providers/implementations/keymgmt/dh_kmgmt.c

   1 /*
   2  * Copyright 2019-2020 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 /*
  11  * DH low level APIs are deprecated for public use, but still ok for
  12  * internal use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include <string.h> /* strcmp */
  17 #include <openssl/core_numbers.h>
  18 #include <openssl/core_names.h>
  19 #include <openssl/bn.h>
  20 #include <openssl/err.h>
  21 #include "prov/implementations.h"
  22 #include "prov/providercommon.h"
  23 #include "prov/provider_ctx.h"
  24 #include "crypto/dh.h"
  25 #include "internal/sizes.h"
  26 #include "internal/nelem.h"
  27 #include "internal/param_build_set.h"
  28
  29 static OSSL_OP_keymgmt_new_fn dh_newdata;
  30 static OSSL_OP_keymgmt_free_fn dh_freedata;
  31 static OSSL_OP_keymgmt_gen_init_fn dh_gen_init;
  32 static OSSL_OP_keymgmt_gen_set_template_fn dh_gen_set_template;
  33 static OSSL_OP_keymgmt_gen_set_params_fn dh_gen_set_params;
  34 static OSSL_OP_keymgmt_gen_settable_params_fn dh_gen_settable_params;
  35 static OSSL_OP_keymgmt_gen_fn dh_gen;
  36 static OSSL_OP_keymgmt_gen_cleanup_fn dh_gen_cleanup;
  37 static OSSL_OP_keymgmt_get_params_fn dh_get_params;
  38 static OSSL_OP_keymgmt_gettable_params_fn dh_gettable_params;
  39 static OSSL_OP_keymgmt_has_fn dh_has;
  40 static OSSL_OP_keymgmt_match_fn dh_match;
  41 static OSSL_OP_keymgmt_validate_fn dh_validate;
  42 static OSSL_OP_keymgmt_import_fn dh_import;
  43 static OSSL_OP_keymgmt_import_types_fn dh_import_types;
  44 static OSSL_OP_keymgmt_export_fn dh_export;
  45 static OSSL_OP_keymgmt_export_types_fn dh_export_types;
  46
  47 #define DH_POSSIBLE_SELECTIONS                                                 \
  48     (OSSL_KEYMGMT_SELECT_KEYPAIR | OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS)
  49
  50 struct dh_gen_ctx {
  51     OPENSSL_CTX *libctx;
  52
  53     FFC_PARAMS *ffc_params;
  54     int selection;
  55     /* All these parameters are used for parameter generation only */
  56     /* If there is a group name then the remaining parameters are not needed */
  57     int group_nid;
  58     size_t pbits;
  59     size_t qbits;
  60     EVP_MD *md;
  61     unsigned char *seed; /* optional FIPS186-4 param for testing */
  62     size_t seedlen;
  63     int gindex; /* optional  FIPS186-4 generator index (ignored if -1) */
  64     int gen_type; /* see dhtype2id */
  65     int generator; /* Used by DH_PARAMGEN_TYPE_GENERATOR in non fips mode only */
  66     int pcounter;
  67     int hindex;
  68
  69     OSSL_CALLBACK *cb;
  70     void *cbarg;
  71 };
  72
  73 typedef struct dh_name2id_st{
  74     const char *name;
  75     int id;
  76 } DH_GENTYPE_NAME2ID;
  77
  78 static const DH_GENTYPE_NAME2ID dhtype2id[]=
  79 {
  80     { "default", DH_PARAMGEN_TYPE_FIPS_186_4 },
  81     { "fips186_4", DH_PARAMGEN_TYPE_FIPS_186_4 },
  82     { "fips186_2", DH_PARAMGEN_TYPE_FIPS_186_2 },
  83     { "group", DH_PARAMGEN_TYPE_GROUP },
  84     { "generator", DH_PARAMGEN_TYPE_GENERATOR }
  85 };
  86
  87 const char *dh_gen_type_id2name(int id)
  88 {
  89     size_t i;
  90
  91     for (i = 0; i < OSSL_NELEM(dhtype2id); ++i) {
  92         if (dhtype2id[i].id == id)
  93             return dhtype2id[i].name;
  94     }
  95     return NULL;
  96 }
  97
  98 static int dh_gen_type_name2id(const char *name)
  99 {
 100     size_t i;
 101
 102     for (i = 0; i < OSSL_NELEM(dhtype2id); ++i) {
