openssl/crypto/evp/pbe_scrypt.c

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/*
* Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include "internal/numbers.h"
#ifndef OPENSSL_NO_SCRYPT
#define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
static void salsa208_word_specification(uint32_t inout[16])
{
int i;
uint32_t x[16];
memcpy(x, inout, sizeof(x));
for (i = 8; i > 0; i -= 2) {
x[4] ^= R(x[0] + x[12], 7);
x[8] ^= R(x[4] + x[0], 9);
x[12] ^= R(x[8] + x[4], 13);
x[0] ^= R(x[12] + x[8], 18);
x[9] ^= R(x[5] + x[1], 7);
x[13] ^= R(x[9] + x[5], 9);
x[1] ^= R(x[13] + x[9], 13);
x[5] ^= R(x[1] + x[13], 18);
x[14] ^= R(x[10] + x[6], 7);
x[2] ^= R(x[14] + x[10], 9);
x[6] ^= R(x[2] + x[14], 13);
x[10] ^= R(x[6] + x[2], 18);
x[3] ^= R(x[15] + x[11], 7);
x[7] ^= R(x[3] + x[15], 9);
x[11] ^= R(x[7] + x[3], 13);
x[15] ^= R(x[11] + x[7], 18);
x[1] ^= R(x[0] + x[3], 7);
x[2] ^= R(x[1] + x[0], 9);
x[3] ^= R(x[2] + x[1], 13);
x[0] ^= R(x[3] + x[2], 18);
x[6] ^= R(x[5] + x[4], 7);
x[7] ^= R(x[6] + x[5], 9);
x[4] ^= R(x[7] + x[6], 13);
x[5] ^= R(x[4] + x[7], 18);
x[11] ^= R(x[10] + x[9], 7);
x[8] ^= R(x[11] + x[10], 9);
x[9] ^= R(x[8] + x[11], 13);
x[10] ^= R(x[9] + x[8], 18);
x[12] ^= R(x[15] + x[14], 7);
x[13] ^= R(x[12] + x[15], 9);
x[14] ^= R(x[13] + x[12], 13);
x[15] ^= R(x[14] + x[13], 18);
}
for (i = 0; i < 16; ++i)
inout[i] += x[i];
OPENSSL_cleanse(x, sizeof(x));
}
static void scryptBlockMix(uint32_t *B_, uint32_t *B, uint64_t r)
{
uint64_t i, j;
uint32_t X[16], *pB;
memcpy(X, B + (r * 2 - 1) * 16, sizeof(X));
pB = B;
for (i = 0; i < r * 2; i++) {
for (j = 0; j < 16; j++)
X[j] ^= *pB++;
salsa208_word_specification(X);
memcpy(B_ + (i / 2 + (i & 1) * r) * 16, X, sizeof(X));
}
OPENSSL_cleanse(X, sizeof(X));
}
static void scryptROMix(unsigned char *B, uint64_t r, uint64_t N,
uint32_t *X, uint32_t *T, uint32_t *V)
{
unsigned char *pB;
uint32_t *pV;
uint64_t i, k;
/* Convert from little endian input */
for (pV = V, i = 0, pB = B; i < 32 * r; i++, pV++) {
*pV = *pB++;
*pV |= *pB++ << 8;
*pV |= *pB++ << 16;
*pV |= (uint32_t)*pB++ << 24;
}
for (i = 1; i < N; i++, pV += 32 * r)
scryptBlockMix(pV, pV - 32 * r, r);
scryptBlockMix(X, V + (N - 1) * 32 * r, r);
for (i = 0; i < N; i++) {
uint32_t j;
j = X[16 * (2 * r - 1)] % N;
pV = V + 32 * r * j;
for (k = 0; k < 32 * r; k++)
T[k] = X[k] ^ *pV++;
scryptBlockMix(X, T, r);
}
/* Convert output to little endian */
for (i = 0, pB = B; i < 32 * r; i++) {
uint32_t xtmp = X[i];
*pB++ = xtmp & 0xff;
*pB++ = (xtmp >> 8) & 0xff;
*pB++ = (xtmp >> 16) & 0xff;
*pB++ = (xtmp >> 24) & 0xff;
}
}
#ifndef SIZE_MAX
# define SIZE_MAX ((size_t)-1)
#endif
/*
* Maximum power of two that will fit in uint64_t: this should work on
* most (all?) platforms.
