crypto/dh/dh_ameth.c

   1 /*
   2  * Copyright 2006-2016 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 "internal/param_build.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     if (pkey->ameth == &dhx_asn1_meth)
  38         return d2i_DHxparams(NULL, pp, length);
  39     return d2i_DHparams(NULL, pp, length);
  40 }
  41
  42 static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
  43 {
  44     if (pkey->ameth == &dhx_asn1_meth)
  45         return i2d_DHxparams(a, pp);
  46     return i2d_DHparams(a, pp);
  47 }
  48
  49 static void int_dh_free(EVP_PKEY *pkey)
  50 {
  51     DH_free(pkey->pkey.dh);
  52 }
  53
  54 static int dh_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
  55 {
  56     const unsigned char *p, *pm;
  57     int pklen, pmlen;
  58     int ptype;
  59     const void *pval;
  60     const ASN1_STRING *pstr;
  61     X509_ALGOR *palg;
  62     ASN1_INTEGER *public_key = NULL;
  63
  64     DH *dh = NULL;
  65
  66     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
  67         return 0;
  68     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
  69
  70     if (ptype != V_ASN1_SEQUENCE) {
  71         DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
  72         goto err;
  73     }
  74
  75     pstr = pval;
  76     pm = pstr->data;
  77     pmlen = pstr->length;
  78
  79     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL) {
  80         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  81         goto err;
  82     }
  83
  84     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
  85         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  86         goto err;
  87     }
  88
  89     /* We have parameters now set public key */
  90     if ((dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
  91         DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
  92         goto err;
  93     }
  94
  95     ASN1_INTEGER_free(public_key);
  96     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
  97     return 1;
  98
  99  err:
 100     ASN1_INTEGER_free(public_key);
 101     DH_free(dh);
 102     return 0;
 103
 104 }
 105
 106 static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 107 {
 108     DH *dh;
 109     int ptype;
 110     unsigned char *penc = NULL;
 111     int penclen;
 112     ASN1_STRING *str;
 113     ASN1_INTEGER *pub_key = NULL;
 114
 115     dh = pkey->pkey.dh;
 116
 117     str = ASN1_STRING_new();
 118     if (str == NULL) {
 119         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 120         goto err;
 121     }
 122     str->length = i2d_dhp(pkey, dh, &str->data);
 123     if (str->length <= 0) {
 124         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 125         goto err;
 126     }
 127     ptype = V_ASN1_SEQUENCE;
 128
 129     pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
 130     if (pub_key == NULL)
 131         goto err;
 132
 133     penclen = i2d_ASN1_INTEGER(pub_key, &penc);
 134
 135     ASN1_INTEGER_free(pub_key);
 136
 137     if (penclen <= 0) {
 138         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 139         goto err;
 140     }
 141
 142     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
 143                                ptype, str, penc, penclen))
 144         return 1;
 145
 146  err:
 147     OPENSSL_free(penc);
 148     ASN1_STRING_free(str);
 149
 150     return 0;
 151 }
 152
 153 /*
 154  * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
 155  * the AlgorithmIdentifier contains the parameters, the private key is
 156  * explicitly included and the pubkey must be recalculated.
