crypto/dh/dh_ameth.c

   1 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   2  * project 2006.
   3  */
   4 /* ====================================================================
   5  * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  *
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  *
  19  * 3. All advertising materials mentioning features or use of this
  20  *    software must display the following acknowledgment:
  21  *    "This product includes software developed by the OpenSSL Project
  22  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  23  *
  24  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  25  *    endorse or promote products derived from this software without
  26  *    prior written permission. For written permission, please contact
  27  *    licensing@OpenSSL.org.
  28  *
  29  * 5. Products derived from this software may not be called "OpenSSL"
  30  *    nor may "OpenSSL" appear in their names without prior written
  31  *    permission of the OpenSSL Project.
  32  *
  33  * 6. Redistributions of any form whatsoever must retain the following
  34  *    acknowledgment:
  35  *    "This product includes software developed by the OpenSSL Project
  36  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  37  *
  38  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  39  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  40  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  41  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  42  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  43  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  44  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  45  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  46  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  47  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  48  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  49  * OF THE POSSIBILITY OF SUCH DAMAGE.
  50  * ====================================================================
  51  *
  52  * This product includes cryptographic software written by Eric Young
  53  * (eay@cryptsoft.com).  This product includes software written by Tim
  54  * Hudson (tjh@cryptsoft.com).
  55  *
  56  */
  57
  58 #include <stdio.h>
  59 #include "cryptlib.h"
  60 #include <openssl/x509.h>
  61 #include <openssl/asn1.h>
  62 #include <openssl/dh.h>
  63 #include <openssl/bn.h>
  64 #include "asn1_locl.h"
  65 #ifndef OPENSSL_NO_CMS
  66 #include <openssl/cms.h>
  67 #endif
  68
  69 extern const EVP_PKEY_ASN1_METHOD dhx_asn1_meth;
  70
  71 /* i2d/d2i like DH parameter functions which use the appropriate routine
  72  * for PKCS#3 DH or X9.42 DH.
  73  */
  74
  75 static DH * d2i_dhp(const EVP_PKEY *pkey, const unsigned char **pp, long length)
  76         {
  77         if (pkey->ameth == &dhx_asn1_meth)
  78                 return d2i_DHxparams(NULL, pp, length);
  79         return d2i_DHparams(NULL, pp, length);
  80         }
  81
  82 static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
  83         {
  84         if (pkey->ameth == &dhx_asn1_meth)
  85                 return i2d_DHxparams(a, pp);
  86         return i2d_DHparams(a, pp);
  87         }
  88
  89 static void int_dh_free(EVP_PKEY *pkey)
  90         {
  91         DH_free(pkey->pkey.dh);
  92         }
  93
  94 static int dh_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
  95         {
  96         const unsigned char *p, *pm;
  97         int pklen, pmlen;
  98         int ptype;
  99         void *pval;
 100         ASN1_STRING *pstr;
 101         X509_ALGOR *palg;
 102         ASN1_INTEGER *public_key = NULL;
 103
 104         DH *dh = NULL;
 105
 106         if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
 107                 return 0;
 108         X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 109
 110         if (ptype != V_ASN1_SEQUENCE)
 111                 {
 112                 DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
 113                 goto err;
 114                 }
 115
 116         pstr = pval;
 117         pm = pstr->data;
 118         pmlen = pstr->length;
 119
 120         if (!(dh = d2i_dhp(pkey, &pm, pmlen)))
 121                 {
 122                 DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
 123                 goto err;
 124                 }
 125
 126         if (!(public_key=d2i_ASN1_INTEGER(NULL, &p, pklen)))
 127                 {
 128                 DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
 129                 goto err;
 130                 }
 131
 132         /* We have parameters now set public key */
 133         if (!(dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)))
 134                 {
 135                 DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
 136                 goto err;
 137                 }
