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 #include <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include <openssl/x509.h>
  13 #include <openssl/asn1.h>
  14 #include "dh_locl.h"
  15 #include <openssl/bn.h>
  16 #include "internal/asn1_int.h"
  17 #include "internal/evp_int.h"
  18 #include <openssl/cms.h>
  19 #include <openssl/core_names.h>
  20 #include "internal/param_build.h"
  21
  22 /*
  23  * i2d/d2i like DH parameter functions which use the appropriate routine for
  24  * PKCS#3 DH or X9.42 DH.
  25  */
  26
  27 static DH *d2i_dhp(const EVP_PKEY *pkey, const unsigned char **pp,
  28                    long length)
  29 {
  30     if (pkey->ameth == &dhx_asn1_meth)
  31         return d2i_DHxparams(NULL, pp, length);
  32     return d2i_DHparams(NULL, pp, length);
  33 }
  34
  35 static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
  36 {
  37     if (pkey->ameth == &dhx_asn1_meth)
  38         return i2d_DHxparams(a, pp);
  39     return i2d_DHparams(a, pp);
  40 }
  41
  42 static void int_dh_free(EVP_PKEY *pkey)
  43 {
  44     DH_free(pkey->pkey.dh);
  45 }
  46
  47 static int dh_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
  48 {
  49     const unsigned char *p, *pm;
  50     int pklen, pmlen;
  51     int ptype;
  52     const void *pval;
  53     const ASN1_STRING *pstr;
  54     X509_ALGOR *palg;
  55     ASN1_INTEGER *public_key = NULL;
  56
  57     DH *dh = NULL;
  58
  59     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
  60         return 0;
  61     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
  62
  63     if (ptype != V_ASN1_SEQUENCE) {
  64         DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
  65         goto err;
  66     }
  67
  68     pstr = pval;
  69     pm = pstr->data;
  70     pmlen = pstr->length;
  71
  72     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL) {
  73         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  74         goto err;
  75     }
  76
  77     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
  78         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  79         goto err;
  80     }
  81
  82     /* We have parameters now set public key */
  83     if ((dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
  84         DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
  85         goto err;
  86     }
  87
  88     ASN1_INTEGER_free(public_key);
  89     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
  90     return 1;
  91
  92  err:
  93     ASN1_INTEGER_free(public_key);
  94     DH_free(dh);
  95     return 0;
  96
  97 }
  98
  99 static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 100 {
 101     DH *dh;
 102     int ptype;
 103     unsigned char *penc = NULL;
 104     int penclen;
 105     ASN1_STRING *str;
 106     ASN1_INTEGER *pub_key = NULL;
 107
 108     dh = pkey->pkey.dh;
 109
 110     str = ASN1_STRING_new();
 111     if (str == NULL) {
 112         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 113         goto err;
 114     }
 115     str->length = i2d_dhp(pkey, dh, &str->data);
 116     if (str->length <= 0) {
 117         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 118         goto err;
 119     }
 120     ptype = V_ASN1_SEQUENCE;
 121
 122     pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
 123     if (!pub_key)
 124         goto err;
 125
 126     penclen = i2d_ASN1_INTEGER(pub_key, &penc);
 127
 128     ASN1_INTEGER_free(pub_key);
 129
 130     if (penclen <= 0) {
 131         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 132         goto err;
 133     }
 134
 135     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
 136                                ptype, str, penc, penclen))
 137         return 1;
 138
 139  err:
 140     OPENSSL_free(penc);
 141     ASN1_STRING_free(str);
 142
 143     return 0;
 144 }
 145
 146 /*
 147  * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
 148  * the AlgorithmIdentifier contains the parameters, the private key is
 149  * explicitly included and the pubkey must be recalculated.
