providers/implementations/kdfs/scrypt.c

   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 #include "prov/provider_util.h"
  25
  26 #ifndef OPENSSL_NO_SCRYPT
  27
  28 static OSSL_FUNC_kdf_newctx_fn kdf_scrypt_new;
  29 static OSSL_FUNC_kdf_dupctx_fn kdf_scrypt_dup;
  30 static OSSL_FUNC_kdf_freectx_fn kdf_scrypt_free;
  31 static OSSL_FUNC_kdf_reset_fn kdf_scrypt_reset;
  32 static OSSL_FUNC_kdf_derive_fn kdf_scrypt_derive;
  33 static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_scrypt_settable_ctx_params;
  34 static OSSL_FUNC_kdf_set_ctx_params_fn kdf_scrypt_set_ctx_params;
  35 static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_scrypt_gettable_ctx_params;
  36 static OSSL_FUNC_kdf_get_ctx_params_fn kdf_scrypt_get_ctx_params;
  37
  38 static int scrypt_alg(const char *pass, size_t passlen,
  39                       const unsigned char *salt, size_t saltlen,
  40                       uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
  41                       unsigned char *key, size_t keylen, EVP_MD *sha256,
  42                       OSSL_LIB_CTX *libctx, const char *propq);
  43
  44 typedef struct {
  45     OSSL_LIB_CTX *libctx;
  46     char *propq;
  47     unsigned char *pass;
  48     size_t pass_len;
  49     unsigned char *salt;
  50     size_t salt_len;
  51     uint64_t N;
  52     uint64_t r, p;
  53     uint64_t maxmem_bytes;
  54     EVP_MD *sha256;
  55 } KDF_SCRYPT;
  56
  57 static void kdf_scrypt_init(KDF_SCRYPT *ctx);
  58
  59 static void *kdf_scrypt_new(void *provctx)
  60 {
  61     KDF_SCRYPT *ctx;
  62
  63     if (!ossl_prov_is_running())
  64         return NULL;
  65
  66     ctx = OPENSSL_zalloc(sizeof(*ctx));
  67     if (ctx == NULL) {
  68         ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
  69         return NULL;
  70     }
  71     ctx->libctx = PROV_LIBCTX_OF(provctx);
  72     kdf_scrypt_init(ctx);
  73     return ctx;
  74 }
  75
  76 static void kdf_scrypt_free(void *vctx)
  77 {
  78     KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
  79
  80     if (ctx != NULL) {
  81         OPENSSL_free(ctx->propq);
  82         EVP_MD_free(ctx->sha256);
  83         kdf_scrypt_reset(ctx);
  84         OPENSSL_free(ctx);
  85     }
  86 }
  87
  88 static void kdf_scrypt_reset(void *vctx)
  89 {
  90     KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
  91
  92     OPENSSL_free(ctx->salt);
  93     OPENSSL_clear_free(ctx->pass, ctx->pass_len);
  94     kdf_scrypt_init(ctx);
  95 }
  96
  97 static void *kdf_scrypt_dup(void *vctx)
  98 {
  99     const KDF_SCRYPT *src = (const KDF_SCRYPT *)vctx;
 100     KDF_SCRYPT *dest;
 101
 102     dest = kdf_scrypt_new(src->libctx);
 103     if (dest != NULL) {
 104         if (src->sha256 != NULL && !EVP_MD_up_ref(src->sha256))
 105             goto err;
 106         if (src->propq != NULL) {
 107             dest->propq = OPENSSL_strdup(src->propq);
 108             if (dest->propq == NULL)
 109                 goto err;
 110         }
 111         if (!ossl_prov_memdup(src->salt, src->salt_len,
 112                               &dest->salt, &dest->salt_len)
 113                 || !ossl_prov_memdup(src->pass, src->pass_len,
 114                                      &dest->pass , &dest->pass_len))
 115             goto err;
 116         dest->N = src->N;
 117         dest->r = src->r;
 118         dest->p = src->p;
 119         dest->maxmem_bytes = src->maxmem_bytes;
 120         dest->sha256 = src->sha256;
 121     }
 122     return dest;
 123
 124  err:
 125     kdf_scrypt_free(dest);
 126     return NULL;
 127 }
 128
 129 static void kdf_scrypt_init(KDF_SCRYPT *ctx)
 130 {
 131     /* Default values are the most conservative recommendation given in the
 132      * original paper of C. Percival. Derivation uses roughly 1 GiB of memory
 133      * for this parameter choice (approx. 128 * r * N * p bytes).
