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{-
10use OpenSSL::paramnames qw(produce_param_decoder);
11-}
12
13#include <stdlib.h>
14#include <stdarg.h>
15#include <string.h>
16#include <openssl/evp.h>
17#include <openssl/kdf.h>
18#include <openssl/err.h>
19#include <openssl/core_names.h>
20#include <openssl/proverr.h>
21#include "crypto/evp.h"
22#include "internal/common.h"
23#include "internal/numbers.h"
24#include "prov/implementations.h"
25#include "prov/provider_ctx.h"
26#include "prov/providercommon.h"
27#include "prov/provider_util.h"
28
29#ifndef OPENSSL_NO_SCRYPT
30
31static OSSL_FUNC_kdf_newctx_fn kdf_scrypt_new;
32static OSSL_FUNC_kdf_dupctx_fn kdf_scrypt_dup;
33static OSSL_FUNC_kdf_freectx_fn kdf_scrypt_free;
34static OSSL_FUNC_kdf_reset_fn kdf_scrypt_reset;
35static OSSL_FUNC_kdf_derive_fn kdf_scrypt_derive;
36static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_scrypt_settable_ctx_params;
37static OSSL_FUNC_kdf_set_ctx_params_fn kdf_scrypt_set_ctx_params;
38static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_scrypt_gettable_ctx_params;
39static OSSL_FUNC_kdf_get_ctx_params_fn kdf_scrypt_get_ctx_params;
40
41static int scrypt_alg(const char *pass, size_t passlen,
42                      const unsigned char *salt, size_t saltlen,
43                      uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
44                      unsigned char *key, size_t keylen, EVP_MD *sha256,
45                      OSSL_LIB_CTX *libctx, const char *propq);
46
47typedef struct {
48    OSSL_LIB_CTX *libctx;
49    char *propq;
50    unsigned char *pass;
51    size_t pass_len;
52    unsigned char *salt;
53    size_t salt_len;
54    uint64_t N;
55    uint64_t r, p;
56    uint64_t maxmem_bytes;
57    EVP_MD *sha256;
58} KDF_SCRYPT;
59
60static void kdf_scrypt_init(KDF_SCRYPT *ctx);
61
62static void *kdf_scrypt_new_inner(OSSL_LIB_CTX *libctx)
63{
64    KDF_SCRYPT *ctx;
65
66    if (!ossl_prov_is_running())
67        return NULL;
68
69    ctx = OPENSSL_zalloc(sizeof(*ctx));
70    if (ctx == NULL)
71        return NULL;
72    ctx->libctx = libctx;
73    kdf_scrypt_init(ctx);
74    return ctx;
75}
76
77static void *kdf_scrypt_new(void *provctx)
78{
79    return kdf_scrypt_new_inner(PROV_LIBCTX_OF(provctx));
80}
81
82static void kdf_scrypt_free(void *vctx)
83{
84    KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
85
86    if (ctx != NULL) {
87        OPENSSL_free(ctx->propq);
88        EVP_MD_free(ctx->sha256);
89        kdf_scrypt_reset(ctx);
90        OPENSSL_free(ctx);
91    }
92}
93
94static void kdf_scrypt_reset(void *vctx)
95{
96    KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
97
98    OPENSSL_free(ctx->salt);
99    ctx->salt = NULL;
100    OPENSSL_clear_free(ctx->pass, ctx->pass_len);
101    ctx->pass = NULL;
102    kdf_scrypt_init(ctx);
103}
104
105static void *kdf_scrypt_dup(void *vctx)
106{
107    const KDF_SCRYPT *src = (const KDF_SCRYPT *)vctx;
108    KDF_SCRYPT *dest;
109
110    dest = kdf_scrypt_new_inner(src->libctx);
111    if (dest != NULL) {
112        if (src->sha256 != NULL && !EVP_MD_up_ref(src->sha256))
113            goto err;
114        if (src->propq != NULL) {
115            dest->propq = OPENSSL_strdup(src->propq);
116            if (dest->propq == NULL)
117                goto err;
118        }
119        if (!ossl_prov_memdup(src->salt, src->salt_len,
120                              &dest->salt, &dest->salt_len)
121                || !ossl_prov_memdup(src->pass, src->pass_len,
122                                     &dest->pass , &dest->pass_len))
123            goto err;
124        dest->N = src->N;
125        dest->r = src->r;
126        dest->p = src->p;
127        dest->maxmem_bytes = src->maxmem_bytes;
128        dest->sha256 = src->sha256;
129    }
130    return dest;
131
132 err:
133    kdf_scrypt_free(dest);
134    return NULL;
135}
136
137static void kdf_scrypt_init(KDF_SCRYPT *ctx)
138{
139    /* Default values are the most conservative recommendation given in the
140     * original paper of C. Percival. Derivation uses roughly 1 GiB of memory
141     * for this parameter choice (approx. 128 * r * N * p bytes).
