint64_t N,
351 uint32_t *X, uint32_t *T, uint32_t *V)
352 {
353 unsigned char *pB;
354 uint32_t *pV;
355 uint64_t i, k;
356
357 /* Convert from little endian input */
358 for (pV = V, i = 0, pB = B; i < 32 * r; i++, pV++) {
359 *pV = *pB++;
360 *pV |= *pB++ << 8;
361 *pV |= *pB++ << 16;
362 *pV |= (uint32_t)*pB++ << 24;
363 }
364
365 for (i = 1; i < N; i++, pV += 32 * r)
366 scryptBlockMix(pV, pV - 32 * r, r);
367
368 scryptBlockMix(X, V + (N - 1) * 32 * r, r);
369
370 for (i = 0; i < N; i++) {
371 uint32_t j;
372 j = X[16 * (2 * r - 1)] % N;
373 pV = V + 32 * r * j;
374 for (k = 0; k < 32 * r; k++)
375 T[k] = X[k] ^ *pV++;
376 scryptBlockMix(X, T, r);
377 }
378 /* Convert output to little endian */
379 for (i = 0, pB = B; i < 32 * r; i++) {
380 uint32_t xtmp = X[i];
381 *pB++ = xtmp & 0xff;
382 *pB++ = (xtmp >> 8) & 0xff;
383 *pB++ = (xtmp >> 16) & 0xff;
384 *pB++ = (xtmp >> 24) & 0xff;
385 }
386 }
387
388 #ifndef SIZE_MAX
389 # define SIZE_MAX ((size_t)-1)
390 #endif
391
392 /*
393 * Maximum power of two that will fit in uint64_t: this should work on
394 * most (all?) platforms.
395 */
396
397 #define LOG2_UINT64_MAX (sizeof(uint64_t) * 8 - 1)
398
399 /*
400 * Maximum value of p * r:
401 * p <= ((2^32-1) * hLen) / MFLen =>
402 * p <= ((2^32-1) * 32) / (128 * r) =>
403 * p * r <= (2^30-1)
404 */
405
406 #define SCRYPT_PR_MAX ((1 << 30) - 1)
407
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)408 static int scrypt_alg(const char *pass, size_t passlen,
409 const unsigned char *salt, size_t saltlen,
410 uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
411 unsigned char *key, size_t keylen, EVP_MD *sha256,
412 OSSL_LIB_CTX *libctx, const char *propq)
413 {
414 int rv = 0;
415 unsigned char *B;
416 uint32_t *X, *V, *T;
417 uint64_t i, Blen, Vlen;
418
419 /* Sanity check parameters */
420 /* initial check, r,p must be non zero, N >= 2 and a power of 2 */
421 if (r == 0 || p == 0 || N < 2 || (N & (N - 1)))
422 return 0;
423 /* Check p * r < SCRYPT_PR_MAX avoiding overflow */
424 if (p > SCRYPT_PR_MAX / r) {
425 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
426 return 0;
427 }
428
429 /*
430 * Need to check N: if 2^(128 * r / 8) overflows limit this is
431 * automatically satisfied since N <= UINT64_MAX.
432 */
433
434 if (16 * r <= LOG2_UINT64_MAX) {
435 if (N >= (((uint64_t)1) << (16 * r))) {
436 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
437 return 0;
438 }
439 }
440
441 /* Memory checks: check total allocated buffer size fits in uint64_t */
442
443 /*
444 * B size in section 5 step 1.S
445 * Note: we know p * 128 * r < UINT64_MAX because we already checked
446 * p * r < SCRYPT_PR_MAX
447 */
448 Blen = p * 128 * r;
449 /*
450 * Yet we pass it as integer to PKCS5_PBKDF2_HMAC... [This would
451 * have to be revised when/if PKCS5_PBKDF2_HMAC accepts size_t.]
452 */
453 if (Blen > INT_MAX) {
454 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
455 return 0;
456 }
457
458 /*
459 * Check 32 * r * (N + 2) * sizeof(uint32_t) fits in uint64_t
460 * This is combined size V, X and T (section 4)
461 */
462 i = UINT64_MAX / (32 * sizeof(uint32_t));
463 if (N + 2 > i / r) {
464 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
465 return 0;
466 }
467 Vlen = 32 * r * (N + 2) * sizeof(uint32_t);
468
469 /* check total allocated size fits in uint64_t */
470 if (Blen > UINT64_MAX - Vlen) {
471 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
472 return 0;
473 }
474
475 /* Check that the maximum memory doesn't exceed a size_t limits */
476 if (maxmem > SIZE_MAX)
477 maxmem = SIZE_MAX;
478
479 if (Blen + Vlen > maxmem) {
480 ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
481 return 0;
482 }
483
484 /* If no key return to indicate parameters are OK */
485 if (key == NULL)
486 return 1;
487
488 B = OPENSSL_malloc((size_t)(Blen + Vlen));
489 if (B == NULL) {
490 ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
491 return 0;
492 }
493 X = (uint32_t *)(B + Blen);
494 T = X + 32 * r;
495 V = T + 32 * r;
496 if (ossl_pkcs5_pbkdf2_hmac_ex(pass, passlen, salt, saltlen, 1, sha256,
497 (int)Blen, B, libctx, propq) == 0)
498 goto err;
499
500 for (i = 0; i < p; i++)
501 scryptROMix(B + 128 * r * i, r, N, X, T, V);
502
503 if (ossl_pkcs5_pbkdf2_hmac_ex(pass, passlen, B, (int)Blen, 1, sha256,
504 keylen, key, libctx, propq) == 0)
505 goto err;
506 rv = 1;
507 err:
508 if (rv == 0)
509 ERR_raise(ERR_LIB_EVP, EVP_R_PBKDF2_ERROR);
510
511 OPENSSL_clear_free(B, (size_t)(Blen + Vlen));
512 return rv;
513 }
514
515 #endif
516