 134      */
 135     ctx->N = 1 << 20;
 136     ctx->r = 8;
 137     ctx->p = 1;
 138     ctx->maxmem_bytes = 1025 * 1024 * 1024;
 139 }
 140
 141 static int scrypt_set_membuf(unsigned char **buffer, size_t *buflen,
 142                              const OSSL_PARAM *p)
 143 {
 144     OPENSSL_clear_free(*buffer, *buflen);
 145     *buffer = NULL;
 146     *buflen = 0;
 147
 148     if (p->data_size == 0) {
 149         if ((*buffer = OPENSSL_malloc(1)) == NULL) {
 150             ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
 151             return 0;
 152         }
 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             ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
 180             return 0;
 181         }
 182     }
 183     return 1;
 184 }
 185
 186 static int kdf_scrypt_derive(void *vctx, unsigned char *key, size_t keylen,
 187                              const OSSL_PARAM params[])
 188 {
 189     KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
 190
 191     if (!ossl_prov_is_running() || !kdf_scrypt_set_ctx_params(ctx, params))
 192         return 0;
 193
 194     if (ctx->pass == NULL) {
 195         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_PASS);
 196         return 0;
 197     }
 198
 199     if (ctx->salt == NULL) {
 200         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SALT);
 201         return 0;
 202     }
 203
 204     if (ctx->sha256 == NULL && !set_digest(ctx))
 205         return 0;
 206
 207     return scrypt_alg((char *)ctx->pass, ctx->pass_len, ctx->salt,
 208                       ctx->salt_len, ctx->N, ctx->r, ctx->p,
 209                       ctx->maxmem_bytes, key, keylen, ctx->sha256,
 210                       ctx->libctx, ctx->propq);
 211 }
 212
 213 static int is_power_of_two(uint64_t value)
 214 {
 215     return (value != 0) && ((value & (value - 1)) == 0);
 216 }
 217
 218 static int kdf_scrypt_set_ctx_params(void *vctx, const OSSL_PARAM params[])
 219 {
 220     const OSSL_PARAM *p;
 221     KDF_SCRYPT *ctx = vctx;
 222     uint64_t u64_value;
 223
 224     if (params == NULL)
 225         return 1;
 226
 227     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL)
 228         if (!scrypt_set_membuf(&ctx->pass, &ctx->pass_len, p))
 229             return 0;
 230
 231     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL)
 232         if (!scrypt_set_membuf(&ctx->salt, &ctx->salt_len, p))
 233             return 0;
 234
 235     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_N))
 236         != NULL) {
 237         if (!OSSL_PARAM_get_uint64(p, &u64_value)
 238             || u64_value <= 1
 239             || !is_power_of_two(u64_value))
 240             return 0;
 241         ctx->N = u64_value;
 242     }
 243
 244     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_R))
 245         != NULL) {
 246         if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
 247             return 0;
 248         ctx->r = u64_value;
 249     }
 250
 251     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_P))
 252         != NULL) {
 253         if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
 254             return 0;
 255         ctx->p = u64_value;
 256     }
 257
 258     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SCRYPT_MAXMEM))