 157  */
 158
 159 static int dh_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 160 {
 161     const unsigned char *p, *pm;
 162     int pklen, pmlen;
 163     int ptype;
 164     const void *pval;
 165     const ASN1_STRING *pstr;
 166     const X509_ALGOR *palg;
 167     ASN1_INTEGER *privkey = NULL;
 168     DH *dh = NULL;
 169
 170     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 171         return 0;
 172
 173     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 174
 175     if (ptype != V_ASN1_SEQUENCE)
 176         goto decerr;
 177     if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
 178         goto decerr;
 179
 180     pstr = pval;
 181     pm = pstr->data;
 182     pmlen = pstr->length;
 183     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
 184         goto decerr;
 185
 186     /* We have parameters now set private key */
 187     if ((dh->priv_key = BN_secure_new()) == NULL
 188         || !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
 189         DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
 190         goto dherr;
 191     }
 192     /* Calculate public key, increments dirty_cnt */
 193     if (!DH_generate_key(dh))
 194         goto dherr;
 195
 196     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 197
 198     ASN1_STRING_clear_free(privkey);
 199
 200     return 1;
 201
 202  decerr:
 203     DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
 204  dherr:
 205     DH_free(dh);
 206     ASN1_STRING_clear_free(privkey);
 207     return 0;
 208 }
 209
 210 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 211 {
 212     ASN1_STRING *params = NULL;
 213     ASN1_INTEGER *prkey = NULL;
 214     unsigned char *dp = NULL;
 215     int dplen;
 216
 217     params = ASN1_STRING_new();
 218
 219     if (params == NULL) {
 220         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 221         goto err;
 222     }
 223
 224     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 225     if (params->length <= 0) {
 226         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 227         goto err;
 228     }
 229     params->type = V_ASN1_SEQUENCE;
 230
 231     /* Get private key into integer */
 232     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 233
 234     if (prkey == NULL) {
 235         DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
 236         goto err;
 237     }
 238
 239     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 240
 241     ASN1_STRING_clear_free(prkey);
 242     prkey = NULL;
 243
 244     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 245                          V_ASN1_SEQUENCE, params, dp, dplen))
 246         goto err;
 247
 248     return 1;
 249
 250  err:
 251     OPENSSL_free(dp);
 252     ASN1_STRING_free(params);
 253     ASN1_STRING_clear_free(prkey);
 254     return 0;
 255 }
 256
 257 static int dh_param_decode(EVP_PKEY *pkey,
 258                            const unsigned char **pder, int derlen)
 259 {
 260     DH *dh;
 261
 262     if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL) {
 263         DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
 264         return 0;
 265     }
 266     dh->dirty_cnt++;
 267     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 268     return 1;
 269 }
 270
 271 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 272 {
 273     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 274 }
 275
 276 static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
 277 {
 278     int reason = ERR_R_BUF_LIB;
 279     const char *ktype = NULL;
 280     BIGNUM *priv_key, *pub_key;
 281
 282     if (ptype == 2)
 283         priv_key = x->priv_key;
 284     else
 285         priv_key = NULL;
 286
 287     if (ptype > 0)
 288         pub_key = x->pub_key;
 289     else
 290         pub_key = NULL;
 291
 292     if (x->params.p == NULL || (ptype == 2 && priv_key == NULL)
 293             || (ptype > 0 && pub_key == NULL)) {
 294         reason = ERR_R_PASSED_NULL_PARAMETER;
 295         goto err;
 296     }
 297
 298     if (ptype == 2)
 299         ktype = "DH Private-Key";
 300     else if (ptype == 1)
 301         ktype = "DH Public-Key";
 302     else
 303         ktype = "DH Parameters";
 304
 305     if (!BIO_indent(bp, indent, 128)
 306             || BIO_printf(bp, "%s: (%d bit)\n", ktype, DH_bits(x)) <= 0)
 307         goto err;
 308     indent += 4;
 309
 310     if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
 311         goto err;
 312     if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
 313         goto err;
 314
 315     if (!ffc_params_print(bp, &x->params, indent))
 316         goto err;
 317
 318     if (x->length != 0) {
 319         if (!BIO_indent(bp, indent, 128)
 320                 || BIO_printf(bp, "recommended-private-length: %d bits\n",
 321                               (int)x->length) <= 0)
 322             goto err;
 323     }
 324
 325     return 1;
 326
 327  err:
 328     DHerr(DH_F_DO_DH_PRINT, reason);
 329     return 0;
