xref: /freebsd/crypto/openssl/apps/dhparam.c (revision e17f5b1d307b7b8910d67883e57a9604305906d5)
1 /*
2  * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (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 #include <stdio.h>
12 #include <stdlib.h>
13 #include <time.h>
14 #include <string.h>
15 #include "apps.h"
16 #include "progs.h"
17 #include <openssl/bio.h>
18 #include <openssl/err.h>
19 #include <openssl/bn.h>
20 #include <openssl/dh.h>
21 #include <openssl/x509.h>
22 #include <openssl/pem.h>
23 
24 #ifndef OPENSSL_NO_DSA
25 # include <openssl/dsa.h>
26 #endif
27 
28 #define DEFBITS 2048
29 
30 static int dh_cb(int p, int n, BN_GENCB *cb);
31 
32 typedef enum OPTION_choice {
33     OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
34     OPT_INFORM, OPT_OUTFORM, OPT_IN, OPT_OUT,
35     OPT_ENGINE, OPT_CHECK, OPT_TEXT, OPT_NOOUT,
36     OPT_DSAPARAM, OPT_C, OPT_2, OPT_5,
37     OPT_R_ENUM
38 } OPTION_CHOICE;
39 
40 const OPTIONS dhparam_options[] = {
41     {OPT_HELP_STR, 1, '-', "Usage: %s [flags] [numbits]\n"},
42     {OPT_HELP_STR, 1, '-', "Valid options are:\n"},
43     {"help", OPT_HELP, '-', "Display this summary"},
44     {"in", OPT_IN, '<', "Input file"},
45     {"inform", OPT_INFORM, 'F', "Input format, DER or PEM"},
46     {"outform", OPT_OUTFORM, 'F', "Output format, DER or PEM"},
47     {"out", OPT_OUT, '>', "Output file"},
48     {"check", OPT_CHECK, '-', "Check the DH parameters"},
49     {"text", OPT_TEXT, '-', "Print a text form of the DH parameters"},
50     {"noout", OPT_NOOUT, '-', "Don't output any DH parameters"},
51     OPT_R_OPTIONS,
52     {"C", OPT_C, '-', "Print C code"},
53     {"2", OPT_2, '-', "Generate parameters using 2 as the generator value"},
54     {"5", OPT_5, '-', "Generate parameters using 5 as the generator value"},
55 #ifndef OPENSSL_NO_DSA
56     {"dsaparam", OPT_DSAPARAM, '-',
57      "Read or generate DSA parameters, convert to DH"},
58 #endif
59 #ifndef OPENSSL_NO_ENGINE
60     {"engine", OPT_ENGINE, 's', "Use engine e, possibly a hardware device"},
61 #endif
62     {NULL}
63 };
64 
65 int dhparam_main(int argc, char **argv)
66 {
67     BIO *in = NULL, *out = NULL;
68     DH *dh = NULL;
69     char *infile = NULL, *outfile = NULL, *prog;
70     ENGINE *e = NULL;
71 #ifndef OPENSSL_NO_DSA
72     int dsaparam = 0;
73 #endif
74     int i, text = 0, C = 0, ret = 1, num = 0, g = 0;
75     int informat = FORMAT_PEM, outformat = FORMAT_PEM, check = 0, noout = 0;
76     OPTION_CHOICE o;
77 
78     prog = opt_init(argc, argv, dhparam_options);
79     while ((o = opt_next()) != OPT_EOF) {
80         switch (o) {
81         case OPT_EOF:
82         case OPT_ERR:
83  opthelp:
84             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
85             goto end;
86         case OPT_HELP:
87             opt_help(dhparam_options);
88             ret = 0;
89             goto end;
90         case OPT_INFORM:
91             if (!opt_format(opt_arg(), OPT_FMT_PEMDER, &informat))
92                 goto opthelp;
93             break;
94         case OPT_OUTFORM:
95             if (!opt_format(opt_arg(), OPT_FMT_PEMDER, &outformat))
96                 goto opthelp;
97             break;
98         case OPT_IN:
99             infile = opt_arg();
100             break;
101         case OPT_OUT:
102             outfile = opt_arg();
103             break;
104         case OPT_ENGINE:
105             e = setup_engine(opt_arg(), 0);
106             break;
107         case OPT_CHECK:
108             check = 1;
109             break;
110         case OPT_TEXT:
111             text = 1;
112             break;
113         case OPT_DSAPARAM:
114 #ifndef OPENSSL_NO_DSA
115             dsaparam = 1;
116 #endif
117             break;
118         case OPT_C:
