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 "internal/cryptlib.h"
  18 #include <openssl/x509.h>
  19 #include <openssl/asn1.h>
  20 #include "dh_local.h"
  21 #include <openssl/bn.h>
  22 #include "crypto/asn1.h"
  23 #include "crypto/dh.h"
  24 #include "crypto/evp.h"
  25 #include <openssl/cms.h>
  26 #include <openssl/core_names.h>
  27 #include <openssl/param_build.h>
  28 #include "internal/ffc.h"
  29
  30 /*
  31  * i2d/d2i like DH parameter functions which use the appropriate routine for
  32  * PKCS#3 DH or X9.42 DH.
  33  */
  34
  35 static DH *d2i_dhp(const EVP_PKEY *pkey, const unsigned char **pp,
  36                    long length)
  37 {
  38     DH *dh = NULL;
  39     int is_dhx = (pkey->ameth == &dhx_asn1_meth);
  40
  41     if (is_dhx)
  42         dh = d2i_DHxparams(NULL, pp, length);
  43     else
  44         dh = d2i_DHparams(NULL, pp, length);
  45
  46     if (dh != NULL) {
  47         DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
  48         DH_set_flags(dh, is_dhx ? DH_FLAG_TYPE_DHX : DH_FLAG_TYPE_DH);
  49     }
  50     return dh;
  51 }
  52
  53 static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
  54 {
  55     if (pkey->ameth == &dhx_asn1_meth)
  56         return i2d_DHxparams(a, pp);
  57     return i2d_DHparams(a, pp);
  58 }
  59
  60 static void int_dh_free(EVP_PKEY *pkey)
  61 {
  62     DH_free(pkey->pkey.dh);
  63 }
  64
  65 static int dh_pub_decode(EVP_PKEY *pkey, const X509_PUBKEY *pubkey)
  66 {
  67     const unsigned char *p, *pm;
  68     int pklen, pmlen;
  69     int ptype;
  70     const void *pval;
  71     const ASN1_STRING *pstr;
  72     X509_ALGOR *palg;
  73     ASN1_INTEGER *public_key = NULL;
  74
  75     DH *dh = NULL;
  76
  77     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
  78         return 0;
  79     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
  80
  81     if (ptype != V_ASN1_SEQUENCE) {
  82         DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
  83         goto err;
  84     }
  85
  86     pstr = pval;
  87     pm = pstr->data;
  88     pmlen = pstr->length;
  89
  90     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL) {
  91         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  92         goto err;
  93     }
  94
  95     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
  96         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  97         goto err;
  98     }
  99
 100     /* We have parameters now set public key */
 101     if ((dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
 102         DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
 103         goto err;
 104     }
 105
 106     ASN1_INTEGER_free(public_key);
 107     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 108     return 1;
 109
 110  err:
 111     ASN1_INTEGER_free(public_key);
 112     DH_free(dh);
 113     return 0;
 114 }
 115
 116 static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 117 {
 118     DH *dh;
 119     int ptype;
 120     unsigned char *penc = NULL;
 121     int penclen;
 122     ASN1_STRING *str;
 123     ASN1_INTEGER *pub_key = NULL;
 124
 125     dh = pkey->pkey.dh;
 126
 127     str = ASN1_STRING_new();
 128     if (str == NULL) {
 129         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 130         goto err;
 131     }
 132     str->length = i2d_dhp(pkey, dh, &str->data);
 133     if (str->length <= 0) {
 134         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 135         goto err;
 136     }
 137     ptype = V_ASN1_SEQUENCE;
 138
 139     pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
 140     if (pub_key == NULL)
 141         goto err;
 142
 143     penclen = i2d_ASN1_INTEGER(pub_key, &penc);
 144
 145     ASN1_INTEGER_free(pub_key);
 146
 147     if (penclen <= 0) {
 148         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 149         goto err;
 150     }
 151
 152     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
 153                                ptype, str, penc, penclen))
 154         return 1;
 155
 156  err:
 157     OPENSSL_free(penc);
 158     ASN1_STRING_free(str);
 159
 160     return 0;
 161 }
 162
 163 /*
 164  * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
 165  * the AlgorithmIdentifier contains the parameters, the private key is
 166  * explicitly included and the pubkey must be recalculated.