 330 }
 331
 332 static int int_dh_size(const EVP_PKEY *pkey)
 333 {
 334     return DH_size(pkey->pkey.dh);
 335 }
 336
 337 static int dh_bits(const EVP_PKEY *pkey)
 338 {
 339     return DH_bits(pkey->pkey.dh);
 340 }
 341
 342 static int dh_security_bits(const EVP_PKEY *pkey)
 343 {
 344     return DH_security_bits(pkey->pkey.dh);
 345 }
 346
 347 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 348 {
 349     return ffc_params_cmp(&a->pkey.dh->params, &a->pkey.dh->params,
 350                           a->ameth != &dhx_asn1_meth);
 351 }
 352
 353 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 354 {
 355     if (is_x942 == -1)
 356         is_x942 = (from->params.q != NULL);
 357     if (!ffc_params_copy(&to->params, &from->params))
 358         return 0;
 359     if (!is_x942)
 360         to->length = from->length;
 361     to->dirty_cnt++;
 362     return 1;
 363 }
 364
 365 DH *DHparams_dup(const DH *dh)
 366 {
 367     DH *ret;
 368     ret = DH_new();
 369     if (ret == NULL)
 370         return NULL;
 371     if (!int_dh_param_copy(ret, dh, -1)) {
 372         DH_free(ret);
 373         return NULL;
 374     }
 375     return ret;
 376 }
 377
 378 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 379 {
 380     if (to->pkey.dh == NULL) {
 381         to->pkey.dh = DH_new();
 382         if (to->pkey.dh == NULL)
 383             return 0;
 384     }
 385     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 386                              from->ameth == &dhx_asn1_meth);
 387 }
 388
 389 static int dh_missing_parameters(const EVP_PKEY *a)
 390 {
 391     return a->pkey.dh == NULL
 392         || a->pkey.dh->params.p == NULL
 393         || a->pkey.dh->params.g == NULL;
 394 }
 395
 396 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 397 {
 398     if (dh_cmp_parameters(a, b) == 0)
 399         return 0;
 400     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 401         return 0;
 402     else
 403         return 1;
 404 }
 405
 406 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 407                           ASN1_PCTX *ctx)
 408 {
 409     return do_dh_print(bp, pkey->pkey.dh, indent, 0);
 410 }
 411
 412 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 413                            ASN1_PCTX *ctx)
 414 {
 415     return do_dh_print(bp, pkey->pkey.dh, indent, 1);
 416 }
 417
 418 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 419                             ASN1_PCTX *ctx)
 420 {
 421     return do_dh_print(bp, pkey->pkey.dh, indent, 2);
 422 }
 423
 424 int DHparams_print(BIO *bp, const DH *x)
 425 {
 426     return do_dh_print(bp, x, 4, 0);
 427 }
 428
 429 #ifndef OPENSSL_NO_CMS
 430 static int dh_cms_decrypt(CMS_RecipientInfo *ri);
 431 static int dh_cms_encrypt(CMS_RecipientInfo *ri);
 432 #endif
 433
 434 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 435 {
 436     switch (op) {
 437     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
 438         return dh_buf2key(EVP_PKEY_get0_DH(pkey), arg2, arg1);
 439     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
 440         return dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2);
 441     default:
 442         return -2;
 443     }
 444 }
 445
 446 static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 447 {
 448     switch (op) {
 449 #ifndef OPENSSL_NO_CMS
 450
 451     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 452         if (arg1 == 1)
 453             return dh_cms_decrypt(arg2);
 454         else if (arg1 == 0)
 455             return dh_cms_encrypt(arg2);
 456         return -2;
 457
 458     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 459         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 460         return 1;
 461 #endif
 462     default:
 463         return -2;
 464     }
 465
 466 }
 467
 468 static int dh_pkey_public_check(const EVP_PKEY *pkey)
 469 {
 470     DH *dh = pkey->pkey.dh;
 471
 472     if (dh->pub_key == NULL) {
 473         DHerr(DH_F_DH_PKEY_PUBLIC_CHECK, DH_R_MISSING_PUBKEY);
 474         return 0;
 475     }
 476
 477     return DH_check_pub_key_ex(dh, dh->pub_key);
 478 }
 479
 480 static int dh_pkey_param_check(const EVP_PKEY *pkey)
 481 {
 482     DH *dh = pkey->pkey.dh;
 483
 484     return DH_check_ex(dh);
 485 }
 486
 487 static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
 488 {
 489     return pkey->pkey.dh->dirty_cnt;
 490 }
 491
 492 static int dh_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
 493                              EVP_KEYMGMT *to_keymgmt)
 494 {
 495     DH *dh = from->pkey.dh;
 496     OSSL_PARAM_BLD tmpl;
 497     const BIGNUM *p = DH_get0_p(dh), *g = DH_get0_g(dh), *q = DH_get0_q(dh);
 498     const BIGNUM *pub_key = DH_get0_pub_key(dh);
 499     const BIGNUM *priv_key = DH_get0_priv_key(dh);
 500     OSSL_PARAM *params;
 501     int selection = 0;
 502     int rv;
 503
 504     /*
 505      * If the DH method is foreign, then we can't be sure of anything, and
 506      * can therefore not export or pretend to export.
