crypto/crmf/crmf_lib.c

   1 /*-
   2  * Copyright 2007-2020 The OpenSSL Project Authors. All Rights Reserved.
   3  * Copyright Nokia 2007-2018
   4  * Copyright Siemens AG 2015-2019
   5  *
   6  * Licensed under the Apache License 2.0 (the "License").  You may not use
   7  * this file except in compliance with the License.  You can obtain a copy
   8  * in the file LICENSE in the source distribution or at
   9  * https://www.openssl.org/source/license.html
  10  *
  11  * CRMF implementation by Martin Peylo, Miikka Viljanen, and David von Oheimb.
  12  */
  13
  14 /*
  15  * This file contains the functions that handle the individual items inside
  16  * the CRMF structures
  17  */
  18
  19 /*
  20  * NAMING
  21  *
  22  * The 0 functions use the supplied structure pointer directly in the parent and
  23  * it will be freed up when the parent is freed.
  24  *
  25  * The 1 functions use a copy of the supplied structure pointer (or in some
  26  * cases increases its link count) in the parent and so both should be freed up.
  27  */
  28
  29 #include <openssl/asn1t.h>
  30
  31 #include "crmf_local.h"
  32 #include "internal/constant_time.h"
  33
  34 /* explicit #includes not strictly needed since implied by the above: */
  35 #include <openssl/crmf.h>
  36 #include <openssl/err.h>
  37 #include <openssl/evp.h>
  38
  39 DEFINE_STACK_OF(OSSL_CRMF_MSG)
  40
  41 /*-
  42  * atyp = Attribute Type
  43  * valt = Value Type
  44  * ctrlinf = "regCtrl" or "regInfo"
  45  */
  46 #define IMPLEMENT_CRMF_CTRL_FUNC(atyp, valt, ctrlinf)                     \
  47 int OSSL_CRMF_MSG_set1_##ctrlinf##_##atyp(OSSL_CRMF_MSG *msg,             \
  48                                           const valt *in)                 \
  49 {                                                                         \
  50     OSSL_CRMF_ATTRIBUTETYPEANDVALUE *atav = NULL;                         \
  51                                                                           \
  52     if (msg == NULL || in == NULL)                                       \
  53         goto err;                                                         \
  54     if ((atav = OSSL_CRMF_ATTRIBUTETYPEANDVALUE_new()) == NULL)           \
  55         goto err;                                                         \
  56     if ((atav->type = OBJ_nid2obj(NID_id_##ctrlinf##_##atyp)) == NULL)    \
  57         goto err;                                                         \
  58     if ((atav->value.atyp = valt##_dup(in)) == NULL)                      \
  59         goto err;                                                         \
  60     if (!OSSL_CRMF_MSG_push0_##ctrlinf(msg, atav))                        \
  61         goto err;                                                         \
  62     return 1;                                                             \
  63  err:                                                                     \
  64     OSSL_CRMF_ATTRIBUTETYPEANDVALUE_free(atav);                           \
  65     return 0;                                                             \
  66 }
  67
  68
  69 /*-
  70  * Pushes the given control attribute into the controls stack of a CertRequest
  71  * (section 6)
  72  * returns 1 on success, 0 on error
  73  */
  74 static int OSSL_CRMF_MSG_push0_regCtrl(OSSL_CRMF_MSG *crm,
  75                                        OSSL_CRMF_ATTRIBUTETYPEANDVALUE *ctrl)
  76 {
  77     int new = 0;
  78
  79     if (crm == NULL || crm->certReq == NULL || ctrl == NULL) {
  80         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_REGCTRL, CRMF_R_NULL_ARGUMENT);
  81         return 0;
  82     }
  83
  84     if (crm->certReq->controls == NULL) {
  85         crm->certReq->controls = sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_new_null();
  86         if (crm->certReq->controls == NULL)
  87             goto err;
  88         new = 1;
  89     }