 167  */
 168
 169 static int dh_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 170 {
 171     const unsigned char *p, *pm;
 172     int pklen, pmlen;
 173     int ptype;
 174     const void *pval;
 175     const ASN1_STRING *pstr;
 176     const X509_ALGOR *palg;
 177     ASN1_INTEGER *privkey = NULL;
 178     DH *dh = NULL;
 179
 180     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 181         return 0;
 182
 183     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 184
 185     if (ptype != V_ASN1_SEQUENCE)
 186         goto decerr;
 187     if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
 188         goto decerr;
 189
 190     pstr = pval;
 191     pm = pstr->data;
 192     pmlen = pstr->length;
 193     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
 194         goto decerr;
 195
 196     /* We have parameters now set private key */
 197     if ((dh->priv_key = BN_secure_new()) == NULL
 198         || !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
 199         DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
 200         goto dherr;
 201     }
 202     /* Calculate public key, increments dirty_cnt */
 203     if (!DH_generate_key(dh))
 204         goto dherr;
 205
 206     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 207
 208     ASN1_STRING_clear_free(privkey);
 209
 210     return 1;
 211
 212  decerr:
 213     DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
 214  dherr:
 215     DH_free(dh);
 216     ASN1_STRING_clear_free(privkey);
 217     return 0;
 218 }
 219
 220 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 221 {
 222     ASN1_STRING *params = NULL;
 223     ASN1_INTEGER *prkey = NULL;
 224     unsigned char *dp = NULL;
 225     int dplen;
 226
 227     params = ASN1_STRING_new();
 228
 229     if (params == NULL) {
 230         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 231         goto err;
 232     }
 233
 234     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 235     if (params->length <= 0) {
 236         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 237         goto err;
 238     }
 239     params->type = V_ASN1_SEQUENCE;
 240
 241     /* Get private key into integer */
 242     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 243
 244     if (prkey == NULL) {
 245         DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
 246         goto err;
 247     }
 248
 249     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 250
 251     ASN1_STRING_clear_free(prkey);
 252     prkey = NULL;
 253
 254     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 255                          V_ASN1_SEQUENCE, params, dp, dplen))
 256         goto err;
 257
 258     return 1;
 259
 260  err:
 261     OPENSSL_free(dp);
 262     ASN1_STRING_free(params);
 263     ASN1_STRING_clear_free(prkey);
 264     return 0;
 265 }
 266
 267 static int dh_param_decode(EVP_PKEY *pkey,
 268                            const unsigned char **pder, int derlen)
 269 {
 270     DH *dh;
 271
 272     if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL)
 273         return 0;
 274     dh->dirty_cnt++;
 275     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 276     return 1;
 277 }
 278
 279 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 280 {
 281     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 282 }
 283
 284 static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
 285 {
 286     int reason = ERR_R_BUF_LIB;
 287     const char *ktype = NULL;
 288     BIGNUM *priv_key, *pub_key;
 289
 290     if (ptype == 2)
 291         priv_key = x->priv_key;
 292     else
 293         priv_key = NULL;
 294
 295     if (ptype > 0)
 296         pub_key = x->pub_key;
 297     else
 298         pub_key = NULL;
 299
 300     if (x->params.p == NULL || (ptype == 2 && priv_key == NULL)
 301             || (ptype > 0 && pub_key == NULL)) {
 302         reason = ERR_R_PASSED_NULL_PARAMETER;
 303         goto err;
 304     }
 305
 306     if (ptype == 2)
 307         ktype = "DH Private-Key";
 308     else if (ptype == 1)
 309         ktype = "DH Public-Key";
 310     else
 311         ktype = "DH Parameters";
 312
 313     if (!BIO_indent(bp, indent, 128)
 314             || BIO_printf(bp, "%s: (%d bit)\n", ktype, DH_bits(x)) <= 0)
 315         goto err;
 316     indent += 4;
 317
 318     if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
 319         goto err;
 320     if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
 321         goto err;
 322
 323     if (!ossl_ffc_params_print(bp, &x->params, indent))
 324         goto err;
 325
 326     if (x->length != 0) {
 327         if (!BIO_indent(bp, indent, 128)
 328                 || BIO_printf(bp, "recommended-private-length: %d bits\n",
 329                               (int)x->length) <= 0)
 330             goto err;
 331     }
 332
 333     return 1;
 334
 335  err:
 336     DHerr(DH_F_DO_DH_PRINT, reason);
 337     return 0;
 338 }
 339
 340 static int int_dh_size(const EVP_PKEY *pkey)
 341 {
 342     return DH_size(pkey->pkey.dh);