142     */
143    ctx->N = 1 << 20;
144    ctx->r = 8;
145    ctx->p = 1;
146    ctx->maxmem_bytes = 1025 * 1024 * 1024;
147}
148
149static int scrypt_set_membuf(unsigned char **buffer, size_t *buflen,
150                             const OSSL_PARAM *p)
151{
152    OPENSSL_clear_free(*buffer, *buflen);
153    *buffer = NULL;
154    *buflen = 0;
155
156    if (p->data_size == 0) {
157        if ((*buffer = OPENSSL_malloc(1)) == NULL)
158            return 0;
159    } else if (p->data != NULL) {
160        if (!OSSL_PARAM_get_octet_string(p, (void **)buffer, 0, buflen))
161            return 0;
162    }
163    return 1;
164}
165
166static int set_digest(KDF_SCRYPT *ctx)
167{
168    EVP_MD_free(ctx->sha256);
169    ctx->sha256 = EVP_MD_fetch(ctx->libctx, "sha256", ctx->propq);
170    if (ctx->sha256 == NULL) {
171        ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_LOAD_SHA256);
172        return 0;
173    }
174    return 1;
175}
176
177static int set_property_query(KDF_SCRYPT *ctx, const char *propq)
178{
179    OPENSSL_free(ctx->propq);
180    ctx->propq = NULL;
181    if (propq != NULL) {
182        ctx->propq = OPENSSL_strdup(propq);
183        if (ctx->propq == NULL)
184            return 0;
185    }
186    return 1;
187}
188
189static int kdf_scrypt_derive(void *vctx, unsigned char *key, size_t keylen,
190                             const OSSL_PARAM params[])
191{
192    KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;
193
194    if (!ossl_prov_is_running() || !kdf_scrypt_set_ctx_params(ctx, params))
195        return 0;
196
197    if (ctx->pass == NULL) {
198        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_PASS);
199        return 0;
200    }
201
202    if (ctx->salt == NULL) {
203        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SALT);
204        return 0;
205    }
206
207    if (ctx->sha256 == NULL && !set_digest(ctx))
208        return 0;
209
210    return scrypt_alg((char *)ctx->pass, ctx->pass_len, ctx->salt,
211                      ctx->salt_len, ctx->N, ctx->r, ctx->p,
212                      ctx->maxmem_bytes, key, keylen, ctx->sha256,
213                      ctx->libctx, ctx->propq);
214}
215
216static int is_power_of_two(uint64_t value)
217{
218    return (value != 0) && ((value & (value - 1)) == 0);
219}
220
221{- produce_param_decoder('scrypt_set_ctx_params',
222                         (['KDF_PARAM_PASSWORD',      'pw',     'octet_string'],
223                          ['KDF_PARAM_SALT',          'salt',   'octet_string'],
224                          ['KDF_PARAM_SCRYPT_N',      'n',      'uint64'],
225                          ['KDF_PARAM_SCRYPT_R',      'r',      'uint32'],
226                          ['KDF_PARAM_SCRYPT_P',      'p',      'uint32'],
227                          ['KDF_PARAM_SCRYPT_MAXMEM', 'maxmem', 'uint64'],
228                          ['KDF_PARAM_PROPERTIES',    'propq',  'utf8_string'],
229                         )); -}
230
231static int kdf_scrypt_set_ctx_params(void *vctx, const OSSL_PARAM params[])
232{
233    struct scrypt_set_ctx_params_st p;
234    KDF_SCRYPT *ctx = vctx;
235    uint64_t u64_value;
236
237    if (ctx == NULL || !scrypt_set_ctx_params_decoder(params, &p))
238        return 0;
239
240    if (p.pw != NULL && !scrypt_set_membuf(&ctx->pass, &ctx->pass_len, p.pw))
