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 an DSA key pair.
12 */
13
14 #include <openssl/evp.h>
15 #include "dsa.inc"
16
17 /*
18 * Generate dsa params using default values.
19 * See the EVP_PKEY_DSA_param_fromdata demo if you need
20 * to load DSA params from raw values.
21 * See the EVP_PKEY_DSA_paramgen demo if you need to
22 * use non default parameters.
23 */
dsa_genparams(OSSL_LIB_CTX * libctx,const char * propq)24 EVP_PKEY *dsa_genparams(OSSL_LIB_CTX *libctx, const char *propq)
25 {
26 EVP_PKEY *dsaparamkey = NULL;
27 EVP_PKEY_CTX *ctx = NULL;
28
29 /* Use the dsa params in a EVP_PKEY ctx */
30 ctx = EVP_PKEY_CTX_new_from_name(libctx, "DSA", propq);
31 if (ctx == NULL) {
32 fprintf(stderr, "EVP_PKEY_CTX_new_from_name() failed\n");
33 return NULL;
34 }
35
36 if (EVP_PKEY_paramgen_init(ctx) <= 0
37 || EVP_PKEY_paramgen(ctx, &dsaparamkey) <= 0) {
38 fprintf(stderr, "DSA paramgen failed\n");
39 goto cleanup;
40 }
41 cleanup:
42 EVP_PKEY_CTX_free(ctx);
43 return dsaparamkey;
44 }
45
main(int argc,char ** argv)46 int main(int argc, char **argv)
47 {
48 int rv = EXIT_FAILURE;
49 OSSL_LIB_CTX *libctx = NULL;
50 const char *propq = NULL;
51 EVP_PKEY *dsaparamskey = NULL;
52 EVP_PKEY *dsakey = NULL;
53 EVP_PKEY_CTX *ctx = NULL;
54
55 /* Generate random dsa params */
56 dsaparamskey = dsa_genparams(libctx, propq);
57 if (dsaparamskey == NULL)
58 goto cleanup;
59
60 /* Use the dsa params in a EVP_PKEY ctx */
61 ctx = EVP_PKEY_CTX_new_from_pkey(libctx, dsaparamskey, propq);
62 if (ctx == NULL) {
63 fprintf(stderr, "EVP_PKEY_CTX_new_from_pkey() failed\n");
64 goto cleanup;
65 }
66
67 /* Generate a key using the dsa params */
68 if (EVP_PKEY_keygen_init(ctx) <= 0
69 || EVP_PKEY_keygen(ctx, &dsakey) <= 0) {
70 fprintf(stderr, "DSA keygen failed\n");
71 goto cleanup;
72 }
73
74 if (!dsa_print_key(dsakey, 1, libctx, propq))
75 goto cleanup;
76
77 rv = EXIT_SUCCESS;
78 cleanup:
79 EVP_PKEY_free(dsakey);
80 EVP_PKEY_free(dsaparamskey);
81 EVP_PKEY_CTX_free(ctx);
82 return rv;
83 }
84