crypto/dh/dh_ameth.c

   1 /*
   2  * Copyright 2006-2020 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 <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 == &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 == &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         DHerr(DH_F_DH_PUB_DECODE, 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         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  87         goto err;
  88     }
  89
  90     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
  91         DHerr(DH_F_DH_PUB_DECODE, 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         DHerr(DH_F_DH_PUB_DECODE, 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         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 125         goto err;
 126     }
 127     str->length = i2d_dhp(pkey, dh, &str->data);
 128     if (str->length <= 0) {
 129         DHerr(DH_F_DH_PUB_ENCODE, 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         DHerr(DH_F_DH_PUB_ENCODE, 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     const unsigned char *p, *pm;
 167     int pklen, pmlen;
 168     int ptype;
 169     const void *pval;
 170     const ASN1_STRING *pstr;
 171     const X509_ALGOR *palg;
 172     ASN1_INTEGER *privkey = NULL;
 173     DH *dh = NULL;
 174
 175     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 176         return 0;
 177
 178     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 179
 180     if (ptype != V_ASN1_SEQUENCE)
 181         goto decerr;
 182     if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
 183         goto decerr;
 184
 185     pstr = pval;
 186     pm = pstr->data;
 187     pmlen = pstr->length;
 188     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
 189         goto decerr;
 190
 191     /* We have parameters now set private key */
 192     if ((dh->priv_key = BN_secure_new()) == NULL
 193         || !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
 194         DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
 195         goto dherr;
 196     }
 197     /* Calculate public key, increments dirty_cnt */
 198     if (!DH_generate_key(dh))
 199         goto dherr;
 200
 201     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 202
 203     ASN1_STRING_clear_free(privkey);
 204
 205     return 1;
 206
 207  decerr:
 208     DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
 209  dherr:
 210     DH_free(dh);
 211     ASN1_STRING_clear_free(privkey);
 212     return 0;
 213 }
 214
 215 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 216 {
 217     ASN1_STRING *params = NULL;
 218     ASN1_INTEGER *prkey = NULL;
 219     unsigned char *dp = NULL;
 220     int dplen;
 221
 222     params = ASN1_STRING_new();
 223
 224     if (params == NULL) {
 225         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 226         goto err;
 227     }
 228
 229     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 230     if (params->length <= 0) {
 231         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 232         goto err;
 233     }
 234     params->type = V_ASN1_SEQUENCE;
 235
 236     /* Get private key into integer */
 237     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 238
 239     if (prkey == NULL) {
 240         DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
 241         goto err;
 242     }
 243
 244     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 245
 246     ASN1_STRING_clear_free(prkey);
 247     prkey = NULL;
 248
 249     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 250                          V_ASN1_SEQUENCE, params, dp, dplen))
 251         goto err;
 252
 253     return 1;
 254
 255  err:
 256     OPENSSL_free(dp);
 257     ASN1_STRING_free(params);
 258     ASN1_STRING_clear_free(prkey);
 259     return 0;
 260 }
 261
 262 static int dh_param_decode(EVP_PKEY *pkey,
 263                            const unsigned char **pder, int derlen)
 264 {
 265     DH *dh;
 266
 267     if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL)
 268         return 0;
 269     dh->dirty_cnt++;
 270     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 271     return 1;
 272 }
 273
 274 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 275 {
 276     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 277 }
 278
 279 static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
 280 {
 281     int reason = ERR_R_BUF_LIB;
 282     const char *ktype = NULL;
 283     BIGNUM *priv_key, *pub_key;
 284
 285     if (ptype == 2)
 286         priv_key = x->priv_key;
 287     else
 288         priv_key = NULL;
 289
 290     if (ptype > 0)
 291         pub_key = x->pub_key;
 292     else
 293         pub_key = NULL;
 294
 295     if (x->params.p == NULL || (ptype == 2 && priv_key == NULL)
 296             || (ptype > 0 && pub_key == NULL)) {
 297         reason = ERR_R_PASSED_NULL_PARAMETER;
 298         goto err;
 299     }
 300
 301     if (ptype == 2)
 302         ktype = "DH Private-Key";
 303     else if (ptype == 1)
 304         ktype = "DH Public-Key";
 305     else
 306         ktype = "DH Parameters";
 307
 308     if (!BIO_indent(bp, indent, 128)
 309             || BIO_printf(bp, "%s: (%d bit)\n", ktype, DH_bits(x)) <= 0)
