xref: /src/crypto/openssl/apps/gendsa.c (revision f25b8c9fb4f58cf61adb47d7570abe7caa6d385d)
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 
25 typedef enum OPTION_choice {
26     OPT_COMMON,
27     OPT_OUT,
28     OPT_PASSOUT,
29     OPT_ENGINE,
30     OPT_CIPHER,
31     OPT_VERBOSE,
32     OPT_QUIET,
33     OPT_R_ENUM,
34     OPT_PROV_ENUM
35 } OPTION_CHOICE;
36 
37 const OPTIONS gendsa_options[] = {
38     { OPT_HELP_STR, 1, '-', "Usage: %s [options] dsaparam-file\n" },
39 
40     OPT_SECTION("General"),
41     { "help", OPT_HELP, '-', "Display this summary" },
42 #ifndef OPENSSL_NO_ENGINE
43     { "engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device" },
44 #endif
45 
46     OPT_SECTION("Output"),
47     { "out", OPT_OUT, '>', "Output the key to the specified file" },
48     { "passout", OPT_PASSOUT, 's', "Output file pass phrase source" },
49     OPT_R_OPTIONS,
50     OPT_PROV_OPTIONS,
51     { "", OPT_CIPHER, '-', "Encrypt the output with any supported cipher" },
52     { "verbose", OPT_VERBOSE, '-', "Verbose output" },
53     { "quiet", OPT_QUIET, '-', "Terse output" },
54 
55     OPT_PARAMETERS(),
56     { "dsaparam-file", 0, 0, "File containing DSA parameters" },
57     { NULL }
58 };
59 
gendsa_main(int argc,char ** argv)60 int gendsa_main(int argc, char **argv)
61 {
62     ENGINE *e = NULL;
63     BIO *out = NULL, *in = NULL;
64     EVP_PKEY *pkey = NULL;
65     EVP_PKEY_CTX *ctx = NULL;
66     EVP_CIPHER *enc = NULL;
67     char *dsaparams = NULL, *ciphername = NULL;
68     char *outfile = NULL, *passoutarg = NULL, *passout = NULL, *prog;
69     OPTION_CHOICE o;
70     int ret = 1, private = 0, verbose = 0, nbits;
71 
72     opt_set_unknown_name("cipher");
73     prog = opt_init(argc, argv, gendsa_options);
74     while ((o = opt_next()) != OPT_EOF) {
75         switch (o) {
76         case OPT_EOF:
77         case OPT_ERR:
78         opthelp:
79             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
80             goto end;
81         case OPT_HELP:
82             ret = 0;
83             opt_help(gendsa_options);
84             goto end;
85         case OPT_OUT:
86             outfile = opt_arg();
87             break;
88         case OPT_PASSOUT:
89             passoutarg = opt_arg();
90             break;
91         case OPT_ENGINE:
92             e = setup_engine(opt_arg(), 0);
93             break;
94         case OPT_R_CASES:
95             if (!opt_rand(o))
96                 goto end;
97             break;
98         case OPT_PROV_CASES:
99             if (!opt_provider(o))
100                 goto end;
101             break;
102         case OPT_CIPHER:
103             ciphername = opt_unknown();
104             break;
105         case OPT_VERBOSE:
106             verbose = 1;
107             break;
108         case OPT_QUIET:
109             verbose = 0;
110             break;
111         }
112     }
113 
114     /* One argument, the params file. */
115     if (!opt_check_rest_arg("params file"))
116         goto opthelp;
117     argv = opt_rest();
118     dsaparams = argv[0];
119 
120     if (!app_RAND_load())
121         goto end;
122 
123     if (!opt_cipher(ciphername, &enc))
124         goto end;
125     private = 1;
126 
127     if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
128         BIO_printf(bio_err, "Error getting password\n");
129         goto end;
130     }
131 
132     pkey = load_keyparams(dsaparams, FORMAT_UNDEF, 1, "DSA", "DSA parameters");
133 
134     out = bio_open_owner(outfile, FORMAT_PEM, private);
135     if (out == NULL)
136         goto end2;
137 
138     nbits = EVP_PKEY_get_bits(pkey);
139     if (nbits > OPENSSL_DSA_MAX_MODULUS_BITS)
140         BIO_printf(bio_err,
141             "Warning: It is not recommended to use more than %d bit for DSA keys.\n"
142             "         Your key size is %d! Larger key size may behave not as expected.\n",
143             OPENSSL_DSA_MAX_MODULUS_BITS, EVP_PKEY_get_bits(pkey));
144 
145     ctx = EVP_PKEY_CTX_new_from_pkey(app_get0_libctx(), pkey, app_get0_propq());
146     if (ctx == NULL) {
147         BIO_printf(bio_err, "unable to create PKEY context\n");
148         goto end;
149     }
150     EVP_PKEY_free(pkey);
151     pkey = NULL;
152     if (EVP_PKEY_keygen_init(ctx) <= 0) {
153         BIO_printf(bio_err, "unable to set up for key generation\n");
154         goto end;
155     }
156     pkey = app_keygen(ctx, "DSA", nbits, verbose);
157     if (pkey == NULL)
158         goto end;
159 
160     assert(private);
161     if (!PEM_write_bio_PrivateKey(out, pkey, enc, NULL, 0, NULL, passout)) {
162         BIO_printf(bio_err, "unable to output generated key\n");
163         goto end;
164     }
165     ret = 0;
166 end:
167     if (ret != 0)
168         ERR_print_errors(bio_err);
169 end2:
170     BIO_free(in);
171     BIO_free_all(out);
172     EVP_PKEY_free(pkey);
173     EVP_PKEY_CTX_free(ctx);
174     EVP_CIPHER_free(enc);
175     release_engine(e);
176     OPENSSL_free(passout);
177     return ret;
178 }
179