 103         if (strcmp(dhtype2id[i].name, name) == 0)
 104             return dhtype2id[i].id;
 105     }
 106     return -1;
 107 }
 108
 109 static int dh_key_todata(DH *dh, OSSL_PARAM_BLD *bld, OSSL_PARAM params[])
 110 {
 111     const BIGNUM *priv = NULL, *pub = NULL;
 112
 113     if (dh == NULL)
 114         return 0;
 115
 116     DH_get0_key(dh, &pub, &priv);
 117     if (priv != NULL
 118         && !ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_PRIV_KEY, priv))
 119         return 0;
 120     if (pub != NULL
 121         && !ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_PUB_KEY, pub))
 122         return 0;
 123
 124     return 1;
 125 }
 126
 127 static void *dh_newdata(void *provctx)
 128 {
 129     return dh_new_with_libctx(PROV_LIBRARY_CONTEXT_OF(provctx));
 130 }
 131
 132 static void dh_freedata(void *keydata)
 133 {
 134     DH_free(keydata);
 135 }
 136
 137 static int dh_has(void *keydata, int selection)
 138 {
 139     DH *dh = keydata;
 140     int ok = 0;
 141
 142     if (dh != NULL) {
 143         if ((selection & DH_POSSIBLE_SELECTIONS) != 0)
 144             ok = 1;
 145
 146         if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
 147             ok = ok && (DH_get0_pub_key(dh) != NULL);
 148         if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)
 149             ok = ok && (DH_get0_priv_key(dh) != NULL);
 150         if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0)
 151             ok = ok && (DH_get0_p(dh) != NULL && DH_get0_g(dh) != NULL);
 152     }
 153     return ok;
 154 }
 155
 156 static int dh_match(const void *keydata1, const void *keydata2, int selection)
 157 {
 158     const DH *dh1 = keydata1;
 159     const DH *dh2 = keydata2;
 160     int ok = 1;
 161
 162     if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
 163         ok = ok && BN_cmp(DH_get0_pub_key(dh1), DH_get0_pub_key(dh2)) == 0;
 164     if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)
 165         ok = ok && BN_cmp(DH_get0_priv_key(dh1), DH_get0_priv_key(dh2)) == 0;
 166     if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0) {
 167         FFC_PARAMS *dhparams1 = dh_get0_params((DH *)dh1);
 168         FFC_PARAMS *dhparams2 = dh_get0_params((DH *)dh2);
 169
 170         ok = ok && ffc_params_cmp(dhparams1, dhparams2, 1);
 171     }
 172     return ok;
 173 }
 174
 175 static int dh_import(void *keydata, int selection, const OSSL_PARAM params[])
 176 {
 177     DH *dh = keydata;
 178     int ok = 1;
 179
 180     if (dh == NULL)
 181         return 0;
 182
 183     if ((selection & DH_POSSIBLE_SELECTIONS) == 0)
 184         return 0;
 185
 186     if ((selection & OSSL_KEYMGMT_SELECT_ALL_PARAMETERS) != 0)
 187         ok = ok && dh_ffc_params_fromdata(dh, params);
 188
 189     if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0)
 190         ok = ok && dh_key_fromdata(dh, params);
 191
 192     return ok;
 193 }
 194
 195 static int dh_export(void *keydata, int selection, OSSL_CALLBACK *param_cb,
 196                      void *cbarg)
 197 {
 198     DH *dh = keydata;
 199     OSSL_PARAM_BLD *tmpl = NULL;
 200     OSSL_PARAM *params = NULL;
 201     int ok = 1;
 202
 203     if (dh == NULL)
 204         return 0;
 205
 206     tmpl = OSSL_PARAM_BLD_new();
 207     if (tmpl == NULL)
 208         return 0;
 209
 210     if ((selection & OSSL_KEYMGMT_SELECT_ALL_PARAMETERS) != 0)
 211         ok = ok && ffc_params_todata(dh_get0_params(dh), tmpl, NULL);
