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 <stdlib.h>
14 #include <time.h>
15 #include <string.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/dh.h>
23 #include <openssl/x509.h>
24 #include <openssl/pem.h>
25 #include <openssl/core_names.h>
26 #include <openssl/core_dispatch.h>
27 #include <openssl/param_build.h>
28 #include <openssl/encoder.h>
29 #include <openssl/decoder.h>
30
31 #define DEFBITS 2048
32
33 static EVP_PKEY *dsa_to_dh(EVP_PKEY *dh);
34 static int gendh_cb(EVP_PKEY_CTX *ctx);
35
36 typedef enum OPTION_choice {
37 OPT_COMMON,
38 OPT_INFORM, OPT_OUTFORM, OPT_IN, OPT_OUT,
39 OPT_ENGINE, OPT_CHECK, OPT_TEXT, OPT_NOOUT,
40 OPT_DSAPARAM, OPT_2, OPT_3, OPT_5,
41 OPT_R_ENUM, OPT_PROV_ENUM
42 } OPTION_CHOICE;
43
44 const OPTIONS dhparam_options[] = {
45 {OPT_HELP_STR, 1, '-', "Usage: %s [options] [numbits]\n"},
46
47 OPT_SECTION("General"),
48 {"help", OPT_HELP, '-', "Display this summary"},
49 {"check", OPT_CHECK, '-', "Check the DH parameters"},
50 #if !defined(OPENSSL_NO_DSA) || !defined(OPENSSL_NO_DEPRECATED_3_0)
51 {"dsaparam", OPT_DSAPARAM, '-',
52 "Read or generate DSA parameters, convert to DH"},
53 #endif
54 #ifndef OPENSSL_NO_ENGINE
55 {"engine", OPT_ENGINE, 's', "Use engine e, possibly a hardware device"},
56 #endif
57
58 OPT_SECTION("Input"),
59 {"in", OPT_IN, '<', "Input file"},
60 {"inform", OPT_INFORM, 'F', "Input format, DER or PEM"},
61
62 OPT_SECTION("Output"),
63 {"out", OPT_OUT, '>', "Output file"},
64 {"outform", OPT_OUTFORM, 'F', "Output format, DER or PEM"},
65 {"text", OPT_TEXT, '-', "Print a text form of the DH parameters"},
66 {"noout", OPT_NOOUT, '-', "Don't output any DH parameters"},
67 {"2", OPT_2, '-', "Generate parameters using 2 as the generator value"},
68 {"3", OPT_3, '-', "Generate parameters using 3 as the generator value"},
69 {"5", OPT_5, '-', "Generate parameters using 5 as the generator value"},
70
71 OPT_R_OPTIONS,
72 OPT_PROV_OPTIONS,
73
74 OPT_PARAMETERS(),
75 {"numbits", 0, 0, "Number of bits if generating parameters (optional)"},
76 {NULL}
77 };
78
dhparam_main(int argc,char ** argv)79 int dhparam_main(int argc, char **argv)
80 {
81 BIO *in = NULL, *out = NULL;
82 EVP_PKEY *pkey = NULL, *tmppkey = NULL;
83 EVP_PKEY_CTX *ctx = NULL;
84 char *infile = NULL, *outfile = NULL, *prog;
85 ENGINE *e = NULL;
86 int dsaparam = 0;
87 int text = 0, ret = 1, num = 0, g = 0;
88 int informat = FORMAT_PEM, outformat = FORMAT_PEM, check = 0, noout = 0;
89 OPTION_CHOICE o;
90
91 prog = opt_init(argc, argv, dhparam_options);
92 while ((o = opt_next()) != OPT_EOF) {
93 switch (o) {
94 case OPT_EOF:
95 case OPT_ERR:
96 opthelp:
97 BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
98 goto end;
99 case OPT_HELP:
100 opt_help(dhparam_options);
101 ret = 0;
102 goto end;
103 case OPT_INFORM:
104 if (!opt_format(opt_arg(), OPT_FMT_PEMDER, &informat))
105 goto opthelp;
106 break;
107 case OPT_OUTFORM:
108 if (!opt_format(opt_arg(), OPT_FMT_PEMDER, &outformat))
109 goto opthelp;
110 break;
111 case OPT_IN:
112 infile = opt_arg();
113 break;
114 case OPT_OUT:
115 outfile = opt_arg();
116 break;
117 case OPT_ENGINE:
118 e = setup_engine(opt_arg(), 0);
119 break;
120 case OPT_CHECK:
121 check = 1;
122 break;
123 case OPT_TEXT:
124 text = 1;
125 break;
126 case OPT_DSAPARAM:
127 dsaparam = 1;
128 break;
129 case OPT_2:
130 g = 2;
131 break;
132 case OPT_3:
133 g = 3;
134 break;
135 case OPT_5:
136 g = 5;
137 break;
138 case OPT_NOOUT:
139 noout = 1;
140 break;
141 case OPT_R_CASES:
142 if (!opt_rand(o))
143 goto end;
144 break;
145 case OPT_PROV_CASES:
146 if (!opt_provider(o))