  90     if (!sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_push(crm->certReq->controls, ctrl))
  91         goto err;
  92
  93     return 1;
  94  err:
  95     if (new != 0) {
  96         sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_free(crm->certReq->controls);
  97         crm->certReq->controls = NULL;
  98     }
  99     return 0;
 100 }
 101
 102 /* id-regCtrl-regToken Control (section 6.1) */
 103 IMPLEMENT_CRMF_CTRL_FUNC(regToken, ASN1_STRING, regCtrl)
 104
 105 /* id-regCtrl-authenticator Control (section 6.2) */
 106 #define ASN1_UTF8STRING_dup ASN1_STRING_dup
 107 IMPLEMENT_CRMF_CTRL_FUNC(authenticator, ASN1_UTF8STRING, regCtrl)
 108
 109 int OSSL_CRMF_MSG_set0_SinglePubInfo(OSSL_CRMF_SINGLEPUBINFO *spi,
 110                                      int method, GENERAL_NAME *nm)
 111 {
 112     if (spi == NULL
 113             || method < OSSL_CRMF_PUB_METHOD_DONTCARE
 114             || method > OSSL_CRMF_PUB_METHOD_LDAP) {
 115         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_SINGLEPUBINFO,
 116                 ERR_R_PASSED_INVALID_ARGUMENT);
 117         return 0;
 118     }
 119
 120     if (!ASN1_INTEGER_set(spi->pubMethod, method))
 121         return 0;
 122     GENERAL_NAME_free(spi->pubLocation);
 123     spi->pubLocation = nm;
 124     return 1;
 125 }
 126
 127 int
 128 OSSL_CRMF_MSG_PKIPublicationInfo_push0_SinglePubInfo(OSSL_CRMF_PKIPUBLICATIONINFO *pi,
 129                                                      OSSL_CRMF_SINGLEPUBINFO *spi)
 130 {
 131     if (pi == NULL || spi == NULL) {
 132         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PKIPUBLICATIONINFO_PUSH0_SINGLEPUBINFO,
 133                 CRMF_R_NULL_ARGUMENT);
 134         return 0;
 135     }
 136     if (pi->pubInfos == NULL)
 137         pi->pubInfos = sk_OSSL_CRMF_SINGLEPUBINFO_new_null();
 138     if (pi->pubInfos == NULL)
 139         return 0;
 140
 141     return sk_OSSL_CRMF_SINGLEPUBINFO_push(pi->pubInfos, spi);
 142 }
 143
 144 int OSSL_CRMF_MSG_set_PKIPublicationInfo_action(OSSL_CRMF_PKIPUBLICATIONINFO *pi,
 145                                                 int action)
 146 {
 147     if (pi == NULL
 148             || action < OSSL_CRMF_PUB_ACTION_DONTPUBLISH
 149             || action > OSSL_CRMF_PUB_ACTION_PLEASEPUBLISH) {
 150         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET_PKIPUBLICATIONINFO_ACTION,
 151                 ERR_R_PASSED_INVALID_ARGUMENT);
 152         return 0;
 153     }
 154
 155     return ASN1_INTEGER_set(pi->action, action);
 156 }
 157
 158 /* id-regCtrl-pkiPublicationInfo Control (section 6.3) */
 159 IMPLEMENT_CRMF_CTRL_FUNC(pkiPublicationInfo, OSSL_CRMF_PKIPUBLICATIONINFO,
 160                          regCtrl)
 161
 162 /* id-regCtrl-oldCertID Control (section 6.5) from the given */
 163 IMPLEMENT_CRMF_CTRL_FUNC(oldCertID, OSSL_CRMF_CERTID, regCtrl)
 164
 165 OSSL_CRMF_CERTID *OSSL_CRMF_CERTID_gen(const X509_NAME *issuer,
 166                                        const ASN1_INTEGER *serial)
 167 {
 168     OSSL_CRMF_CERTID *cid = NULL;
 169
 170     if (issuer == NULL || serial == NULL) {
 171         CRMFerr(CRMF_F_OSSL_CRMF_CERTID_GEN, CRMF_R_NULL_ARGUMENT);
 172         return NULL;
 173     }
 174
 175     if ((cid = OSSL_CRMF_CERTID_new()) == NULL)
 176         goto err;
 177
 178     if (!X509_NAME_set(&cid->issuer->d.directoryName, issuer))
 179         goto err;
 180     cid->issuer->type = GEN_DIRNAME;
 181
 182     ASN1_INTEGER_free(cid->serialNumber);
 183     if ((cid->serialNumber = ASN1_INTEGER_dup(serial)) == NULL)
 184         goto err;
 185
 186     return cid;
 187
 188  err:
 189     OSSL_CRMF_CERTID_free(cid);
 190     return NULL;
 191 }
 192
 193 /*
 194  * id-regCtrl-protocolEncrKey Control (section 6.6)
 195  */
 196 IMPLEMENT_CRMF_CTRL_FUNC(protocolEncrKey, X509_PUBKEY, regCtrl)
 197
 198 /*-
 199  * Pushes the attribute given in regInfo in to the CertReqMsg->regInfo stack.