 212     if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0)
 213         ok = ok && dh_key_todata(dh, tmpl, NULL);
 214
 215     if (!ok
 216         || (params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL) {
 217         ok = 0;
 218         goto err;
 219     }
 220     ok = param_cb(params, cbarg);
 221     OSSL_PARAM_BLD_free_params(params);
 222 err:
 223     OSSL_PARAM_BLD_free(tmpl);
 224     return ok;
 225 }
 226
 227 /* IMEXPORT = IMPORT + EXPORT */
 228
 229 # define DH_IMEXPORTABLE_PARAMETERS                                            \
 230     OSSL_PARAM_BN(OSSL_PKEY_PARAM_FFC_P, NULL, 0),                             \
 231     OSSL_PARAM_BN(OSSL_PKEY_PARAM_FFC_Q, NULL, 0),                             \
 232     OSSL_PARAM_BN(OSSL_PKEY_PARAM_FFC_G, NULL, 0),                             \
 233     OSSL_PARAM_BN(OSSL_PKEY_PARAM_FFC_COFACTOR, NULL, 0),                      \
 234     OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_GINDEX, NULL),                          \
 235     OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_PCOUNTER, NULL),                        \
 236     OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_H, NULL),                               \
 237     OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_FFC_GROUP, NULL, 0),                \
 238     OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_FFC_SEED, NULL, 0)
 239 # define DH_IMEXPORTABLE_PUBLIC_KEY                                            \
 240     OSSL_PARAM_BN(OSSL_PKEY_PARAM_PUB_KEY, NULL, 0)
 241 # define DH_IMEXPORTABLE_PRIVATE_KEY                                           \
 242     OSSL_PARAM_BN(OSSL_PKEY_PARAM_PRIV_KEY, NULL, 0)
 243 static const OSSL_PARAM dh_all_types[] = {
 244     DH_IMEXPORTABLE_PARAMETERS,
 245     DH_IMEXPORTABLE_PUBLIC_KEY,
 246     DH_IMEXPORTABLE_PRIVATE_KEY,
 247     OSSL_PARAM_END
 248 };
 249 static const OSSL_PARAM dh_parameter_types[] = {
 250     DH_IMEXPORTABLE_PARAMETERS,
 251     OSSL_PARAM_END
 252 };
 253 static const OSSL_PARAM dh_key_types[] = {
 254     DH_IMEXPORTABLE_PUBLIC_KEY,
 255     DH_IMEXPORTABLE_PRIVATE_KEY,
 256     OSSL_PARAM_END
 257 };
 258 static const OSSL_PARAM *dh_types[] = {
 259     NULL,                        /* Index 0 = none of them */
 260     dh_parameter_types,          /* Index 1 = parameter types */
 261     dh_key_types,                /* Index 2 = key types */
 262     dh_all_types                 /* Index 3 = 1 + 2 */
 263 };
 264
 265 static const OSSL_PARAM *dh_imexport_types(int selection)
 266 {
 267     int type_select = 0;
 268
 269     if ((selection & OSSL_KEYMGMT_SELECT_ALL_PARAMETERS) != 0)
 270         type_select += 1;
 271     if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0)
 272         type_select += 2;
 273     return dh_types[type_select];
 274 }
 275
 276 static const OSSL_PARAM *dh_import_types(int selection)
 277 {
 278     return dh_imexport_types(selection);
 279 }
 280
 281 static const OSSL_PARAM *dh_export_types(int selection)
 282 {
 283     return dh_imexport_types(selection);
 284 }
 285
 286 static ossl_inline int dh_get_params(void *key, OSSL_PARAM params[])
 287 {
 288     DH *dh = key;
 289     OSSL_PARAM *p;
 290
 291     if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_BITS)) != NULL
 292         && !OSSL_PARAM_set_int(p, DH_bits(dh)))
 293         return 0;
 294     if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_SECURITY_BITS)) != NULL