 259         != NULL) {
 260         if (!OSSL_PARAM_get_uint64(p, &u64_value) || u64_value < 1)
 261             return 0;
 262         ctx->maxmem_bytes = u64_value;
 263     }
 264
 265     p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PROPERTIES);
 266     if (p != NULL) {
 267         if (p->data_type != OSSL_PARAM_UTF8_STRING
 268             || !set_property_query(ctx, p->data)
 269             || !set_digest(ctx))
 270             return 0;
 271     }
 272     return 1;
 273 }
 274
 275 static const OSSL_PARAM *kdf_scrypt_settable_ctx_params(ossl_unused void *ctx,
 276                                                         ossl_unused void *p_ctx)
 277 {
 278     static const OSSL_PARAM known_settable_ctx_params[] = {
 279         OSSL_PARAM_octet_string(OSSL_KDF_PARAM_PASSWORD, NULL, 0),
 280         OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
 281         OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_N, NULL),
 282         OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_R, NULL),
 283         OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_P, NULL),
 284         OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_MAXMEM, NULL),
 285         OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
 286         OSSL_PARAM_END
 287     };
 288     return known_settable_ctx_params;
 289 }
 290
 291 static int kdf_scrypt_get_ctx_params(void *vctx, OSSL_PARAM params[])
 292 {
 293     OSSL_PARAM *p;
 294
 295     if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
 296         return OSSL_PARAM_set_size_t(p, SIZE_MAX);
 297     return -2;
 298 }
 299
 300 static const OSSL_PARAM *kdf_scrypt_gettable_ctx_params(ossl_unused void *ctx,
 301                                                         ossl_unused void *p_ctx)
 302 {
 303     static const OSSL_PARAM known_gettable_ctx_params[] = {
 304         OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
 305         OSSL_PARAM_END
 306     };
 307     return known_gettable_ctx_params;
 308 }
 309
 310 const OSSL_DISPATCH ossl_kdf_scrypt_functions[] = {
 311     { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_scrypt_new },
 312     { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_scrypt_dup },
 313     { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_scrypt_free },
 314     { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_scrypt_reset },
 315     { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_scrypt_derive },
 316     { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
 317       (void(*)(void))kdf_scrypt_settable_ctx_params },
 318     { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_scrypt_set_ctx_params },
 319     { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
 320       (void(*)(void))kdf_scrypt_gettable_ctx_params },
 321     { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_scrypt_get_ctx_params },
 322     { 0, NULL }
 323 };
 324
 325 #define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
 326 static void salsa208_word_specification(uint32_t inout[16])
 327 {
 328     int i;
 329     uint32_t x[16];
 330
 331     memcpy(x, inout, sizeof(x));
 332     for (i = 8; i > 0; i -= 2) {
 333         x[4] ^= R(x[0] + x[12], 7);
 334         x[8] ^= R(x[4] + x[0], 9);
