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(X509_EXTENSION)
  40 DEFINE_STACK_OF(OSSL_CRMF_MSG)
  41
  42 /*-
  43  * atyp = Attribute Type
  44  * valt = Value Type
  45  * ctrlinf = "regCtrl" or "regInfo"
  46  */
  47 #define IMPLEMENT_CRMF_CTRL_FUNC(atyp, valt, ctrlinf)                     \
  48 int OSSL_CRMF_MSG_set1_##ctrlinf##_##atyp(OSSL_CRMF_MSG *msg,             \
  49                                           const valt *in)                 \
  50 {                                                                         \
  51     OSSL_CRMF_ATTRIBUTETYPEANDVALUE *atav = NULL;                         \
  52                                                                           \
  53     if (msg == NULL || in == NULL)                                       \
  54         goto err;                                                         \
  55     if ((atav = OSSL_CRMF_ATTRIBUTETYPEANDVALUE_new()) == NULL)           \
  56         goto err;                                                         \
  57     if ((atav->type = OBJ_nid2obj(NID_id_##ctrlinf##_##atyp)) == NULL)    \
  58         goto err;                                                         \
  59     if ((atav->value.atyp = valt##_dup(in)) == NULL)                      \
  60         goto err;                                                         \
  61     if (!OSSL_CRMF_MSG_push0_##ctrlinf(msg, atav))                        \
  62         goto err;                                                         \
  63     return 1;                                                             \
  64  err:                                                                     \
  65     OSSL_CRMF_ATTRIBUTETYPEANDVALUE_free(atav);                           \
  66     return 0;                                                             \
  67 }
  68
  69
  70 /*-
  71  * Pushes the given control attribute into the controls stack of a CertRequest
  72  * (section 6)
  73  * returns 1 on success, 0 on error
  74  */
  75 static int OSSL_CRMF_MSG_push0_regCtrl(OSSL_CRMF_MSG *crm,
  76                                        OSSL_CRMF_ATTRIBUTETYPEANDVALUE *ctrl)
  77 {
  78     int new = 0;
  79
  80     if (crm == NULL || crm->certReq == NULL || ctrl == NULL) {
  81         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_REGCTRL, CRMF_R_NULL_ARGUMENT);
  82         return 0;
  83     }
  84
  85     if (crm->certReq->controls == NULL) {
  86         crm->certReq->controls = sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_new_null();
  87         if (crm->certReq->controls == NULL)
  88             goto err;
  89         new = 1;
  90     }
  91     if (!sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_push(crm->certReq->controls, ctrl))
  92         goto err;
  93
  94     return 1;
  95  err:
  96     if (new != 0) {
  97         sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_free(crm->certReq->controls);
  98         crm->certReq->controls = NULL;
  99     }
 100     return 0;
 101 }
 102
 103 /* id-regCtrl-regToken Control (section 6.1) */
 104 IMPLEMENT_CRMF_CTRL_FUNC(regToken, ASN1_STRING, regCtrl)
 105
 106 /* id-regCtrl-authenticator Control (section 6.2) */
 107 #define ASN1_UTF8STRING_dup ASN1_STRING_dup
 108 IMPLEMENT_CRMF_CTRL_FUNC(authenticator, ASN1_UTF8STRING, regCtrl)