 295         && !OSSL_PARAM_set_int(p, DH_security_bits(dh)))
 296         return 0;
 297     if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_MAX_SIZE)) != NULL
 298         && !OSSL_PARAM_set_int(p, DH_size(dh)))
 299         return 0;
 300     return ffc_params_todata(dh_get0_params(dh), NULL, params)
 301            && dh_key_todata(dh, NULL, params);
 302 }
 303
 304 static const OSSL_PARAM dh_params[] = {
 305     OSSL_PARAM_int(OSSL_PKEY_PARAM_BITS, NULL),
 306     OSSL_PARAM_int(OSSL_PKEY_PARAM_SECURITY_BITS, NULL),
 307     OSSL_PARAM_int(OSSL_PKEY_PARAM_MAX_SIZE, NULL),
 308     DH_IMEXPORTABLE_PARAMETERS,
 309     DH_IMEXPORTABLE_PUBLIC_KEY,
 310     DH_IMEXPORTABLE_PRIVATE_KEY,
 311     OSSL_PARAM_END
 312 };
 313
 314 static const OSSL_PARAM *dh_gettable_params(void)
 315 {
 316     return dh_params;
 317 }
 318
 319 static int dh_validate_public(DH *dh)
 320 {
 321     const BIGNUM *pub_key = NULL;
 322
 323     DH_get0_key(dh, &pub_key, NULL);
 324     return DH_check_pub_key_ex(dh, pub_key);
 325 }
 326
 327 static int dh_validate_private(DH *dh)
 328 {
 329     int status = 0;
 330     const BIGNUM *priv_key = NULL;
 331
 332     DH_get0_key(dh, NULL, &priv_key);
 333     return dh_check_priv_key(dh, priv_key, &status);;
 334 }
 335
 336 static int dh_validate(void *keydata, int selection)
 337 {
 338     DH *dh = keydata;
 339     int ok = 0;
 340
 341     if ((selection & DH_POSSIBLE_SELECTIONS) != 0)
 342         ok = 1;
 343
 344     if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0)
 345         ok = ok && DH_check_params_ex(dh);
 346
 347     if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
 348         ok = ok && dh_validate_public(dh);
 349
 350     if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)
 351         ok = ok && dh_validate_private(dh);
 352
 353     if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR)
 354             == OSSL_KEYMGMT_SELECT_KEYPAIR)
 355         ok = ok && dh_check_pairwise(dh);
 356     return ok;
 357 }
 358
 359 static void *dh_gen_init(void *provctx, int selection)
 360 {
 361     OPENSSL_CTX *libctx = PROV_LIBRARY_CONTEXT_OF(provctx);
 362     struct dh_gen_ctx *gctx = NULL;
 363
 364     if ((selection & (OSSL_KEYMGMT_SELECT_KEYPAIR
 365                       | OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS)) == 0)
 366         return NULL;
 367
 368     if ((gctx = OPENSSL_zalloc(sizeof(*gctx))) != NULL) {
 369         gctx->selection = selection;
 370         gctx->libctx = libctx;
 371         gctx->pbits = 2048;
 372         gctx->qbits = 224;
 373         gctx->md = NULL;
 374         gctx->gen_type = DH_PARAMGEN_TYPE_FIPS_186_4;
 375         gctx->gindex = -1;
 376         gctx->hindex = 0;
 377         gctx->pcounter = -1;
 378         gctx->generator = DH_GENERATOR_2;
 379     }
 380     return gctx;
 381 }
 382
 383 static int dh_gen_set_template(void *genctx, void *templ)
 384 {
 385     struct dh_gen_ctx *gctx = genctx;
 386     DH *dh = templ;
 387
 388     if (gctx == NULL || dh == NULL)
 389         return 0;
 390     gctx->ffc_params = dh_get0_params(dh);
 391     return 1;
 392 }
 393
 394 static int dh_set_gen_seed(struct dh_gen_ctx *gctx, unsigned char *seed,
 395                            size_t seedlen)
 396 {
 397     OPENSSL_clear_free(gctx->seed, gctx->seedlen);
 398     gctx->seed = NULL;
 399     gctx->seedlen = 0;
 400     if (seed != NULL && seedlen > 0) {
