crypto/dh/dh_ameth.c

   1 /*
   2  * Copyright 2006-2021 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 <stdio.h>
  17 #include <openssl/x509.h>
  18 #include <openssl/asn1.h>
  19 #include <openssl/bn.h>
  20 #include <openssl/core_names.h>
  21 #include <openssl/param_build.h>
  22 #include "internal/ffc.h"
  23 #include "internal/cryptlib.h"
  24 #include "crypto/asn1.h"
  25 #include "crypto/dh.h"
  26 #include "crypto/evp.h"
  27 #include "dh_local.h"
  28
  29 /*
  30  * i2d/d2i like DH parameter functions which use the appropriate routine for
  31  * PKCS#3 DH or X9.42 DH.
  32  */
  33
  34 static DH *d2i_dhp(const EVP_PKEY *pkey, const unsigned char **pp,
  35                    long length)
  36 {
  37     DH *dh = NULL;
  38     int is_dhx = (pkey->ameth == &ossl_dhx_asn1_meth);
  39
  40     if (is_dhx)
  41         dh = d2i_DHxparams(NULL, pp, length);
  42     else
  43         dh = d2i_DHparams(NULL, pp, length);
  44
  45     return dh;
  46 }
  47
  48 static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
  49 {
  50     if (pkey->ameth == &ossl_dhx_asn1_meth)
  51         return i2d_DHxparams(a, pp);
  52     return i2d_DHparams(a, pp);
  53 }
  54
  55 static void int_dh_free(EVP_PKEY *pkey)
  56 {
  57     DH_free(pkey->pkey.dh);
  58 }
  59
  60 static int dh_pub_decode(EVP_PKEY *pkey, const X509_PUBKEY *pubkey)
  61 {
  62     const unsigned char *p, *pm;
  63     int pklen, pmlen;
  64     int ptype;
  65     const void *pval;
  66     const ASN1_STRING *pstr;
  67     X509_ALGOR *palg;
  68     ASN1_INTEGER *public_key = NULL;
  69
  70     DH *dh = NULL;
  71
  72     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
  73         return 0;
  74     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
  75
  76     if (ptype != V_ASN1_SEQUENCE) {
  77         ERR_raise(ERR_LIB_DH, DH_R_PARAMETER_ENCODING_ERROR);
  78         goto err;
  79     }
  80
  81     pstr = pval;
  82     pm = pstr->data;
  83     pmlen = pstr->length;
  84
  85     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL) {
  86         ERR_raise(ERR_LIB_DH, DH_R_DECODE_ERROR);
  87         goto err;
  88     }
  89
  90     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
  91         ERR_raise(ERR_LIB_DH, DH_R_DECODE_ERROR);
  92         goto err;
  93     }
  94
  95     /* We have parameters now set public key */
  96     if ((dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
  97         ERR_raise(ERR_LIB_DH, DH_R_BN_DECODE_ERROR);
  98         goto err;
  99     }
 100
 101     ASN1_INTEGER_free(public_key);
 102     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 103     return 1;
 104
 105  err:
 106     ASN1_INTEGER_free(public_key);
 107     DH_free(dh);
 108     return 0;
 109 }
 110
 111 static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 112 {
 113     DH *dh;
 114     int ptype;
 115     unsigned char *penc = NULL;
 116     int penclen;
 117     ASN1_STRING *str;
 118     ASN1_INTEGER *pub_key = NULL;
 119
 120     dh = pkey->pkey.dh;
 121
 122     str = ASN1_STRING_new();
 123     if (str == NULL) {
 124         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
 125         goto err;
 126     }
 127     str->length = i2d_dhp(pkey, dh, &str->data);
 128     if (str->length <= 0) {
 129         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
 130         goto err;
 131     }
 132     ptype = V_ASN1_SEQUENCE;
 133
 134     pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
 135     if (pub_key == NULL)
 136         goto err;
 137
 138     penclen = i2d_ASN1_INTEGER(pub_key, &penc);
 139
 140     ASN1_INTEGER_free(pub_key);
 141
 142     if (penclen <= 0) {
 143         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
 144         goto err;
 145     }
 146
 147     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
 148                                ptype, str, penc, penclen))
 149         return 1;
 150
 151  err:
 152     OPENSSL_free(penc);
 153     ASN1_STRING_free(str);
 154
 155     return 0;
 156 }
 157
 158 /*
 159  * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
 160  * the AlgorithmIdentifier contains the parameters, the private key is
 161  * explicitly included and the pubkey must be recalculated.