*/
#define LOG2_UINT64_MAX (sizeof(uint64_t) * 8 - 1)
/*
* Maximum value of p * r:
* p <= ((2^32-1) * hLen) / MFLen =>
* p <= ((2^32-1) * 32) / (128 * r) =>
* p * r <= (2^30-1)
*
*/
#define SCRYPT_PR_MAX ((1 << 30) - 1)
/*
* Maximum permitted memory allow this to be overridden with Configuration
* option: e.g. -DSCRYPT_MAX_MEM=0 for maximum possible.
*/
#ifdef SCRYPT_MAX_MEM
# if SCRYPT_MAX_MEM == 0
# undef SCRYPT_MAX_MEM
/*
* Although we could theoretically allocate SIZE_MAX memory that would leave
* no memory available for anything else so set limit as half that.
*/
# define SCRYPT_MAX_MEM (SIZE_MAX/2)
# endif
#else
/* Default memory limit: 32 MB */
# define SCRYPT_MAX_MEM (1024 * 1024 * 32)
#endif
int EVP_PBE_scrypt(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)
{
int rv = 0;
unsigned char *B;
uint32_t *X, *V, *T;
uint64_t i, Blen, Vlen;
/* Sanity check parameters */
/* initial check, r,p must be non zero, N >= 2 and a power of 2 */
if (r == 0 || p == 0 || N < 2 || (N & (N - 1)))
return 0;
/* Check p * r < SCRYPT_PR_MAX avoiding overflow */
if (p > SCRYPT_PR_MAX / r)
return 0;
/*
* Need to check N: if 2^(128 * r / 8) overflows limit this is
* automatically satisfied since N <= UINT64_MAX.
*/
if (16 * r <= LOG2_UINT64_MAX) {
if (N >= (((uint64_t)1) << (16 * r)))
return 0;
}
/* Memory checks: check total allocated buffer size fits in uint64_t */
/*
* B size in section 5 step 1.S
* Note: we know p * 128 * r < UINT64_MAX because we already checked
* p * r < SCRYPT_PR_MAX
*/
Blen = p * 128 * r;
/*
* Check 32 * r * (N + 2) * sizeof(uint32_t) fits in uint64_t
* This is combined size V, X and T (section 4)
*/
i = UINT64_MAX / (32 * sizeof(uint32_t));
if (N + 2 > i / r)
return 0;
Vlen = 32 * r * (N + 2) * sizeof(uint32_t);
/* check total allocated size fits in uint64_t */
if (Blen > UINT64_MAX - Vlen)
return 0;
if (maxmem == 0)
maxmem = SCRYPT_MAX_MEM;
if (Blen + Vlen > maxmem) {
EVPerr(EVP_F_EVP_PBE_SCRYPT, EVP_R_MEMORY_LIMIT_EXCEEDED);
return 0;
}
/* If no key return to indicate parameters are OK */
if (key == NULL)
return 1;
B = OPENSSL_malloc(Blen + Vlen);
if (B == NULL)
return 0;
X = (uint32_t *)(B + Blen);
T = X + 32 * r;
V = T + 32 * r;
if (PKCS5_PBKDF2_HMAC(pass, passlen, salt, saltlen, 1, EVP_sha256(),
Blen, B) == 0)
goto err;
for (i = 0; i < p; i++)
scryptROMix(B + 128 * r * i, r, N, X, T, V);
if (PKCS5_PBKDF2_HMAC(pass, passlen, B, Blen, 1, EVP_sha256(),
keylen, key) == 0)
goto err;
rv = 1;
err:
OPENSSL_clear_free(B, Blen + Vlen);
return rv;
}
#endif