147 goto end;
148 break;
149 }
150 }
151
152 /* One optional argument, bitsize to generate. */
153 argc = opt_num_rest();
154 argv = opt_rest();
155 if (argc == 1) {
156 if (!opt_int(argv[0], &num) || num <= 0)
157 goto opthelp;
158 } else if (argc != 0) {
159 goto opthelp;
160 }
161 if (!app_RAND_load())
162 goto end;
163
164 if (g && !num)
165 num = DEFBITS;
166
167 if (dsaparam && g) {
168 BIO_printf(bio_err,
169 "Error, generator may not be chosen for DSA parameters\n");
170 goto end;
171 }
172
173 out = bio_open_default(outfile, 'w', outformat);
174 if (out == NULL)
175 goto end;
176
177 /* DH parameters */
178 if (num && !g)
179 g = 2;
180
181 if (num) {
182 const char *alg = dsaparam ? "DSA" : "DH";
183
184 if (infile != NULL) {
185 BIO_printf(bio_err, "Warning, input file %s ignored\n", infile);
186 }
187
188 ctx = EVP_PKEY_CTX_new_from_name(app_get0_libctx(), alg, app_get0_propq());
189 if (ctx == NULL) {
190 BIO_printf(bio_err,
191 "Error, %s param generation context allocation failed\n",
192 alg);
193 goto end;
194 }
195 EVP_PKEY_CTX_set_cb(ctx, gendh_cb);
196 EVP_PKEY_CTX_set_app_data(ctx, bio_err);
197 BIO_printf(bio_err,
198 "Generating %s parameters, %d bit long %sprime\n",
199 alg, num, dsaparam ? "" : "safe ");
200
201 if (EVP_PKEY_paramgen_init(ctx) <= 0) {
202 BIO_printf(bio_err,
203 "Error, unable to initialise %s parameters\n",
204 alg);
205 goto end;
206 }
207
208 if (dsaparam) {
209 if (EVP_PKEY_CTX_set_dsa_paramgen_bits(ctx, num) <= 0) {
210 BIO_printf(bio_err, "Error, unable to set DSA prime length\n");
211 goto end;
212 }
213 } else {
214 if (EVP_PKEY_CTX_set_dh_paramgen_prime_len(ctx, num) <= 0) {
215 BIO_printf(bio_err, "Error, unable to set DH prime length\n");
216 goto end;
217 }
218 if (EVP_PKEY_CTX_set_dh_paramgen_generator(ctx, g) <= 0) {
219 BIO_printf(bio_err, "Error, unable to set generator\n");
220 goto end;
221 }
222 }
223
224 tmppkey = app_paramgen(ctx, alg);
225 if (tmppkey == NULL)
226 goto end;
227 EVP_PKEY_CTX_free(ctx);
228 ctx = NULL;
229 if (dsaparam) {
230 pkey = dsa_to_dh(tmppkey);
231 if (pkey == NULL)
232 goto end;
233 EVP_PKEY_free(tmppkey);
234 } else {
235 pkey = tmppkey;
236 }
237 tmppkey = NULL;
238 } else {
239 OSSL_DECODER_CTX *decoderctx = NULL;
240 const char *keytype = "DH";
241 int done;
242
243 in = bio_open_default(infile, 'r', informat);
244 if (in == NULL)
245 goto end;
246
247 do {
248 /*
249 * We assume we're done unless we explicitly want to retry and set
250 * this to 0 below.
251 */
252 done = 1;
253 /*
254 * We set NULL for the keytype to allow any key type. We don't know
255 * if we're going to get DH or DHX (or DSA in the event of dsaparam).
256 * We check that we got one of those key types afterwards.
257 */
258 decoderctx
259 = OSSL_DECODER_CTX_new_for_pkey(&tmppkey,
260 (informat == FORMAT_ASN1)
261 ? "DER" : "PEM",
262 NULL,
263 (informat == FORMAT_ASN1)
264 ? keytype : NULL,
265 OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS,
266 NULL, NULL);
267
268 if (decoderctx != NULL
269 && !OSSL_DECODER_from_bio(decoderctx, in)
270 && informat == FORMAT_ASN1
271 && strcmp(keytype, "DH") == 0) {
272 /*
273 * When reading DER we explicitly state the expected keytype
274 * because, unlike PEM, there is no header to declare what
275 * the contents of the DER file are. The decoders just try
276 * and guess. Unfortunately with DHX key types they may guess
277 * wrong and think we have a DSA keytype. Therefore we try
278 * both DH and DHX sequentially.
279 */
280 keytype = "DHX";
281 /*
282 * BIO_reset() returns 0 for success for file BIOs only!!!