 200  * (section 7)
 201  * returns 1 on success, 0 on error
 202  */
 203 static int OSSL_CRMF_MSG_push0_regInfo(OSSL_CRMF_MSG *crm,
 204                                        OSSL_CRMF_ATTRIBUTETYPEANDVALUE *ri)
 205 {
 206     STACK_OF(OSSL_CRMF_ATTRIBUTETYPEANDVALUE) *info = NULL;
 207
 208     if (crm == NULL || ri == NULL) {
 209         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_REGINFO, CRMF_R_NULL_ARGUMENT);
 210         return 0;
 211     }
 212
 213     if (crm->regInfo == NULL)
 214         crm->regInfo = info = sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_new_null();
 215     if (crm->regInfo == NULL)
 216         goto err;
 217     if (!sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_push(crm->regInfo, ri))
 218         goto err;
 219     return 1;
 220
 221  err:
 222     if (info != NULL)
 223         crm->regInfo = NULL;
 224     sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_free(info);
 225     return 0;
 226 }
 227
 228 /* id-regInfo-utf8Pairs to regInfo (section 7.1) */
 229 IMPLEMENT_CRMF_CTRL_FUNC(utf8Pairs, ASN1_UTF8STRING, regInfo)
 230
 231 /* id-regInfo-certReq to regInfo (section 7.2) */
 232 IMPLEMENT_CRMF_CTRL_FUNC(certReq, OSSL_CRMF_CERTREQUEST, regInfo)
 233
 234
 235 /* retrieves the certificate template of crm */
 236 OSSL_CRMF_CERTTEMPLATE *OSSL_CRMF_MSG_get0_tmpl(const OSSL_CRMF_MSG *crm)
 237 {
 238     if (crm == NULL || crm->certReq == NULL) {
 239         CRMFerr(CRMF_F_OSSL_CRMF_MSG_GET0_TMPL, CRMF_R_NULL_ARGUMENT);
 240         return NULL;
 241     }
 242     return crm->certReq->certTemplate;
 243 }
 244
 245
 246 int OSSL_CRMF_MSG_set0_validity(OSSL_CRMF_MSG *crm,
 247                                 ASN1_TIME *notBefore, ASN1_TIME *notAfter)
 248 {
 249     OSSL_CRMF_OPTIONALVALIDITY *vld;
 250     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 251
 252     if (tmpl == NULL) { /* also crm == NULL implies this */
 253         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_VALIDITY, CRMF_R_NULL_ARGUMENT);
 254         return 0;
 255     }
 256
 257     if ((vld = OSSL_CRMF_OPTIONALVALIDITY_new()) == NULL)
 258         return 0;
 259     vld->notBefore = notBefore;
 260     vld->notAfter = notAfter;
 261     tmpl->validity = vld;
 262     return 1;
 263 }
 264
 265
 266 int OSSL_CRMF_MSG_set_certReqId(OSSL_CRMF_MSG *crm, int rid)
 267 {
 268     if (crm == NULL || crm->certReq == NULL || crm->certReq->certReqId == NULL) {
 269         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET_CERTREQID, CRMF_R_NULL_ARGUMENT);
 270         return 0;
 271     }
 272
 273     return ASN1_INTEGER_set(crm->certReq->certReqId, rid);
 274 }
 275
 276 /* get ASN.1 encoded integer, return -1 on error */
 277 static int crmf_asn1_get_int(const ASN1_INTEGER *a)
 278 {
 279     int64_t res;
 280
 281     if (!ASN1_INTEGER_get_int64(&res, a)) {
 282         CRMFerr(0, ASN1_R_INVALID_NUMBER);
 283         return -1;
 284     }
 285     if (res < INT_MIN) {
 286         CRMFerr(0, ASN1_R_TOO_SMALL);
 287         return -1;
 288     }
 289     if (res > INT_MAX) {
 290         CRMFerr(0, ASN1_R_TOO_LARGE);
 291         return -1;
 292     }