 109
 110 int OSSL_CRMF_MSG_set0_SinglePubInfo(OSSL_CRMF_SINGLEPUBINFO *spi,
 111                                      int method, GENERAL_NAME *nm)
 112 {
 113     if (spi == NULL
 114             || method < OSSL_CRMF_PUB_METHOD_DONTCARE
 115             || method > OSSL_CRMF_PUB_METHOD_LDAP) {
 116         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_SINGLEPUBINFO,
 117                 ERR_R_PASSED_INVALID_ARGUMENT);
 118         return 0;
 119     }
 120
 121     if (!ASN1_INTEGER_set(spi->pubMethod, method))
 122         return 0;
 123     GENERAL_NAME_free(spi->pubLocation);
 124     spi->pubLocation = nm;
 125     return 1;
 126 }
 127
 128 int
 129 OSSL_CRMF_MSG_PKIPublicationInfo_push0_SinglePubInfo(OSSL_CRMF_PKIPUBLICATIONINFO *pi,
 130                                                      OSSL_CRMF_SINGLEPUBINFO *spi)
 131 {
 132     if (pi == NULL || spi == NULL) {
 133         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PKIPUBLICATIONINFO_PUSH0_SINGLEPUBINFO,
 134                 CRMF_R_NULL_ARGUMENT);
 135         return 0;
 136     }
 137     if (pi->pubInfos == NULL)
 138         pi->pubInfos = sk_OSSL_CRMF_SINGLEPUBINFO_new_null();
 139     if (pi->pubInfos == NULL)
 140         return 0;
 141
 142     return sk_OSSL_CRMF_SINGLEPUBINFO_push(pi->pubInfos, spi);
 143 }
 144
 145 int OSSL_CRMF_MSG_set_PKIPublicationInfo_action(OSSL_CRMF_PKIPUBLICATIONINFO *pi,
 146                                                 int action)
 147 {
 148     if (pi == NULL
 149             || action < OSSL_CRMF_PUB_ACTION_DONTPUBLISH
 150             || action > OSSL_CRMF_PUB_ACTION_PLEASEPUBLISH) {
 151         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET_PKIPUBLICATIONINFO_ACTION,
 152                 ERR_R_PASSED_INVALID_ARGUMENT);
 153         return 0;
 154     }
 155
 156     return ASN1_INTEGER_set(pi->action, action);
 157 }
 158
 159 /* id-regCtrl-pkiPublicationInfo Control (section 6.3) */
 160 IMPLEMENT_CRMF_CTRL_FUNC(pkiPublicationInfo, OSSL_CRMF_PKIPUBLICATIONINFO,
 161                          regCtrl)
 162
 163 /* id-regCtrl-oldCertID Control (section 6.5) from the given */
 164 IMPLEMENT_CRMF_CTRL_FUNC(oldCertID, OSSL_CRMF_CERTID, regCtrl)
 165
 166 OSSL_CRMF_CERTID *OSSL_CRMF_CERTID_gen(const X509_NAME *issuer,
 167                                        const ASN1_INTEGER *serial)
 168 {
 169     OSSL_CRMF_CERTID *cid = NULL;
 170
 171     if (issuer == NULL || serial == NULL) {
 172         CRMFerr(CRMF_F_OSSL_CRMF_CERTID_GEN, CRMF_R_NULL_ARGUMENT);
 173         return NULL;
 174     }
 175
 176     if ((cid = OSSL_CRMF_CERTID_new()) == NULL)
 177         goto err;
 178
 179     if (!X509_NAME_set(&cid->issuer->d.directoryName, issuer))
 180         goto err;
 181     cid->issuer->type = GEN_DIRNAME;
 182
 183     ASN1_INTEGER_free(cid->serialNumber);
 184     if ((cid->serialNumber = ASN1_INTEGER_dup(serial)) == NULL)
 185         goto err;
 186
 187     return cid;
 188
 189  err:
 190     OSSL_CRMF_CERTID_free(cid);
 191     return NULL;
 192 }
 193
 194 /*
 195  * id-regCtrl-protocolEncrKey Control (section 6.6)
 196  */
 197 IMPLEMENT_CRMF_CTRL_FUNC(protocolEncrKey, X509_PUBKEY, regCtrl)
 198
 199 /*-
 200  * Pushes the attribute given in regInfo in to the CertReqMsg->regInfo stack.
