1/*
2 * Copyright 1995-2023 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#include <openssl/opensslconf.h>
11
12#include <stdio.h>
13#include <string.h>
14#include <sys/types.h>
15#include <sys/stat.h>
16#include "apps.h"
17#include "progs.h"
18#include <openssl/bio.h>
19#include <openssl/err.h>
20#include <openssl/bn.h>
21#include <openssl/dsa.h>
22#include <openssl/x509.h>
23#include <openssl/pem.h>
24
25typedef enum OPTION_choice {
26    OPT_COMMON,
27    OPT_OUT, OPT_PASSOUT, OPT_ENGINE, OPT_CIPHER, OPT_VERBOSE,
28    OPT_R_ENUM, OPT_PROV_ENUM
29} OPTION_CHOICE;
30
31const OPTIONS gendsa_options[] = {
32    {OPT_HELP_STR, 1, '-', "Usage: %s [options] dsaparam-file\n"},
33
34    OPT_SECTION("General"),
35    {"help", OPT_HELP, '-', "Display this summary"},
36#ifndef OPENSSL_NO_ENGINE
37    {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
38#endif
39
40    OPT_SECTION("Output"),
41    {"out", OPT_OUT, '>', "Output the key to the specified file"},
42    {"passout", OPT_PASSOUT, 's', "Output file pass phrase source"},
43    OPT_R_OPTIONS,
44    OPT_PROV_OPTIONS,
45    {"", OPT_CIPHER, '-', "Encrypt the output with any supported cipher"},
46    {"verbose", OPT_VERBOSE, '-', "Verbose output"},
47
48    OPT_PARAMETERS(),
49    {"dsaparam-file", 0, 0, "File containing DSA parameters"},
50    {NULL}
51};
52
53int gendsa_main(int argc, char **argv)
54{
55    ENGINE *e = NULL;
56    BIO *out = NULL, *in = NULL;
57    EVP_PKEY *pkey = NULL;
58    EVP_PKEY_CTX *ctx = NULL;
59    EVP_CIPHER *enc = NULL;
60    char *dsaparams = NULL, *ciphername = NULL;
61    char *outfile = NULL, *passoutarg = NULL, *passout = NULL, *prog;
62    OPTION_CHOICE o;
63    int ret = 1, private = 0, verbose = 0, nbits;
64
65    prog = opt_init(argc, argv, gendsa_options);
66    while ((o = opt_next()) != OPT_EOF) {
67        switch (o) {
68        case OPT_EOF:
69        case OPT_ERR:
70 opthelp:
71            BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
72            goto end;
73        case OPT_HELP:
74            ret = 0;
75            opt_help(gendsa_options);
76            goto end;
77        case OPT_OUT:
78            outfile = opt_arg();
79            break;
80        case OPT_PASSOUT:
81            passoutarg = opt_arg();
82            break;
83        case OPT_ENGINE:
84            e = setup_engine(opt_arg(), 0);
85            break;
86        case OPT_R_CASES:
87            if (!opt_rand(o))
88                goto end;
89            break;
90        case OPT_PROV_CASES:
91            if (!opt_provider(o))
92                goto end;
93            break;
94        case OPT_CIPHER:
95            ciphername = opt_unknown();
96            break;
97        case OPT_VERBOSE:
98            verbose = 1;
99            break;
100        }
101    }
102
103    /* One argument, the params file. */
104    argc = opt_num_rest();
105    argv = opt_rest();
106    if (argc != 1)
107        goto opthelp;
108    dsaparams = argv[0];
109
110    if (!app_RAND_load())
111        goto end;
112
113    if (ciphername != NULL) {
114        if (!opt_cipher(ciphername, &enc))
115            goto end;
116    }
117    private = 1;
118
119    if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
120        BIO_printf(bio_err, "Error getting password\n");
121        goto end;
122    }
123
124    pkey = load_keyparams(dsaparams, FORMAT_UNDEF, 1, "DSA", "DSA parameters");
125
126    out = bio_open_owner(outfile, FORMAT_PEM, private);
127    if (out == NULL)
128        goto end2;
129
130    nbits = EVP_PKEY_get_bits(pkey);
131    if (nbits > OPENSSL_DSA_MAX_MODULUS_BITS)
132        BIO_printf(bio_err,
133                   "Warning: It is not recommended to use more than %d bit for DSA keys.\n"
134                   "         Your key size is %d! Larger key size may behave not as expected.\n",
135                   OPENSSL_DSA_MAX_MODULUS_BITS, EVP_PKEY_get_bits(pkey));
136
137    ctx = EVP_PKEY_CTX_new_from_pkey(app_get0_libctx(), pkey, app_get0_propq());
138    if (ctx == NULL) {
139        BIO_printf(bio_err, "unable to create PKEY context\n");
140        goto end;
141    }
142    EVP_PKEY_free(pkey);
143    pkey = NULL;
144    if (EVP_PKEY_keygen_init(ctx) <= 0) {
145        BIO_printf(bio_err, "unable to set up for key generation\n");
146        goto end;
147    }
148    pkey = app_keygen(ctx, "DSA", nbits, verbose);
149    if (pkey == NULL)
150        goto end;
151
152    assert(private);
153    if (!PEM_write_bio_PrivateKey(out, pkey, enc, NULL, 0, NULL, passout)) {
154        BIO_printf(bio_err, "unable to output generated key\n");
155        goto end;
156    }
157    ret = 0;
158 end:
159    if (ret != 0)
160        ERR_print_errors(bio_err);
161 end2:
162    BIO_free(in);
163    BIO_free_all(out);
164    EVP_PKEY_free(pkey);
165    EVP_PKEY_CTX_free(ctx);
166    EVP_CIPHER_free(enc);
167    release_engine(e);
168    OPENSSL_free(passout);
169    return ret;
170}
171