 401         gctx->seed = OPENSSL_memdup(seed, seedlen);
 402         if (gctx->seed == NULL)
 403             return 0;
 404         gctx->seedlen = seedlen;
 405     }
 406     return 1;
 407 }
 408
 409 static int dh_gen_set_params(void *genctx, const OSSL_PARAM params[])
 410 {
 411     struct dh_gen_ctx *gctx = genctx;
 412     const OSSL_PARAM *p;
 413
 414     if (gctx == NULL)
 415         return 0;
 416
 417     p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_TYPE);
 418     if (p != NULL) {
 419         if (p->data_type != OSSL_PARAM_UTF8_STRING
 420             || ((gctx->gen_type = dh_gen_type_name2id(p->data)) == -1)) {
 421             ERR_raise(ERR_LIB_PROV, ERR_R_PASSED_INVALID_ARGUMENT);
 422             return 0;
 423         }
 424     }
 425     p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_GROUP);
 426     if (p != NULL) {
 427         if (p->data_type != OSSL_PARAM_UTF8_STRING
 428            || ((gctx->group_nid = ffc_named_group_to_uid(p->data)) == NID_undef)) {
 429             ERR_raise(ERR_LIB_PROV, ERR_R_PASSED_INVALID_ARGUMENT);
 430             return 0;
 431         }
 432         gctx->gen_type = DH_PARAMGEN_TYPE_GROUP;
 433     }
 434     p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_GENERATOR);
 435     if (p != NULL
 436         && !OSSL_PARAM_get_int(p, &gctx->generator))
 437         return 0;
 438     p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_GINDEX);
 439     if (p != NULL
 440         && !OSSL_PARAM_get_int(p, &gctx->gindex))
 441         return 0;
 442     p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_PCOUNTER);
 443     if (p != NULL
 444         && !OSSL_PARAM_get_int(p, &gctx->pcounter))
 445         return 0;
 446     p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_H);
 447     if (p != NULL
 448         && !OSSL_PARAM_get_int(p, &gctx->hindex))
 449         return 0;
 450     p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_SEED);
 451     if (p != NULL
 452         && (p->data_type != OSSL_PARAM_OCTET_STRING
 453             || !dh_set_gen_seed(gctx, p->data, p->data_size)))
 454             return 0;
 455
 456     if ((p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_PBITS)) != NULL
 457         && !OSSL_PARAM_get_size_t(p, &gctx->pbits))
 458         return 0;
 459     if ((p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_QBITS)) != NULL
 460         && !OSSL_PARAM_get_size_t(p, &gctx->qbits))
 461         return 0;
 462     p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_DIGEST);
 463     if (p != NULL) {
 464         const OSSL_PARAM *p1;
 465         char mdprops[OSSL_MAX_PROPQUERY_SIZE] = { '\0' };
 466         char *str = mdprops;
 467
 468         if (p->data_type != OSSL_PARAM_UTF8_STRING)
 469             return 0;
 470         p1 = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_DIGEST_PROPS);
 471         if (p1 != NULL
 472             && !OSSL_PARAM_get_utf8_string(p1, &str, sizeof(mdprops)))
 473             return 0;
 474         EVP_MD_free(gctx->md);
 475         gctx->md = EVP_MD_fetch(gctx->libctx, p->data, mdprops);
 476         if (gctx->md == NULL)
 477             return 0;
 478     }
 479     return 1;
 480 }
 481
 482 static const OSSL_PARAM *dh_gen_settable_params(void *provctx)
 483 {
 484     static OSSL_PARAM settable[] = {
 485         OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_FFC_GROUP, NULL, 0),
