crypto/cmp/cmp_server.c

   1 /*
   2  * Copyright 2007-2020 The OpenSSL Project Authors. All Rights Reserved.
   3  * Copyright Nokia 2007-2019
   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
  12 /* general CMP server functions */
  13
  14 #include <openssl/asn1t.h>
  15
  16 #include "cmp_local.h"
  17
  18 /* explicit #includes not strictly needed since implied by the above: */
  19 #include <openssl/cmp.h>
  20 #include <openssl/err.h>
  21
  22 DEFINE_STACK_OF(OSSL_CRMF_MSG)
  23 DEFINE_STACK_OF(X509)
  24 DEFINE_STACK_OF(OSSL_CMP_ITAV)
  25 DEFINE_STACK_OF(OSSL_CMP_CERTSTATUS)
  26
  27 /* the context for the generic CMP server */
  28 struct ossl_cmp_srv_ctx_st
  29 {
  30     OSSL_CMP_CTX *ctx; /* Client CMP context, partly reused for srv */
  31     void *custom_ctx;  /* pointer to specific server context */
  32
  33     OSSL_CMP_SRV_cert_request_cb_t process_cert_request;
  34     OSSL_CMP_SRV_rr_cb_t process_rr;
  35     OSSL_CMP_SRV_genm_cb_t process_genm;
  36     OSSL_CMP_SRV_error_cb_t process_error;
  37     OSSL_CMP_SRV_certConf_cb_t process_certConf;
  38     OSSL_CMP_SRV_pollReq_cb_t process_pollReq;
  39
  40     int sendUnprotectedErrors; /* Send error and rejection msgs unprotected */
  41     int acceptUnprotected;     /* Accept requests with no/invalid prot. */
  42     int acceptRAVerified;      /* Accept ir/cr/kur with POPO RAVerified */
  43     int grantImplicitConfirm;  /* Grant implicit confirmation if requested */
  44
  45 }; /* OSSL_CMP_SRV_CTX */
  46
  47 void OSSL_CMP_SRV_CTX_free(OSSL_CMP_SRV_CTX *srv_ctx)
  48 {
  49     if (srv_ctx == NULL)
  50         return;
  51
  52     OSSL_CMP_CTX_free(srv_ctx->ctx);
  53     OPENSSL_free(srv_ctx);
  54 }
  55
  56 OSSL_CMP_SRV_CTX *OSSL_CMP_SRV_CTX_new(OPENSSL_CTX *libctx, const char *propq)
  57 {
  58     OSSL_CMP_SRV_CTX *ctx = OPENSSL_zalloc(sizeof(OSSL_CMP_SRV_CTX));
  59
  60     if (ctx == NULL)
  61         goto err;
  62
  63     if ((ctx->ctx = OSSL_CMP_CTX_new(libctx, propq)) == NULL)
  64         goto err;
  65
  66     /* all other elements are initialized to 0 or NULL, respectively */
  67     return ctx;
  68  err:
  69     OSSL_CMP_SRV_CTX_free(ctx);
  70     return NULL;
  71 }
  72
  73 int OSSL_CMP_SRV_CTX_init(OSSL_CMP_SRV_CTX *srv_ctx, void *custom_ctx,
  74                           OSSL_CMP_SRV_cert_request_cb_t process_cert_request,
  75                           OSSL_CMP_SRV_rr_cb_t process_rr,
  76                           OSSL_CMP_SRV_genm_cb_t process_genm,
  77                           OSSL_CMP_SRV_error_cb_t process_error,
  78                           OSSL_CMP_SRV_certConf_cb_t process_certConf,
  79                           OSSL_CMP_SRV_pollReq_cb_t process_pollReq)
  80 {
  81     if (srv_ctx == NULL) {
  82         CMPerr(0, CMP_R_NULL_ARGUMENT);
  83         return 0;
  84     }
  85     srv_ctx->custom_ctx = custom_ctx;
  86     srv_ctx->process_cert_request = process_cert_request;
  87     srv_ctx->process_rr = process_rr;
  88     srv_ctx->process_genm = process_genm;
  89     srv_ctx->process_error = process_error;
  90     srv_ctx->process_certConf = process_certConf;
  91     srv_ctx->process_pollReq = process_pollReq;
  92     return 1;
  93 }
  94
  95 OSSL_CMP_CTX *OSSL_CMP_SRV_CTX_get0_cmp_ctx(const OSSL_CMP_SRV_CTX *srv_ctx)
  96 {
  97     if (srv_ctx == NULL) {
  98         CMPerr(0, CMP_R_NULL_ARGUMENT);
  99         return NULL;
 100     }
 101     return srv_ctx->ctx;
 102 }
 103
 104 void *OSSL_CMP_SRV_CTX_get0_custom_ctx(const OSSL_CMP_SRV_CTX *srv_ctx)
 105 {
 106     if (srv_ctx == NULL) {
 107         CMPerr(0, CMP_R_NULL_ARGUMENT);
 108         return NULL;
 109     }
 110     return srv_ctx->custom_ctx;
 111 }
 112
 113 int OSSL_CMP_SRV_CTX_set_send_unprotected_errors(OSSL_CMP_SRV_CTX *srv_ctx,
 114                                                  int val)
 115 {
 116     if (srv_ctx == NULL) {
 117         CMPerr(0, CMP_R_NULL_ARGUMENT);
 118         return 0;
 119     }
 120     srv_ctx->sendUnprotectedErrors = val != 0;
 121     return 1;
 122 }
 123
 124 int OSSL_CMP_SRV_CTX_set_accept_unprotected(OSSL_CMP_SRV_CTX *srv_ctx, int val)
 125 {
 126     if (srv_ctx == NULL) {
 127         CMPerr(0, CMP_R_NULL_ARGUMENT);
 128         return 0;
 129     }
 130     srv_ctx->acceptUnprotected = val != 0;
 131     return 1;
 132 }
 133
 134 int OSSL_CMP_SRV_CTX_set_accept_raverified(OSSL_CMP_SRV_CTX *srv_ctx, int val)
 135 {
 136     if (srv_ctx == NULL) {
 137         CMPerr(0, CMP_R_NULL_ARGUMENT);
 138         return 0;
 139     }
 140     srv_ctx->acceptRAVerified = val != 0;
 141     return 1;
 142 }
 143
 144 int OSSL_CMP_SRV_CTX_set_grant_implicit_confirm(OSSL_CMP_SRV_CTX *srv_ctx,
 145                                                 int val)
 146 {
 147     if (srv_ctx == NULL) {
 148         CMPerr(0, CMP_R_NULL_ARGUMENT);
 149         return 0;
 150     }
 151     srv_ctx->grantImplicitConfirm = val != 0;
 152     return 1;
 153 }
 154
 155 /*
 156  * Processes an ir/cr/p10cr/kur and returns a certification response.