 507      */
 508     if (dh_get_method(dh) != DH_OpenSSL())
 509         return 0;
 510
 511     if (p == NULL || g == NULL)
 512         return 0;
 513
 514     ossl_param_bld_init(&tmpl);
 515     if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_FFC_P, p)
 516         || !ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_FFC_G, g))
 517         return 0;
 518     if (q != NULL) {
 519         if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_FFC_Q, q))
 520             return 0;
 521     }
 522     selection |= OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS;
 523     if (pub_key != NULL) {
 524         if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_PUB_KEY, pub_key))
 525             return 0;
 526         selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
 527     }
 528     if (priv_key != NULL) {
 529         if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_PRIV_KEY,
 530                                     priv_key))
 531             return 0;
 532         selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
 533     }
 534
 535     if ((params = ossl_param_bld_to_param(&tmpl)) == NULL)
 536         return 0;
 537
 538     /* We export, the provider imports */
 539     rv = evp_keymgmt_import(to_keymgmt, to_keydata, selection, params);
 540
 541     ossl_param_bld_free(params);
 542
 543     return rv;
 544 }
 545
 546 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
 547     EVP_PKEY_DH,
 548     EVP_PKEY_DH,
 549     0,
 550
 551     "DH",
 552     "OpenSSL PKCS#3 DH method",
 553
 554     dh_pub_decode,
 555     dh_pub_encode,
 556     dh_pub_cmp,
 557     dh_public_print,
 558
 559     dh_priv_decode,
 560     dh_priv_encode,
 561     dh_private_print,
 562
 563     int_dh_size,
 564     dh_bits,
 565     dh_security_bits,
 566
 567     dh_param_decode,
 568     dh_param_encode,
 569     dh_missing_parameters,
 570     dh_copy_parameters,
 571     dh_cmp_parameters,
 572     dh_param_print,
 573     0,
 574
 575     int_dh_free,
 576     dh_pkey_ctrl,
 577
 578     0, 0, 0, 0, 0,
 579
 580     0,
 581     dh_pkey_public_check,
 582     dh_pkey_param_check,
 583
 584     0, 0, 0, 0,
 585
 586     dh_pkey_dirty_cnt,
 587     dh_pkey_export_to,
 588 };
 589
 590 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
 591     EVP_PKEY_DHX,
 592     EVP_PKEY_DHX,
 593     0,
 594
 595     "X9.42 DH",
 596     "OpenSSL X9.42 DH method",
 597
 598     dh_pub_decode,
 599     dh_pub_encode,
 600     dh_pub_cmp,
 601     dh_public_print,
 602
 603     dh_priv_decode,
 604     dh_priv_encode,
 605     dh_private_print,
 606
 607     int_dh_size,
 608     dh_bits,
 609     dh_security_bits,
 610
 611     dh_param_decode,
 612     dh_param_encode,
 613     dh_missing_parameters,
 614     dh_copy_parameters,
 615     dh_cmp_parameters,
 616     dh_param_print,
 617     0,
 618
 619     int_dh_free,
 620     dhx_pkey_ctrl,
 621
 622     0, 0, 0, 0, 0,
 623
 624     0,
 625     dh_pkey_public_check,
 626     dh_pkey_param_check
 627 };
 628
 629 #ifndef OPENSSL_NO_CMS
 630
 631 static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 632                               X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 633 {
 634     const ASN1_OBJECT *aoid;
 635     int atype;
 636     const void *aval;
 637     ASN1_INTEGER *public_key = NULL;
 638     int rv = 0;
 639     EVP_PKEY *pkpeer = NULL, *pk = NULL;
 640     DH *dhpeer = NULL;
 641     const unsigned char *p;
 642     int plen;
 643
 644     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 645     if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
 646         goto err;
 647     /* Only absent parameters allowed in RFC XXXX */
 648     if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
 649         goto err;
 650
 651     pk = EVP_PKEY_CTX_get0_pkey(pctx);
 652     if (pk == NULL)
 653         goto err;
 654     if (pk->type != EVP_PKEY_DHX)
 655         goto err;
 656     /* Get parameters from parent key */
 657     dhpeer = DHparams_dup(pk->pkey.dh);
 658     /* We have parameters now set public key */
 659     plen = ASN1_STRING_length(pubkey);
 660     p = ASN1_STRING_get0_data(pubkey);
 661     if (p == NULL || plen == 0)
 662         goto err;
 663
 664     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) {
 665         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
 666         goto err;
 667     }
 668
 669     /* We have parameters now set public key */