 343 }
 344
 345 static int dh_bits(const EVP_PKEY *pkey)
 346 {
 347     return DH_bits(pkey->pkey.dh);
 348 }
 349
 350 static int dh_security_bits(const EVP_PKEY *pkey)
 351 {
 352     return DH_security_bits(pkey->pkey.dh);
 353 }
 354
 355 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 356 {
 357     return ossl_ffc_params_cmp(&a->pkey.dh->params, &a->pkey.dh->params,
 358                                a->ameth != &dhx_asn1_meth);
 359 }
 360
 361 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 362 {
 363     if (is_x942 == -1)
 364         is_x942 = (from->params.q != NULL);
 365     if (!ossl_ffc_params_copy(&to->params, &from->params))
 366         return 0;
 367     if (!is_x942)
 368         to->length = from->length;
 369     to->dirty_cnt++;
 370     return 1;
 371 }
 372
 373 DH *DHparams_dup(const DH *dh)
 374 {
 375     DH *ret;
 376     ret = DH_new();
 377     if (ret == NULL)
 378         return NULL;
 379     if (!int_dh_param_copy(ret, dh, -1)) {
 380         DH_free(ret);
 381         return NULL;
 382     }
 383     return ret;
 384 }
 385
 386 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 387 {
 388     if (to->pkey.dh == NULL) {
 389         to->pkey.dh = DH_new();
 390         if (to->pkey.dh == NULL)
 391             return 0;
 392     }
 393     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 394                              from->ameth == &dhx_asn1_meth);
 395 }
 396
 397 static int dh_missing_parameters(const EVP_PKEY *a)
 398 {
 399     return a->pkey.dh == NULL
 400         || a->pkey.dh->params.p == NULL
 401         || a->pkey.dh->params.g == NULL;
 402 }
 403
 404 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 405 {
 406     if (dh_cmp_parameters(a, b) == 0)
 407         return 0;
 408     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 409         return 0;
 410     else
 411         return 1;
 412 }
 413
 414 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 415                           ASN1_PCTX *ctx)
 416 {
 417     return do_dh_print(bp, pkey->pkey.dh, indent, 0);
 418 }
 419
 420 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 421                            ASN1_PCTX *ctx)
 422 {
 423     return do_dh_print(bp, pkey->pkey.dh, indent, 1);
 424 }
 425
 426 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 427                             ASN1_PCTX *ctx)
 428 {
 429     return do_dh_print(bp, pkey->pkey.dh, indent, 2);
 430 }
 431
 432 int DHparams_print(BIO *bp, const DH *x)
 433 {
 434     return do_dh_print(bp, x, 4, 0);
 435 }
 436
 437 #ifndef OPENSSL_NO_CMS
 438 static int dh_cms_decrypt(CMS_RecipientInfo *ri);
 439 static int dh_cms_encrypt(CMS_RecipientInfo *ri);
 440 #endif
 441
 442 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 443 {
 444     switch (op) {
 445     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
 446         return dh_buf2key(EVP_PKEY_get0_DH(pkey), arg2, arg1);
 447     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
 448         return dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2, 0, 1);
 449     default:
 450         return -2;
 451     }
 452 }
 453
 454 static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 455 {
 456     switch (op) {
 457 #ifndef OPENSSL_NO_CMS
 458
 459     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 460         if (arg1 == 1)
 461             return dh_cms_decrypt(arg2);
 462         else if (arg1 == 0)
 463             return dh_cms_encrypt(arg2);
 464         return -2;
 465
 466     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 467         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 468         return 1;
 469 #endif
 470     default:
 471         return -2;
 472     }
 473
 474 }
 475
 476 static int dh_pkey_public_check(const EVP_PKEY *pkey)
 477 {
 478     DH *dh = pkey->pkey.dh;
 479
 480     if (dh->pub_key == NULL) {
 481         DHerr(DH_F_DH_PKEY_PUBLIC_CHECK, DH_R_MISSING_PUBKEY);
 482         return 0;
 483     }
 484
 485     return DH_check_pub_key_ex(dh, dh->pub_key);
 486 }
 487
 488 static int dh_pkey_param_check(const EVP_PKEY *pkey)
 489 {
 490     DH *dh = pkey->pkey.dh;
 491
 492     return DH_check_ex(dh);
 493 }
 494
 495 static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
 496 {
 497     return pkey->pkey.dh->dirty_cnt;
 498 }
 499
 500 static int dh_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
 501                              EVP_KEYMGMT *to_keymgmt, OPENSSL_CTX *libctx,
 502                              const char *propq)
 503 {
 504     DH *dh = from->pkey.dh;
 505     OSSL_PARAM_BLD *tmpl;
 506     const BIGNUM *p = DH_get0_p(dh), *g = DH_get0_g(dh), *q = DH_get0_q(dh);
 507     const BIGNUM *pub_key = DH_get0_pub_key(dh);
 508     const BIGNUM *priv_key = DH_get0_priv_key(dh);
 509     OSSL_PARAM *params = NULL;
 510     int selection = 0;
 511     int rv = 0;
 512
 513     /*
 514      * If the DH method is foreign, then we can't be sure of anything, and
 515      * can therefore not export or pretend to export.