 201  * (section 7)
 202  * returns 1 on success, 0 on error
 203  */
 204 static int OSSL_CRMF_MSG_push0_regInfo(OSSL_CRMF_MSG *crm,
 205                                        OSSL_CRMF_ATTRIBUTETYPEANDVALUE *ri)
 206 {
 207     STACK_OF(OSSL_CRMF_ATTRIBUTETYPEANDVALUE) *info = NULL;
 208
 209     if (crm == NULL || ri == NULL) {
 210         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_REGINFO, CRMF_R_NULL_ARGUMENT);
 211         return 0;
 212     }
 213
 214     if (crm->regInfo == NULL)
 215         crm->regInfo = info = sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_new_null();
 216     if (crm->regInfo == NULL)
 217         goto err;
 218     if (!sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_push(crm->regInfo, ri))
 219         goto err;
 220     return 1;
 221
 222  err:
 223     if (info != NULL)
 224         crm->regInfo = NULL;
 225     sk_OSSL_CRMF_ATTRIBUTETYPEANDVALUE_free(info);
 226     return 0;
 227 }
 228
 229 /* id-regInfo-utf8Pairs to regInfo (section 7.1) */
 230 IMPLEMENT_CRMF_CTRL_FUNC(utf8Pairs, ASN1_UTF8STRING, regInfo)
 231
 232 /* id-regInfo-certReq to regInfo (section 7.2) */
 233 IMPLEMENT_CRMF_CTRL_FUNC(certReq, OSSL_CRMF_CERTREQUEST, regInfo)
 234
 235
 236 /* retrieves the certificate template of crm */
 237 OSSL_CRMF_CERTTEMPLATE *OSSL_CRMF_MSG_get0_tmpl(const OSSL_CRMF_MSG *crm)
 238 {
 239     if (crm == NULL || crm->certReq == NULL) {
 240         CRMFerr(CRMF_F_OSSL_CRMF_MSG_GET0_TMPL, CRMF_R_NULL_ARGUMENT);
 241         return NULL;
 242     }
 243     return crm->certReq->certTemplate;
 244 }
 245
 246
 247 int OSSL_CRMF_MSG_set0_validity(OSSL_CRMF_MSG *crm,
 248                                 ASN1_TIME *notBefore, ASN1_TIME *notAfter)
 249 {
 250     OSSL_CRMF_OPTIONALVALIDITY *vld;
 251     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 252
 253     if (tmpl == NULL) { /* also crm == NULL implies this */
 254         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_VALIDITY, CRMF_R_NULL_ARGUMENT);
 255         return 0;
 256     }
 257
 258     if ((vld = OSSL_CRMF_OPTIONALVALIDITY_new()) == NULL)
 259         return 0;
 260     vld->notBefore = notBefore;
 261     vld->notAfter = notAfter;
 262     tmpl->validity = vld;
 263     return 1;
 264 }
 265
 266
 267 int OSSL_CRMF_MSG_set_certReqId(OSSL_CRMF_MSG *crm, int rid)
 268 {
 269     if (crm == NULL || crm->certReq == NULL || crm->certReq->certReqId == NULL) {
 270         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET_CERTREQID, CRMF_R_NULL_ARGUMENT);
 271         return 0;
 272     }
 273
 274     return ASN1_INTEGER_set(crm->certReq->certReqId, rid);
 275 }
 276
 277 /* get ASN.1 encoded integer, return -1 on error */
 278 static int crmf_asn1_get_int(const ASN1_INTEGER *a)
 279 {
 280     int64_t res;
 281
 282     if (!ASN1_INTEGER_get_int64(&res, a)) {
 283         CRMFerr(0, ASN1_R_INVALID_NUMBER);
 284         return -1;
 285     }
 286     if (res < INT_MIN) {
 287         CRMFerr(0, ASN1_R_TOO_SMALL);
 288         return -1;
 289     }
 290     if (res > INT_MAX) {
 291         CRMFerr(0, ASN1_R_TOO_LARGE);
 292         return -1;
 293     }
 294     return (int)res;
 295 }
 296
 297 int OSSL_CRMF_MSG_get_certReqId(const OSSL_CRMF_MSG *crm)
 298 {
 299     if (crm == NULL || /* not really needed: */ crm->certReq == NULL) {
