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 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 73 static void *kdf_scrypt_new(void *provctx) 74 { 75 return kdf_scrypt_new_inner(PROV_LIBCTX_OF(provctx)); 76 } 77 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 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 } 100 101 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 } 132 133 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 } 144 145 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 } 161 162 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 } 172 173 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 } 184 185 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 } 211 212 static int is_power_of_two(uint64_t value) 213 { 214 return (value != 0) && ((value & (value - 1)) == 0); 215 } 216 217 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 } 273 274 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 } 289 290 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 } 298 299 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)))) 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 } 369 370 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 } 385 386 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) 443 444 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