 310         goto err;
 311     indent += 4;
 312
 313     if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
 314         goto err;
 315     if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
 316         goto err;
 317
 318     if (!ossl_ffc_params_print(bp, &x->params, indent))
 319         goto err;
 320
 321     if (x->length != 0) {
 322         if (!BIO_indent(bp, indent, 128)
 323                 || BIO_printf(bp, "recommended-private-length: %d bits\n",
 324                               (int)x->length) <= 0)
 325             goto err;
 326     }
 327
 328     return 1;
 329
 330  err:
 331     DHerr(DH_F_DO_DH_PRINT, reason);
 332     return 0;
 333 }
 334
 335 static int int_dh_size(const EVP_PKEY *pkey)
 336 {
 337     return DH_size(pkey->pkey.dh);
 338 }
 339
 340 static int dh_bits(const EVP_PKEY *pkey)
 341 {
 342     return DH_bits(pkey->pkey.dh);
 343 }
 344
 345 static int dh_security_bits(const EVP_PKEY *pkey)
 346 {
 347     return DH_security_bits(pkey->pkey.dh);
 348 }
 349
 350 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 351 {
 352     return ossl_ffc_params_cmp(&a->pkey.dh->params, &a->pkey.dh->params,
 353                                a->ameth != &dhx_asn1_meth);
 354 }
 355
 356 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 357 {
 358     if (is_x942 == -1)
 359         is_x942 = (from->params.q != NULL);
 360     if (!ossl_ffc_params_copy(&to->params, &from->params))
 361         return 0;
 362     if (!is_x942)
 363         to->length = from->length;
 364     to->dirty_cnt++;
 365     return 1;
 366 }
 367
 368 DH *DHparams_dup(const DH *dh)
 369 {
 370     DH *ret;
 371     ret = DH_new();
 372     if (ret == NULL)
 373         return NULL;
 374     if (!int_dh_param_copy(ret, dh, -1)) {
 375         DH_free(ret);
 376         return NULL;
 377     }
 378     return ret;
 379 }
 380
 381 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 382 {
 383     if (to->pkey.dh == NULL) {
 384         to->pkey.dh = DH_new();
 385         if (to->pkey.dh == NULL)
 386             return 0;
 387     }
 388     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 389                              from->ameth == &dhx_asn1_meth);
 390 }
 391
 392 static int dh_missing_parameters(const EVP_PKEY *a)
 393 {
 394     return a->pkey.dh == NULL
 395         || a->pkey.dh->params.p == NULL
 396         || a->pkey.dh->params.g == NULL;
 397 }
 398
 399 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 400 {
 401     if (dh_cmp_parameters(a, b) == 0)
 402         return 0;
 403     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 404         return 0;
 405     else
 406         return 1;
 407 }
 408
 409 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 410                           ASN1_PCTX *ctx)
 411 {
 412     return do_dh_print(bp, pkey->pkey.dh, indent, 0);
 413 }
 414
 415 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 416                            ASN1_PCTX *ctx)
 417 {
 418     return do_dh_print(bp, pkey->pkey.dh, indent, 1);
 419 }
 420
 421 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 422                             ASN1_PCTX *ctx)
 423 {
 424     return do_dh_print(bp, pkey->pkey.dh, indent, 2);
 425 }
 426
 427 int DHparams_print(BIO *bp, const DH *x)
 428 {
 429     return do_dh_print(bp, x, 4, 0);
 430 }
 431
 432 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 433 {
 434     switch (op) {
 435     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
 436         return dh_buf2key(EVP_PKEY_get0_DH(pkey), arg2, arg1);
 437     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
 438         return dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2, 0, 1);
 439     default:
 440         return -2;
 441     }
 442 }
 443
 444 static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 445 {
 446     switch (op) {
 447     default:
 448         return -2;
 449     }
 450
 451 }
 452
 453 static int dh_pkey_public_check(const EVP_PKEY *pkey)
 454 {
 455     DH *dh = pkey->pkey.dh;
 456
 457     if (dh->pub_key == NULL) {
 458         DHerr(DH_F_DH_PKEY_PUBLIC_CHECK, DH_R_MISSING_PUBKEY);
 459         return 0;
 460     }
 461
 462     return DH_check_pub_key_ex(dh, dh->pub_key);
 463 }
 464
 465 static int dh_pkey_param_check(const EVP_PKEY *pkey)
 466 {
 467     DH *dh = pkey->pkey.dh;
 468
 469     return DH_check_ex(dh);
 470 }
 471
 472 static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
 473 {
 474     return pkey->pkey.dh->dirty_cnt;
 475 }
 476
 477 static int dh_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
 478                              EVP_KEYMGMT *to_keymgmt, OSSL_LIB_CTX *libctx,
 479                              const char *propq)
 480 {
 481     DH *dh = from->pkey.dh;
 482     OSSL_PARAM_BLD *tmpl;
 483     const BIGNUM *p = DH_get0_p(dh), *g = DH_get0_g(dh), *q = DH_get0_q(dh);
 484     long l = DH_get_length(dh);
 485     const BIGNUM *pub_key = DH_get0_pub_key(dh);
 486     const BIGNUM *priv_key = DH_get0_priv_key(dh);
 487     OSSL_PARAM *params = NULL;
 488     int selection = 0;
 489     int rv = 0;
 490
 491     /*
 492      * If the DH method is foreign, then we can't be sure of anything, and
 493      * can therefore not export or pretend to export.
