demos/kdf/argon2.c

   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, &parallel_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     rv = EXIT_SUCCESS;
 149 end:
 150     EVP_KDF_CTX_free(kctx);
 151     EVP_KDF_free(kdf);
 152     OSSL_LIB_CTX_free(library_context);
 153     return rv;
 154 }