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 */ 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 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