 138
 139         ASN1_INTEGER_free(public_key);
 140         EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 141         return 1;
 142
 143         err:
 144         if (public_key)
 145                 ASN1_INTEGER_free(public_key);
 146         if (dh)
 147                 DH_free(dh);
 148         return 0;
 149
 150         }
 151
 152 static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 153         {
 154         DH *dh;
 155         void *pval = NULL;
 156         int ptype;
 157         unsigned char *penc = NULL;
 158         int penclen;
 159         ASN1_STRING *str;
 160         ASN1_INTEGER *pub_key = NULL;
 161
 162         dh=pkey->pkey.dh;
 163
 164         str = ASN1_STRING_new();
 165         str->length = i2d_dhp(pkey, dh, &str->data);
 166         if (str->length <= 0)
 167                 {
 168                 DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 169                 goto err;
 170                 }
 171         pval = str;
 172         ptype = V_ASN1_SEQUENCE;
 173
 174         pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
 175         if (!pub_key)
 176                 goto err;
 177
 178         penclen = i2d_ASN1_INTEGER(pub_key, &penc);
 179
 180         ASN1_INTEGER_free(pub_key);
 181
 182         if (penclen <= 0)
 183                 {
 184                 DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 185                 goto err;
 186                 }
 187
 188         if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
 189                                 ptype, pval, penc, penclen))
 190                 return 1;
 191
 192         err:
 193         if (penc)
 194                 OPENSSL_free(penc);
 195         if (pval)
 196                 ASN1_STRING_free(pval);
 197
 198         return 0;
 199         }
 200
 201
 202 /* PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in
 203  * that the AlgorithmIdentifier contains the parameters, the private key
 204  * is explcitly included and the pubkey must be recalculated.
 205  */
 206
 207 static int dh_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
 208         {
 209         const unsigned char *p, *pm;
 210         int pklen, pmlen;
 211         int ptype;
 212         void *pval;
 213         ASN1_STRING *pstr;
 214         X509_ALGOR *palg;
 215         ASN1_INTEGER *privkey = NULL;
 216
 217         DH *dh = NULL;
 218
 219         if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 220                 return 0;
 221
 222         X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 223
 224         if (ptype != V_ASN1_SEQUENCE)
 225                         goto decerr;
 226
 227         if (!(privkey=d2i_ASN1_INTEGER(NULL, &p, pklen)))
 228                 goto decerr;
 229
 230
 231         pstr = pval;
 232         pm = pstr->data;
 233         pmlen = pstr->length;
 234         if (!(dh = d2i_dhp(pkey, &pm, pmlen)))
 235                 goto decerr;
 236         /* We have parameters now set private key */
 237         if (!(dh->priv_key = ASN1_INTEGER_to_BN(privkey, NULL)))
 238                 {
 239                 DHerr(DH_F_DH_PRIV_DECODE,DH_R_BN_ERROR);
 240                 goto dherr;
 241                 }
 242         /* Calculate public key */
 243         if (!DH_generate_key(dh))
 244                 goto dherr;
 245
 246         EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 247
 248         ASN1_INTEGER_free(privkey);
 249
 250         return 1;
 251
 252         decerr:
 253         DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
 254         dherr:
 255         DH_free(dh);
 256         return 0;
 257         }
 258
 259 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 260 {
 261         ASN1_STRING *params = NULL;
 262         ASN1_INTEGER *prkey = NULL;
 263         unsigned char *dp = NULL;
 264         int dplen;
 265
 266         params = ASN1_STRING_new();
 267
 268         if (!params)
 269                 {
 270                 DHerr(DH_F_DH_PRIV_ENCODE,ERR_R_MALLOC_FAILURE);
 271                 goto err;
 272                 }
 273
 274         params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 275         if (params->length <= 0)
 276                 {
 277                 DHerr(DH_F_DH_PRIV_ENCODE,ERR_R_MALLOC_FAILURE);
 278                 goto err;
 279                 }
 280         params->type = V_ASN1_SEQUENCE;
 281
 282         /* Get private key into integer */
 283         prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 284
 285         if (!prkey)
 286                 {
 287                 DHerr(DH_F_DH_PRIV_ENCODE,DH_R_BN_ERROR);
 288                 goto err;
 289                 }
 290
 291         dplen = i2d_ASN1_INTEGER(prkey, &dp);
 292
 293         ASN1_INTEGER_free(prkey);
 294
 295         if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 296                                 V_ASN1_SEQUENCE, params, dp, dplen))