 300         CRMFerr(CRMF_F_OSSL_CRMF_MSG_GET_CERTREQID, CRMF_R_NULL_ARGUMENT);
 301         return -1;
 302     }
 303     return crmf_asn1_get_int(crm->certReq->certReqId);
 304 }
 305
 306
 307 int OSSL_CRMF_MSG_set0_extensions(OSSL_CRMF_MSG *crm,
 308                                   X509_EXTENSIONS *exts)
 309 {
 310     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 311
 312     if (tmpl == NULL) { /* also crm == NULL implies this */
 313         CRMFerr(CRMF_F_OSSL_CRMF_MSG_SET0_EXTENSIONS, CRMF_R_NULL_ARGUMENT);
 314         return 0;
 315     }
 316
 317     if (sk_X509_EXTENSION_num(exts) == 0) {
 318         sk_X509_EXTENSION_free(exts);
 319         exts = NULL; /* do not include empty extensions list */
 320     }
 321
 322     sk_X509_EXTENSION_pop_free(tmpl->extensions, X509_EXTENSION_free);
 323     tmpl->extensions = exts;
 324     return 1;
 325 }
 326
 327
 328 int OSSL_CRMF_MSG_push0_extension(OSSL_CRMF_MSG *crm,
 329                                   X509_EXTENSION *ext)
 330 {
 331     int new = 0;
 332     OSSL_CRMF_CERTTEMPLATE *tmpl = OSSL_CRMF_MSG_get0_tmpl(crm);
 333
 334     if (tmpl == NULL || ext == NULL) { /* also crm == NULL implies this */
 335         CRMFerr(CRMF_F_OSSL_CRMF_MSG_PUSH0_EXTENSION, CRMF_R_NULL_ARGUMENT);
 336         return 0;
 337     }
 338
 339     if (tmpl->extensions == NULL) {
 340         if ((tmpl->extensions = sk_X509_EXTENSION_new_null()) == NULL)
 341             goto err;
 342         new = 1;
 343     }
 344
 345     if (!sk_X509_EXTENSION_push(tmpl->extensions, ext))
 346         goto err;
 347     return 1;
 348  err:
 349     if (new != 0) {
 350         sk_X509_EXTENSION_free(tmpl->extensions);
 351         tmpl->extensions = NULL;
 352     }
 353     return 0;
 354 }
 355
 356 static int create_popo_signature(OSSL_CRMF_POPOSIGNINGKEY *ps,
 357                                  const OSSL_CRMF_CERTREQUEST *cr,
 358                                  EVP_PKEY *pkey, const EVP_MD *digest,
 359                                  OPENSSL_CTX *libctx, const char *propq)
 360 {
 361     if (ps == NULL || cr == NULL || pkey == NULL) {
 362         CRMFerr(0, CRMF_R_NULL_ARGUMENT);
 363         return 0;
 364     }
 365     if (ps->poposkInput != NULL) {
 366         /* TODO: support cases 1+2 defined in RFC 4211, section 4.1 */
 367         CRMFerr(0, CRMF_R_POPOSKINPUT_NOT_SUPPORTED);
 368         return 0;
 369     }
 370
 371     return ASN1_item_sign_with_libctx(ASN1_ITEM_rptr(OSSL_CRMF_CERTREQUEST),
 372                                       ps->algorithmIdentifier, NULL,
 373                                       ps->signature, cr, NULL, pkey, digest,
 374                                       libctx, propq);
 375 }
 376
 377
 378 int OSSL_CRMF_MSG_create_popo(int meth, OSSL_CRMF_MSG *crm,
 379                               EVP_PKEY *pkey, const EVP_MD *digest,
 380                               OPENSSL_CTX *libctx, const char *propq)
 381 {
 382     OSSL_CRMF_POPO *pp = NULL;
 383     ASN1_INTEGER *tag = NULL;
 384
 385     if (crm == NULL || (meth == OSSL_CRMF_POPO_SIGNATURE && pkey == NULL)) {
 386         CRMFerr(CRMF_F_OSSL_CRMF_MSG_CREATE_POPO, CRMF_R_NULL_ARGUMENT);
 387         return 0;
 388     }
 389
 390     if (meth == OSSL_CRMF_POPO_NONE)
 391         goto end;
