demos/pkey/EVP_PKEY_DSA_paramgen.c

   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
  18 int 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;
  62 cleanup:
  63     EVP_PKEY_free(dsaparamkey);
  64     EVP_PKEY_CTX_free(ctx);
  65     return rv;
  66 }