openssl/demos/pkey/EVP_PKEY_DSA_keygen.c

84 lines
2.2 KiB
C

/*-
* Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/*
* Example showing how to generate an DSA key pair.
*/
#include <openssl/evp.h>
#include "dsa.inc"
/*
* Generate dsa params using default values.
* See the EVP_PKEY_DSA_param_fromdata demo if you need
* to load DSA params from raw values.
* See the EVP_PKEY_DSA_paramgen demo if you need to
* use non default parameters.
*/
EVP_PKEY *dsa_genparams(OSSL_LIB_CTX *libctx, const char *propq)
{
EVP_PKEY *dsaparamkey = NULL;
EVP_PKEY_CTX *ctx = NULL;
/* Use the dsa params in a EVP_PKEY ctx */
ctx = EVP_PKEY_CTX_new_from_name(libctx, "DSA", propq);
if (ctx == NULL) {
fprintf(stderr, "EVP_PKEY_CTX_new_from_name() failed\n");
return NULL;
}
if (EVP_PKEY_paramgen_init(ctx) <= 0
|| EVP_PKEY_paramgen(ctx, &dsaparamkey) <= 0) {
fprintf(stderr, "DSA paramgen failed\n");
goto cleanup;
}
cleanup:
EVP_PKEY_CTX_free(ctx);
return dsaparamkey;
}
int main(int argc, char **argv)
{
int rv = EXIT_FAILURE;
OSSL_LIB_CTX *libctx = NULL;
const char *propq = NULL;
EVP_PKEY *dsaparamskey = NULL;
EVP_PKEY *dsakey = NULL;
EVP_PKEY_CTX *ctx = NULL;
/* Generate random dsa params */
dsaparamskey = dsa_genparams(libctx, propq);
if (dsaparamskey == NULL)
goto cleanup;
/* Use the dsa params in a EVP_PKEY ctx */
ctx = EVP_PKEY_CTX_new_from_pkey(libctx, dsaparamskey, propq);
if (ctx == NULL) {
fprintf(stderr, "EVP_PKEY_CTX_new_from_pkey() failed\n");
goto cleanup;
}
/* Generate a key using the dsa params */
if (EVP_PKEY_keygen_init(ctx) <= 0
|| EVP_PKEY_keygen(ctx, &dsakey) <= 0) {
fprintf(stderr, "DSA keygen failed\n");
goto cleanup;
}
if (!dsa_print_key(dsakey, 1, libctx, propq))
goto cleanup;
rv = EXIT_SUCCESS;
cleanup:
EVP_PKEY_free(dsakey);
EVP_PKEY_free(dsaparamskey);
EVP_PKEY_CTX_free(ctx);
return rv;
}