 670     if ((dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
 671         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
 672         goto err;
 673     }
 674
 675     pkpeer = EVP_PKEY_new();
 676     if (pkpeer == NULL)
 677         goto err;
 678     EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
 679     dhpeer = NULL;
 680     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 681         rv = 1;
 682  err:
 683     ASN1_INTEGER_free(public_key);
 684     EVP_PKEY_free(pkpeer);
 685     DH_free(dhpeer);
 686     return rv;
 687 }
 688
 689 static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 690 {
 691     int rv = 0;
 692
 693     X509_ALGOR *alg, *kekalg = NULL;
 694     ASN1_OCTET_STRING *ukm;
 695     const unsigned char *p;
 696     unsigned char *dukm = NULL;
 697     size_t dukmlen = 0;
 698     int keylen, plen;
 699     const EVP_CIPHER *kekcipher;
 700     EVP_CIPHER_CTX *kekctx;
 701
 702     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 703         goto err;
 704
 705     /*
 706      * For DH we only have one OID permissible. If ever any more get defined
 707      * we will need something cleverer.
 708      */
 709     if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
 710         DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
 711         goto err;
 712     }
 713
 714     if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
 715         goto err;
 716
 717     if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
 718         goto err;
 719
 720     if (alg->parameter->type != V_ASN1_SEQUENCE)
 721         goto err;
 722
 723     p = alg->parameter->value.sequence->data;
 724     plen = alg->parameter->value.sequence->length;
 725     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 726     if (!kekalg)
 727         goto err;
 728     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 729     if (!kekctx)
 730         goto err;
 731     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 732     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 733         goto err;
 734     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 735         goto err;
 736     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 737         goto err;
 738
 739     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 740     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 741         goto err;
 742     /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
 743     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
 744                                      OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
 745         <= 0)
 746         goto err;
 747
 748     if (ukm) {
 749         dukmlen = ASN1_STRING_length(ukm);
 750         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
 751         if (!dukm)
 752             goto err;
 753     }
 754
 755     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 756         goto err;
 757     dukm = NULL;
 758
 759     rv = 1;
 760  err:
 761     X509_ALGOR_free(kekalg);
 762     OPENSSL_free(dukm);
 763     return rv;
 764 }
 765
 766 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 767 {
 768     EVP_PKEY_CTX *pctx;
 769
 770     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 771
 772     if (pctx == NULL)
 773         return 0;
 774     /* See if we need to set peer key */
 775     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 776         X509_ALGOR *alg;
 777         ASN1_BIT_STRING *pubkey;
 778         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 779                                                  NULL, NULL, NULL))
 780             return 0;
 781         if (!alg || !pubkey)
 782             return 0;
 783         if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
 784             DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
 785             return 0;
 786         }
 787     }
 788     /* Set DH derivation parameters and initialise unwrap context */
 789     if (!dh_cms_set_shared_info(pctx, ri)) {
 790         DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
 791         return 0;
 792     }
 793     return 1;
 794 }
 795
 796 static int dh_cms_encrypt(CMS_RecipientInfo *ri)
 797 {
 798     EVP_PKEY_CTX *pctx;
 799     EVP_PKEY *pkey;
 800     EVP_CIPHER_CTX *ctx;
 801     int keylen;
 802     X509_ALGOR *talg, *wrap_alg = NULL;
 803     const ASN1_OBJECT *aoid;