 150  */
 151
 152 static int dh_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 153 {
 154     const unsigned char *p, *pm;
 155     int pklen, pmlen;
 156     int ptype;
 157     const void *pval;
 158     const ASN1_STRING *pstr;
 159     const X509_ALGOR *palg;
 160     ASN1_INTEGER *privkey = NULL;
 161
 162     DH *dh = NULL;
 163
 164     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 165         return 0;
 166
 167     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 168
 169     if (ptype != V_ASN1_SEQUENCE)
 170         goto decerr;
 171     if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
 172         goto decerr;
 173
 174     pstr = pval;
 175     pm = pstr->data;
 176     pmlen = pstr->length;
 177     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
 178         goto decerr;
 179
 180     /* We have parameters now set private key */
 181     if ((dh->priv_key = BN_secure_new()) == NULL
 182         || !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
 183         DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
 184         goto dherr;
 185     }
 186     /* Calculate public key, increments dirty_cnt */
 187     if (!DH_generate_key(dh))
 188         goto dherr;
 189
 190     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 191
 192     ASN1_STRING_clear_free(privkey);
 193
 194     return 1;
 195
 196  decerr:
 197     DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
 198  dherr:
 199     DH_free(dh);
 200     ASN1_STRING_clear_free(privkey);
 201     return 0;
 202 }
 203
 204 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 205 {
 206     ASN1_STRING *params = NULL;
 207     ASN1_INTEGER *prkey = NULL;
 208     unsigned char *dp = NULL;
 209     int dplen;
 210
 211     params = ASN1_STRING_new();
 212
 213     if (params == NULL) {
 214         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 215         goto err;
 216     }
 217
 218     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 219     if (params->length <= 0) {
 220         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 221         goto err;
 222     }
 223     params->type = V_ASN1_SEQUENCE;
 224
 225     /* Get private key into integer */
 226     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 227
 228     if (!prkey) {
 229         DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
 230         goto err;
 231     }
 232
 233     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 234
 235     ASN1_STRING_clear_free(prkey);
 236     prkey = NULL;
 237
 238     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 239                          V_ASN1_SEQUENCE, params, dp, dplen))
 240         goto err;
 241
 242     return 1;
 243
 244  err:
 245     OPENSSL_free(dp);
 246     ASN1_STRING_free(params);
 247     ASN1_STRING_clear_free(prkey);
 248     return 0;
 249 }
 250
 251 static int dh_param_decode(EVP_PKEY *pkey,
 252                            const unsigned char **pder, int derlen)
 253 {
 254     DH *dh;
 255
 256     if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL) {
 257         DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
 258         return 0;
 259     }
 260     dh->dirty_cnt++;
 261     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 262     return 1;
 263 }
 264
 265 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 266 {
 267     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 268 }
 269
 270 static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
 271 {
 272     int reason = ERR_R_BUF_LIB;
 273     const char *ktype = NULL;
 274     BIGNUM *priv_key, *pub_key;
 275
 276     if (ptype == 2)
 277         priv_key = x->priv_key;
 278     else
 279         priv_key = NULL;
 280
 281     if (ptype > 0)
 282         pub_key = x->pub_key;
 283     else
 284         pub_key = NULL;
 285
 286     if (x->p == NULL || (ptype == 2 && priv_key == NULL)
 287             || (ptype > 0 && pub_key == NULL)) {
 288         reason = ERR_R_PASSED_NULL_PARAMETER;
 289         goto err;
 290     }
 291
 292     if (ptype == 2)
 293         ktype = "DH Private-Key";
 294     else if (ptype == 1)
 295         ktype = "DH Public-Key";
 296     else
 297         ktype = "DH Parameters";
 298
 299     BIO_indent(bp, indent, 128);
 300     if (BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
 301         goto err;
 302     indent += 4;
 303
 304     if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
 305         goto err;
 306     if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
 307         goto err;
 308
 309     if (!ASN1_bn_print(bp, "prime:", x->p, NULL, indent))
 310         goto err;
 311     if (!ASN1_bn_print(bp, "generator:", x->g, NULL, indent))
 312         goto err;
 313     if (x->q && !ASN1_bn_print(bp, "subgroup order:", x->q, NULL, indent))
