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/*
* Copyright 2021 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (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 <stdio.h>
#include <openssl/core_names.h>
#include <openssl/crypto.h>
#include <openssl/kdf.h>
#include <openssl/obj_mac.h>
#include <openssl/params.h>
/*
* test vector from
* https://datatracker.ietf.org/doc/html/rfc7914
*/
/*
* Hard coding a password into an application is very bad.
* It is done here solely for educational purposes.
*/
static unsigned char password[] = {
'p', 'a', 's', 's', 'w', 'o', 'r', 'd'
};
/*
* The salt is better not being hard coded too. Each password should have a
* different salt if possible. The salt is not considered secret information
* and is safe to store with an encrypted password.
*/
static unsigned char scrypt_salt[] = {
'N', 'a', 'C', 'l'
};
/*
* The SCRYPT parameters can be variable or hard coded. The disadvantage with
* hard coding them is that they cannot easily be adjusted for future
* technological improvements appear.
*/
static unsigned int scrypt_n = 1024;
static unsigned int scrypt_r = 8;
static unsigned int scrypt_p = 16;
static const unsigned char expected_output[] = {
0xfd, 0xba, 0xbe, 0x1c, 0x9d, 0x34, 0x72, 0x00,
0x78, 0x56, 0xe7, 0x19, 0x0d, 0x01, 0xe9, 0xfe,
0x7c, 0x6a, 0xd7, 0xcb, 0xc8, 0x23, 0x78, 0x30,
0xe7, 0x73, 0x76, 0x63, 0x4b, 0x37, 0x31, 0x62,
0x2e, 0xaf, 0x30, 0xd9, 0x2e, 0x22, 0xa3, 0x88,
0x6f, 0xf1, 0x09, 0x27, 0x9d, 0x98, 0x30, 0xda,
0xc7, 0x27, 0xaf, 0xb9, 0x4a, 0x83, 0xee, 0x6d,
0x83, 0x60, 0xcb, 0xdf, 0xa2, 0xcc, 0x06, 0x40
};
int main(int argc, char **argv)
{
int ret = EXIT_FAILURE;
EVP_KDF *kdf = NULL;
EVP_KDF_CTX *kctx = NULL;
unsigned char out[64];
OSSL_PARAM params[6], *p = params;
OSSL_LIB_CTX *library_context = NULL;
library_context = OSSL_LIB_CTX_new();
if (library_context == NULL) {
fprintf(stderr, "OSSL_LIB_CTX_new() returned NULL\n");
goto end;
}
/* Fetch the key derivation function implementation */
kdf = EVP_KDF_fetch(library_context, "SCRYPT", NULL);
if (kdf == NULL) {
fprintf(stderr, "EVP_KDF_fetch() returned NULL\n");
goto end;
}
/* Create a context for the key derivation operation */
kctx = EVP_KDF_CTX_new(kdf);
if (kctx == NULL) {
fprintf(stderr, "EVP_KDF_CTX_new() returned NULL\n");
goto end;
}
/* Set password */
*p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PASSWORD, password,
sizeof(password));
/* Set salt */
*p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT, scrypt_salt,
sizeof(scrypt_salt));
/* Set N (default 1048576) */
*p++ = OSSL_PARAM_construct_uint(OSSL_KDF_PARAM_SCRYPT_N, &scrypt_n);
/* Set R (default 8) */
*p++ = OSSL_PARAM_construct_uint(OSSL_KDF_PARAM_SCRYPT_R, &scrypt_r);
/* Set P (default 1) */
*p++ = OSSL_PARAM_construct_uint(OSSL_KDF_PARAM_SCRYPT_P, &scrypt_p);
*p = OSSL_PARAM_construct_end();
/* Derive the key */
if (EVP_KDF_derive(kctx, out, sizeof(out), params) != 1) {
fprintf(stderr, "EVP_KDF_derive() failed\n");
goto end;
}
if (CRYPTO_memcmp(expected_output, out, sizeof(expected_output)) != 0) {
fprintf(stderr, "Generated key does not match expected value\n");
goto end;
}
ret = EXIT_SUCCESS;
end:
EVP_KDF_CTX_free(kctx);
EVP_KDF_free(kdf);
OSSL_LIB_CTX_free(library_context);
return ret;
}
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