xref: /openssl/apps/gendsa.c (revision 556009c5)
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, OPT_PASSOUT, OPT_ENGINE, OPT_CIPHER, OPT_VERBOSE, OPT_QUIET,
28     OPT_R_ENUM, OPT_PROV_ENUM
29 } OPTION_CHOICE;
30 
31 const 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     {"quiet", OPT_QUIET, '-', "Terse output"},
48 
49     OPT_PARAMETERS(),
50     {"dsaparam-file", 0, 0, "File containing DSA parameters"},
51     {NULL}
52 };
53 
gendsa_main(int argc,char ** argv)54 int gendsa_main(int argc, char **argv)
55 {
56     ENGINE *e = NULL;
57     BIO *out = NULL, *in = NULL;
58     EVP_PKEY *pkey = NULL;
59     EVP_PKEY_CTX *ctx = NULL;
60     EVP_CIPHER *enc = NULL;
61     char *dsaparams = NULL, *ciphername = NULL;
62     char *outfile = NULL, *passoutarg = NULL, *passout = NULL, *prog;
63     OPTION_CHOICE o;
64     int ret = 1, private = 0, verbose = 0, nbits;
65 
66     opt_set_unknown_name("cipher");
67     prog = opt_init(argc, argv, gendsa_options);
68     while ((o = opt_next()) != OPT_EOF) {
69         switch (o) {
70         case OPT_EOF:
71         case OPT_ERR:
72  opthelp:
73             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
74             goto end;
75         case OPT_HELP:
76             ret = 0;
77             opt_help(gendsa_options);
78             goto end;
79         case OPT_OUT:
80             outfile = opt_arg();
81             break;
82         case OPT_PASSOUT:
83             passoutarg = opt_arg();
84             break;
85         case OPT_ENGINE:
86             e = setup_engine(opt_arg(), 0);
87             break;
88         case OPT_R_CASES:
89             if (!opt_rand(o))
90                 goto end;
91             break;
92         case OPT_PROV_CASES:
93             if (!opt_provider(o))
94                 goto end;
95             break;
96         case OPT_CIPHER:
97             ciphername = opt_unknown();
98             break;
99         case OPT_VERBOSE:
100             verbose = 1;
101             break;
102         case OPT_QUIET:
103             verbose = 0;
104             break;
105         }
106     }
107 
108     /* One argument, the params file. */
109     if (!opt_check_rest_arg("params file"))
110         goto opthelp;
111     argv = opt_rest();
112     dsaparams = argv[0];
113 
114     if (!app_RAND_load())
115         goto end;
116 
117     if (!opt_cipher(ciphername, &enc))
118         goto end;
119     private = 1;
120 
121     if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
122         BIO_printf(bio_err, "Error getting password\n");
123         goto end;
124     }
125 
126     pkey = load_keyparams(dsaparams, FORMAT_UNDEF, 1, "DSA", "DSA parameters");
127 
128     out = bio_open_owner(outfile, FORMAT_PEM, private);
129     if (out == NULL)
130         goto end2;
131 
132     nbits = EVP_PKEY_get_bits(pkey);
133     if (nbits > OPENSSL_DSA_MAX_MODULUS_BITS)
134         BIO_printf(bio_err,
135                    "Warning: It is not recommended to use more than %d bit for DSA keys.\n"
136                    "         Your key size is %d! Larger key size may behave not as expected.\n",
137                    OPENSSL_DSA_MAX_MODULUS_BITS, EVP_PKEY_get_bits(pkey));
138 
139     ctx = EVP_PKEY_CTX_new_from_pkey(app_get0_libctx(), pkey, app_get0_propq());
140     if (ctx == NULL) {
141         BIO_printf(bio_err, "unable to create PKEY context\n");
142         goto end;
143     }
144     EVP_PKEY_free(pkey);
145     pkey = NULL;
146     if (EVP_PKEY_keygen_init(ctx) <= 0) {
147         BIO_printf(bio_err, "unable to set up for key generation\n");
148         goto end;
149     }
150     pkey = app_keygen(ctx, "DSA", nbits, verbose);
151     if (pkey == NULL)
152         goto end;
153 
154     assert(private);
155     if (!PEM_write_bio_PrivateKey(out, pkey, enc, NULL, 0, NULL, passout)) {
156         BIO_printf(bio_err, "unable to output generated key\n");
157         goto end;
158     }
159     ret = 0;
160  end:
161     if (ret != 0)
162         ERR_print_errors(bio_err);
163  end2:
164     BIO_free(in);
165     BIO_free_all(out);
166     EVP_PKEY_free(pkey);
167     EVP_PKEY_CTX_free(ctx);
168     EVP_CIPHER_free(enc);
169     release_engine(e);
170     OPENSSL_free(passout);
171     return ret;
172 }
173