crypto/dh/dh_ameth.c

   1 /*
   2  * Copyright 2006-2022 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_ASN1_LIB);
 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_ASN1_LIB);
 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_ASN1_LIB);
 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_ASN1_LIB);
 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_ASN1_LIB);
 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
 210     if (dplen <= 0) {
 211         ERR_raise(ERR_LIB_DH, DH_R_BN_ERROR);
 212         goto err;
 213     }
 214
 215     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 216                          V_ASN1_SEQUENCE, params, dp, dplen)) {
 217         OPENSSL_clear_free(dp, dplen);
 218         goto err;
 219     }
 220     return 1;
 221
 222  err:
 223     ASN1_STRING_free(params);
 224     return 0;
 225 }
 226
 227 static int dh_param_decode(EVP_PKEY *pkey,
 228                            const unsigned char **pder, int derlen)
 229 {
 230     DH *dh;
 231
 232     if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL)
 233         return 0;
 234     dh->dirty_cnt++;
 235     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 236     return 1;
 237 }
 238
 239 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 240 {
 241     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 242 }
 243
 244 static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
 245 {
 246     int reason = ERR_R_BUF_LIB;
 247     const char *ktype = NULL;
 248     BIGNUM *priv_key, *pub_key;
 249
 250     if (ptype == 2)
 251         priv_key = x->priv_key;
 252     else
 253         priv_key = NULL;
 254
 255     if (ptype > 0)
 256         pub_key = x->pub_key;
 257     else
 258         pub_key = NULL;
 259
 260     if (x->params.p == NULL || (ptype == 2 && priv_key == NULL)
 261             || (ptype > 0 && pub_key == NULL)) {
 262         reason = ERR_R_PASSED_NULL_PARAMETER;
 263         goto err;
 264     }
 265
 266     if (ptype == 2)
 267         ktype = "DH Private-Key";
 268     else if (ptype == 1)
 269         ktype = "DH Public-Key";
 270     else
 271         ktype = "DH Parameters";
 272
 273     if (!BIO_indent(bp, indent, 128)
 274             || BIO_printf(bp, "%s: (%d bit)\n", ktype, DH_bits(x)) <= 0)
 275         goto err;
 276     indent += 4;
 277
 278     if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
 279         goto err;
 280     if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
 281         goto err;
 282
 283     if (!ossl_ffc_params_print(bp, &x->params, indent))
 284         goto err;
 285
 286     if (x->length != 0) {
 287         if (!BIO_indent(bp, indent, 128)
 288                 || BIO_printf(bp, "recommended-private-length: %d bits\n",
 289                               (int)x->length) <= 0)
 290             goto err;
 291     }
 292
 293     return 1;
 294
 295  err:
 296     ERR_raise(ERR_LIB_DH, reason);
 297     return 0;
 298 }
 299
 300 static int int_dh_size(const EVP_PKEY *pkey)
 301 {
 302     return DH_size(pkey->pkey.dh);
 303 }
 304
 305 static int dh_bits(const EVP_PKEY *pkey)
 306 {
 307     return DH_bits(pkey->pkey.dh);
 308 }
 309
 310 static int dh_security_bits(const EVP_PKEY *pkey)
 311 {
 312     return DH_security_bits(pkey->pkey.dh);
 313 }
 314
 315 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 316 {
 317     return ossl_ffc_params_cmp(&a->pkey.dh->params, &b->pkey.dh->params,
 318                                a->ameth != &ossl_dhx_asn1_meth);
 319 }
 320
 321 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 322 {
 323     if (is_x942 == -1)
 324         is_x942 = (from->params.q != NULL);
 325     if (!ossl_ffc_params_copy(&to->params, &from->params))
 326         return 0;
 327     if (!is_x942)
 328         to->length = from->length;
 329     to->dirty_cnt++;
 330     return 1;
 331 }
 332
 333 DH *DHparams_dup(const DH *dh)
 334 {
 335     DH *ret;
 336     ret = DH_new();
 337     if (ret == NULL)
 338         return NULL;
 339     if (!int_dh_param_copy(ret, dh, -1)) {
 340         DH_free(ret);
 341         return NULL;
 342     }
 343     return ret;
 344 }
 345
 346 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 347 {
