crypto/evp/pbe_scrypt.c

   1 /*
   2  * Copyright 2015-2018 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 <openssl/evp.h>
  11 #include <openssl/err.h>
  12 #include <openssl/kdf.h>
  13 #include "internal/numbers.h"
  14
  15 #ifndef OPENSSL_NO_SCRYPT
  16
  17 /*
  18  * Maximum permitted memory allow this to be overridden with Configuration
  19  * option: e.g. -DSCRYPT_MAX_MEM=0 for maximum possible.
  20  */
  21
  22 #ifdef SCRYPT_MAX_MEM
  23 # if SCRYPT_MAX_MEM == 0
  24 #  undef SCRYPT_MAX_MEM
  25 /*
  26  * Although we could theoretically allocate SIZE_MAX memory that would leave
  27  * no memory available for anything else so set limit as half that.
  28  */
  29 #  define SCRYPT_MAX_MEM (SIZE_MAX/2)
  30 # endif
  31 #else
  32 /* Default memory limit: 32 MB */
  33 # define SCRYPT_MAX_MEM  (1024 * 1024 * 32)
  34 #endif
  35
  36 int EVP_PBE_scrypt(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)
  40 {
  41     const char *empty = "";
  42     int rv = 1;
  43     EVP_KDF_CTX *kctx;
  44
  45     if (r > UINT32_MAX || p > UINT32_MAX) {
  46         EVPerr(EVP_F_EVP_PBE_SCRYPT, EVP_R_PARAMETER_TOO_LARGE);
  47         return 0;
  48     }
  49
  50     /* Maintain existing behaviour. */
  51     if (pass == NULL) {
  52         pass = empty;
  53         passlen = 0;
  54     }
  55     if (salt == NULL) {
  56         salt = (const unsigned char *)empty;
  57         saltlen = 0;
  58     }
  59     if (maxmem == 0)
  60         maxmem = SCRYPT_MAX_MEM;
  61
  62     kctx = EVP_KDF_CTX_new_id(EVP_KDF_SCRYPT);
  63     if (kctx == NULL)
  64         return 0;
  65
  66     if (EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_PASS, pass, (size_t)passlen) != 1
  67             || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_SALT,
  68                             salt, (size_t)saltlen) != 1
  69             || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_SCRYPT_N, N) != 1
  70             || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_SCRYPT_R, (uint32_t)r) != 1
  71             || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_SCRYPT_P, (uint32_t)p) != 1
  72             || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_MAXMEM_BYTES, maxmem) != 1
  73             || EVP_KDF_derive(kctx, key, keylen) != 1)
  74         rv = 0;
  75
  76     EVP_KDF_CTX_free(kctx);
  77     return rv;
  78 }
  79
  80 #endif