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