 293     return (int)res;
 294 }
 295
 296 int OSSL_CRMF_MSG_get_certReqId(const OSSL_CRMF_MSG *crm)
 297 {
 298     if (crm == NULL || /* not really needed: */ crm->certReq == NULL) {
 299         CRMFerr(CRMF_F_OSSL_CRMF_MSG_GET_CERTREQID, CRMF_R_NULL_ARGUMENT);
 300         return -1;
 301     }
 302     return crmf_asn1_get_int(crm->certReq->certReqId);
 303 }
 304
 305
 306 int OSSL_CRMF_MSG_set0_extensions(OSSL_CRMF_MSG *crm,
 307                                   X509_EXTENSIONS *exts)
 308 {
 309     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 310
 311     if (tmpl == NULL) { /* also crm == NULL implies this */
 312         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_EXTENSIONS, CRMF_R_NULL_ARGUMENT);
 313         return 0;
 314     }
 315
 316     if (sk_X509_EXTENSION_num(exts) == 0) {
 317         sk_X509_EXTENSION_free(exts);
 318         exts = NULL; /* do not include empty extensions list */
 319     }
 320
 321     sk_X509_EXTENSION_pop_free(tmpl->extensions, X509_EXTENSION_free);
 322     tmpl->extensions = exts;
 323     return 1;
 324 }
 325
 326
 327 int OSSL_CRMF_MSG_push0_extension(OSSL_CRMF_MSG *crm,
 328                                   X509_EXTENSION *ext)
 329 {
 330     int new = 0;
 331     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 332
 333     if (tmpl == NULL || ext == NULL) { /* also crm == NULL implies this */
 334         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_EXTENSION, CRMF_R_NULL_ARGUMENT);
 335         return 0;
 336     }
 337
 338     if (tmpl->extensions == NULL) {
 339         if ((tmpl->extensions = sk_X509_EXTENSION_new_null()) == NULL)
 340             goto err;
 341         new = 1;
 342     }
 343
 344     if (!sk_X509_EXTENSION_push(tmpl->extensions, ext))
 345         goto err;
 346     return 1;
 347  err:
 348     if (new != 0) {
 349         sk_X509_EXTENSION_free(tmpl->extensions);
 350         tmpl->extensions = NULL;
 351     }
 352     return 0;
 353 }
 354
 355 static int create_popo_signature(OSSL_CRMF_POPOSIGNINGKEY *ps,
 356                                  const OSSL_CRMF_CERTREQUEST *cr,
 357                                  EVP_PKEY *pkey, const EVP_MD *digest,
 358                                  OPENSSL_CTX *libctx, const char *propq)
 359 {
 360     if (ps == NULL || cr == NULL || pkey == NULL) {
 361         CRMFerr(0, CRMF_R_NULL_ARGUMENT);
 362         return 0;
 363     }
 364     if (ps->poposkInput != NULL) {
 365         /* TODO: support cases 1+2 defined in RFC 4211, section 4.1 */
 366         CRMFerr(0, CRMF_R_POPOSKINPUT_NOT_SUPPORTED);
 367         return 0;
 368     }
 369
 370     return ASN1_item_sign_with_libctx(ASN1_ITEM_rptr(OSSL_CRMF_CERTREQUEST),
 371                                       ps->algorithmIdentifier, NULL,
 372                                       ps->signature, cr, NULL, pkey, digest,
 373                                       libctx, propq);
 374 }
 375
 376
 377 int OSSL_CRMF_MSG_create_popo(int meth, OSSL_CRMF_MSG *crm,
 378                               EVP_PKEY *pkey, const EVP_MD *digest,
 379                               OPENSSL_CTX *libctx, const char *propq)
 380 {
