providers/implementations/kdfs/scrypt.c

   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
  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     OPENSSL_clear_free(ctx->pass, ctx->pass_len);
  96     kdf_scrypt_init(ctx);
  97 }
  98
  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
 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
 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
 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
 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
 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
 211 static int is_power_of_two(uint64_t value)
 212 {
 213     return (value != 0) && ((value & (value - 1)) == 0);
 214 }
 215
 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 (params == NULL)
 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
 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
 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
 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))))
 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
 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
 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
 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