 297                 goto err;
 298
 299         return 1;
 300
 301 err:
 302         if (dp != NULL)
 303                 OPENSSL_free(dp);
 304         if (params != NULL)
 305                 ASN1_STRING_free(params);
 306         if (prkey != NULL)
 307                 ASN1_INTEGER_free(prkey);
 308         return 0;
 309 }
 310
 311
 312 static void update_buflen(const BIGNUM *b, size_t *pbuflen)
 313         {
 314         size_t i;
 315         if (!b)
 316                 return;
 317         if (*pbuflen < (i = (size_t)BN_num_bytes(b)))
 318                         *pbuflen = i;
 319         }
 320
 321 static int dh_param_decode(EVP_PKEY *pkey,
 322                                         const unsigned char **pder, int derlen)
 323         {
 324         DH *dh;
 325         if (!(dh = d2i_dhp(pkey, pder, derlen)))
 326                 {
 327                 DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
 328                 return 0;
 329                 }
 330         EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 331         return 1;
 332         }
 333
 334 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 335         {
 336         return i2d_dhp(pkey, pkey->pkey.dh, pder);
 337         }
 338
 339 static int do_dh_print(BIO *bp, const DH *x, int indent,
 340                                                 ASN1_PCTX *ctx, int ptype)
 341         {
 342         unsigned char *m=NULL;
 343         int reason=ERR_R_BUF_LIB,ret=0;
 344         size_t buf_len=0;
 345
 346         const char *ktype = NULL;
 347
 348         BIGNUM *priv_key, *pub_key;
 349
 350         if (ptype == 2)
 351                 priv_key = x->priv_key;
 352         else
 353                 priv_key = NULL;
 354
 355         if (ptype > 0)
 356                 pub_key = x->pub_key;
 357         else
 358                 pub_key = NULL;
 359
 360         update_buflen(x->p, &buf_len);
 361
 362         if (buf_len == 0)
 363                 {
 364                 reason = ERR_R_PASSED_NULL_PARAMETER;
 365                 goto err;
 366                 }
 367
 368         update_buflen(x->g, &buf_len);
 369         update_buflen(x->q, &buf_len);
 370         update_buflen(x->j, &buf_len);
 371         update_buflen(x->counter, &buf_len);
 372         update_buflen(pub_key, &buf_len);
 373         update_buflen(priv_key, &buf_len);
 374
 375         if (ptype == 2)
 376                 ktype = "DH Private-Key";
 377         else if (ptype == 1)
 378                 ktype = "DH Public-Key";
 379         else
 380                 ktype = "DH Parameters";
 381
 382         m= OPENSSL_malloc(buf_len+10);
 383         if (m == NULL)
 384                 {
 385                 reason=ERR_R_MALLOC_FAILURE;
 386                 goto err;
 387                 }
 388
 389         BIO_indent(bp, indent, 128);
 390         if (BIO_printf(bp,"%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
 391                 goto err;
 392         indent += 4;
 393
 394         if (!ASN1_bn_print(bp,"private-key:",priv_key,m,indent)) goto err;
 395         if (!ASN1_bn_print(bp,"public-key:",pub_key,m,indent)) goto err;
 396
 397         if (!ASN1_bn_print(bp,"prime:",x->p,m,indent)) goto err;
 398         if (!ASN1_bn_print(bp,"generator:",x->g,m,indent)) goto err;
 399         if (x->q && !ASN1_bn_print(bp,"subgroup order:",x->q,m,indent)) goto err;
 400         if (x->j && !ASN1_bn_print(bp,"subgroup factor:",x->j,m,indent))
 401                 goto err;
 402         if (x->seed)
 403                 {
 404                 int i;
 405                 BIO_indent(bp, indent, 128);
 406                 BIO_puts(bp, "seed:");
 407                 for (i=0; i < x->seedlen; i++)
 408                         {
 409                         if ((i%15) == 0)
 410                                 {
 411                                 if(BIO_puts(bp,"\n") <= 0
 412                                    || !BIO_indent(bp,indent+4,128))
 413                                     goto err;
 414                                 }
 415                         if (BIO_printf(bp,"%02x%s", x->seed[i],
 416                                         ((i+1) == x->seedlen)?"":":") <= 0)
 417                                 goto err;
 418                         }
 419                 if (BIO_write(bp,"\n",1) <= 0) return(0);
 420                 }
 421         if (x->counter && !ASN1_bn_print(bp,"counter:",x->counter,m,indent))
 422                 goto err;
 423         if (x->length != 0)
 424                 {
 425                 BIO_indent(bp, indent, 128);
 426                 if (BIO_printf(bp,"recommended-private-length: %d bits\n",
 427                         (int)x->length) <= 0) goto err;
 428                 }
 429
 430
 431         ret=1;
 432         if (0)
 433                 {
 434 err:
 435                 DHerr(DH_F_DO_DH_PRINT,reason);
 436                 }
 437         if (m != NULL) OPENSSL_free(m);
 438         return(ret);
 439         }
 440
 441 static int int_dh_size(const EVP_PKEY *pkey)
 442         {
 443         return(DH_size(pkey->pkey.dh));
 444         }
 445
 446 static int dh_bits(const EVP_PKEY *pkey)
 447         {
 448         return BN_num_bits(pkey->pkey.dh->p);
 449         }
 450
 451 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 452         {
 453         if (    BN_cmp(a->pkey.dh->p,b->pkey.dh->p) ||
 454                 BN_cmp(a->pkey.dh->g,b->pkey.dh->g))
 455                 return 0;
 456         else if (a->ameth == &dhx_asn1_meth)
 457                 {
 458                 if (BN_cmp(a->pkey.dh->q,b->pkey.dh->q))
 459                         return 0;
 460                 }
 461         return 1;
 462         }
 463
 464 static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
 465         {
 466         BIGNUM *a;
 467         if (src)
 468                 {
 469                 a = BN_dup(src);
 470                 if (!a)
 471                         return 0;
 472                 }
 473         else
 474                 a = NULL;
 475         if (*dst)
 476                 BN_free(*dst);
 477         *dst = a;
 478         return 1;
 479         }
 480
 481 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 482         {
 483         if (is_x942 == -1)
 484                 is_x942 = !!from->q;
 485         if (!int_dh_bn_cpy(&to->p, from->p))
 486                 return 0;
 487         if (!int_dh_bn_cpy(&to->g, from->g))
 488                 return 0;
 489         if (is_x942)
 490                 {
 491                 if (!int_dh_bn_cpy(&to->q, from->q))
 492                         return 0;
 493                 if (!int_dh_bn_cpy(&to->j, from->j))
 494                         return 0;
 495                 if(to->seed)
 496                         {
 497                         OPENSSL_free(to->seed);
 498                         to->seed = NULL;
 499                         to->seedlen = 0;
 500                         }
 501                 if (from->seed)
 502                         {
 503                         to->seed = BUF_memdup(from->seed, from->seedlen);
 504                         if (!to->seed)
 505                                 return 0;
 506                         to->seedlen = from->seedlen;
 507                         }
 508                 }
 509         else
 510                 to->length = from->length;
 511         return 1;
 512         }
 513
 514
 515 DH *DHparams_dup(DH *dh)
 516         {
 517         DH *ret;
 518         ret = DH_new();
 519         if (!ret)
 520                 return NULL;
 521         if (!int_dh_param_copy(ret, dh, -1))
 522                 {
 523                 DH_free(ret);
 524                 return NULL;
 525                 }
 526         return ret;
 527         }
 528
 529 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 530         {
 531         return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 532                                  from->ameth == &dhx_asn1_meth);
 533         }
 534
 535 static int dh_missing_parameters(const EVP_PKEY *a)
 536         {
 537         if (!a->pkey.dh->p || !a->pkey.dh->g)
 538                 return 1;
 539         return 0;
 540         }
 541
 542 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 543         {
 544         if (dh_cmp_parameters(a, b) == 0)
 545                 return 0;
 546         if (BN_cmp(b->pkey.dh->pub_key,a->pkey.dh->pub_key) != 0)
 547                 return 0;
 548         else
 549                 return 1;
 550         }
 551
 552 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 553                                                         ASN1_PCTX *ctx)
 554         {
 555         return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 0);
 556         }
 557
 558 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 559                                                         ASN1_PCTX *ctx)
 560         {
 561         return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 1);
 562         }
 563
 564 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 565                                                         ASN1_PCTX *ctx)
 566         {
 567         return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 2);
 568         }
 569
 570 int DHparams_print(BIO *bp, const DH *x)
 571         {
 572         return do_dh_print(bp, x, 4, NULL, 0);
 573         }
 574
 575 #ifndef OPENSSL_NO_CMS
 576 static int dh_cms_decrypt(CMS_RecipientInfo *ri);
 577 static int dh_cms_encrypt(CMS_RecipientInfo *ri);
 578 #endif
 579
 580 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 581         {
 582         switch (op)
 583                 {
 584 #ifndef OPENSSL_NO_CMS
 585