 348     if (to->pkey.dh == NULL) {
 349         to->pkey.dh = DH_new();
 350         if (to->pkey.dh == NULL)
 351             return 0;
 352     }
 353     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 354                              from->ameth == &ossl_dhx_asn1_meth);
 355 }
 356
 357 static int dh_missing_parameters(const EVP_PKEY *a)
 358 {
 359     return a->pkey.dh == NULL
 360         || a->pkey.dh->params.p == NULL
 361         || a->pkey.dh->params.g == NULL;
 362 }
 363
 364 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 365 {
 366     if (dh_cmp_parameters(a, b) == 0)
 367         return 0;
 368     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 369         return 0;
 370     else
 371         return 1;
 372 }
 373
 374 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 375                           ASN1_PCTX *ctx)
 376 {
 377     return do_dh_print(bp, pkey->pkey.dh, indent, 0);
 378 }
 379
 380 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 381                            ASN1_PCTX *ctx)
 382 {
 383     return do_dh_print(bp, pkey->pkey.dh, indent, 1);
 384 }
 385
 386 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 387                             ASN1_PCTX *ctx)
 388 {
 389     return do_dh_print(bp, pkey->pkey.dh, indent, 2);
 390 }
 391
 392 int DHparams_print(BIO *bp, const DH *x)
 393 {
 394     return do_dh_print(bp, x, 4, 0);
 395 }
 396
 397 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 398 {
 399     DH *dh;
 400     switch (op) {
 401     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
 402         /* We should only be here if we have a legacy key */
 403         if (!ossl_assert(evp_pkey_is_legacy(pkey)))
 404             return 0;
 405         dh = (DH *) evp_pkey_get0_DH_int(pkey);
 406         if (dh == NULL)
 407             return 0;
 408         return ossl_dh_buf2key(dh, arg2, arg1);
 409     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
 410         dh = (DH *) EVP_PKEY_get0_DH(pkey);
 411         if (dh == NULL)
 412             return 0;
 413         return ossl_dh_key2buf(dh, arg2, 0, 1);
 414     default:
 415         return -2;
 416     }
 417 }
 418
 419 static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 420 {
 421     switch (op) {
 422     default:
 423         return -2;
 424     }
 425
 426 }
 427
 428 static int dh_pkey_public_check(const EVP_PKEY *pkey)
 429 {
 430     DH *dh = pkey->pkey.dh;
 431
 432     if (dh->pub_key == NULL) {
 433         ERR_raise(ERR_LIB_DH, DH_R_MISSING_PUBKEY);
 434         return 0;
 435     }
 436
 437     return DH_check_pub_key_ex(dh, dh->pub_key);
 438 }
 439
 440 static int dh_pkey_param_check(const EVP_PKEY *pkey)
 441 {
 442     DH *dh = pkey->pkey.dh;
 443
 444     return DH_check_ex(dh);
 445 }
 446
 447 static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
 448 {
 449     return pkey->pkey.dh->dirty_cnt;
 450 }
 451
 452 static int dh_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
 453                              OSSL_FUNC_keymgmt_import_fn *importer,
 454                              OSSL_LIB_CTX *libctx, const char *propq)
 455 {
 456     DH *dh = from->pkey.dh;
 457     OSSL_PARAM_BLD *tmpl;
 458     const BIGNUM *p = DH_get0_p(dh), *g = DH_get0_g(dh), *q = DH_get0_q(dh);
 459     long l = DH_get_length(dh);
 460     const BIGNUM *pub_key = DH_get0_pub_key(dh);
 461     const BIGNUM *priv_key = DH_get0_priv_key(dh);
 462     OSSL_PARAM *params = NULL;
 463     int selection = 0;
 464     int rv = 0;
 465
 466     if (p == NULL || g == NULL)
 467         return 0;
 468
 469     tmpl = OSSL_PARAM_BLD_new();
 470     if (tmpl == NULL)
 471         return 0;
 472     if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_P, p)
 473         || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_G, g))
 474         goto err;
 475     if (q != NULL) {
 476         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_Q, q))
 477             goto err;
 478     }
 479     selection |= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
 480     if (l > 0) {
 481         if (!OSSL_PARAM_BLD_push_long(tmpl, OSSL_PKEY_PARAM_DH_PRIV_LEN, l))
 482             goto err;
 483         selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