 516      */
 517     if (dh_get_method(dh) != DH_OpenSSL())
 518         return 0;
 519
 520     if (p == NULL || g == NULL)
 521         return 0;
 522
 523     tmpl = OSSL_PARAM_BLD_new();
 524     if (tmpl == NULL)
 525         return 0;
 526     if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_P, p)
 527         || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_G, g))
 528         goto err;
 529     if (q != NULL) {
 530         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_Q, q))
 531             goto err;
 532     }
 533     selection |= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
 534     if (pub_key != NULL) {
 535         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PUB_KEY, pub_key))
 536             goto err;
 537         selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
 538     }
 539     if (priv_key != NULL) {
 540         if (!OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_PRIV_KEY,
 541                                     priv_key))
 542             goto err;
 543         selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
 544     }
 545
 546     if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
 547         goto err;
 548
 549     /* We export, the provider imports */
 550     rv = evp_keymgmt_import(to_keymgmt, to_keydata, selection, params);
 551
 552     OSSL_PARAM_BLD_free_params(params);
 553 err:
 554     OSSL_PARAM_BLD_free(tmpl);
 555     return rv;
 556 }
 557
 558 static int dh_pkey_import_from_type(const OSSL_PARAM params[], void *vpctx,
 559                                     int type)
 560 {
 561     EVP_PKEY_CTX *pctx = vpctx;
 562     EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 563     DH *dh = dh_new_ex(pctx->libctx);
 564
 565     if (dh == NULL) {
 566         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
 567         return 0;
 568     }
 569     DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
 570     DH_set_flags(dh, type == EVP_PKEY_DH ? DH_FLAG_TYPE_DH : DH_FLAG_TYPE_DHX);
 571
 572     if (!dh_ffc_params_fromdata(dh, params)
 573         || !dh_key_fromdata(dh, params)
 574         || !EVP_PKEY_assign(pkey, type, dh)) {
 575         DH_free(dh);
 576         return 0;
 577     }
 578     return 1;
 579 }
 580
 581 static int dh_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 582 {
 583     return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DH);
 584 }
 585
 586 static int dhx_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 587 {
 588     return dh_pkey_import_from_type(params, vpctx, EVP_PKEY_DHX);
 589 }
 590
 591 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
 592     EVP_PKEY_DH,
 593     EVP_PKEY_DH,
 594     0,
 595
 596     "DH",
 597     "OpenSSL PKCS#3 DH method",
 598
 599     dh_pub_decode,
 600     dh_pub_encode,
 601     dh_pub_cmp,
 602     dh_public_print,
 603
 604     dh_priv_decode,
 605     dh_priv_encode,
 606     dh_private_print,
 607
 608     int_dh_size,
 609     dh_bits,
 610     dh_security_bits,
 611
 612     dh_param_decode,
 613     dh_param_encode,
 614     dh_missing_parameters,
 615     dh_copy_parameters,
 616     dh_cmp_parameters,
 617     dh_param_print,
 618     0,
 619
 620     int_dh_free,
 621     dh_pkey_ctrl,
 622
 623     0, 0, 0, 0, 0,
 624
 625     0,
 626     dh_pkey_public_check,
 627     dh_pkey_param_check,
 628
 629     0, 0, 0, 0,
 630
 631     dh_pkey_dirty_cnt,
 632     dh_pkey_export_to,
 633     dh_pkey_import_from,
 634 };
 635
 636 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
 637     EVP_PKEY_DHX,
 638     EVP_PKEY_DHX,
 639     0,
 640
 641     "X9.42 DH",
 642     "OpenSSL X9.42 DH method",
 643
 644     dh_pub_decode,
 645     dh_pub_encode,
 646     dh_pub_cmp,
 647     dh_public_print,
 648
 649     dh_priv_decode,
 650     dh_priv_encode,
 651     dh_private_print,
 652
 653     int_dh_size,
 654     dh_bits,
 655     dh_security_bits,
 656
 657     dh_param_decode,
 658     dh_param_encode,
 659     dh_missing_parameters,
 660     dh_copy_parameters,
 661     dh_cmp_parameters,
 662     dh_param_print,
 663     0,
 664
 665     int_dh_free,
 666     dhx_pkey_ctrl,
 667
 668     0, 0, 0, 0, 0,
 669
 670     0,
 671     dh_pkey_public_check,
 672     dh_pkey_param_check,
 673     0, 0, 0, 0,
 674     dh_pkey_dirty_cnt,
 675     dh_pkey_export_to,
 676     dhx_pkey_import_from,
 677 };
 678
 679 #ifndef OPENSSL_NO_CMS
 680
 681 static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 682                               X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 683 {
 684     const ASN1_OBJECT *aoid;
 685     int atype;
 686     const void *aval;
 687     ASN1_INTEGER *public_key = NULL;
 688     int rv = 0;
 689     EVP_PKEY *pkpeer = NULL, *pk = NULL;
 690     DH *dhpeer = NULL;
 691     const unsigned char *p;
 692     int plen;
 693