 392     if ((pp = OSSL_CRMF_POPO_new()) == NULL)
 393         goto err;
 394     pp->type = meth;
 395
 396     switch (meth) {
 397     case OSSL_CRMF_POPO_RAVERIFIED:
 398         if ((pp->value.raVerified = ASN1_NULL_new()) == NULL)
 399             goto err;
 400         break;
 401
 402     case OSSL_CRMF_POPO_SIGNATURE:
 403         {
 404             OSSL_CRMF_POPOSIGNINGKEY *ps = OSSL_CRMF_POPOSIGNINGKEY_new();
 405
 406             if (ps == NULL)
 407                 goto err;
 408             if (!create_popo_signature(ps, crm->certReq, pkey, digest,
 409                                        libctx, propq)) {
 410                 OSSL_CRMF_POPOSIGNINGKEY_free(ps);
 411                 goto err;
 412             }
 413             pp->value.signature = ps;
 414         }
 415         break;
 416
 417     case OSSL_CRMF_POPO_KEYENC:
 418         if ((pp->value.keyEncipherment = OSSL_CRMF_POPOPRIVKEY_new()) == NULL)
 419             goto err;
 420         tag = ASN1_INTEGER_new();
 421         pp->value.keyEncipherment->type =
 422             OSSL_CRMF_POPOPRIVKEY_SUBSEQUENTMESSAGE;
 423         pp->value.keyEncipherment->value.subsequentMessage = tag;
 424         if (tag == NULL
 425                 || !ASN1_INTEGER_set(tag, OSSL_CRMF_SUBSEQUENTMESSAGE_ENCRCERT))
 426             goto err;
 427         break;
 428
 429     default:
 430         CRMFerr(CRMF_F_OSSL_CRMF_MSG_CREATE_POPO,
 431                 CRMF_R_UNSUPPORTED_METHOD_FOR_CREATING_POPO);
 432         goto err;
 433     }
 434
 435  end:
 436     OSSL_CRMF_POPO_free(crm->popo);
 437     crm->popo = pp;
 438
 439     return 1;
 440  err:
 441     OSSL_CRMF_POPO_free(pp);
 442     return 0;
 443 }
 444
 445 /* verifies the Proof-of-Possession of the request with the given rid in reqs */
 446 int OSSL_CRMF_MSGS_verify_popo(const OSSL_CRMF_MSGS *reqs,
 447                                int rid, int acceptRAVerified,
 448                                OPENSSL_CTX *libctx, const char *propq)
 449 {
 450     OSSL_CRMF_MSG *req = NULL;
 451     X509_PUBKEY *pubkey = NULL;
 452     OSSL_CRMF_POPOSIGNINGKEY *sig = NULL;
 453     const ASN1_ITEM *it;
 454     void *asn;
 455
 456     if (reqs == NULL || (req = sk_OSSL_CRMF_MSG_value(reqs, rid)) == NULL) {
 457         CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO, CRMF_R_NULL_ARGUMENT);
 458         return 0;
 459     }
 460
 461     if (req->popo == NULL) {
 462         CRMFerr(0, CRMF_R_POPO_MISSING);
 463         return 0;
 464     }
 465
 466     switch (req->popo->type) {
 467     case OSSL_CRMF_POPO_RAVERIFIED:
 468         if (!acceptRAVerified) {
 469             CRMFerr(0, CRMF_R_POPO_RAVERIFIED_NOT_ACCEPTED);
 470             return 0;
 471         }
 472         break;
 473     case OSSL_CRMF_POPO_SIGNATURE:
 474         pubkey = req->certReq->certTemplate->publicKey;
 475         if (pubkey == NULL) {
 476             CRMFerr(0, CRMF_R_POPO_MISSING_PUBLIC_KEY);
 477             return 0;
 478         }
 479         sig = req->popo->value.signature;
 480         if (sig->poposkInput != NULL) {
 481             /*
 482              * According to RFC 4211: publicKey contains a copy of
 483              * the public key from the certificate template. This MUST be
 484              * exactly the same value as contained in the certificate template.