 486         OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_FFC_TYPE, NULL, 0),
 487         OSSL_PARAM_size_t(OSSL_PKEY_PARAM_FFC_PBITS, NULL),
 488         OSSL_PARAM_size_t(OSSL_PKEY_PARAM_FFC_QBITS, NULL),
 489         OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_FFC_DIGEST, NULL, 0),
 490         OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_FFC_DIGEST_PROPS, NULL, 0),
 491         OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_GINDEX, NULL),
 492         OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_FFC_SEED, NULL, 0),
 493         OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_GENERATOR, NULL),
 494         OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_PCOUNTER, NULL),
 495         OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_H, NULL),
 496         OSSL_PARAM_END
 497     };
 498     return settable;
 499 }
 500
 501 static int dh_gencb(int p, int n, BN_GENCB *cb)
 502 {
 503     struct dh_gen_ctx *gctx = BN_GENCB_get_arg(cb);
 504     OSSL_PARAM params[] = { OSSL_PARAM_END, OSSL_PARAM_END, OSSL_PARAM_END };
 505
 506     params[0] = OSSL_PARAM_construct_int(OSSL_GEN_PARAM_POTENTIAL, &p);
 507     params[1] = OSSL_PARAM_construct_int(OSSL_GEN_PARAM_ITERATION, &n);
 508
 509     return gctx->cb(params, gctx->cbarg);
 510 }
 511
 512 static void *dh_gen(void *genctx, OSSL_CALLBACK *osslcb, void *cbarg)
 513 {
 514     int ret = 0;
 515     struct dh_gen_ctx *gctx = genctx;
 516     DH *dh = NULL;
 517     BN_GENCB *gencb = NULL;
 518     FFC_PARAMS *ffc;
 519
 520     if (gctx == NULL)
 521         return NULL;
 522
 523     /* For parameter generation - If there is a group name just create it */
 524     if (gctx->gen_type == DH_PARAMGEN_TYPE_GROUP) {
 525         /* Select a named group if there is not one already */
 526         if (gctx->group_nid == NID_undef)
 527             gctx->group_nid = dh_get_named_group_uid_from_size(gctx->pbits);
 528         if (gctx->group_nid == NID_undef)
 529             return NULL;
 530         dh = dh_new_by_nid_with_libctx(gctx->libctx, gctx->group_nid);
 531         if (dh == NULL)
 532             return NULL;
 533         ffc = dh_get0_params(dh);
 534     } else {
 535         dh = dh_new_with_libctx(gctx->libctx);
 536         if (dh == NULL)
 537             return NULL;
 538         ffc = dh_get0_params(dh);
 539
 540         /* Copy the template value if one was passed */
 541         if (gctx->ffc_params != NULL
 542             && !ffc_params_copy(ffc, gctx->ffc_params))
 543             goto end;
 544
 545         if (!ffc_params_set_seed(ffc, gctx->seed, gctx->seedlen))
 546             goto end;
 547         if (gctx->gindex != -1) {
 548             ffc_params_set_gindex(ffc, gctx->gindex);
 549             if (gctx->pcounter != -1)
 550                 ffc_params_set_pcounter(ffc, gctx->pcounter);
 551         } else if (gctx->hindex != 0) {
 552             ffc_params_set_h(ffc, gctx->hindex);
 553         }
 554         gctx->cb = osslcb;
 555         gctx->cbarg = cbarg;
 556         gencb = BN_GENCB_new();
 557         if (gencb != NULL)
 558             BN_GENCB_set(gencb, dh_gencb, genctx);
 559
 560         if ((gctx->selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0) {
 561             /*
 562              * NOTE: The old safe prime generator code is not used in fips mode,
 563              * (i.e internally it ignores the generator and chooses a named
 564              * group based on pbits.