 381     OSSL_CRMF_POPO *pp = NULL;
 382     ASN1_INTEGER *tag = NULL;
 383
 384     if (crm == NULL || (meth == OSSL_CRMF_POPO_SIGNATURE && pkey == NULL)) {
 385         CRMFerr(CRMF_F_OSSL_CRMF_MSG_CREATE_POPO, CRMF_R_NULL_ARGUMENT);
 386         return 0;
 387     }
 388
 389     if (meth == OSSL_CRMF_POPO_NONE)
 390         goto end;
 391     if ((pp = OSSL_CRMF_POPO_new()) == NULL)
 392         goto err;
 393     pp->type = meth;
 394
 395     switch (meth) {
 396     case OSSL_CRMF_POPO_RAVERIFIED:
 397         if ((pp->value.raVerified = ASN1_NULL_new()) == NULL)
 398             goto err;
 399         break;
 400
 401     case OSSL_CRMF_POPO_SIGNATURE:
 402         {
 403             OSSL_CRMF_POPOSIGNINGKEY *ps = OSSL_CRMF_POPOSIGNINGKEY_new();
 404
 405             if (ps == NULL)
 406                 goto err;
 407             if (!create_popo_signature(ps, crm->certReq, pkey, digest,
 408                                        libctx, propq)) {
 409                 OSSL_CRMF_POPOSIGNINGKEY_free(ps);
 410                 goto err;
 411             }
 412             pp->value.signature = ps;
 413         }
 414         break;
 415
 416     case OSSL_CRMF_POPO_KEYENC:
 417         if ((pp->value.keyEncipherment = OSSL_CRMF_POPOPRIVKEY_new()) == NULL)
 418             goto err;
 419         tag = ASN1_INTEGER_new();
 420         pp->value.keyEncipherment->type =
 421             OSSL_CRMF_POPOPRIVKEY_SUBSEQUENTMESSAGE;
 422         pp->value.keyEncipherment->value.subsequentMessage = tag;
 423         if (tag == NULL
 424                 || !ASN1_INTEGER_set(tag, OSSL_CRMF_SUBSEQUENTMESSAGE_ENCRCERT))
 425             goto err;
 426         break;
 427
 428     default:
 429         CRMFerr(CRMF_F_OSSL_CRMF_MSG_CREATE_POPO,
 430                 CRMF_R_UNSUPPORTED_METHOD_FOR_CREATING_POPO);
 431         goto err;
 432     }
 433
 434  end:
 435     OSSL_CRMF_POPO_free(crm->popo);
 436     crm->popo = pp;
 437
 438     return 1;
 439  err:
 440     OSSL_CRMF_POPO_free(pp);
 441     return 0;
 442 }
 443
 444 /* verifies the Proof-of-Possession of the request with the given rid in reqs */
 445 int OSSL_CRMF_MSGS_verify_popo(const OSSL_CRMF_MSGS *reqs,
 446                                int rid, int acceptRAVerified,
 447                                OPENSSL_CTX *libctx, const char *propq)
 448 {
 449     OSSL_CRMF_MSG *req = NULL;
 450     X509_PUBKEY *pubkey = NULL;
 451     OSSL_CRMF_POPOSIGNINGKEY *sig = NULL;
 452     const ASN1_ITEM *it;
 453     void *asn;
 454
 455     if (reqs == NULL || (req = sk_OSSL_CRMF_MSG_value(reqs, rid)) == NULL) {
 456         CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO, CRMF_R_NULL_ARGUMENT);
 457         return 0;
 458     }
 459
 460     if (req->popo == NULL) {
 461         CRMFerr(0, CRMF_R_POPO_MISSING);
 462         return 0;
 463     }
 464
 465     switch (req->popo->type) {
 466     case OSSL_CRMF_POPO_RAVERIFIED:
 467         if (!acceptRAVerified) {
 468             CRMFerr(0, CRMF_R_POPO_RAVERIFIED_NOT_ACCEPTED);
 469             return 0;
 470         }
 471         break;
 472     case OSSL_CRMF_POPO_SIGNATURE:
 473         pubkey = req->certReq->certTemplate->publicKey;