 485              */
 486             if (sig->poposkInput->publicKey == NULL) {
 487                 CRMFerr(0, CRMF_R_POPO_MISSING_PUBLIC_KEY);
 488                 return 0;
 489             }
 490             if (X509_PUBKEY_eq(pubkey, sig->poposkInput->publicKey) != 1) {
 491                 CRMFerr(0, CRMF_R_POPO_INCONSISTENT_PUBLIC_KEY);
 492                 return 0;
 493             }
 494             /*
 495              * TODO check the contents of the authInfo sub-field,
 496              * see RFC 4211 https://tools.ietf.org/html/rfc4211#section-4.1
 497              */
 498             it = ASN1_ITEM_rptr(OSSL_CRMF_POPOSIGNINGKEYINPUT);
 499             asn = sig->poposkInput;
 500         } else {
 501             if (req->certReq->certTemplate->subject == NULL) {
 502                 CRMFerr(0, CRMF_R_POPO_MISSING_SUBJECT);
 503                 return 0;
 504             }
 505             it = ASN1_ITEM_rptr(OSSL_CRMF_CERTREQUEST);
 506             asn = req->certReq;
 507         }
 508         if (ASN1_item_verify_with_libctx(it, sig->algorithmIdentifier,
 509                                          sig->signature, asn, NULL,
 510                                          X509_PUBKEY_get0(pubkey),
 511                                          libctx, propq) < 1)
 512             return 0;
 513         break;
 514     case OSSL_CRMF_POPO_KEYENC:
 515         /*
 516          * TODO: when OSSL_CMP_certrep_new() supports encrypted certs,
 517          * return 1 if the type of req->popo->value.keyEncipherment
 518          * is OSSL_CRMF_POPOPRIVKEY_SUBSEQUENTMESSAGE and
 519          * its value.subsequentMessage == OSSL_CRMF_SUBSEQUENTMESSAGE_ENCRCERT
 520          */
 521     case OSSL_CRMF_POPO_KEYAGREE:
 522     default:
 523         CRMFerr(CRMF_F_OSSL_CRMF_MSGS_VERIFY_POPO,
 524                 CRMF_R_UNSUPPORTED_POPO_METHOD);
 525         return 0;
 526     }
 527     return 1;
 528 }
 529
 530 /* retrieves the serialNumber of the given cert template or NULL on error */
 531 ASN1_INTEGER
 532 *OSSL_CRMF_CERTTEMPLATE_get0_serialNumber(const OSSL_CRMF_CERTTEMPLATE *tmpl)
 533 {
 534     return tmpl != NULL ? tmpl->serialNumber : NULL;
 535 }
 536
 537 /* retrieves the issuer name of the given cert template or NULL on error */
 538 const X509_NAME
 539     *OSSL_CRMF_CERTTEMPLATE_get0_issuer(const OSSL_CRMF_CERTTEMPLATE *tmpl)
 540 {
 541     return tmpl != NULL ? tmpl->issuer : NULL;
 542 }
 543
 544 /* retrieves the issuer name of the given CertId or NULL on error */
 545 const X509_NAME *OSSL_CRMF_CERTID_get0_issuer(const OSSL_CRMF_CERTID *cid)
 546 {
 547     return cid != NULL && cid->issuer->type == GEN_DIRNAME ?
