apps/dhparam.c

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