1 /* 2 * Copyright 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 <stdio.h> 11 #include <openssl/core_names.h> 12 #include <openssl/crypto.h> 13 #include <openssl/kdf.h> 14 #include <openssl/obj_mac.h> 15 #include <openssl/params.h> 16 17 /* 18 * test vector from 19 * https://datatracker.ietf.org/doc/html/rfc7914 20 */ 21 22 /* 23 * Hard coding a password into an application is very bad. 24 * It is done here solely for educational purposes. 25 */ 26 static unsigned char password[] = { 27 'p', 'a', 's', 's', 'w', 'o', 'r', 'd' 28 }; 29 30 /* 31 * The salt is better not being hard coded too. Each password should have a 32 * different salt if possible. The salt is not considered secret information 33 * and is safe to store with an encrypted password. 34 */ 35 static unsigned char scrypt_salt[] = { 36 'N', 'a', 'C', 'l' 37 }; 38 39 /* 40 * The SCRYPT parameters can be variable or hard coded. The disadvantage with 41 * hard coding them is that they cannot easily be adjusted for future 42 * technological improvements appear. 43 */ 44 static unsigned int scrypt_n = 1024; 45 static unsigned int scrypt_r = 8; 46 static unsigned int scrypt_p = 16; 47 48 static const unsigned char expected_output[] = { 49 50 0xfd, 0xba, 0xbe, 0x1c, 0x9d, 0x34, 0x72, 0x00, 51 0x78, 0x56, 0xe7, 0x19, 0x0d, 0x01, 0xe9, 0xfe, 52 0x7c, 0x6a, 0xd7, 0xcb, 0xc8, 0x23, 0x78, 0x30, 53 0xe7, 0x73, 0x76, 0x63, 0x4b, 0x37, 0x31, 0x62, 54 0x2e, 0xaf, 0x30, 0xd9, 0x2e, 0x22, 0xa3, 0x88, 55 0x6f, 0xf1, 0x09, 0x27, 0x9d, 0x98, 0x30, 0xda, 56 0xc7, 0x27, 0xaf, 0xb9, 0x4a, 0x83, 0xee, 0x6d, 57 0x83, 0x60, 0xcb, 0xdf, 0xa2, 0xcc, 0x06, 0x40 58 }; 59 60 int main(int argc, char **argv) 61 { 62 int rv = 1; 63 EVP_KDF *kdf = NULL; 64 EVP_KDF_CTX *kctx = NULL; 65 unsigned char out[64]; 66 OSSL_PARAM params[6], *p = params; 67 OSSL_LIB_CTX *library_context = NULL; 68 69 library_context = OSSL_LIB_CTX_new(); 70 if (library_context == NULL) { 71 fprintf(stderr, "OSSL_LIB_CTX_new() returned NULL\n"); 72 goto end; 73 } 74 75 /* Fetch the key derivation function implementation */ 76 kdf = EVP_KDF_fetch(library_context, "SCRYPT", NULL); 77 if (kdf == NULL) { 78 fprintf(stderr, "EVP_KDF_fetch() returned NULL\n"); 79 goto end; 80 } 81 82 /* Create a context for the key derivation operation */ 83 kctx = EVP_KDF_CTX_new(kdf); 84 if (kctx == NULL) { 85 fprintf(stderr, "EVP_KDF_CTX_new() returned NULL\n"); 86 goto end; 87 } 88 89 /* Set password */ 90 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PASSWORD, password, 91 sizeof(password)); 92 /* Set salt */ 93 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT, scrypt_salt, 94 sizeof(scrypt_salt)); 95 /* Set N (default 1048576) */ 96 *p++ = OSSL_PARAM_construct_uint(OSSL_KDF_PARAM_SCRYPT_N, &scrypt_n); 97 /* Set R (default 8) */ 98 *p++ = OSSL_PARAM_construct_uint(OSSL_KDF_PARAM_SCRYPT_R, &scrypt_r); 99 /* Set P (default 1) */ 100 *p++ = OSSL_PARAM_construct_uint(OSSL_KDF_PARAM_SCRYPT_P, &scrypt_p); 101 *p = OSSL_PARAM_construct_end(); 102 103 /* Derive the key */ 104 if (EVP_KDF_derive(kctx, out, sizeof(out), params) != 1) { 105 fprintf(stderr, "EVP_KDF_derive() failed\n"); 106 goto end; 107 } 108 109 if (CRYPTO_memcmp(expected_output, out, sizeof(expected_output)) != 0) { 110 fprintf(stderr, "Generated key does not match expected value\n"); 111 goto end; 112 } 113 114 rv = 0; 115 end: 116 EVP_KDF_CTX_free(kctx); 117 EVP_KDF_free(kdf); 118 OSSL_LIB_CTX_free(library_context); 119 return rv; 120 } 121