241        return 0;
242
243    if (p.salt != NULL && !scrypt_set_membuf(&ctx->salt, &ctx->salt_len, p.salt))
244        return 0;
245
246    if (p.n != NULL) {
247        if (!OSSL_PARAM_get_uint64(p.n, &u64_value)
248            || u64_value <= 1
249            || !is_power_of_two(u64_value))
250            return 0;
251        ctx->N = u64_value;
252    }
253
254    if (p.r != NULL) {
255        if (!OSSL_PARAM_get_uint64(p.r, &u64_value) || u64_value < 1)
256            return 0;
257        ctx->r = u64_value;
258    }
259
260    if (p.p != NULL) {
261        if (!OSSL_PARAM_get_uint64(p.p, &u64_value) || u64_value < 1)
262            return 0;
263        ctx->p = u64_value;
264    }
265
266    if (p.maxmem != NULL) {
267        if (!OSSL_PARAM_get_uint64(p.maxmem, &u64_value) || u64_value < 1)
268            return 0;
269        ctx->maxmem_bytes = u64_value;
270    }
271
272    if (p.propq != NULL) {
273        if (p.propq->data_type != OSSL_PARAM_UTF8_STRING
274            || !set_property_query(ctx, p.propq->data)
275            || !set_digest(ctx))
276            return 0;
277    }
278    return 1;
279}
280
281static const OSSL_PARAM *kdf_scrypt_settable_ctx_params(ossl_unused void *ctx,
282                                                        ossl_unused void *p_ctx)
283{
284    return scrypt_set_ctx_params_list;
285}
286
287{- produce_param_decoder('scrypt_get_ctx_params',
288                         (['KDF_PARAM_SIZE',                    'size', 'size_t'],
289                         )); -}
290
291static int kdf_scrypt_get_ctx_params(void *vctx, OSSL_PARAM params[])
292{
293    struct scrypt_get_ctx_params_st p;
294    KDF_SCRYPT *ctx = vctx;
295
296    if (ctx == NULL || !scrypt_get_ctx_params_decoder(params, &p))
297        return 0;
298
299    if (p.size != NULL && !OSSL_PARAM_set_size_t(p.size, SIZE_MAX))
300            return 0;
301    return 1;
302}
303
304static const OSSL_PARAM *kdf_scrypt_gettable_ctx_params(ossl_unused void *ctx,
305                                                        ossl_unused void *p_ctx)
306{
307    return scrypt_get_ctx_params_list;
308}
309
310const 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    OSSL_DISPATCH_END
323};
324
325#define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
326static 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
371static 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
387static 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
445static 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        return 0;
528    X = (uint32_t *)(B + Blen);
529    T = X + 32 * r;
530    V = T + 32 * r;
531    if (ossl_pkcs5_pbkdf2_hmac_ex(pass, (int)passlen, salt, (int)saltlen, 1,
532                                  sha256, (int)Blen, B, libctx, propq) == 0)
533        goto err;
534
535    for (i = 0; i < p; i++)
536        scryptROMix(B + 128 * r * i, r, N, X, T, V);
537
538    if (ossl_pkcs5_pbkdf2_hmac_ex(pass, (int)passlen, B, (int)Blen, 1, sha256,
539                                  (int)keylen, key, libctx, propq) == 0)
540        goto err;
541    rv = 1;
542 err:
543    if (rv == 0)
544        ERR_raise(ERR_LIB_EVP, EVP_R_PBKDF2_ERROR);
545
546    OPENSSL_clear_free(B, (size_t)(Blen + Vlen));
547    return rv;
548}
549
550#endif
551