 314         goto err;
 315     if (x->j && !ASN1_bn_print(bp, "subgroup factor:", x->j, NULL, indent))
 316         goto err;
 317     if (x->seed) {
 318         int i;
 319         BIO_indent(bp, indent, 128);
 320         BIO_puts(bp, "seed:");
 321         for (i = 0; i < x->seedlen; i++) {
 322             if ((i % 15) == 0) {
 323                 if (BIO_puts(bp, "\n") <= 0
 324                     || !BIO_indent(bp, indent + 4, 128))
 325                     goto err;
 326             }
 327             if (BIO_printf(bp, "%02x%s", x->seed[i],
 328                            ((i + 1) == x->seedlen) ? "" : ":") <= 0)
 329                 goto err;
 330         }
 331         if (BIO_write(bp, "\n", 1) <= 0)
 332             return 0;
 333     }
 334     if (x->counter && !ASN1_bn_print(bp, "counter:", x->counter, NULL, indent))
 335         goto err;
 336     if (x->length != 0) {
 337         BIO_indent(bp, indent, 128);
 338         if (BIO_printf(bp, "recommended-private-length: %d bits\n",
 339                        (int)x->length) <= 0)
 340             goto err;
 341     }
 342
 343     return 1;
 344
 345  err:
 346     DHerr(DH_F_DO_DH_PRINT, reason);
 347     return 0;
 348 }
 349
 350 static int int_dh_size(const EVP_PKEY *pkey)
 351 {
 352     return DH_size(pkey->pkey.dh);
 353 }
 354
 355 static int dh_bits(const EVP_PKEY *pkey)
 356 {
 357     return BN_num_bits(pkey->pkey.dh->p);
 358 }
 359
 360 static int dh_security_bits(const EVP_PKEY *pkey)
 361 {
 362     return DH_security_bits(pkey->pkey.dh);
 363 }
 364
 365 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 366 {
 367     if (BN_cmp(a->pkey.dh->p, b->pkey.dh->p) ||
 368         BN_cmp(a->pkey.dh->g, b->pkey.dh->g))
 369         return 0;
 370     else if (a->ameth == &dhx_asn1_meth) {
 371         if (BN_cmp(a->pkey.dh->q, b->pkey.dh->q))
 372             return 0;
 373     }
 374     return 1;
 375 }
 376
 377 static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
 378 {
 379     BIGNUM *a;
 380
 381     /*
 382      * If source is read only just copy the pointer, so
 383      * we don't have to reallocate it.
 384      */
 385     if (src == NULL)
 386         a = NULL;
 387     else if (BN_get_flags(src, BN_FLG_STATIC_DATA)
 388                 && !BN_get_flags(src, BN_FLG_MALLOCED))
 389         a = (BIGNUM *)src;
 390     else if ((a = BN_dup(src)) == NULL)
 391         return 0;
 392     BN_clear_free(*dst);
 393     *dst = a;
 394     return 1;
 395 }
 396
 397 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 398 {
 399     if (is_x942 == -1)
 400         is_x942 = ! !from->q;
 401     if (!int_dh_bn_cpy(&to->p, from->p))
 402         return 0;
 403     if (!int_dh_bn_cpy(&to->g, from->g))
 404         return 0;
 405     if (is_x942) {
 406         if (!int_dh_bn_cpy(&to->q, from->q))
 407             return 0;
 408         if (!int_dh_bn_cpy(&to->j, from->j))
 409             return 0;
 410         OPENSSL_free(to->seed);
 411         to->seed = NULL;
 412         to->seedlen = 0;
 413         if (from->seed) {
 414             to->seed = OPENSSL_memdup(from->seed, from->seedlen);
 415             if (!to->seed)
 416                 return 0;
 417             to->seedlen = from->seedlen;
 418         }
 419     } else
 420         to->length = from->length;
 421     to->dirty_cnt++;
 422     return 1;
 423 }
 424
 425 DH *DHparams_dup(const DH *dh)
 426 {
 427     DH *ret;
 428     ret = DH_new();
 429     if (ret == NULL)
 430         return NULL;
 431     if (!int_dh_param_copy(ret, dh, -1)) {
 432         DH_free(ret);
 433         return NULL;
 434     }
 435     return ret;
 436 }
 437
 438 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 439 {
 440     if (to->pkey.dh == NULL) {
 441         to->pkey.dh = DH_new();
 442         if (to->pkey.dh == NULL)
 443             return 0;
 444     }
 445     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 446                              from->ameth == &dhx_asn1_meth);
 447 }
 448
 449 static int dh_missing_parameters(const EVP_PKEY *a)
 450 {
 451     if (a->pkey.dh == NULL || a->pkey.dh->p == NULL || a->pkey.dh->g == NULL)
 452         return 1;
 453     return 0;
 454 }
 455
 456 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 457 {
 458     if (dh_cmp_parameters(a, b) == 0)
 459         return 0;
 460     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 461         return 0;
 462     else
 463         return 1;
 464 }
 465
 466 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 467                           ASN1_PCTX *ctx)
 468 {
 469     return do_dh_print(bp, pkey->pkey.dh, indent, 0);
 470 }
 471
 472 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 473                            ASN1_PCTX *ctx)
 474 {
 475     return do_dh_print(bp, pkey->pkey.dh, indent, 1);
 476 }
 477