 548         cid->issuer->d.directoryName : NULL;
 549 }
 550
 551 /* retrieves the serialNumber of the given CertId or NULL on error */
 552 ASN1_INTEGER *OSSL_CRMF_CERTID_get0_serialNumber(const OSSL_CRMF_CERTID *cid)
 553 {
 554     return cid != NULL ? cid->serialNumber : NULL;
 555 }
 556
 557 /*-
 558  * fill in certificate template.
 559  * Any value argument that is NULL will leave the respective field unchanged.
 560  */
 561 int OSSL_CRMF_CERTTEMPLATE_fill(OSSL_CRMF_CERTTEMPLATE *tmpl,
 562                                 EVP_PKEY *pubkey,
 563                                 const X509_NAME *subject,
 564                                 const X509_NAME *issuer,
 565                                 const ASN1_INTEGER *serial)
 566 {
 567     if (tmpl == NULL) {
 568         CRMFerr(CRMF_F_OSSL_CRMF_CERTTEMPLATE_FILL, CRMF_R_NULL_ARGUMENT);
 569         return 0;
 570     }
 571     if (subject != NULL && !X509_NAME_set((X509_NAME **)&tmpl->subject, subject))
 572         return 0;
 573     if (issuer != NULL && !X509_NAME_set((X509_NAME **)&tmpl->issuer, issuer))
 574         return 0;
 575     if (serial != NULL) {
 576         ASN1_INTEGER_free(tmpl->serialNumber);
 577         if ((tmpl->serialNumber = ASN1_INTEGER_dup(serial)) == NULL)
 578             return 0;
 579     }
 580     if (pubkey != NULL && !X509_PUBKEY_set(&tmpl->publicKey, pubkey))
 581         return 0;
 582     return 1;
 583 }
 584
 585
 586 /*-
 587  * Decrypts the certificate in the given encryptedValue using private key pkey.
 588  * This is needed for the indirect PoP method as in RFC 4210 section 5.2.8.2.
 589  *
 590  * returns a pointer to the decrypted certificate
 591  * returns NULL on error or if no certificate available
 592  */
 593 X509
 594 *OSSL_CRMF_ENCRYPTEDVALUE_get1_encCert(const OSSL_CRMF_ENCRYPTEDVALUE *ecert,
 595                                        OPENSSL_CTX *libctx, const char *propq,
 596                                        EVP_PKEY *pkey)
 597 {
 598     X509 *cert = NULL; /* decrypted certificate */
 599     EVP_CIPHER_CTX *evp_ctx = NULL; /* context for symmetric encryption */
 600     unsigned char *ek = NULL; /* decrypted symmetric encryption key */
 601     size_t eksize = 0; /* size of decrypted symmetric encryption key */
 602     const EVP_CIPHER *cipher = NULL; /* used cipher */
 603     int cikeysize = 0; /* key size from cipher */
 604     unsigned char *iv = NULL; /* initial vector for symmetric encryption */
 605     unsigned char *outbuf = NULL; /* decryption output buffer */
 606     const unsigned char *p = NULL; /* needed for decoding ASN1 */
 607     int symmAlg = 0; /* NIDs for symmetric algorithm */
 608     int n, outlen = 0;
 609     EVP_PKEY_CTX *pkctx = NULL; /* private key context */
 610
 611     if (ecert == NULL || ecert->symmAlg == NULL || ecert->encSymmKey == NULL
 612             || ecert->encValue == NULL || pkey == NULL) {
 613         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 614                 CRMF_R_NULL_ARGUMENT);
 615         return NULL;
 616     }
 617     if ((symmAlg = OBJ_obj2nid(ecert->symmAlg->algorithm)) == 0) {
 618         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 619                 CRMF_R_UNSUPPORTED_CIPHER);
 620         return NULL;
 621     }
 622     /* select symmetric cipher based on algorithm given in message */
 623     if ((cipher = EVP_get_cipherbynid(symmAlg)) == NULL) {