119             C = 1;
120             break;
121         case OPT_2:
122             g = 2;
123             break;
124         case OPT_5:
125             g = 5;
126             break;
127         case OPT_NOOUT:
128             noout = 1;
129             break;
130         case OPT_R_CASES:
131             if (!opt_rand(o))
132                 goto end;
133             break;
134         }
135     }
136     argc = opt_num_rest();
137     argv = opt_rest();
138 
139     if (argv[0] != NULL && (!opt_int(argv[0], &num) || num <= 0))
140         goto end;
141 
142     if (g && !num)
143         num = DEFBITS;
144 
145 #ifndef OPENSSL_NO_DSA
146     if (dsaparam && g) {
147         BIO_printf(bio_err,
148                    "generator may not be chosen for DSA parameters\n");
149         goto end;
150     }
151 #endif
152 
153     out = bio_open_default(outfile, 'w', outformat);
154     if (out == NULL)
155         goto end;
156 
157     /* DH parameters */
158     if (num && !g)
159         g = 2;
160 
161     if (num) {
162 
163         BN_GENCB *cb;
164         cb = BN_GENCB_new();
165         if (cb == NULL) {
166             ERR_print_errors(bio_err);
167             goto end;
168         }
169 
170         BN_GENCB_set(cb, dh_cb, bio_err);
171 
172 #ifndef OPENSSL_NO_DSA
173         if (dsaparam) {
174             DSA *dsa = DSA_new();
175 
176             BIO_printf(bio_err,
177                        "Generating DSA parameters, %d bit long prime\n", num);
178             if (dsa == NULL
179                 || !DSA_generate_parameters_ex(dsa, num, NULL, 0, NULL, NULL,
180                                                cb)) {
181                 DSA_free(dsa);
182                 BN_GENCB_free(cb);
183                 ERR_print_errors(bio_err);
184                 goto end;
185             }
186 
187             dh = DSA_dup_DH(dsa);
188             DSA_free(dsa);
189             if (dh == NULL) {
190                 BN_GENCB_free(cb);
191                 ERR_print_errors(bio_err);
192                 goto end;
193             }
194         } else
195 #endif
196         {
197             dh = DH_new();
198             BIO_printf(bio_err,
199                        "Generating DH parameters, %d bit long safe prime, generator %d\n",
200                        num, g);
201             BIO_printf(bio_err, "This is going to take a long time\n");
202             if (dh == NULL || !DH_generate_parameters_ex(dh, num, g, cb)) {
203                 BN_GENCB_free(cb);
204                 ERR_print_errors(bio_err);
205                 goto end;
206             }
207         }
208 
209         BN_GENCB_free(cb);
210     } else {
211 
212         in = bio_open_default(infile, 'r', informat);
213         if (in == NULL)
214             goto end;
215 
216 #ifndef OPENSSL_NO_DSA
217         if (dsaparam) {
218             DSA *dsa;
219 
220             if (informat == FORMAT_ASN1)
221                 dsa = d2i_DSAparams_bio(in, NULL);
222             else                /* informat == FORMAT_PEM */
223                 dsa = PEM_read_bio_DSAparams(in, NULL, NULL, NULL);
224 
225             if (dsa == NULL) {
226                 BIO_printf(bio_err, "unable to load DSA parameters\n");
227                 ERR_print_errors(bio_err);
228                 goto end;
229             }
230 
231             dh = DSA_dup_DH(dsa);
232             DSA_free(dsa);
233             if (dh == NULL) {
234                 ERR_print_errors(bio_err);
235                 goto end;
236             }
237         } else
238 #endif
239         {
240             if (informat == FORMAT_ASN1) {
241                 /*
242                  * We have no PEM header to determine what type of DH params it
243                  * is. We'll just try both.