 694     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 695     if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
 696         goto err;
 697     /* Only absent parameters allowed in RFC XXXX */
 698     if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
 699         goto err;
 700
 701     pk = EVP_PKEY_CTX_get0_pkey(pctx);
 702     if (pk == NULL)
 703         goto err;
 704     if (pk->type != EVP_PKEY_DHX)
 705         goto err;
 706     /* Get parameters from parent key */
 707     dhpeer = DHparams_dup(pk->pkey.dh);
 708     /* We have parameters now set public key */
 709     plen = ASN1_STRING_length(pubkey);
 710     p = ASN1_STRING_get0_data(pubkey);
 711     if (p == NULL || plen == 0)
 712         goto err;
 713
 714     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) {
 715         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
 716         goto err;
 717     }
 718
 719     /* We have parameters now set public key */
 720     if ((dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
 721         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
 722         goto err;
 723     }
 724
 725     pkpeer = EVP_PKEY_new();
 726     if (pkpeer == NULL)
 727         goto err;
 728     EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
 729     dhpeer = NULL;
 730     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 731         rv = 1;
 732  err:
 733     ASN1_INTEGER_free(public_key);
 734     EVP_PKEY_free(pkpeer);
 735     DH_free(dhpeer);
 736     return rv;
 737 }
 738
 739 static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 740 {
 741     int rv = 0;
 742
 743     X509_ALGOR *alg, *kekalg = NULL;
 744     ASN1_OCTET_STRING *ukm;
 745     const unsigned char *p;
 746     unsigned char *dukm = NULL;
 747     size_t dukmlen = 0;
 748     int keylen, plen;
 749     const EVP_CIPHER *kekcipher;
 750     EVP_CIPHER_CTX *kekctx;
 751
 752     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 753         goto err;
 754
 755     /*
 756      * For DH we only have one OID permissible. If ever any more get defined
 757      * we will need something cleverer.
 758      */
 759     if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
 760         DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
 761         goto err;
 762     }
 763
 764     if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
 765         goto err;
 766
 767     if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
 768         goto err;
 769
 770     if (alg->parameter->type != V_ASN1_SEQUENCE)
 771         goto err;
 772
 773     p = alg->parameter->value.sequence->data;
 774     plen = alg->parameter->value.sequence->length;
 775     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 776     if (!kekalg)
 777         goto err;
 778     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 779     if (!kekctx)
 780         goto err;
 781     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 782     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 783         goto err;
 784     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 785         goto err;
 786     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 787         goto err;
 788
 789     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 790     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 791         goto err;
 792     /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
 793     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
 794                                      OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
 795         <= 0)
 796         goto err;
 797
 798     if (ukm) {
 799         dukmlen = ASN1_STRING_length(ukm);
 800         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
 801         if (!dukm)
 802             goto err;
 803     }
 804
 805     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 806         goto err;
 807     dukm = NULL;
 808
 809     rv = 1;
 810  err:
 811     X509_ALGOR_free(kekalg);
 812     OPENSSL_free(dukm);
 813     return rv;
 814 }
 815
 816 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 817 {
 818     EVP_PKEY_CTX *pctx;
 819
 820     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 821
 822     if (pctx == NULL)
 823         return 0;
 824     /* See if we need to set peer key */
 825     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 826         X509_ALGOR *alg;
 827         ASN1_BIT_STRING *pubkey;
 828         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 829                                                  NULL, NULL, NULL))
 830             return 0;
 831         if (!alg || !pubkey)
 832             return 0;
 833         if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
 834             DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
 835             return 0;
 836         }
 837     }
 838     /* Set DH derivation parameters and initialise unwrap context */