 478 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 479                             ASN1_PCTX *ctx)
 480 {
 481     return do_dh_print(bp, pkey->pkey.dh, indent, 2);
 482 }
 483
 484 int DHparams_print(BIO *bp, const DH *x)
 485 {
 486     return do_dh_print(bp, x, 4, 0);
 487 }
 488
 489 #ifndef OPENSSL_NO_CMS
 490 static int dh_cms_decrypt(CMS_RecipientInfo *ri);
 491 static int dh_cms_encrypt(CMS_RecipientInfo *ri);
 492 #endif
 493
 494 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 495 {
 496     switch (op) {
 497     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
 498         return dh_buf2key(EVP_PKEY_get0_DH(pkey), arg2, arg1);
 499     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
 500         return dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2);
 501     default:
 502         return -2;
 503     }
 504 }
 505
 506 static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 507 {
 508     switch (op) {
 509 #ifndef OPENSSL_NO_CMS
 510
 511     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 512         if (arg1 == 1)
 513             return dh_cms_decrypt(arg2);
 514         else if (arg1 == 0)
 515             return dh_cms_encrypt(arg2);
 516         return -2;
 517
 518     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 519         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 520         return 1;
 521 #endif
 522     default:
 523         return -2;
 524     }
 525
 526 }
 527
 528 static int dh_pkey_public_check(const EVP_PKEY *pkey)
 529 {
 530     DH *dh = pkey->pkey.dh;
 531
 532     if (dh->pub_key == NULL) {
 533         DHerr(DH_F_DH_PKEY_PUBLIC_CHECK, DH_R_MISSING_PUBKEY);
 534         return 0;
 535     }
 536
 537     return DH_check_pub_key_ex(dh, dh->pub_key);
 538 }
 539
 540 static int dh_pkey_param_check(const EVP_PKEY *pkey)
 541 {
 542     DH *dh = pkey->pkey.dh;
 543
 544     return DH_check_ex(dh);
 545 }
 546
 547 static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
 548 {
 549     return pkey->pkey.dh->dirty_cnt;
 550 }
 551
 552 static void *dh_pkey_export_to(const EVP_PKEY *pk, EVP_KEYMGMT *keymgmt)
 553 {
 554     DH *dh = pk->pkey.dh;
 555     OSSL_PARAM_BLD tmpl;
 556     const BIGNUM *p = DH_get0_p(dh), *g = DH_get0_g(dh), *q = DH_get0_q(dh);
 557     const BIGNUM *pub_key = DH_get0_pub_key(dh);
 558     const BIGNUM *priv_key = DH_get0_priv_key(dh);
 559     OSSL_PARAM *params;
 560     void *provkey = NULL;
 561
 562     if (p == NULL || g == NULL || pub_key == NULL)
 563         return NULL;
 564
 565     ossl_param_bld_init(&tmpl);
 566     if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_DH_P, p)
 567         || !ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_DH_G, g)
 568         || !ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_DH_PUB_KEY, pub_key))
 569         return NULL;
 570
 571     if (q != NULL) {
 572         if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_DH_Q, q))
 573             return NULL;
 574     }
 575
 576     if (priv_key != NULL) {
 577         if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_DH_PRIV_KEY,
 578                                     priv_key))
 579             return NULL;
 580     }
 581
 582     params = ossl_param_bld_to_param(&tmpl);
 583
 584     /* We export, the provider imports */
 585     provkey = evp_keymgmt_importkey(keymgmt, params);
 586
 587     ossl_param_bld_free(params);
 588     return provkey;
 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 };
 634
 635 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
 636     EVP_PKEY_DHX,
 637     EVP_PKEY_DHX,
 638     0,
 639
 640     "X9.42 DH",
 641     "OpenSSL X9.42 DH method",
 642
 643     dh_pub_decode,
 644     dh_pub_encode,
 645     dh_pub_cmp,
 646     dh_public_print,
 647
 648     dh_priv_decode,
 649     dh_priv_encode,
 650     dh_private_print,
 651
 652     int_dh_size,
 653     dh_bits,
 654     dh_security_bits,
 655
 656     dh_param_decode,
 657     dh_param_encode,
 658     dh_missing_parameters,
 659     dh_copy_parameters,
 660     dh_cmp_parameters,
 661     dh_param_print,
 662     0,
 663
 664     int_dh_free,
 665     dhx_pkey_ctrl,
 666
 667     0, 0, 0, 0, 0,
 668
 669     0,
 670     dh_pkey_public_check,
 671     dh_pkey_param_check
 672 };
 673
 674 #ifndef OPENSSL_NO_CMS
 675
 676 static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 677                               X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 678 {
 679     const ASN1_OBJECT *aoid;
 680     int atype;
 681     const void *aval;
 682     ASN1_INTEGER *public_key = NULL;
 683     int rv = 0;
 684     EVP_PKEY *pkpeer = NULL, *pk = NULL;
 685     DH *dhpeer = NULL;
 686     const unsigned char *p;
 687     int plen;
 688
 689     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 690     if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