244                  */
245                 dh = d2i_DHparams_bio(in, NULL);
246                 /* BIO_reset() returns 0 for success for file BIOs only!!! */
247                 if (dh == NULL && BIO_reset(in) == 0)
248                     dh = d2i_DHxparams_bio(in, NULL);
249             } else {
250                 /* informat == FORMAT_PEM */
251                 dh = PEM_read_bio_DHparams(in, NULL, NULL, NULL);
252             }
253 
254             if (dh == NULL) {
255                 BIO_printf(bio_err, "unable to load DH parameters\n");
256                 ERR_print_errors(bio_err);
257                 goto end;
258             }
259         }
260 
261         /* dh != NULL */
262     }
263 
264     if (text) {
265         DHparams_print(out, dh);
266     }
267 
268     if (check) {
269         if (!DH_check(dh, &i)) {
270             ERR_print_errors(bio_err);
271             goto end;
272         }
273         if (i & DH_CHECK_P_NOT_PRIME)
274             BIO_printf(bio_err, "WARNING: p value is not prime\n");
275         if (i & DH_CHECK_P_NOT_SAFE_PRIME)
276             BIO_printf(bio_err, "WARNING: p value is not a safe prime\n");
277         if (i & DH_CHECK_Q_NOT_PRIME)
278             BIO_printf(bio_err, "WARNING: q value is not a prime\n");
279         if (i & DH_CHECK_INVALID_Q_VALUE)
280             BIO_printf(bio_err, "WARNING: q value is invalid\n");
281         if (i & DH_CHECK_INVALID_J_VALUE)
282             BIO_printf(bio_err, "WARNING: j value is invalid\n");
283         if (i & DH_UNABLE_TO_CHECK_GENERATOR)
284             BIO_printf(bio_err,
285                        "WARNING: unable to check the generator value\n");
286         if (i & DH_NOT_SUITABLE_GENERATOR)
287             BIO_printf(bio_err, "WARNING: the g value is not a generator\n");
288         if (i == 0)
289             BIO_printf(bio_err, "DH parameters appear to be ok.\n");
290         if (num != 0 && i != 0) {
291             /*
292              * We have generated parameters but DH_check() indicates they are
293              * invalid! This should never happen!
294              */
295             BIO_printf(bio_err, "ERROR: Invalid parameters generated\n");
296             goto end;
297         }
298     }
299     if (C) {
300         unsigned char *data;
301         int len, bits;
302         const BIGNUM *pbn, *gbn;
303 
304         len = DH_size(dh);
305         bits = DH_bits(dh);
306         DH_get0_pqg(dh, &pbn, NULL, &gbn);
307         data = app_malloc(len, "print a BN");
308 
309         BIO_printf(out, "static DH *get_dh%d(void)\n{\n", bits);
310         print_bignum_var(out, pbn, "dhp", bits, data);
311         print_bignum_var(out, gbn, "dhg", bits, data);
312         BIO_printf(out, "    DH *dh = DH_new();\n"
313                         "    BIGNUM *p, *g;\n"
314                         "\n"
315                         "    if (dh == NULL)\n"
316                         "        return NULL;\n");
317         BIO_printf(out, "    p = BN_bin2bn(dhp_%d, sizeof(dhp_%d), NULL);\n",
318                    bits, bits);
319         BIO_printf(out, "    g = BN_bin2bn(dhg_%d, sizeof(dhg_%d), NULL);\n",
320                    bits, bits);
321         BIO_printf(out, "    if (p == NULL || g == NULL\n"
322                         "            || !DH_set0_pqg(dh, p, NULL, g)) {\n"
323                         "        DH_free(dh);\n"
324                         "        BN_free(p);\n"
325                         "        BN_free(g);\n"
326                         "        return NULL;\n"
327                         "    }\n");
328         if (DH_get_length(dh) > 0)
329             BIO_printf(out,
330                         "    if (!DH_set_length(dh, %ld)) {\n"
331                         "        DH_free(dh);\n"
332                         "        return NULL;\n"
333                         "    }\n", DH_get_length(dh));
334         BIO_printf(out, "    return dh;\n}\n");
335         OPENSSL_free(data);
336     }
337 
338     if (!noout) {
339         const BIGNUM *q;
340         DH_get0_pqg(dh, NULL, &q, NULL);
341         if (outformat == FORMAT_ASN1) {
342             if (q != NULL)
343                 i = i2d_DHxparams_bio(out, dh);
344             else
345                 i = i2d_DHparams_bio(out, dh);
346         } else if (q != NULL) {
347             i = PEM_write_bio_DHxparams(out, dh);
348         } else {
349             i = PEM_write_bio_DHparams(out, dh);
350         }
351         if (!i) {
352             BIO_printf(bio_err, "unable to write DH parameters\n");
353             ERR_print_errors(bio_err);
354             goto end;
355         }
356     }
357     ret = 0;
358  end:
359     BIO_free(in);
360     BIO_free_all(out);
361     DH_free(dh);
362     release_engine(e);
363     return ret;
364 }
365 
366 static int dh_cb(int p, int n, BN_GENCB *cb)
367 {
368     static const char symbols[] = ".+*\n";
369     char c = (p >= 0 && (size_t)p < sizeof(symbols) - 1) ? symbols[p] : '?';
370 
371     BIO_write(BN_GENCB_get_arg(cb), &c, 1);
372     (void)BIO_flush(BN_GENCB_get_arg(cb));
373     return 1;
374 }
375