 494      */
 495     if (dh_get_method(dh) != DH_OpenSSL())
 496         return 0;
 497
 498     if (p == NULL || g == NULL)
 499         return 0;
 500
 501     tmpl = OSSL_PARAM_BLD_new();
 502     if (tmpl == NULL)
 503         return 0;
 504     if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_P, p)
 505         || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_G, g))
 506         goto err;
 507     if (q != NULL) {
 508         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_Q, q))
 509             goto err;
 510     }
 511     selection |= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
 512     if (l > 0) {
 513         if (!OSSL_PARAM_BLD_push_long(tmpl, OSSL_PKEY_PARAM_DH_PRIV_LEN, l))
 514             goto err;
 515         selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
 516     }
 517     if (pub_key != NULL) {
 518         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PUB_KEY, pub_key))
 519             goto err;
 520         selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
 521     }
 522     if (priv_key != NULL) {
 523         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PRIV_KEY,
 524                                     priv_key))
 525             goto err;
 526         selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
 527     }
 528
 529     if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
 530         goto err;
 531
 532     /* We export, the provider imports */
 533     rv = evp_keymgmt_import(to_keymgmt, to_keydata, selection, params);
 534
 535     OSSL_PARAM_BLD_free_params(params);
 536 err:
 537     OSSL_PARAM_BLD_free(tmpl);
 538     return rv;
 539 }
 540
 541 static int dh_pkey_import_from_type(const OSSL_PARAM params[], void *vpctx,
 542                                     int type)
 543 {
 544     EVP_PKEY_CTX *pctx = vpctx;
 545     EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 546     DH *dh = dh_new_ex(pctx->libctx);
 547
 548     if (dh == NULL) {
 549         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
 550         return 0;
 551     }
 552     DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
 553     DH_set_flags(dh, type == EVP_PKEY_DH ? DH_FLAG_TYPE_DH : DH_FLAG_TYPE_DHX);
 554
 555     if (!dh_params_fromdata(dh, params)
 556         || !dh_key_fromdata(dh, params)
 557         || !EVP_PKEY_assign(pkey, type, dh)) {
 558         DH_free(dh);
 559         return 0;
 560     }
 561     return 1;
 562 }
 563
 564 static int dh_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 565 {
 566     return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DH);
 567 }
 568
 569 static int dhx_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 570 {
 571     return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DHX);
 572 }
 573
 574 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
 575     EVP_PKEY_DH,
 576     EVP_PKEY_DH,
 577     0,
 578
 579     "DH",
 580     "OpenSSL PKCS#3 DH method",
 581
 582     dh_pub_decode,
 583     dh_pub_encode,
 584     dh_pub_cmp,
 585     dh_public_print,
 586
 587     dh_priv_decode,
 588     dh_priv_encode,
 589     dh_private_print,
 590
 591     int_dh_size,
 592     dh_bits,
 593     dh_security_bits,
 594
 595     dh_param_decode,
 596     dh_param_encode,
 597     dh_missing_parameters,
 598     dh_copy_parameters,
 599     dh_cmp_parameters,
 600     dh_param_print,
 601     0,
 602
 603     int_dh_free,
 604     dh_pkey_ctrl,
 605
 606     0, 0, 0, 0, 0,
 607
 608     0,
 609     dh_pkey_public_check,
 610     dh_pkey_param_check,
 611
 612     0, 0, 0, 0,
 613
 614     dh_pkey_dirty_cnt,
 615     dh_pkey_export_to,
 616     dh_pkey_import_from,
 617 };
 618
 619 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
 620     EVP_PKEY_DHX,
 621     EVP_PKEY_DHX,
 622     0,
 623
 624     "X9.42 DH",
 625     "OpenSSL X9.42 DH method",
 626
 627     dh_pub_decode,
 628     dh_pub_encode,
 629     dh_pub_cmp,
 630     dh_public_print,
 631
 632     dh_priv_decode,
 633     dh_priv_encode,
 634     dh_private_print,
 635
 636     int_dh_size,
 637     dh_bits,
 638     dh_security_bits,
 639
 640     dh_param_decode,
 641     dh_param_encode,
 642     dh_missing_parameters,
 643     dh_copy_parameters,
 644     dh_cmp_parameters,
 645     dh_param_print,
 646     0,
 647
 648     int_dh_free,
 649     dhx_pkey_ctrl,
 650
 651     0, 0, 0, 0, 0,
 652
 653     0,
 654     dh_pkey_public_check,
 655     dh_pkey_param_check,
 656     0, 0, 0, 0,
 657     dh_pkey_dirty_cnt,
 658     dh_pkey_export_to,
 659     dhx_pkey_import_from,
 660 };