2 * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
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
10 #include <openssl/opensslconf.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>
33 static EVP_PKEY *dsa_to_dh(EVP_PKEY *dh);
34 static int gendh_cb(EVP_PKEY_CTX *ctx);
36 typedef enum OPTION_choice {
37 OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
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
44 const OPTIONS dhparam_options[] = {
45 {OPT_HELP_STR, 1, '-', "Usage: %s [options] [numbits]\n"},
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"},
54 #ifndef OPENSSL_NO_ENGINE
55 {"engine", OPT_ENGINE, 's', "Use engine e, possibly a hardware device"},
59 {"in", OPT_IN, '<', "Input file"},
60 {"inform", OPT_INFORM, 'F', "Input format, DER or PEM"},
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"},
75 {"numbits", 0, 0, "Number of bits if generating parameters (optional)"},
79 int dhparam_main(int argc, char **argv)
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;
87 int text = 0, ret = 1, num = 0, g = 0;
88 int informat = FORMAT_PEM, outformat = FORMAT_PEM, check = 0, noout = 0;
91 prog = opt_init(argc, argv, dhparam_options);
92 while ((o = opt_next()) != OPT_EOF) {
97 BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
100 opt_help(dhparam_options);
104 if (!opt_format(opt_arg(), OPT_FMT_PEMDER, &informat))
108 if (!opt_format(opt_arg(), OPT_FMT_PEMDER, &outformat))
118 e = setup_engine(opt_arg(), 0);
146 if (!opt_provider(o))
152 /* One optional argument, bitsize to generate. */
153 argc = opt_num_rest();
156 if (!opt_int(argv[0], &num) || num <= 0)
158 } else if (argc != 0) {
169 "Error, generator may not be chosen for DSA parameters\n");
173 out = bio_open_default(outfile, 'w', outformat);
182 const char *alg = dsaparam ? "DSA" : "DH";
184 ctx = EVP_PKEY_CTX_new_from_name(NULL, alg, NULL);
187 "Error, %s param generation context allocation failed\n",
191 EVP_PKEY_CTX_set_cb(ctx, gendh_cb);
192 EVP_PKEY_CTX_set_app_data(ctx, bio_err);
194 "Generating %s parameters, %d bit long %sprime\n",
195 alg, num, dsaparam ? "" : "safe ");
197 if (!EVP_PKEY_paramgen_init(ctx)) {
199 "Error, unable to initialise %s parameters\n",
205 if (!EVP_PKEY_CTX_set_dsa_paramgen_bits(ctx, num)) {
206 BIO_printf(bio_err, "Error, unable to set DSA prime length\n");
210 if (!EVP_PKEY_CTX_set_dh_paramgen_prime_len(ctx, num)) {
211 BIO_printf(bio_err, "Error, unable to set DH prime length\n");
214 if (!EVP_PKEY_CTX_set_dh_paramgen_generator(ctx, g)) {
215 BIO_printf(bio_err, "Error, unable to set generator\n");
220 if (!EVP_PKEY_paramgen(ctx, &tmppkey)) {
221 BIO_printf(bio_err, "Error, %s generation failed\n", alg);
225 EVP_PKEY_CTX_free(ctx);
228 pkey = dsa_to_dh(tmppkey);
231 EVP_PKEY_free(tmppkey);
237 OSSL_DECODER_CTX *decoderctx = NULL;
238 const char *keytype = "DH";
241 in = bio_open_default(infile, 'r', informat);
247 * We assume we're done unless we explicitly want to retry and set
252 * We set NULL for the keytype to allow any key type. We don't know
253 * if we're going to get DH or DHX (or DSA in the event of dsaparam).
254 * We check that we got one of those key types afterwards.
257 = OSSL_DECODER_CTX_new_for_pkey(&tmppkey,
258 (informat == FORMAT_ASN1)
261 (informat == FORMAT_ASN1)
263 OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS,
266 if (decoderctx != NULL
267 && !OSSL_DECODER_from_bio(decoderctx, in)
268 && informat == FORMAT_ASN1
269 && strcmp(keytype, "DH") == 0) {
271 * When reading DER we explicitly state the expected keytype
272 * because, unlike PEM, there is no header to declare what
273 * the contents of the DER file are. The decoders just try
274 * and guess. Unfortunately with DHX key types they may guess
275 * wrong and think we have a DSA keytype. Therefore we try
276 * both DH and DHX sequentially.