 474         if (pubkey == NULL) {
 475             CRMFerr(0, CRMF_R_POPO_MISSING_PUBLIC_KEY);
 476             return 0;
 477         }
 478         sig = req->popo->value.signature;
 479         if (sig->poposkInput != NULL) {
 480             /*
 481              * According to RFC 4211: publicKey contains a copy of
 482              * the public key from the certificate template. This MUST be
 483              * exactly the same value as contained in the certificate template.
 484              */
 485             if (sig->poposkInput->publicKey == NULL) {
 486                 CRMFerr(0, CRMF_R_POPO_MISSING_PUBLIC_KEY);
 487                 return 0;
 488             }
 489             if (X509_PUBKEY_eq(pubkey, sig->poposkInput->publicKey) != 1) {
 490                 CRMFerr(0, CRMF_R_POPO_INCONSISTENT_PUBLIC_KEY);
 491                 return 0;
 492             }
 493             /*
 494              * TODO check the contents of the authInfo sub-field,
 495              * see RFC 4211 https://tools.ietf.org/html/rfc4211#section-4.1
 496              */
 497             it = ASN1_ITEM_rptr(OSSL_CRMF_POPOSIGNINGKEYINPUT);
 498             asn = sig->poposkInput;
 499         } else {
 500             if (req->certReq->certTemplate->subject == NULL) {
 501                 CRMFerr(0, CRMF_R_POPO_MISSING_SUBJECT);
 502                 return 0;
 503             }
 504             it = ASN1_ITEM_rptr(OSSL_CRMF_CERTREQUEST);
 505             asn = req->certReq;
 506         }
 507         if (ASN1_item_verify_with_libctx(it, sig->algorithmIdentifier,
 508                                          sig->signature, asn, NULL,
 509                                          X509_PUBKEY_get0(pubkey),
 510                                          libctx, propq) < 1)
 511             return 0;
 512         break;
 513     case OSSL_CRMF_POPO_KEYENC:
 514         /*
 515          * TODO: when OSSL_CMP_certrep_new() supports encrypted certs,
 516          * return 1 if the type of req->popo->value.keyEncipherment
 517          * is OSSL_CRMF_POPOPRIVKEY_SUBSEQUENTMESSAGE and
 518          * its value.subsequentMessage == OSSL_CRMF_SUBSEQUENTMESSAGE_ENCRCERT
 519          */
 520     case OSSL_CRMF_POPO_KEYAGREE:
 521     default:
 522         CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO,
 523                 CRMF_R_UNSUPPORTED_POPO_METHOD);
 524         return 0;
 525     }
 526     return 1;
 527 }
 528
 529 /* retrieves the serialNumber of the given cert template or NULL on error */
 530 ASN1_INTEGER
 531 *OSSL_CRMF_CERTTEMPLATE_get0_serialNumber(const OSSL_CRMF_CERTTEMPLATE *tmpl)
 532 {
 533     return tmpl != NULL ? tmpl->serialNumber : NULL;
 534 }
 535
 536 /* retrieves the issuer name of the given cert template or NULL on error */
 537 const X509_NAME
 538     *OSSL_CRMF_CERTTEMPLATE_get0_issuer(const OSSL_CRMF_CERTTEMPLATE *tmpl)
 539 {
 540     return tmpl != NULL ? tmpl->issuer : NULL;
 541 }
 542
 543 /* retrieves the issuer name of the given CertId or NULL on error */
 544 const X509_NAME *OSSL_CRMF_CERTID_get0_issuer(const OSSL_CRMF_CERTID *cid)
 545 {
 546     return cid != NULL && cid->issuer->type == GEN_DIRNAME ?