 335         x[12] ^= R(x[8] + x[4], 13);
 336         x[0] ^= R(x[12] + x[8], 18);
 337         x[9] ^= R(x[5] + x[1], 7);
 338         x[13] ^= R(x[9] + x[5], 9);
 339         x[1] ^= R(x[13] + x[9], 13);
 340         x[5] ^= R(x[1] + x[13], 18);
 341         x[14] ^= R(x[10] + x[6], 7);
 342         x[2] ^= R(x[14] + x[10], 9);
 343         x[6] ^= R(x[2] + x[14], 13);
 344         x[10] ^= R(x[6] + x[2], 18);
 345         x[3] ^= R(x[15] + x[11], 7);
 346         x[7] ^= R(x[3] + x[15], 9);
 347         x[11] ^= R(x[7] + x[3], 13);
 348         x[15] ^= R(x[11] + x[7], 18);
 349         x[1] ^= R(x[0] + x[3], 7);
 350         x[2] ^= R(x[1] + x[0], 9);
 351         x[3] ^= R(x[2] + x[1], 13);
 352         x[0] ^= R(x[3] + x[2], 18);
 353         x[6] ^= R(x[5] + x[4], 7);
 354         x[7] ^= R(x[6] + x[5], 9);
 355         x[4] ^= R(x[7] + x[6], 13);
 356         x[5] ^= R(x[4] + x[7], 18);
 357         x[11] ^= R(x[10] + x[9], 7);
 358         x[8] ^= R(x[11] + x[10], 9);
 359         x[9] ^= R(x[8] + x[11], 13);
 360         x[10] ^= R(x[9] + x[8], 18);
 361         x[12] ^= R(x[15] + x[14], 7);
 362         x[13] ^= R(x[12] + x[15], 9);
 363         x[14] ^= R(x[13] + x[12], 13);
 364         x[15] ^= R(x[14] + x[13], 18);
 365     }
 366     for (i = 0; i < 16; ++i)
 367         inout[i] += x[i];
 368     OPENSSL_cleanse(x, sizeof(x));
 369 }
 370
 371 static void scryptBlockMix(uint32_t *B_, uint32_t *B, uint64_t r)
 372 {
 373     uint64_t i, j;
 374     uint32_t X[16], *pB;
 375
 376     memcpy(X, B + (r * 2 - 1) * 16, sizeof(X));
 377     pB = B;
 378     for (i = 0; i < r * 2; i++) {
 379         for (j = 0; j < 16; j++)
 380             X[j] ^= *pB++;
 381         salsa208_word_specification(X);
 382         memcpy(B_ + (i / 2 + (i & 1) * r) * 16, X, sizeof(X));
 383     }
 384     OPENSSL_cleanse(X, sizeof(X));
 385 }
 386
 387 static void scryptROMix(unsigned char *B, uint64_t r, uint64_t N,
 388                         uint32_t *X, uint32_t *T, uint32_t *V)
 389 {
 390     unsigned char *pB;
 391     uint32_t *pV;
 392     uint64_t i, k;
 393
 394     /* Convert from little endian input */
 395     for (pV = V, i = 0, pB = B; i < 32 * r; i++, pV++) {
 396         *pV = *pB++;
 397         *pV |= *pB++ << 8;
 398         *pV |= *pB++ << 16;
 399         *pV |= (uint32_t)*pB++ << 24;
 400     }
 401
 402     for (i = 1; i < N; i++, pV += 32 * r)
 403         scryptBlockMix(pV, pV - 32 * r, r);
 404
 405     scryptBlockMix(X, V + (N - 1) * 32 * r, r);
 406
 407     for (i = 0; i < N; i++) {
 408         uint32_t j;
 409         j = X[16 * (2 * r - 1)] % N;
 410         pV = V + 32 * r * j;
 411         for (k = 0; k < 32 * r; k++)
 412             T[k] = X[k] ^ *pV++;
 413         scryptBlockMix(X, T, r);
 414     }
 415     /* Convert output to little endian */
 416     for (i = 0, pB = B; i < 32 * r; i++) {
 417         uint32_t xtmp = X[i];
 418         *pB++ = xtmp & 0xff;
 419         *pB++ = (xtmp >> 8) & 0xff;
 420         *pB++ = (xtmp >> 16) & 0xff;
 421         *pB++ = (xtmp >> 24) & 0xff;
 422     }
 423 }
 424
 425 #ifndef SIZE_MAX
 426 # define SIZE_MAX    ((size_t)-1)
 427 #endif
 428
 429 /*
 430  * Maximum power of two that will fit in uint64_t: this should work on
 431  * most (all?) platforms.