 162  */
 163
 164 static int dh_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 165 {
 166     int ret = 0;
 167     DH *dh = ossl_dh_key_from_pkcs8(p8, NULL, NULL);
 168
 169     if (dh != NULL) {
 170         ret = 1;
 171         EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 172     }
 173
 174     return ret;
 175 }
 176
 177 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 178 {
 179     ASN1_STRING *params = NULL;
 180     ASN1_INTEGER *prkey = NULL;
 181     unsigned char *dp = NULL;
 182     int dplen;
 183
 184     params = ASN1_STRING_new();
 185
 186     if (params == NULL) {
 187         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
 188         goto err;
 189     }
 190
 191     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 192     if (params->length <= 0) {
 193         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
 194         goto err;
 195     }
 196     params->type = V_ASN1_SEQUENCE;
 197
 198     /* Get private key into integer */
 199     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 200
 201     if (prkey == NULL) {
 202         ERR_raise(ERR_LIB_DH, DH_R_BN_ERROR);
 203         goto err;
 204     }
 205
 206     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 207
 208     ASN1_STRING_clear_free(prkey);
 209     prkey = NULL;
 210
 211     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 212                          V_ASN1_SEQUENCE, params, dp, dplen))
 213         goto err;
 214
 215     return 1;
 216
 217  err:
 218     OPENSSL_free(dp);
 219     ASN1_STRING_free(params);
 220     ASN1_STRING_clear_free(prkey);
 221     return 0;
 222 }
 223
 224 static int dh_param_decode(EVP_PKEY *pkey,
 225                            const unsigned char **pder, int derlen)
 226 {
 227     DH *dh;
 228
 229     if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL)
 230         return 0;
 231     dh->dirty_cnt++;
 232     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 233     return 1;
 234 }
 235
 236 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 237 {
 238     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 239 }
 240
 241 static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
 242 {
 243     int reason = ERR_R_BUF_LIB;
 244     const char *ktype = NULL;
 245     BIGNUM *priv_key, *pub_key;
 246
 247     if (ptype == 2)
 248         priv_key = x->priv_key;
 249     else
 250         priv_key = NULL;
 251
 252     if (ptype > 0)
 253         pub_key = x->pub_key;
 254     else
 255         pub_key = NULL;
 256
 257     if (x->params.p == NULL || (ptype == 2 && priv_key == NULL)
 258             || (ptype > 0 && pub_key == NULL)) {
 259         reason = ERR_R_PASSED_NULL_PARAMETER;
 260         goto err;
 261     }
 262
 263     if (ptype == 2)
 264         ktype = "DH Private-Key";
 265     else if (ptype == 1)
 266         ktype = "DH Public-Key";
 267     else
 268         ktype = "DH Parameters";
 269
 270     if (!BIO_indent(bp, indent, 128)
 271             || BIO_printf(bp, "%s: (%d bit)\n", ktype, DH_bits(x)) <= 0)
 272         goto err;
 273     indent += 4;
 274
 275     if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
 276         goto err;
 277     if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
 278         goto err;
 279
 280     if (!ossl_ffc_params_print(bp, &x->params, indent))
 281         goto err;
 282
 283     if (x->length != 0) {
 284         if (!BIO_indent(bp, indent, 128)
 285                 || BIO_printf(bp, "recommended-private-length: %d bits\n",
 286                               (int)x->length) <= 0)
 287             goto err;
 288     }
 289
 290     return 1;
 291
 292  err:
 293     ERR_raise(ERR_LIB_DH, reason);
 294     return 0;
 295 }
 296
 297 static int int_dh_size(const EVP_PKEY *pkey)
 298 {
 299     return DH_size(pkey->pkey.dh);
 300 }
 301
 302 static int dh_bits(const EVP_PKEY *pkey)
 303 {
 304     return DH_bits(pkey->pkey.dh);
 305 }
 306
 307 static int dh_security_bits(const EVP_PKEY *pkey)
 308 {
 309     return DH_security_bits(pkey->pkey.dh);
 310 }
 311
 312 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 313 {
 314     return ossl_ffc_params_cmp(&a->pkey.dh->params, &a->pkey.dh->params,