 565              */
 566             if (gctx->gen_type == DH_PARAMGEN_TYPE_GENERATOR)
 567                 ret = DH_generate_parameters_ex(dh, gctx->pbits,
 568                                                 gctx->generator, gencb);
 569             else
 570                 ret = dh_generate_ffc_parameters(dh, gctx->gen_type, gctx->pbits,
 571                                                  gctx->qbits, gctx->md, gencb);
 572             if (ret <= 0)
 573                 goto end;
 574         }
 575     }
 576
 577     if ((gctx->selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0) {
 578         if (ffc->p == NULL || ffc->g == NULL)
 579             goto end;
 580         if (DH_generate_key(dh) <= 0)
 581             goto end;
 582     }
 583     ret = 1;
 584 end:
 585     if (ret <= 0) {
 586         DH_free(dh);
 587         dh = NULL;
 588     }
 589     BN_GENCB_free(gencb);
 590     return dh;
 591 }
 592
 593 static void dh_gen_cleanup(void *genctx)
 594 {
 595     struct dh_gen_ctx *gctx = genctx;
 596
 597     if (gctx == NULL)
 598         return;
 599
 600     OPENSSL_clear_free(gctx->seed, gctx->seedlen);
 601     EVP_MD_free(gctx->md);
 602     OPENSSL_free(gctx);
 603 }
 604
 605 const OSSL_DISPATCH dh_keymgmt_functions[] = {
 606     { OSSL_FUNC_KEYMGMT_NEW, (void (*)(void))dh_newdata },
 607     { OSSL_FUNC_KEYMGMT_GEN_INIT, (void (*)(void))dh_gen_init },
 608     { OSSL_FUNC_KEYMGMT_GEN_SET_TEMPLATE, (void (*)(void))dh_gen_set_template },
 609     { OSSL_FUNC_KEYMGMT_GEN_SET_PARAMS, (void (*)(void))dh_gen_set_params },
 610     { OSSL_FUNC_KEYMGMT_GEN_SETTABLE_PARAMS,
 611       (void (*)(void))dh_gen_settable_params },
 612     { OSSL_FUNC_KEYMGMT_GEN, (void (*)(void))dh_gen },
 613     { OSSL_FUNC_KEYMGMT_GEN_CLEANUP, (void (*)(void))dh_gen_cleanup },
 614     { OSSL_FUNC_KEYMGMT_FREE, (void (*)(void))dh_freedata },
 615     { OSSL_FUNC_KEYMGMT_GET_PARAMS, (void (*) (void))dh_get_params },
 616     { OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS, (void (*) (void))dh_gettable_params },
 617     { OSSL_FUNC_KEYMGMT_HAS, (void (*)(void))dh_has },
 618     { OSSL_FUNC_KEYMGMT_MATCH, (void (*)(void))dh_match },
 619     { OSSL_FUNC_KEYMGMT_VALIDATE, (void (*)(void))dh_validate },
 620     { OSSL_FUNC_KEYMGMT_IMPORT, (void (*)(void))dh_import },
 621     { OSSL_FUNC_KEYMGMT_IMPORT_TYPES, (void (*)(void))dh_import_types },
 622     { OSSL_FUNC_KEYMGMT_EXPORT, (void (*)(void))dh_export },
 623     { OSSL_FUNC_KEYMGMT_EXPORT_TYPES, (void (*)(void))dh_export_types },
 624     { 0, NULL }
 625 };