 432  */
 433
 434 #define LOG2_UINT64_MAX         (sizeof(uint64_t) * 8 - 1)
 435
 436 /*
 437  * Maximum value of p * r:
 438  * p <= ((2^32-1) * hLen) / MFLen =>
 439  * p <= ((2^32-1) * 32) / (128 * r) =>
 440  * p * r <= (2^30-1)
 441  */
 442
 443 #define SCRYPT_PR_MAX   ((1 << 30) - 1)
 444
 445 static int scrypt_alg(const char *pass, size_t passlen,
 446                       const unsigned char *salt, size_t saltlen,
 447                       uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
 448                       unsigned char *key, size_t keylen, EVP_MD *sha256,
 449                       OSSL_LIB_CTX *libctx, const char *propq)
 450 {
 451     int rv = 0;
 452     unsigned char *B;
 453     uint32_t *X, *V, *T;
 454     uint64_t i, Blen, Vlen;
 455
 456     /* Sanity check parameters */
 457     /* initial check, r,p must be non zero, N >= 2 and a power of 2 */
 458     if (r == 0 || p == 0 || N < 2 || (N & (N - 1)))
 459         return 0;
 460     /* Check p * r < SCRYPT_PR_MAX avoiding overflow */
 461     if (p > SCRYPT_PR_MAX / r) {
 462         ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
 463         return 0;
 464     }
 465
 466     /*
 467      * Need to check N: if 2^(128 * r / 8) overflows limit this is
 468      * automatically satisfied since N <= UINT64_MAX.
 469      */
 470
 471     if (16 * r <= LOG2_UINT64_MAX) {
 472         if (N >= (((uint64_t)1) << (16 * r))) {
 473             ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
 474             return 0;
 475         }
 476     }
 477
 478     /* Memory checks: check total allocated buffer size fits in uint64_t */
 479
 480     /*
 481      * B size in section 5 step 1.S
 482      * Note: we know p * 128 * r < UINT64_MAX because we already checked
 483      * p * r < SCRYPT_PR_MAX
 484      */
 485     Blen = p * 128 * r;
 486     /*
 487      * Yet we pass it as integer to PKCS5_PBKDF2_HMAC... [This would
 488      * have to be revised when/if PKCS5_PBKDF2_HMAC accepts size_t.]
 489      */
 490     if (Blen > INT_MAX) {
 491         ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
 492         return 0;
 493     }
 494
 495     /*
 496      * Check 32 * r * (N + 2) * sizeof(uint32_t) fits in uint64_t
 497      * This is combined size V, X and T (section 4)
 498      */
 499     i = UINT64_MAX / (32 * sizeof(uint32_t));
 500     if (N + 2 > i / r) {
 501         ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
 502         return 0;
 503     }
 504     Vlen = 32 * r * (N + 2) * sizeof(uint32_t);
 505
 506     /* check total allocated size fits in uint64_t */
 507     if (Blen > UINT64_MAX - Vlen) {
 508         ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
 509         return 0;
 510     }
 511
 512     /* Check that the maximum memory doesn't exceed a size_t limits */
 513     if (maxmem > SIZE_MAX)
 514         maxmem = SIZE_MAX;
 515
 516     if (Blen + Vlen > maxmem) {
 517         ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
 518         return 0;
 519     }
 520
 521     /* If no key return to indicate parameters are OK */
 522     if (key == NULL)
 523         return 1;
 524
 525     B = OPENSSL_malloc((size_t)(Blen + Vlen));
 526     if (B == NULL) {
 527         ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
 528         return 0;
 529     }
 530     X = (uint32_t *)(B + Blen);
 531     T = X + 32 * r;
 532     V = T + 32 * r;
 533     if (ossl_pkcs5_pbkdf2_hmac_ex(pass, passlen, salt, saltlen, 1, sha256,
 534                                   (int)Blen, B, libctx, propq) == 0)
 535         goto err;
 536
 537     for (i = 0; i < p; i++)
 538         scryptROMix(B + 128 * r * i, r, N, X, T, V);
 539
 540     if (ossl_pkcs5_pbkdf2_hmac_ex(pass, passlen, B, (int)Blen, 1, sha256,
 541                                   keylen, key, libctx, propq) == 0)
 542         goto err;
 543     rv = 1;
 544  err:
 545     if (rv == 0)
 546         ERR_raise(ERR_LIB_EVP, EVP_R_PBKDF2_ERROR);
 547
 548     OPENSSL_clear_free(B, (size_t)(Blen + Vlen));
 549     return rv;
 550 }
 551
 552 #endif