 586                 case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 587                 if (arg1 == 1)
 588                         return dh_cms_decrypt(arg2);
 589                 else if (arg1 == 0)
 590                         return dh_cms_encrypt(arg2);
 591                 return -2;
 592
 593                 case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 594                 *(int *)arg2 = CMS_RECIPINFO_AGREE;
 595                 return 1;
 596 #endif
 597                 default:
 598                 return -2;
 599                 }
 600
 601         }
 602
 603 const EVP_PKEY_ASN1_METHOD dh_asn1_meth =
 604         {
 605         EVP_PKEY_DH,
 606         EVP_PKEY_DH,
 607         0,
 608
 609         "DH",
 610         "OpenSSL PKCS#3 DH method",
 611
 612         dh_pub_decode,
 613         dh_pub_encode,
 614         dh_pub_cmp,
 615         dh_public_print,
 616
 617         dh_priv_decode,
 618         dh_priv_encode,
 619         dh_private_print,
 620
 621         int_dh_size,
 622         dh_bits,
 623
 624         dh_param_decode,
 625         dh_param_encode,
 626         dh_missing_parameters,
 627         dh_copy_parameters,
 628         dh_cmp_parameters,
 629         dh_param_print,
 630         0,
 631
 632         int_dh_free,
 633         0
 634         };
 635
 636 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth =
 637         {
 638         EVP_PKEY_DHX,
 639         EVP_PKEY_DHX,
 640         0,
 641
 642         "X9.42 DH",
 643         "OpenSSL X9.42 DH method",
 644
 645         dh_pub_decode,
 646         dh_pub_encode,
 647         dh_pub_cmp,
 648         dh_public_print,
 649
 650         dh_priv_decode,
 651         dh_priv_encode,
 652         dh_private_print,
 653
 654         int_dh_size,
 655         dh_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         dh_pkey_ctrl
 667         };
 668 #ifndef OPENSSL_NO_CMS
 669
 670 static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 671                                 X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 672         {
 673         ASN1_OBJECT *aoid;
 674         int atype;
 675         void *aval;
 676         ASN1_INTEGER *public_key = NULL;
 677         int rv = 0;
 678         EVP_PKEY *pkpeer = NULL, *pk = NULL;
 679         DH *dhpeer = NULL;
 680         const unsigned char *p;
 681         int plen;
 682
 683         X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 684         if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
 685                 goto err;
 686         /* Only absent parameters allowed in RFC XXXX */
 687         if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
 688                 goto err;
 689
 690         pk = EVP_PKEY_CTX_get0_pkey(pctx);
 691         if (!pk)
 692                 goto err;
 693         if (pk->type != EVP_PKEY_DHX)
 694                 goto err;
 695         /* Get parameters from parent key */
 696         dhpeer = DHparams_dup(pk->pkey.dh);
 697         /* We have parameters now set public key */
 698         plen = ASN1_STRING_length(pubkey);
 699         p = ASN1_STRING_data(pubkey);
 700         if (!p || !plen)
 701                 goto err;
 702
 703         if (!(public_key=d2i_ASN1_INTEGER(NULL, &p, plen)))
 704                 {
 705                 DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
 706                 goto err;
 707                 }
 708
 709         /* We have parameters now set public key */
 710         if (!(dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)))
 711                 {
 712                 DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
 713                 goto err;
 714                 }
 715
 716         pkpeer = EVP_PKEY_new();
 717         if (!pkpeer)
 718                 goto err;
 719         EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
 720         dhpeer = NULL;
 721         if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 722                 rv = 1;
 723         err:
 724         if (public_key)
 725                 ASN1_INTEGER_free(public_key);
 726         if (pkpeer)
 727                 EVP_PKEY_free(pkpeer);
 728         if (dhpeer)
 729                 DH_free(dhpeer);
 730         return rv;
 731         }
 732
 733 static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 734         {
 735         int rv = 0;
 736
 737         X509_ALGOR *alg, *kekalg = NULL;
 738         ASN1_OCTET_STRING *ukm;
 739         const unsigned char *p;
 740         unsigned char *dukm = NULL;
 741         size_t dukmlen = 0;
 742         int keylen, plen;
 743         const EVP_CIPHER *kekcipher;
 744         EVP_CIPHER_CTX *kekctx;
 745
 746         if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 747                 goto err;
 748
 749         /* For DH we only have one OID permissible. If ever any more get
 750          * defined we will need something cleverer.
