1 /* 2 * Copyright 2023 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/params.h> 15 #include <openssl/thread.h> 16 17 /* 18 * Example showing how to use Argon2 KDF. 19 * See man EVP_KDF-ARGON2 for more information. 20 * 21 * test vector from 22 * https://datatracker.ietf.org/doc/html/rfc9106 23 */ 24 25 /* 26 * Hard coding a password into an application is very bad. 27 * It is done here solely for educational purposes. 28 */ 29 static unsigned char password[] = { 30 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 31 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 32 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 33 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01 34 }; 35 36 /* 37 * The salt is better not being hard coded too. Each password should have a 38 * different salt if possible. The salt is not considered secret information 39 * and is safe to store with an encrypted password. 40 */ 41 static unsigned char salt[] = { 42 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 43 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02 44 }; 45 46 /* 47 * Optional secret for KDF 48 */ 49 static unsigned char secret[] = { 50 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03 51 }; 52 53 /* 54 * Optional additional data 55 */ 56 static unsigned char ad[] = { 57 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 58 0x04, 0x04, 0x04, 0x04 59 }; 60 61 /* 62 * Argon2 cost parameters 63 */ 64 static uint32_t memory_cost = 32; 65 static uint32_t iteration_cost = 3; 66 static uint32_t parallel_cost = 4; 67 68 static const unsigned char expected_output[] = { 69 0x0d, 0x64, 0x0d, 0xf5, 0x8d, 0x78, 0x76, 0x6c, 70 0x08, 0xc0, 0x37, 0xa3, 0x4a, 0x8b, 0x53, 0xc9, 71 0xd0, 0x1e, 0xf0, 0x45, 0x2d, 0x75, 0xb6, 0x5e, 72 0xb5, 0x25, 0x20, 0xe9, 0x6b, 0x01, 0xe6, 0x59 73 }; 74 75 int main(int argc, char **argv) 76 { 77 int rv = EXIT_FAILURE; 78 EVP_KDF *kdf = NULL; 79 EVP_KDF_CTX *kctx = NULL; 80 unsigned char out[32]; 81 OSSL_PARAM params[9], *p = params; 82 OSSL_LIB_CTX *library_context = NULL; 83 unsigned int threads; 84 85 library_context = OSSL_LIB_CTX_new(); 86 if (library_context == NULL) { 87 fprintf(stderr, "OSSL_LIB_CTX_new() returned NULL\n"); 88 goto end; 89 } 90 91 /* Fetch the key derivation function implementation */ 92 kdf = EVP_KDF_fetch(library_context, "argon2id", NULL); 93 if (kdf == NULL) { 94 fprintf(stderr, "EVP_KDF_fetch() returned NULL\n"); 95 goto end; 96 } 97 98 /* Create a context for the key derivation operation */ 99 kctx = EVP_KDF_CTX_new(kdf); 100 if (kctx == NULL) { 101 fprintf(stderr, "EVP_KDF_CTX_new() returned NULL\n"); 102 goto end; 103 } 104 105 /* 106 * Thread support can be turned off; use serialization if we cannot 107 * set requested number of threads. 108 */ 109 threads = parallel_cost; 110 if (OSSL_set_max_threads(library_context, parallel_cost) != 1) { 111 uint64_t max_threads = OSSL_get_max_threads(library_context); 112 113 if (max_threads == 0) 114 threads = 1; 115 else if (max_threads < parallel_cost) 116 threads = max_threads; 117 } 118 119 /* Set password */ 120 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PASSWORD, password, sizeof(password)); 121 /* Set salt */ 122 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT, salt, sizeof(salt)); 123 /* Set optional additional data */ 124 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_ARGON2_AD, ad, sizeof(ad)); 125 /* Set optional secret */ 126 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SECRET, secret, sizeof(secret)); 127 /* Set iteration count */ 128 *p++ = OSSL_PARAM_construct_uint32(OSSL_KDF_PARAM_ITER, &iteration_cost); 129 /* Set threads performing derivation (can be decreased) */ 130 *p++ = OSSL_PARAM_construct_uint(OSSL_KDF_PARAM_THREADS, &threads); 131 /* Set parallel cost */ 132 *p++ = OSSL_PARAM_construct_uint32(OSSL_KDF_PARAM_ARGON2_LANES, ¶llel_cost); 133 /* Set memory requirement */ 134 *p++ = OSSL_PARAM_construct_uint32(OSSL_KDF_PARAM_ARGON2_MEMCOST, &memory_cost); 135 *p = OSSL_PARAM_construct_end(); 136 137 /* Derive the key */ 138 if (EVP_KDF_derive(kctx, out, sizeof(out), params) != 1) { 139 fprintf(stderr, "EVP_KDF_derive() failed\n"); 140 goto end; 141 } 142 143 if (CRYPTO_memcmp(expected_output, out, sizeof(expected_output)) != 0) { 144 fprintf(stderr, "Generated key does not match expected value\n"); 145 goto end; 146 } 147 148 printf("Success\n"); 149 150 rv = EXIT_SUCCESS; 151 end: 152 EVP_KDF_CTX_free(kctx); 153 EVP_KDF_free(kdf); 154 OSSL_LIB_CTX_free(library_context); 155 return rv; 156 } 157