280 * BIO_reset() returns 0 for success for file BIOs only!!!
281 * This won't work for stdin (and never has done)
282 * TODO: We should fix this at some point
284 if (BIO_reset(in) == 0)
287 OSSL_DECODER_CTX_free(decoderctx);
289 if (tmppkey == NULL) {
290 BIO_printf(bio_err, "Error, unable to load parameters\n");
295 if (!EVP_PKEY_is_a(tmppkey, "DSA")) {
296 BIO_printf(bio_err, "Error, unable to load DSA parameters\n");
299 pkey = dsa_to_dh(tmppkey);
303 if (!EVP_PKEY_is_a(tmppkey, "DH")
304 && !EVP_PKEY_is_a(tmppkey, "DHX")) {
305 BIO_printf(bio_err, "Error, unable to load DH parameters\n");
314 EVP_PKEY_print_params(out, pkey, 4, NULL);
317 ctx = EVP_PKEY_CTX_new_from_pkey(NULL, pkey, NULL);
319 BIO_printf(bio_err, "Error, failed to check DH parameters\n");
322 if (!EVP_PKEY_param_check(ctx)) {
323 BIO_printf(bio_err, "Error, invalid parameters generated\n");
326 BIO_printf(bio_err, "DH parameters appear to be ok.\n");
330 OSSL_ENCODER_CTX *ectx =
331 OSSL_ENCODER_CTX_new_for_pkey(pkey,
332 OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS,
333 outformat == FORMAT_ASN1
337 if (ectx == NULL || !OSSL_ENCODER_to_bio(ectx, out)) {
338 OSSL_ENCODER_CTX_free(ectx);
339 BIO_printf(bio_err, "Error, unable to write DH parameters\n");
342 OSSL_ENCODER_CTX_free(ectx);
347 ERR_print_errors(bio_err);
351 EVP_PKEY_free(tmppkey);
352 EVP_PKEY_CTX_free(ctx);
358 * Historically we had the low level call DSA_dup_DH() to do this.
359 * That is now deprecated with no replacement. Since we still need to do this
360 * for backwards compatibility reasons, we do it "manually".
362 static EVP_PKEY *dsa_to_dh(EVP_PKEY *dh)
364 OSSL_PARAM_BLD *tmpl = NULL;
365 OSSL_PARAM *params = NULL;
366 BIGNUM *bn_p = NULL, *bn_q = NULL, *bn_g = NULL;
367 EVP_PKEY_CTX *ctx = NULL;
368 EVP_PKEY *pkey = NULL;
370 if (!EVP_PKEY_get_bn_param(dh, OSSL_PKEY_PARAM_FFC_P, &bn_p)
371 || !EVP_PKEY_get_bn_param(dh, OSSL_PKEY_PARAM_FFC_Q, &bn_q)
372 || !EVP_PKEY_get_bn_param(dh, OSSL_PKEY_PARAM_FFC_G, &bn_g)) {
373 BIO_printf(bio_err, "Error, failed to set DH parameters\n");
377 if ((tmpl = OSSL_PARAM_BLD_new()) == NULL
378 || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_P,
380 || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_Q,
382 || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_G,
384 || (params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL) {
385 BIO_printf(bio_err, "Error, failed to set DH parameters\n");
389 ctx = EVP_PKEY_CTX_new_from_name(NULL, "DHX", NULL);
391 || !EVP_PKEY_fromdata_init(ctx)
392 || !EVP_PKEY_fromdata(ctx, &pkey, EVP_PKEY_KEY_PARAMETERS, params)) {
393 BIO_printf(bio_err, "Error, failed to set DH parameters\n");
398 EVP_PKEY_CTX_free(ctx);
399 OSSL_PARAM_BLD_free_params(params);
400 OSSL_PARAM_BLD_free(tmpl);
407 static int gendh_cb(EVP_PKEY_CTX *ctx)
409 int p = EVP_PKEY_CTX_get_keygen_info(ctx, 0);
410 BIO *b = EVP_PKEY_CTX_get_app_data(ctx);
411 static const char symbols[] = ".+*\n";
412 char c = (p >= 0 && (size_t)p < sizeof(symbols) - 1) ? symbols[p] : '?';