 751          */
 752         if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH)
 753                 {
 754                 DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
 755                 goto err;
 756                 }
 757
 758         if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
 759                 goto err;
 760
 761         if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
 762                 goto err;
 763
 764         if (alg->parameter->type != V_ASN1_SEQUENCE)
 765                 goto err;
 766
 767         p = alg->parameter->value.sequence->data;
 768         plen = alg->parameter->value.sequence->length;
 769         kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 770         if (!kekalg)
 771                 goto err;
 772         kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 773         if (!kekctx)
 774                 goto err;
 775         kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 776         if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 777                 goto err;
 778         if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 779                 goto err;
 780         if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 781                 goto err;
 782
 783         keylen = EVP_CIPHER_CTX_key_length(kekctx);
 784         if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 785                 goto err;
 786         /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
 787         if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
 788                                 OBJ_nid2obj(EVP_CIPHER_type(kekcipher))) <= 0)
 789                 goto err;
 790
 791         if (ukm)
 792                 {
 793                 dukmlen = ASN1_STRING_length(ukm);
 794                 dukm = BUF_memdup(ASN1_STRING_data(ukm), dukmlen);
 795                 if (!dukm)
 796                         goto err;
 797                 }
 798
 799         if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 800                 goto err;
 801         dukm = NULL;
 802
 803         rv = 1;
 804         err:
 805         if (kekalg)
 806                 X509_ALGOR_free(kekalg);
 807         if (dukm)
 808                 OPENSSL_free(dukm);
 809         return rv;
 810         }
 811
 812 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 813         {
 814         EVP_PKEY_CTX *pctx;
 815         pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 816         if (!pctx)
 817                 return 0;
 818         /* See if we need to set peer key */
 819         if (!EVP_PKEY_CTX_get0_peerkey(pctx))
 820                 {
 821                 X509_ALGOR *alg;
 822                 ASN1_BIT_STRING *pubkey;
 823                 if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 824                                                         NULL, NULL, NULL))
 825                         return 0;
 826                 if (!alg || !pubkey)
 827                         return 0;
 828                 if (!dh_cms_set_peerkey(pctx, alg, pubkey))
 829                         {
 830                         DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
 831                         return 0;
 832                         }
 833                 }
 834         /* Set DH derivation parameters and initialise unwrap context */
 835         if (!dh_cms_set_shared_info(pctx, ri))
 836                 {
 837                 DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
 838                 return 0;
 839                 }
 840         return 1;
 841         }
 842
 843 static int dh_cms_encrypt(CMS_RecipientInfo *ri)
 844         {
 845         EVP_PKEY_CTX *pctx;
 846         EVP_PKEY *pkey;
 847         EVP_CIPHER_CTX *ctx;
 848         int keylen;
 849         X509_ALGOR *talg, *wrap_alg = NULL;
 850         ASN1_OBJECT *aoid;
 851         ASN1_BIT_STRING *pubkey;
 852         ASN1_STRING *wrap_str;
 853         ASN1_OCTET_STRING *ukm;
 854         unsigned char *penc = NULL, *dukm = NULL;
 855         int penclen;
 856         size_t dukmlen = 0;
 857         int rv = 0;
 858         int kdf_type, wrap_nid;
 859         const EVP_MD *kdf_md;
 860         pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 861         if (!pctx)
 862                 return 0;
 863         /* Get ephemeral key */
 864         pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 865         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 866                                                         NULL, NULL, NULL))