 624         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 625                 CRMF_R_UNSUPPORTED_CIPHER);
 626         goto end;
 627     }
 628     cikeysize = EVP_CIPHER_key_length(cipher);
 629     /* first the symmetric key needs to be decrypted */
 630     pkctx = EVP_PKEY_CTX_new_from_pkey(libctx, pkey, propq);
 631     if (pkctx != NULL && EVP_PKEY_decrypt_init(pkctx)) {
 632         ASN1_BIT_STRING *encKey = ecert->encSymmKey;
 633         size_t failure;
 634         int retval;
 635
 636         if (EVP_PKEY_decrypt(pkctx, NULL, &eksize,
 637                              encKey->data, encKey->length) <= 0
 638                 || (ek = OPENSSL_malloc(eksize)) == NULL)
 639             goto end;
 640         retval = EVP_PKEY_decrypt(pkctx, ek, &eksize,
 641                                   encKey->data, encKey->length);
 642         ERR_clear_error(); /* error state may have sensitive information */
 643         failure = ~constant_time_is_zero_s(constant_time_msb(retval)
 644                                            | constant_time_is_zero(retval));
 645         failure |= ~constant_time_eq_s(eksize, (size_t)cikeysize);
 646         if (failure) {
 647             CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 648                     CRMF_R_ERROR_DECRYPTING_SYMMETRIC_KEY);
 649             goto end;
 650         }
 651     } else {
 652         goto end;
 653     }
 654     if ((iv = OPENSSL_malloc(EVP_CIPHER_iv_length(cipher))) == NULL)
 655         goto end;
 656     if (ASN1_TYPE_get_octetstring(ecert->symmAlg->parameter, iv,
 657                                   EVP_CIPHER_iv_length(cipher))
 658         != EVP_CIPHER_iv_length(cipher)) {
 659         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 660                 CRMF_R_MALFORMED_IV);
 661         goto end;
 662     }
 663
 664     /*
 665      * d2i_X509 changes the given pointer, so use p for decoding the message and
 666      * keep the original pointer in outbuf so the memory can be freed later
 667      */
 668     if ((p = outbuf = OPENSSL_malloc(ecert->encValue->length +
 669                                      EVP_CIPHER_block_size(cipher))) == NULL
 670             || (evp_ctx = EVP_CIPHER_CTX_new()) == NULL)
 671         goto end;
 672     EVP_CIPHER_CTX_set_padding(evp_ctx, 0);
 673
 674     if (!EVP_DecryptInit(evp_ctx, cipher, ek, iv)
 675             || !EVP_DecryptUpdate(evp_ctx, outbuf, &outlen,
 676                                   ecert->encValue->data,
 677                                   ecert->encValue->length)
 678             || !EVP_DecryptFinal(evp_ctx, outbuf + outlen, &n)) {
 679         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 680                 CRMF_R_ERROR_DECRYPTING_CERTIFICATE);
 681         goto end;
 682     }
 683     outlen += n;
 684
 685     /* convert decrypted certificate from DER to internal ASN.1 structure */
 686     if ((cert = X509_new_with_libctx(libctx, propq)) == NULL)
 687         goto end;
 688     if (d2i_X509(&cert, &p, outlen) == NULL)
 689         CRMFerr(CRMF_F_OSSL_CRMF_ENCRYPTEDVALUE_GET1_ENCCERT,
 690                 CRMF_R_ERROR_DECODING_CERTIFICATE);
 691  end:
 692     EVP_PKEY_CTX_free(pkctx);
 693     OPENSSL_free(outbuf);
 694     EVP_CIPHER_CTX_free(evp_ctx);
 695     OPENSSL_clear_free(ek, eksize);
 696     OPENSSL_free(iv);
 697     return cert;
 698 }