 315                                a->ameth != &ossl_dhx_asn1_meth);
 316 }
 317
 318 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 319 {
 320     if (is_x942 == -1)
 321         is_x942 = (from->params.q != NULL);
 322     if (!ossl_ffc_params_copy(&to->params, &from->params))
 323         return 0;
 324     if (!is_x942)
 325         to->length = from->length;
 326     to->dirty_cnt++;
 327     return 1;
 328 }
 329
 330 DH *DHparams_dup(const DH *dh)
 331 {
 332     DH *ret;
 333     ret = DH_new();
 334     if (ret == NULL)
 335         return NULL;
 336     if (!int_dh_param_copy(ret, dh, -1)) {
 337         DH_free(ret);
 338         return NULL;
 339     }
 340     return ret;
 341 }
 342
 343 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 344 {
 345     if (to->pkey.dh == NULL) {
 346         to->pkey.dh = DH_new();
 347         if (to->pkey.dh == NULL)
 348             return 0;
 349     }
 350     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 351                              from->ameth == &ossl_dhx_asn1_meth);
 352 }
 353
 354 static int dh_missing_parameters(const EVP_PKEY *a)
 355 {
 356     return a->pkey.dh == NULL
 357         || a->pkey.dh->params.p == NULL
 358         || a->pkey.dh->params.g == NULL;
 359 }
 360
 361 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 362 {
 363     if (dh_cmp_parameters(a, b) == 0)
 364         return 0;
 365     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 366         return 0;
 367     else
 368         return 1;
 369 }
 370
 371 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 372                           ASN1_PCTX *ctx)
 373 {
 374     return do_dh_print(bp, pkey->pkey.dh, indent, 0);
 375 }
 376
 377 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 378                            ASN1_PCTX *ctx)
 379 {
 380     return do_dh_print(bp, pkey->pkey.dh, indent, 1);
 381 }
 382
 383 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 384                             ASN1_PCTX *ctx)
 385 {
 386     return do_dh_print(bp, pkey->pkey.dh, indent, 2);
 387 }
 388
 389 int DHparams_print(BIO *bp, const DH *x)
 390 {
 391     return do_dh_print(bp, x, 4, 0);
 392 }
 393
 394 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 395 {
 396     switch (op) {
 397     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
 398         /* We should only be here if we have a legacy key */
 399         if (!ossl_assert(evp_pkey_is_legacy(pkey)))
 400             return 0;
 401         return ossl_dh_buf2key(evp_pkey_get0_DH_int(pkey), arg2, arg1);
 402     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
 403         return ossl_dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2, 0, 1);
 404     default:
 405         return -2;
 406     }
 407 }
 408
 409 static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 410 {
 411     switch (op) {
 412     default:
 413         return -2;
 414     }
 415
 416 }
 417
 418 static int dh_pkey_public_check(const EVP_PKEY *pkey)
 419 {
 420     DH *dh = pkey->pkey.dh;
 421
 422     if (dh->pub_key == NULL) {
 423         ERR_raise(ERR_LIB_DH, DH_R_MISSING_PUBKEY);
 424         return 0;
 425     }
 426
 427     return DH_check_pub_key_ex(dh, dh->pub_key);
 428 }
 429
 430 static int dh_pkey_param_check(const EVP_PKEY *pkey)
 431 {
 432     DH *dh = pkey->pkey.dh;
 433
 434     return DH_check_ex(dh);
 435 }
 436
 437 static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
 438 {
 439     return pkey->pkey.dh->dirty_cnt;
 440 }
 441
 442 static int dh_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
 443                              EVP_KEYMGMT *to_keymgmt, OSSL_LIB_CTX *libctx,
 444                              const char *propq)
 445 {
 446     DH *dh = from->pkey.dh;
 447     OSSL_PARAM_BLD *tmpl;
 448     const BIGNUM *p = DH_get0_p(dh), *g = DH_get0_g(dh), *q = DH_get0_q(dh);
 449     long l = DH_get_length(dh);
 450     const BIGNUM *pub_key = DH_get0_pub_key(dh);
 451     const BIGNUM *priv_key = DH_get0_priv_key(dh);
 452     OSSL_PARAM *params = NULL;
 453     int selection = 0;
 454     int rv = 0;
 455
 456     /*
 457      * If the DH method is foreign, then we can't be sure of anything, and
 458      * can therefore not export or pretend to export.