 867                 goto err;
 868         X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 869         /* Is everything uninitialised? */
 870         if (aoid == OBJ_nid2obj(NID_undef))
 871                 {
 872                 ASN1_INTEGER *pubk;
 873                 pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
 874                 if (!pubk)
 875                         goto err;
 876                 /* Set the key */
 877
 878                 penclen = i2d_ASN1_INTEGER(pubk, &penc);
 879                 ASN1_INTEGER_free(pubk);
 880                 if (penclen <= 0)
 881                         goto err;
 882                 ASN1_STRING_set0(pubkey, penc, penclen);
 883                 pubkey->flags&= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07);
 884                 pubkey->flags|=ASN1_STRING_FLAG_BITS_LEFT;
 885
 886                 penc = NULL;
 887                 X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
 888                                                         V_ASN1_UNDEF, NULL);
 889                 }
 890
 891         /* See if custom paraneters set */
 892         kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
 893         if (kdf_type <= 0)
 894                 goto err;
 895         if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
 896                 goto err;
 897
 898         if (kdf_type == EVP_PKEY_DH_KDF_NONE)
 899                 {
 900                 kdf_type = EVP_PKEY_DH_KDF_X9_42;
 901                 if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
 902                         goto err;
 903                 }
 904         else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
 905                 /* Unknown KDF */
 906                 goto err;
 907         if (kdf_md == NULL)
 908                 {
 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                 }
 914         else if (EVP_MD_type(kdf_md) != NID_sha1)
 915                 /* Unsupported digest */
 916                 goto err;
 917
 918         if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 919                 goto err;
 920
 921         /* Get wrap NID */
 922         ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 923         wrap_nid = EVP_CIPHER_CTX_type(ctx);
 924         if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
 925                 goto err;
 926         keylen = EVP_CIPHER_CTX_key_length(ctx);
 927
 928         /* Package wrap algorithm in an AlgorithmIdentifier */
 929
 930         wrap_alg = X509_ALGOR_new();
 931         if (!wrap_alg)
 932                 goto err;
 933         wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 934         wrap_alg->parameter = ASN1_TYPE_new();
 935         if (!wrap_alg->parameter)
 936                 goto err;
 937         if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 938                 goto err;
 939         if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef)
 940                 {
 941                 ASN1_TYPE_free(wrap_alg->parameter);
 942                 wrap_alg->parameter = NULL;
 943                 }
 944
 945         if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 946                 goto err;
 947
 948         if (ukm)
 949                 {
 950                 dukmlen = ASN1_STRING_length(ukm);
 951                 dukm = BUF_memdup(ASN1_STRING_data(ukm), dukmlen);
 952                 if (!dukm)
 953                         goto err;
 954                 }
 955
 956         if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 957                 goto err;
 958         dukm = NULL;
 959
 960         /* Now need to wrap encoding of wrap AlgorithmIdentifier into
 961          * parameter of another AlgorithmIdentifier.
 962          */
 963         penc = NULL;
 964         penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 965         if (!penc || !penclen)
 966                 goto err;
 967         wrap_str = ASN1_STRING_new();
 968         if (!wrap_str)
 969                 goto err;
 970         ASN1_STRING_set0(wrap_str, penc, penclen);
 971         penc = NULL;
 972         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
 973                                                 V_ASN1_SEQUENCE, wrap_str);
 974
 975         rv = 1;
 976
 977         err:
 978         if (penc)
 979                 OPENSSL_free(penc);
 980         if (wrap_alg)
 981                 X509_ALGOR_free(wrap_alg);
 982         return rv;
 983         }
 984
 985 #endif
 986