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 pbkdf2_salt[] = {
36 'N', 'a', 'C', 'l'
37 };
38
39 /*
40 * The iteration parameter 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 pbkdf2_iterations = 80000;
45
46 static const unsigned char expected_output[] = {
47
48 0x4d, 0xdc, 0xd8, 0xf6, 0x0b, 0x98, 0xbe, 0x21,
49 0x83, 0x0c, 0xee, 0x5e, 0xf2, 0x27, 0x01, 0xf9,
50 0x64, 0x1a, 0x44, 0x18, 0xd0, 0x4c, 0x04, 0x14,
51 0xae, 0xff, 0x08, 0x87, 0x6b, 0x34, 0xab, 0x56,
52 0xa1, 0xd4, 0x25, 0xa1, 0x22, 0x58, 0x33, 0x54,
53 0x9a, 0xdb, 0x84, 0x1b, 0x51, 0xc9, 0xb3, 0x17,
54 0x6a, 0x27, 0x2b, 0xde, 0xbb, 0xa1, 0xd0, 0x78,
55 0x47, 0x8f, 0x62, 0xb3, 0x97, 0xf3, 0x3c, 0x8d
56 };
57
main(int argc,char ** argv)58 int main(int argc, char **argv)
59 {
60 int rv = 1;
61 EVP_KDF *kdf = NULL;
62 EVP_KDF_CTX *kctx = NULL;
63 unsigned char out[64];
64 OSSL_PARAM params[5], *p = params;
65 OSSL_LIB_CTX *library_context = NULL;
66
67 library_context = OSSL_LIB_CTX_new();
68 if (library_context == NULL) {
69 fprintf(stderr, "OSSL_LIB_CTX_new() returned NULL\n");
70 goto end;
71 }
72
73 /* Fetch the key derivation function implementation */
74 kdf = EVP_KDF_fetch(library_context, "PBKDF2", NULL);
75 if (kdf == NULL) {
76 fprintf(stderr, "EVP_KDF_fetch() returned NULL\n");
77 goto end;
78 }
79
80 /* Create a context for the key derivation operation */
81 kctx = EVP_KDF_CTX_new(kdf);
82 if (kctx == NULL) {
83 fprintf(stderr, "EVP_KDF_CTX_new() returned NULL\n");
84 goto end;
85 }
86
87 /* Set password */
88 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PASSWORD, password,
89 sizeof(password));
90 /* Set salt */
91 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT, pbkdf2_salt,
92 sizeof(pbkdf2_salt));
93 /* Set iteration count (default 2048) */
94 *p++ = OSSL_PARAM_construct_uint(OSSL_KDF_PARAM_ITER, &pbkdf2_iterations);
95 /* Set the underlying hash function used to derive the key */
96 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
97 "SHA256", 0);
98 *p = OSSL_PARAM_construct_end();
99
100 /* Derive the key */
101 if (EVP_KDF_derive(kctx, out, sizeof(out), params) != 1) {
102 fprintf(stderr, "EVP_KDF_derive() failed\n");
103 goto end;
104 }
105
106 if (CRYPTO_memcmp(expected_output, out, sizeof(expected_output)) != 0) {
107 fprintf(stderr, "Generated key does not match expected value\n");
108 goto end;
109 }
110
111 rv = 0;
112 end:
113 EVP_KDF_CTX_free(kctx);
114 EVP_KDF_free(kdf);
115 OSSL_LIB_CTX_free(library_context);
116 return rv;
117 }
118