 459      */
 460     if (ossl_dh_get_method(dh) != DH_OpenSSL())
 461         return 0;
 462
 463     if (p == NULL || g == NULL)
 464         return 0;
 465
 466     tmpl = OSSL_PARAM_BLD_new();
 467     if (tmpl == NULL)
 468         return 0;
 469     if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_P, p)
 470         || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_G, g))
 471         goto err;
 472     if (q != NULL) {
 473         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_Q, q))
 474             goto err;
 475     }
 476     selection |= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
 477     if (l > 0) {
 478         if (!OSSL_PARAM_BLD_push_long(tmpl, OSSL_PKEY_PARAM_DH_PRIV_LEN, l))
 479             goto err;
 480         selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
 481     }
 482     if (pub_key != NULL) {
 483         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PUB_KEY, pub_key))
 484             goto err;
 485         selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
 486     }
 487     if (priv_key != NULL) {
 488         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PRIV_KEY,
 489                                     priv_key))
 490             goto err;
 491         selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
 492     }
 493
 494     if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
 495         goto err;
 496
 497     /* We export, the provider imports */
 498     rv = evp_keymgmt_import(to_keymgmt, to_keydata, selection, params);
 499
 500     OSSL_PARAM_BLD_free_params(params);
 501 err:
 502     OSSL_PARAM_BLD_free(tmpl);
 503     return rv;
 504 }
 505
 506 static int dh_pkey_import_from_type(const OSSL_PARAM params[], void *vpctx,
 507                                     int type)
 508 {
 509     EVP_PKEY_CTX *pctx = vpctx;
 510     EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 511     DH *dh = ossl_dh_new_ex(pctx->libctx);
 512
 513     if (dh == NULL) {
 514         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
 515         return 0;
 516     }
 517     DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
 518     DH_set_flags(dh, type == EVP_PKEY_DH ? DH_FLAG_TYPE_DH : DH_FLAG_TYPE_DHX);
 519
 520     if (!ossl_dh_params_fromdata(dh, params)
 521         || !ossl_dh_key_fromdata(dh, params)
 522         || !EVP_PKEY_assign(pkey, type, dh)) {
 523         DH_free(dh);
 524         return 0;
 525     }
 526     return 1;
 527 }
 528
 529 static int dh_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 530 {
 531     return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DH);
 532 }
 533
 534 static int dhx_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 535 {
 536     return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DHX);
 537 }
 538
 539 static ossl_inline int dh_bn_dup_check(BIGNUM **out, const BIGNUM *f)
 540 {
 541     if (f != NULL && (*out = BN_dup(f)) == NULL)
 542         return 0;
 543     return 1;
 544 }
 545
 546 static DH *dh_dup(const DH *dh)
 547 {
 548     DH *dupkey = NULL;
