2 * Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
13 #include <openssl/evp.h>
14 #include <openssl/err.h>
15 #include <internal/numbers.h>
17 #ifndef OPENSSL_NO_SCRYPT
19 #define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
20 static void salsa208_word_specification(uint32_t inout[16])
24 memcpy(x, inout, sizeof(x));
25 for (i = 8; i > 0; i -= 2) {
26 x[4] ^= R(x[0] + x[12], 7);
27 x[8] ^= R(x[4] + x[0], 9);
28 x[12] ^= R(x[8] + x[4], 13);
29 x[0] ^= R(x[12] + x[8], 18);
30 x[9] ^= R(x[5] + x[1], 7);
31 x[13] ^= R(x[9] + x[5], 9);
32 x[1] ^= R(x[13] + x[9], 13);
33 x[5] ^= R(x[1] + x[13], 18);
34 x[14] ^= R(x[10] + x[6], 7);
35 x[2] ^= R(x[14] + x[10], 9);
36 x[6] ^= R(x[2] + x[14], 13);
37 x[10] ^= R(x[6] + x[2], 18);
38 x[3] ^= R(x[15] + x[11], 7);
39 x[7] ^= R(x[3] + x[15], 9);
40 x[11] ^= R(x[7] + x[3], 13);
41 x[15] ^= R(x[11] + x[7], 18);
42 x[1] ^= R(x[0] + x[3], 7);
43 x[2] ^= R(x[1] + x[0], 9);
44 x[3] ^= R(x[2] + x[1], 13);
45 x[0] ^= R(x[3] + x[2], 18);
46 x[6] ^= R(x[5] + x[4], 7);
47 x[7] ^= R(x[6] + x[5], 9);
48 x[4] ^= R(x[7] + x[6], 13);
49 x[5] ^= R(x[4] + x[7], 18);
50 x[11] ^= R(x[10] + x[9], 7);
51 x[8] ^= R(x[11] + x[10], 9);
52 x[9] ^= R(x[8] + x[11], 13);
53 x[10] ^= R(x[9] + x[8], 18);
54 x[12] ^= R(x[15] + x[14], 7);
55 x[13] ^= R(x[12] + x[15], 9);
56 x[14] ^= R(x[13] + x[12], 13);
57 x[15] ^= R(x[14] + x[13], 18);
59 for (i = 0; i < 16; ++i)
61 OPENSSL_cleanse(x, sizeof(x));
64 static void scryptBlockMix(uint32_t *B_, uint32_t *B, uint64_t r)
69 memcpy(X, B + (r * 2 - 1) * 16, sizeof(X));
71 for (i = 0; i < r * 2; i++) {
72 for (j = 0; j < 16; j++)
74 salsa208_word_specification(X);
75 memcpy(B_ + (i / 2 + (i & 1) * r) * 16, X, sizeof(X));
77 OPENSSL_cleanse(X, sizeof(X));
80 static void scryptROMix(unsigned char *B, uint64_t r, uint64_t N,
81 uint32_t *X, uint32_t *T, uint32_t *V)
87 /* Convert from little endian input */
88 for (pV = V, i = 0, pB = B; i < 32 * r; i++, pV++) {
92 *pV |= (uint32_t)*pB++ << 24;
95 for (i = 1; i < N; i++, pV += 32 * r)
96 scryptBlockMix(pV, pV - 32 * r, r);
98 scryptBlockMix(X, V + (N - 1) * 32 * r, r);
100 for (i = 0; i < N; i++) {
102 j = X[16 * (2 * r - 1)] % N;
104 for (k = 0; k < 32 * r; k++)
106 scryptBlockMix(X, T, r);
108 /* Convert output to little endian */
109 for (i = 0, pB = B; i < 32 * r; i++) {
110 uint32_t xtmp = X[i];
112 *pB++ = (xtmp >> 8) & 0xff;
113 *pB++ = (xtmp >> 16) & 0xff;
114 *pB++ = (xtmp >> 24) & 0xff;
119 # define SIZE_MAX ((size_t)-1)
123 * Maximum power of two that will fit in uint64_t: this should work on
124 * most (all?) platforms.
127 #define LOG2_UINT64_MAX (sizeof(uint64_t) * 8 - 1)
130 * Maximum value of p * r:
131 * p <= ((2^32-1) * hLen) / MFLen =>
132 * p <= ((2^32-1) * 32) / (128 * r) =>
137 #define SCRYPT_PR_MAX ((1 << 30) - 1)
140 * Maximum permitted memory allow this to be overridden with Configuration
141 * option: e.g. -DSCRYPT_MAX_MEM=0 for maximum possible.
144 #ifdef SCRYPT_MAX_MEM
145 # if SCRYPT_MAX_MEM == 0
146 # undef SCRYPT_MAX_MEM
148 * Although we could theoretically allocate SIZE_MAX memory that would leave
149 * no memory available for anything else so set limit as half that.
151 # define SCRYPT_MAX_MEM (SIZE_MAX/2)
154 /* Default memory limit: 32 MB */
155 # define SCRYPT_MAX_MEM (1024 * 1024 * 32)
158 int EVP_PBE_scrypt(const char *pass, size_t passlen,
159 const unsigned char *salt, size_t saltlen,
160 uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
161 unsigned char *key, size_t keylen)
166 uint64_t i, Blen, Vlen;
169 /* Sanity check parameters */
170 /* initial check, r,p must be non zero, N >= 2 and a power of 2 */
171 if (r == 0 || p == 0 || N < 2 || (N & (N - 1)))
173 /* Check p * r < SCRYPT_PR_MAX avoiding overflow */
174 if (p > SCRYPT_PR_MAX / r)
178 * Need to check N: if 2^(128 * r / 8) overflows limit this is
179 * automatically satisfied since N <= UINT64_MAX.
182 if (16 * r <= LOG2_UINT64_MAX) {
183 if (N >= (((uint64_t)1) << (16 * r)))
187 /* Memory checks: check total allocated buffer size fits in uint64_t */
190 * B size in section 5 step 1.S
191 * Note: we know p * 128 * r < UINT64_MAX because we already checked
192 * p * r < SCRYPT_PR_MAX
197 * Check 32 * r * (N + 2) * sizeof(uint32_t) fits in
198 * uint64_t and also size_t (their sizes are unrelated).
199 * This is combined size V, X and T (section 4)
201 i = UINT64_MAX / (32 * sizeof(uint32_t));
204 Vlen = 32 * r * (N + 2) * sizeof(uint32_t);
206 /* check total allocated size fits in uint64_t */
207 if (Blen > UINT64_MAX - Vlen)
209 /* check total allocated size fits in size_t */
210 if (Blen > SIZE_MAX - Vlen)
213 allocsize = (size_t)(Blen + Vlen);
216 maxmem = SCRYPT_MAX_MEM;
218 if (allocsize > maxmem) {
219 EVPerr(EVP_F_EVP_PBE_SCRYPT, EVP_R_MEMORY_LIMIT_EXCEEDED);
223 /* If no key return to indicate parameters are OK */
227 B = OPENSSL_malloc(allocsize);
230 X = (uint32_t *)(B + Blen);
233 if (PKCS5_PBKDF2_HMAC(pass, passlen, salt, saltlen, 1, EVP_sha256(),
237 for (i = 0; i < p; i++)
238 scryptROMix(B + 128 * r * i, r, N, X, T, V);
240 if (PKCS5_PBKDF2_HMAC(pass, passlen, B, Blen, 1, EVP_sha256(),
245 OPENSSL_clear_free(B, allocsize);