 547         cid->issuer->d.directoryName : NULL;
 548 }
 549
 550 /* retrieves the serialNumber of the given CertId or NULL on error */
 551 ASN1_INTEGER *OSSL_CRMF_CERTID_get0_serialNumber(const OSSL_CRMF_CERTID *cid)
 552 {
 553     return cid != NULL ? cid->serialNumber : NULL;
 554 }
 555
 556 /*-
 557  * fill in certificate template.
 558  * Any value argument that is NULL will leave the respective field unchanged.
 559  */
 560 int OSSL_CRMF_CERTTEMPLATE_fill(OSSL_CRMF_CERTTEMPLATE *tmpl,
 561                                 EVP_PKEY *pubkey,
 562                                 const X509_NAME *subject,
 563                                 const X509_NAME *issuer,
 564                                 const ASN1_INTEGER *serial)
 565 {
 566     if (tmpl == NULL) {
 567         CRMFerr(CRMF_F_OSSL_CRMF_CERTTEMPLATE_FILL, CRMF_R_NULL_ARGUMENT);
 568         return 0;
 569     }
 570     if (subject != NULL && !X509_NAME_set((X509_NAME **)&tmpl->subject, subject))
 571         return 0;
 572     if (issuer != NULL && !X509_NAME_set((X509_NAME **)&tmpl->issuer, issuer))
 573         return 0;
 574     if (serial != NULL) {
 575         ASN1_INTEGER_free(tmpl->serialNumber);
 576         if ((tmpl->serialNumber = ASN1_INTEGER_dup(serial)) == NULL)
 577             return 0;
 578     }
 579     if (pubkey != NULL && !X509_PUBKEY_set(&tmpl->publicKey, pubkey))
 580         return 0;
 581     return 1;
 582 }
 583
 584
 585 /*-
 586  * Decrypts the certificate in the given encryptedValue using private key pkey.
 587  * This is needed for the indirect PoP method as in RFC 4210 section 5.2.8.2.
 588  *
 589  * returns a pointer to the decrypted certificate
 590  * returns NULL on error or if no certificate available
 591  */
 592 X509
 593 *OSSL_CRMF_ENCRYPTEDVALUE_get1_encCert(const OSSL_CRMF_ENCRYPTEDVALUE *ecert,
 594                                        OPENSSL_CTX *libctx, const char *propq,
 595                                        EVP_PKEY *pkey)
 596 {
 597     X509 *cert = NULL; /* decrypted certificate */
 598     EVP_CIPHER_CTX *evp_ctx = NULL; /* context for symmetric encryption */
 599     unsigned char *ek = NULL; /* decrypted symmetric encryption key */
 600     size_t eksize = 0; /* size of decrypted symmetric encryption key */
 601     const EVP_CIPHER *cipher = NULL; /* used cipher */
 602     int cikeysize = 0; /* key size from cipher */
 603     unsigned char *iv = NULL; /* initial vector for symmetric encryption */
 604     unsigned char *outbuf = NULL; /* decryption output buffer */
 605     const unsigned char *p = NULL; /* needed for decoding ASN1 */
 606     int symmAlg = 0; /* NIDs for symmetric algorithm */
 607     int n, outlen = 0;
 608     EVP_PKEY_CTX *pkctx = NULL; /* private key context */
 609
 610     if (ecert == NULL || ecert->symmAlg == NULL || ecert->encSymmKey == NULL
 611             || ecert->encValue == NULL || pkey == NULL) {
 612         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 613                 CRMF_R_NULL_ARGUMENT);
 614         return NULL;
 615     }
 616     if ((symmAlg = OBJ_obj2nid(ecert->symmAlg->algorithm)) == 0) {
 617         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 618                 CRMF_R_UNSUPPORTED_CIPHER);
 619         return NULL;
 620     }
 621     /* select symmetric cipher based on algorithm given in message */
 622     if ((cipher = EVP_get_cipherbynid(symmAlg)) == NULL) {