 839     if (!dh_cms_set_shared_info(pctx, ri)) {
 840         DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
 841         return 0;
 842     }
 843     return 1;
 844 }
 845
 846 static int dh_cms_encrypt(CMS_RecipientInfo *ri)
 847 {
 848     EVP_PKEY_CTX *pctx;
 849     EVP_PKEY *pkey;
 850     EVP_CIPHER_CTX *ctx;
 851     int keylen;
 852     X509_ALGOR *talg, *wrap_alg = NULL;
 853     const ASN1_OBJECT *aoid;
 854     ASN1_BIT_STRING *pubkey;
 855     ASN1_STRING *wrap_str;
 856     ASN1_OCTET_STRING *ukm;
 857     unsigned char *penc = NULL, *dukm = NULL;
 858     int penclen;
 859     size_t dukmlen = 0;
 860     int rv = 0;
 861     int kdf_type, wrap_nid;
 862     const EVP_MD *kdf_md;
 863
 864     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 865     if (pctx == NULL)
 866         return 0;
 867     /* Get ephemeral key */
 868     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 869     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 870                                              NULL, NULL, NULL))
 871         goto err;
 872     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 873     /* Is everything uninitialised? */
 874     if (aoid == OBJ_nid2obj(NID_undef)) {
 875         ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
 876
 877         if (pubk == NULL)
 878             goto err;
 879         /* Set the key */
 880
 881         penclen = i2d_ASN1_INTEGER(pubk, &penc);
 882         ASN1_INTEGER_free(pubk);
 883         if (penclen <= 0)
 884             goto err;
 885         ASN1_STRING_set0(pubkey, penc, penclen);
 886         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 887         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 888
 889         penc = NULL;
 890         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
 891                         V_ASN1_UNDEF, NULL);
 892     }
 893
 894     /* See if custom parameters set */
 895     kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
 896     if (kdf_type <= 0)
 897         goto err;
 898     if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
 899         goto err;
 900
 901     if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
 902         kdf_type = EVP_PKEY_DH_KDF_X9_42;
 903         if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
 904             goto err;
 905     } else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
 906         /* Unknown KDF */
 907         goto err;
 908     if (kdf_md == NULL) {
 909         /* Only SHA1 supported */
 910         kdf_md = EVP_sha1();
 911         if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
 912             goto err;
 913     } else if (EVP_MD_type(kdf_md) != NID_sha1)
 914         /* Unsupported digest */
 915         goto err;
 916
 917     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 918         goto err;
 919
 920     /* Get wrap NID */
 921     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 922     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 923     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
 924         goto err;
 925     keylen = EVP_CIPHER_CTX_key_length(ctx);
 926
 927     /* Package wrap algorithm in an AlgorithmIdentifier */
 928
 929     wrap_alg = X509_ALGOR_new();
 930     if (wrap_alg == NULL)
 931         goto err;
 932     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 933     wrap_alg->parameter = ASN1_TYPE_new();
 934     if (wrap_alg->parameter == NULL)
 935         goto err;
 936     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 937         goto err;
 938     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 939         ASN1_TYPE_free(wrap_alg->parameter);
 940         wrap_alg->parameter = NULL;
 941     }
 942
 943     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 944         goto err;
 945
 946     if (ukm) {
 947         dukmlen = ASN1_STRING_length(ukm);
 948         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
 949         if (!dukm)
 950             goto err;
 951     }
 952
 953     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 954         goto err;
 955     dukm = NULL;
 956
 957     /*
 958      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 959      * of another AlgorithmIdentifier.
 960      */
 961     penc = NULL;
 962     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 963     if (penc == NULL || penclen == 0)
 964         goto err;
 965     wrap_str = ASN1_STRING_new();
 966     if (wrap_str == NULL)
 967         goto err;
 968     ASN1_STRING_set0(wrap_str, penc, penclen);
 969     penc = NULL;
 970     X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
 971                     V_ASN1_SEQUENCE, wrap_str);
 972
 973     rv = 1;
 974
 975  err:
 976     OPENSSL_free(penc);
 977     X509_ALGOR_free(wrap_alg);
 978     OPENSSL_free(dukm);
 979     return rv;
 980 }
 981
 982 #endif