1/*-
2 * Copyright 2022 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/*
11 * Example showing how to generate DSA params using
12 * FIPS 186-4 DSA FFC parameter generation.
13 */
14
15#include <openssl/evp.h>
16#include "dsa.inc"
17
18int main(int argc, char **argv)
19{
20    int rv = EXIT_FAILURE;
21    OSSL_LIB_CTX *libctx = NULL;
22    const char *propq = NULL;
23    EVP_PKEY_CTX *ctx = NULL;
24    EVP_PKEY *dsaparamkey = NULL;
25    OSSL_PARAM params[7];
26    unsigned int pbits = 2048;
27    unsigned int qbits = 256;
28    int gindex = 42;
29
30    ctx = EVP_PKEY_CTX_new_from_name(libctx, "DSA", propq);
31    if (ctx == NULL)
32        goto cleanup;
33
34    /*
35     * Demonstrate how to set optional DSA fields as params.
36     * See doc/man7/EVP_PKEY-FFC.pod and doc/man7/EVP_PKEY-DSA.pod
37     * for more information.
38     */
39    params[0] = OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_FFC_TYPE,
40                                                 "fips186_4", 0);
41    params[1] = OSSL_PARAM_construct_uint(OSSL_PKEY_PARAM_FFC_PBITS, &pbits);
42    params[2] = OSSL_PARAM_construct_uint(OSSL_PKEY_PARAM_FFC_QBITS, &qbits);
43    params[3] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_FFC_GINDEX, &gindex);
44    params[4] = OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_FFC_DIGEST,
45                                                 "SHA384", 0);
46    params[5] = OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_FFC_DIGEST_PROPS,
47                                                 "provider=default", 0);
48    params[6] = OSSL_PARAM_construct_end();
49
50    /* Generate a dsa param key using optional params */
51    if (EVP_PKEY_paramgen_init(ctx) <= 0
52            || EVP_PKEY_CTX_set_params(ctx, params) <= 0
53            || EVP_PKEY_paramgen(ctx, &dsaparamkey) <= 0) {
54        fprintf(stderr, "DSA paramgen failed\n");
55        goto cleanup;
56    }
57
58    if (!dsa_print_key(dsaparamkey, 0, libctx, propq))
59        goto cleanup;
60
61    rv = EXIT_SUCCESS;
62cleanup:
63    EVP_PKEY_free(dsaparamkey);
64    EVP_PKEY_CTX_free(ctx);
65    return rv;
66}
67