 804     ASN1_BIT_STRING *pubkey;
 805     ASN1_STRING *wrap_str;
 806     ASN1_OCTET_STRING *ukm;
 807     unsigned char *penc = NULL, *dukm = NULL;
 808     int penclen;
 809     size_t dukmlen = 0;
 810     int rv = 0;
 811     int kdf_type, wrap_nid;
 812     const EVP_MD *kdf_md;
 813
 814     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 815     if (pctx == NULL)
 816         return 0;
 817     /* Get ephemeral key */
 818     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 819     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 820                                              NULL, NULL, NULL))
 821         goto err;
 822     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 823     /* Is everything uninitialised? */
 824     if (aoid == OBJ_nid2obj(NID_undef)) {
 825         ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
 826
 827         if (pubk == NULL)
 828             goto err;
 829         /* Set the key */
 830
 831         penclen = i2d_ASN1_INTEGER(pubk, &penc);
 832         ASN1_INTEGER_free(pubk);
 833         if (penclen <= 0)
 834             goto err;
 835         ASN1_STRING_set0(pubkey, penc, penclen);
 836         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 837         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 838
 839         penc = NULL;
 840         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
 841                         V_ASN1_UNDEF, NULL);
 842     }
 843
 844     /* See if custom parameters set */
 845     kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
 846     if (kdf_type <= 0)
 847         goto err;
 848     if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
 849         goto err;
 850
 851     if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
 852         kdf_type = EVP_PKEY_DH_KDF_X9_42;
 853         if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
 854             goto err;
 855     } else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
 856         /* Unknown KDF */
 857         goto err;
 858     if (kdf_md == NULL) {
 859         /* Only SHA1 supported */
 860         kdf_md = EVP_sha1();
 861         if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
 862             goto err;
 863     } else if (EVP_MD_type(kdf_md) != NID_sha1)
 864         /* Unsupported digest */
 865         goto err;
 866
 867     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 868         goto err;
 869
 870     /* Get wrap NID */
 871     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 872     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 873     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
 874         goto err;
 875     keylen = EVP_CIPHER_CTX_key_length(ctx);
 876
 877     /* Package wrap algorithm in an AlgorithmIdentifier */
 878
 879     wrap_alg = X509_ALGOR_new();
 880     if (wrap_alg == NULL)
 881         goto err;
 882     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 883     wrap_alg->parameter = ASN1_TYPE_new();
 884     if (wrap_alg->parameter == NULL)
 885         goto err;
 886     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 887         goto err;
 888     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 889         ASN1_TYPE_free(wrap_alg->parameter);
 890         wrap_alg->parameter = NULL;
 891     }
 892
 893     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 894         goto err;
 895
 896     if (ukm) {
 897         dukmlen = ASN1_STRING_length(ukm);
 898         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
 899         if (!dukm)
 900             goto err;
 901     }
 902
 903     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 904         goto err;
 905     dukm = NULL;
 906
 907     /*
 908      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 909      * of another AlgorithmIdentifier.
 910      */
 911     penc = NULL;
 912     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 913     if (penc == NULL || penclen == 0)
 914         goto err;
 915     wrap_str = ASN1_STRING_new();
 916     if (wrap_str == NULL)
 917         goto err;
 918     ASN1_STRING_set0(wrap_str, penc, penclen);
 919     penc = NULL;
 920     X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
 921                     V_ASN1_SEQUENCE, wrap_str);
 922
 923     rv = 1;
 924
 925  err:
 926     OPENSSL_free(penc);
 927     X509_ALGOR_free(wrap_alg);
 928     OPENSSL_free(dukm);
 929     return rv;
 930 }
 931
 932 #endif