 549
 550     /* Do not try to duplicate foreign DH keys */
 551     if (ossl_dh_get_method(dh) != DH_OpenSSL())
 552         return NULL;
 553
 554     if ((dupkey = ossl_dh_new_ex(dh->libctx)) == NULL)
 555         return NULL;
 556
 557     dupkey->length = DH_get_length(dh);
 558     if (!ossl_ffc_params_copy(&dupkey->params, &dh->params))
 559         goto err;
 560
 561     dupkey->flags = dh->flags;
 562
 563     if (!dh_bn_dup_check(&dupkey->pub_key, dh->pub_key))
 564         goto err;
 565     if (!dh_bn_dup_check(&dupkey->priv_key, dh->priv_key))
 566         goto err;
 567
 568     if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_DH,
 569                             &dupkey->ex_data, &dh->ex_data))
 570         goto err;
 571
 572     return dupkey;
 573
 574  err:
 575     DH_free(dupkey);
 576     return NULL;
 577 }
 578
 579 static int dh_pkey_copy(EVP_PKEY *to, EVP_PKEY *from)
 580 {
 581     DH *dh = from->pkey.dh;
 582     DH *dupkey = NULL;
 583     int ret;
 584
 585     if (dh != NULL) {
 586         dupkey = dh_dup(dh);
 587         if (dupkey == NULL)
 588             return 0;
 589     }
 590
 591     ret = EVP_PKEY_assign(to, from->type, dupkey);
 592     if (!ret)
 593         DH_free(dupkey);
 594     return ret;
 595 }
 596
 597 const EVP_PKEY_ASN1_METHOD ossl_dh_asn1_meth = {
 598     EVP_PKEY_DH,
 599     EVP_PKEY_DH,
 600     0,
 601
 602     "DH",
 603     "OpenSSL PKCS#3 DH method",
 604
 605     dh_pub_decode,
 606     dh_pub_encode,
 607     dh_pub_cmp,
 608     dh_public_print,
 609
 610     dh_priv_decode,
 611     dh_priv_encode,
 612     dh_private_print,
 613
 614     int_dh_size,
 615     dh_bits,
 616     dh_security_bits,
 617
 618     dh_param_decode,
 619     dh_param_encode,
 620     dh_missing_parameters,
 621     dh_copy_parameters,
 622     dh_cmp_parameters,
 623     dh_param_print,
 624     0,
 625
 626     int_dh_free,
 627     dh_pkey_ctrl,
 628
 629     0, 0, 0, 0, 0,
 630
 631     0,
 632     dh_pkey_public_check,
 633     dh_pkey_param_check,
 634
 635     0, 0, 0, 0,
 636
 637     dh_pkey_dirty_cnt,
 638     dh_pkey_export_to,
 639     dh_pkey_import_from,
 640     dh_pkey_copy
 641 };
 642
 643 const EVP_PKEY_ASN1_METHOD ossl_dhx_asn1_meth = {
 644     EVP_PKEY_DHX,
 645     EVP_PKEY_DHX,
 646     0,
 647
 648     "X9.42 DH",
 649     "OpenSSL X9.42 DH method",
 650
 651     dh_pub_decode,
 652     dh_pub_encode,
 653     dh_pub_cmp,
 654     dh_public_print,
 655
 656     dh_priv_decode,
 657     dh_priv_encode,
 658     dh_private_print,
 659
 660     int_dh_size,
 661     dh_bits,
 662     dh_security_bits,
 663
 664     dh_param_decode,
 665     dh_param_encode,
 666     dh_missing_parameters,
 667     dh_copy_parameters,
 668     dh_cmp_parameters,
 669     dh_param_print,
 670     0,
 671
 672     int_dh_free,
 673     dhx_pkey_ctrl,
 674
 675     0, 0, 0, 0, 0,
 676
 677     0,
 678     dh_pkey_public_check,
 679     dh_pkey_param_check,
 680     0, 0, 0, 0,
 681     dh_pkey_dirty_cnt,
 682     dh_pkey_export_to,
 683     dhx_pkey_import_from,
 684     dh_pkey_copy
 685 };