 691         goto err;
 692     /* Only absent parameters allowed in RFC XXXX */
 693     if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
 694         goto err;
 695
 696     pk = EVP_PKEY_CTX_get0_pkey(pctx);
 697     if (!pk)
 698         goto err;
 699     if (pk->type != EVP_PKEY_DHX)
 700         goto err;
 701     /* Get parameters from parent key */
 702     dhpeer = DHparams_dup(pk->pkey.dh);
 703     /* We have parameters now set public key */
 704     plen = ASN1_STRING_length(pubkey);
 705     p = ASN1_STRING_get0_data(pubkey);
 706     if (!p || !plen)
 707         goto err;
 708
 709     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) {
 710         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
 711         goto err;
 712     }
 713
 714     /* We have parameters now set public key */
 715     if ((dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
 716         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
 717         goto err;
 718     }
 719
 720     pkpeer = EVP_PKEY_new();
 721     if (pkpeer == NULL)
 722         goto err;
 723     EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
 724     dhpeer = NULL;
 725     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 726         rv = 1;
 727  err:
 728     ASN1_INTEGER_free(public_key);
 729     EVP_PKEY_free(pkpeer);
 730     DH_free(dhpeer);
 731     return rv;
 732 }
 733
 734 static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 735 {
 736     int rv = 0;
 737
 738     X509_ALGOR *alg, *kekalg = NULL;
 739     ASN1_OCTET_STRING *ukm;
 740     const unsigned char *p;
 741     unsigned char *dukm = NULL;
 742     size_t dukmlen = 0;
 743     int keylen, plen;
 744     const EVP_CIPHER *kekcipher;
 745     EVP_CIPHER_CTX *kekctx;
 746
 747     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 748         goto err;
 749
 750     /*
 751      * For DH we only have one OID permissible. If ever any more get defined
 752      * we will need something cleverer.
 753      */
 754     if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
 755         DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
 756         goto err;
 757     }
 758
 759     if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
 760         goto err;
 761
 762     if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
 763         goto err;
 764
 765     if (alg->parameter->type != V_ASN1_SEQUENCE)
 766         goto err;
 767
 768     p = alg->parameter->value.sequence->data;
 769     plen = alg->parameter->value.sequence->length;
 770     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 771     if (!kekalg)
 772         goto err;
 773     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 774     if (!kekctx)
 775         goto err;
 776     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 777     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 778         goto err;
 779     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 780         goto err;
 781     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 782         goto err;
 783
 784     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 785     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 786         goto err;
 787     /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
 788     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
 789                                      OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
 790         <= 0)
 791         goto err;
 792
 793     if (ukm) {
 794         dukmlen = ASN1_STRING_length(ukm);
 795         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
 796         if (!dukm)
 797             goto err;
 798     }
 799
 800     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 801         goto err;
 802     dukm = NULL;
 803
 804     rv = 1;
 805  err:
 806     X509_ALGOR_free(kekalg);
 807     OPENSSL_free(dukm);
 808     return rv;
 809 }
 810
 811 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 812 {
 813     EVP_PKEY_CTX *pctx;
 814     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 815     if (!pctx)
 816         return 0;
 817     /* See if we need to set peer key */
 818     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 819         X509_ALGOR *alg;
 820         ASN1_BIT_STRING *pubkey;
 821         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 822                                                  NULL, NULL, NULL))
 823             return 0;
 824         if (!alg || !pubkey)
 825             return 0;
 826         if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
 827             DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
 828             return 0;
 829         }
 830     }
 831     /* Set DH derivation parameters and initialise unwrap context */