 623         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 624                 CRMF_R_UNSUPPORTED_CIPHER);
 625         goto end;
 626     }
 627     cikeysize = EVP_CIPHER_key_length(cipher);
 628     /* first the symmetric key needs to be decrypted */
 629     pkctx = EVP_PKEY_CTX_new_from_pkey(libctx, pkey, propq);
 630     if (pkctx != NULL && EVP_PKEY_decrypt_init(pkctx)) {
 631         ASN1_BIT_STRING *encKey = ecert->encSymmKey;
 632         size_t failure;
 633         int retval;
 634
 635         if (EVP_PKEY_decrypt(pkctx, NULL, &eksize,
 636                              encKey->data, encKey->length) <= 0
 637                 || (ek = OPENSSL_malloc(eksize)) == NULL)
 638             goto end;
 639         retval = EVP_PKEY_decrypt(pkctx, ek, &eksize,
 640                                   encKey->data, encKey->length);
 641         ERR_clear_error(); /* error state may have sensitive information */
 642         failure = ~constant_time_is_zero_s(constant_time_msb(retval)
 643                                            | constant_time_is_zero(retval));
 644         failure |= ~constant_time_eq_s(eksize, (size_t)cikeysize);
 645         if (failure) {
 646             CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 647                     CRMF_R_ERROR_DECRYPTING_SYMMETRIC_KEY);
 648             goto end;
 649         }
 650     } else {
 651         goto end;
 652     }
 653     if ((iv = OPENSSL_malloc(EVP_CIPHER_iv_length(cipher))) == NULL)
 654         goto end;
 655     if (ASN1_TYPE_get_octetstring(ecert->symmAlg->parameter, iv,
 656                                   EVP_CIPHER_iv_length(cipher))
 657         != EVP_CIPHER_iv_length(cipher)) {
 658         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 659                 CRMF_R_MALFORMED_IV);
 660         goto end;
 661     }
 662
 663     /*
 664      * d2i_X509 changes the given pointer, so use p for decoding the message and
 665      * keep the original pointer in outbuf so the memory can be freed later
 666      */
 667     if ((p = outbuf = OPENSSL_malloc(ecert->encValue->length +
 668                                      EVP_CIPHER_block_size(cipher))) == NULL
 669             || (evp_ctx = EVP_CIPHER_CTX_new()) == NULL)
 670         goto end;
 671     EVP_CIPHER_CTX_set_padding(evp_ctx, 0);
 672
 673     if (!EVP_DecryptInit(evp_ctx, cipher, ek, iv)
 674             || !EVP_DecryptUpdate(evp_ctx, outbuf, &outlen,
 675                                   ecert->encValue->data,
 676                                   ecert->encValue->length)
 677             || !EVP_DecryptFinal(evp_ctx, outbuf + outlen, &n)) {
 678         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 679                 CRMF_R_ERROR_DECRYPTING_CERTIFICATE);
 680         goto end;
 681     }
 682     outlen += n;
 683
 684     /* convert decrypted certificate from DER to internal ASN.1 structure */
 685     if ((cert = X509_new_with_libctx(libctx, propq)) == NULL)
 686         goto end;
 687     if (d2i_X509(&cert, &p, outlen) == NULL)
 688         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 689                 CRMF_R_ERROR_DECODING_CERTIFICATE);
 690  end:
 691     EVP_PKEY_CTX_free(pkctx);
 692     OPENSSL_free(outbuf);
 693     EVP_CIPHER_CTX_free(evp_ctx);
 694     OPENSSL_clear_free(ek, eksize);
 695     OPENSSL_free(iv);
 696     return cert;
 697 }