 484     }
 485     if (pub_key != NULL) {
 486         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PUB_KEY, pub_key))
 487             goto err;
 488         selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
 489     }
 490     if (priv_key != NULL) {
 491         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PRIV_KEY,
 492                                     priv_key))
 493             goto err;
 494         selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
 495     }
 496
 497     if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
 498         goto err;
 499
 500     /* We export, the provider imports */
 501     rv = importer(to_keydata, selection, params);
 502
 503     OSSL_PARAM_free(params);
 504 err:
 505     OSSL_PARAM_BLD_free(tmpl);
 506     return rv;
 507 }
 508
 509 static int dh_pkey_import_from_type(const OSSL_PARAM params[], void *vpctx,
 510                                     int type)
 511 {
 512     EVP_PKEY_CTX *pctx = vpctx;
 513     EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 514     DH *dh = ossl_dh_new_ex(pctx->libctx);
 515
 516     if (dh == NULL) {
 517         ERR_raise(ERR_LIB_DH, ERR_R_DH_LIB);
 518         return 0;
 519     }
 520     DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
 521     DH_set_flags(dh, type == EVP_PKEY_DH ? DH_FLAG_TYPE_DH : DH_FLAG_TYPE_DHX);
 522
 523     if (!ossl_dh_params_fromdata(dh, params)
 524         || !ossl_dh_key_fromdata(dh, params, 1)
 525         || !EVP_PKEY_assign(pkey, type, dh)) {
 526         DH_free(dh);
 527         return 0;
 528     }
 529     return 1;
 530 }
 531
 532 static int dh_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 533 {
 534     return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DH);
 535 }
 536
 537 static int dhx_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 538 {
 539     return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DHX);
 540 }
 541
 542 static int dh_pkey_copy(EVP_PKEY *to, EVP_PKEY *from)
 543 {
 544     DH *dh = from->pkey.dh;
 545     DH *dupkey = NULL;
 546     int ret;
 547
 548     if (dh != NULL) {
 549         dupkey = ossl_dh_dup(dh, OSSL_KEYMGMT_SELECT_ALL);
 550         if (dupkey == NULL)
 551             return 0;
 552     }
 553
 554     ret = EVP_PKEY_assign(to, from->type, dupkey);
 555     if (!ret)
 556         DH_free(dupkey);
 557     return ret;
 558 }
 559
 560 const EVP_PKEY_ASN1_METHOD ossl_dh_asn1_meth = {
 561     EVP_PKEY_DH,
 562     EVP_PKEY_DH,
 563     0,
 564
 565     "DH",
 566     "OpenSSL PKCS#3 DH method",
 567
 568     dh_pub_decode,
 569     dh_pub_encode,
 570     dh_pub_cmp,
 571     dh_public_print,
 572
 573     dh_priv_decode,
 574     dh_priv_encode,
 575     dh_private_print,
 576
 577     int_dh_size,
 578     dh_bits,
 579     dh_security_bits,
 580
 581     dh_param_decode,
 582     dh_param_encode,
 583     dh_missing_parameters,
 584     dh_copy_parameters,
 585     dh_cmp_parameters,
 586     dh_param_print,
 587     0,
 588
 589     int_dh_free,
 590     dh_pkey_ctrl,
 591
 592     0, 0, 0, 0, 0,
 593
 594     0,
 595     dh_pkey_public_check,
 596     dh_pkey_param_check,
 597
 598     0, 0, 0, 0,
 599
 600     dh_pkey_dirty_cnt,
 601     dh_pkey_export_to,
 602     dh_pkey_import_from,
 603     dh_pkey_copy
 604 };
 605
 606 const EVP_PKEY_ASN1_METHOD ossl_dhx_asn1_meth = {
 607     EVP_PKEY_DHX,
 608     EVP_PKEY_DHX,
 609     0,
 610
 611     "X9.42 DH",
 612     "OpenSSL X9.42 DH method",
 613
 614     dh_pub_decode,
 615     dh_pub_encode,
 616     dh_pub_cmp,
 617     dh_public_print,
 618
 619     dh_priv_decode,
 620     dh_priv_encode,
 621     dh_private_print,
 622
 623     int_dh_size,
 624     dh_bits,
 625     dh_security_bits,
 626
 627     dh_param_decode,
 628     dh_param_encode,
 629     dh_missing_parameters,
 630     dh_copy_parameters,
 631     dh_cmp_parameters,
 632     dh_param_print,
 633     0,
 634
 635     int_dh_free,
 636     dhx_pkey_ctrl,
 637
 638     0, 0, 0, 0, 0,
 639
 640     0,
 641     dh_pkey_public_check,
 642     dh_pkey_param_check,
 643     0, 0, 0, 0,
 644     dh_pkey_dirty_cnt,
 645     dh_pkey_export_to,
 646     dhx_pkey_import_from,
 647     dh_pkey_copy
 648 };