283 * This won't work for stdin (and never has done)
284 */
285 if (BIO_reset(in) == 0)
286 done = 0;
287 }
288 OSSL_DECODER_CTX_free(decoderctx);
289 } while (!done);
290 if (tmppkey == NULL) {
291 BIO_printf(bio_err, "Error, unable to load parameters\n");
292 goto end;
293 }
294
295 if (dsaparam) {
296 if (!EVP_PKEY_is_a(tmppkey, "DSA")) {
297 BIO_printf(bio_err, "Error, unable to load DSA parameters\n");
298 goto end;
299 }
300 pkey = dsa_to_dh(tmppkey);
301 if (pkey == NULL)
302 goto end;
303 } else {
304 if (!EVP_PKEY_is_a(tmppkey, "DH")
305 && !EVP_PKEY_is_a(tmppkey, "DHX")) {
306 BIO_printf(bio_err, "Error, unable to load DH parameters\n");
307 goto end;
308 }
309 pkey = tmppkey;
310 tmppkey = NULL;
311 }
312 }
313
314 if (text)
315 EVP_PKEY_print_params(out, pkey, 4, NULL);
316
317 if (check) {
318 ctx = EVP_PKEY_CTX_new_from_pkey(app_get0_libctx(), pkey, app_get0_propq());
319 if (ctx == NULL) {
320 BIO_printf(bio_err, "Error, failed to check DH parameters\n");
321 goto end;
322 }
323 if (EVP_PKEY_param_check(ctx) <= 0) {
324 BIO_printf(bio_err, "Error, invalid parameters generated\n");
325 goto end;
326 }
327 BIO_printf(bio_err, "DH parameters appear to be ok.\n");
328 }
329
330 if (!noout) {
331 OSSL_ENCODER_CTX *ectx =
332 OSSL_ENCODER_CTX_new_for_pkey(pkey,
333 OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS,
334 outformat == FORMAT_ASN1
335 ? "DER" : "PEM",
336 NULL, NULL);
337
338 if (ectx == NULL || !OSSL_ENCODER_to_bio(ectx, out)) {
339 OSSL_ENCODER_CTX_free(ectx);
340 BIO_printf(bio_err, "Error, unable to write DH parameters\n");
341 goto end;
342 }
343 OSSL_ENCODER_CTX_free(ectx);
344 }
345 ret = 0;
346 end:
347 if (ret != 0)
348 ERR_print_errors(bio_err);
349 BIO_free(in);
350 BIO_free_all(out);
351 EVP_PKEY_free(pkey);
352 EVP_PKEY_free(tmppkey);
353 EVP_PKEY_CTX_free(ctx);
354 release_engine(e);
355 return ret;
356 }
357
358 /*
359 * Historically we had the low level call DSA_dup_DH() to do this.
360 * That is now deprecated with no replacement. Since we still need to do this
361 * for backwards compatibility reasons, we do it "manually".
362 */
dsa_to_dh(EVP_PKEY * dh)363 static EVP_PKEY *dsa_to_dh(EVP_PKEY *dh)
364 {
365 OSSL_PARAM_BLD *tmpl = NULL;
366 OSSL_PARAM *params = NULL;
367 BIGNUM *bn_p = NULL, *bn_q = NULL, *bn_g = NULL;
368 EVP_PKEY_CTX *ctx = NULL;
369 EVP_PKEY *pkey = NULL;
370
371 if (!EVP_PKEY_get_bn_param(dh, OSSL_PKEY_PARAM_FFC_P, &bn_p)
372 || !EVP_PKEY_get_bn_param(dh, OSSL_PKEY_PARAM_FFC_Q, &bn_q)
373 || !EVP_PKEY_get_bn_param(dh, OSSL_PKEY_PARAM_FFC_G, &bn_g)) {
374 BIO_printf(bio_err, "Error, failed to set DH parameters\n");
375 goto err;
376 }
377
378 if ((tmpl = OSSL_PARAM_BLD_new()) == NULL
379 || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_P,
380 bn_p)
381 || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_Q,
382 bn_q)
383 || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_G,
384 bn_g)
385 || (params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL) {
386 BIO_printf(bio_err, "Error, failed to set DH parameters\n");
387 goto err;
388 }
389
390 ctx = EVP_PKEY_CTX_new_from_name(app_get0_libctx(), "DHX", app_get0_propq());
391 if (ctx == NULL
392 || EVP_PKEY_fromdata_init(ctx) <= 0
393 || EVP_PKEY_fromdata(ctx, &pkey, EVP_PKEY_KEY_PARAMETERS, params) <= 0) {
394 BIO_printf(bio_err, "Error, failed to set DH parameters\n");
395 goto err;
396 }
397
398 err:
399 EVP_PKEY_CTX_free(ctx);
400 OSSL_PARAM_free(params);
401 OSSL_PARAM_BLD_free(tmpl);
402 BN_free(bn_p);
403 BN_free(bn_q);
404 BN_free(bn_g);
405 return pkey;
406 }
407
gendh_cb(EVP_PKEY_CTX * ctx)408 static int gendh_cb(EVP_PKEY_CTX *ctx)
409 {
410 int p = EVP_PKEY_CTX_get_keygen_info(ctx, 0);
411 BIO *b = EVP_PKEY_CTX_get_app_data(ctx);
412 static const char symbols[] = ".+*\n";
413 char c = (p >= 0 && (size_t)p < sizeof(symbols) - 1) ? symbols[p] : '?';
414
415 BIO_write(b, &c, 1);
416 (void)BIO_flush(b);
417 return 1;
418 }
419