 832     if (!dh_cms_set_shared_info(pctx, ri)) {
 833         DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
 834         return 0;
 835     }
 836     return 1;
 837 }
 838
 839 static int dh_cms_encrypt(CMS_RecipientInfo *ri)
 840 {
 841     EVP_PKEY_CTX *pctx;
 842     EVP_PKEY *pkey;
 843     EVP_CIPHER_CTX *ctx;
 844     int keylen;
 845     X509_ALGOR *talg, *wrap_alg = NULL;
 846     const ASN1_OBJECT *aoid;
 847     ASN1_BIT_STRING *pubkey;
 848     ASN1_STRING *wrap_str;
 849     ASN1_OCTET_STRING *ukm;
 850     unsigned char *penc = NULL, *dukm = NULL;
 851     int penclen;
 852     size_t dukmlen = 0;
 853     int rv = 0;
 854     int kdf_type, wrap_nid;
 855     const EVP_MD *kdf_md;
 856     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 857     if (!pctx)
 858         return 0;
 859     /* Get ephemeral key */
 860     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 861     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 862                                              NULL, NULL, NULL))
 863         goto err;
 864     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 865     /* Is everything uninitialised? */
 866     if (aoid == OBJ_nid2obj(NID_undef)) {
 867         ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
 868         if (!pubk)
 869             goto err;
 870         /* Set the key */
 871
 872         penclen = i2d_ASN1_INTEGER(pubk, &penc);
 873         ASN1_INTEGER_free(pubk);
 874         if (penclen <= 0)
 875             goto err;
 876         ASN1_STRING_set0(pubkey, penc, penclen);
 877         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 878         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 879
 880         penc = NULL;
 881         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
 882                         V_ASN1_UNDEF, NULL);
 883     }
 884
 885     /* See if custom parameters set */
 886     kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
 887     if (kdf_type <= 0)
 888         goto err;
 889     if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
 890         goto err;
 891
 892     if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
 893         kdf_type = EVP_PKEY_DH_KDF_X9_42;
 894         if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
 895             goto err;
 896     } else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
 897         /* Unknown KDF */
 898         goto err;
 899     if (kdf_md == NULL) {
 900         /* Only SHA1 supported */
 901         kdf_md = EVP_sha1();
 902         if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
 903             goto err;
 904     } else if (EVP_MD_type(kdf_md) != NID_sha1)
 905         /* Unsupported digest */
 906         goto err;
 907
 908     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 909         goto err;
 910
 911     /* Get wrap NID */
 912     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 913     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 914     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
 915         goto err;
 916     keylen = EVP_CIPHER_CTX_key_length(ctx);
 917
 918     /* Package wrap algorithm in an AlgorithmIdentifier */
 919
 920     wrap_alg = X509_ALGOR_new();
 921     if (wrap_alg == NULL)
 922         goto err;
 923     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 924     wrap_alg->parameter = ASN1_TYPE_new();
 925     if (wrap_alg->parameter == NULL)
 926         goto err;
 927     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 928         goto err;
 929     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 930         ASN1_TYPE_free(wrap_alg->parameter);
 931         wrap_alg->parameter = NULL;
 932     }
 933
 934     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 935         goto err;
 936
 937     if (ukm) {
 938         dukmlen = ASN1_STRING_length(ukm);
 939         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
 940         if (!dukm)
 941             goto err;
 942     }
 943
 944     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 945         goto err;
 946     dukm = NULL;
 947
 948     /*
 949      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 950      * of another AlgorithmIdentifier.
 951      */
 952     penc = NULL;
 953     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 954     if (!penc || !penclen)
 955         goto err;
 956     wrap_str = ASN1_STRING_new();
 957     if (wrap_str == NULL)
 958         goto err;
 959     ASN1_STRING_set0(wrap_str, penc, penclen);
 960     penc = NULL;
 961     X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
 962                     V_ASN1_SEQUENCE, wrap_str);
 963
 964     rv = 1;
 965
 966  err:
 967     OPENSSL_free(penc);
 968     X509_ALGOR_free(wrap_alg);
 969     return rv;
 970 }
 971
 972 #endif