 157  * Only handles the first certification request contained in req
 158  * returns an ip/cp/kup on success and NULL on error
 159  */
 160 static OSSL_CMP_MSG *process_cert_request(OSSL_CMP_SRV_CTX *srv_ctx,
 161                                           const OSSL_CMP_MSG *req)
 162 {
 163     OSSL_CMP_MSG *msg = NULL;
 164     OSSL_CMP_PKISI *si = NULL;
 165     X509 *certOut = NULL;
 166     STACK_OF(X509) *chainOut = NULL, *caPubs = NULL;
 167     const OSSL_CRMF_MSG *crm = NULL;
 168     const X509_REQ *p10cr = NULL;
 169     int bodytype;
 170     int certReqId;
 171
 172     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 173         return NULL;
 174
 175     switch (ossl_cmp_msg_get_bodytype(req)) {
 176     case OSSL_CMP_PKIBODY_P10CR:
 177     case OSSL_CMP_PKIBODY_CR:
 178         bodytype = OSSL_CMP_PKIBODY_CP;
 179         break;
 180     case OSSL_CMP_PKIBODY_IR:
 181         bodytype = OSSL_CMP_PKIBODY_IP;
 182         break;
 183     case OSSL_CMP_PKIBODY_KUR:
 184         bodytype = OSSL_CMP_PKIBODY_KUP;
 185         break;
 186     default:
 187         CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 188         return NULL;
 189     }
 190
 191     if (ossl_cmp_msg_get_bodytype(req) == OSSL_CMP_PKIBODY_P10CR) {
 192         certReqId = OSSL_CMP_CERTREQID;
 193         p10cr = req->body->value.p10cr;
 194     } else {
 195         OSSL_CRMF_MSGS *reqs = req->body->value.ir; /* same for cr and kur */
 196
 197         if (sk_OSSL_CRMF_MSG_num(reqs) != 1) { /* TODO: handle case > 1 */
 198             CMPerr(0, CMP_R_MULTIPLE_REQUESTS_NOT_SUPPORTED);
 199             return NULL;
 200         }
 201
 202         if ((crm = sk_OSSL_CRMF_MSG_value(reqs, OSSL_CMP_CERTREQID)) == NULL) {
 203             CMPerr(0, CMP_R_CERTREQMSG_NOT_FOUND);
 204             return NULL;
 205         }
 206         certReqId = OSSL_CRMF_MSG_get_certReqId(crm);
 207     }
 208
 209     if (!ossl_cmp_verify_popo(srv_ctx->ctx, req, srv_ctx->acceptRAVerified)) {
 210         /* Proof of possession could not be verified */
 211         si = OSSL_CMP_STATUSINFO_new(OSSL_CMP_PKISTATUS_rejection,
 212                                      1 << OSSL_CMP_PKIFAILUREINFO_badPOP,
 213                                      ERR_reason_error_string(ERR_peek_error()));
 214         if (si == NULL)
 215             return NULL;
 216     } else {
 217         OSSL_CMP_PKIHEADER *hdr = OSSL_CMP_MSG_get0_header(req);
 218
 219         si = srv_ctx->process_cert_request(srv_ctx, req, certReqId, crm, p10cr,
 220                                            &certOut, &chainOut, &caPubs);
 221         if (si == NULL)
 222             goto err;
 223         /* set OSSL_CMP_OPT_IMPLICIT_CONFIRM if and only if transaction ends */
 224         if (!OSSL_CMP_CTX_set_option(srv_ctx->ctx,
 225                                      OSSL_CMP_OPT_IMPLICIT_CONFIRM,
 226                                      ossl_cmp_hdr_has_implicitConfirm(hdr)
 227                                          && srv_ctx->grantImplicitConfirm
 228                                          /* do not set if polling starts: */
 229                                          && certOut != NULL))
 230             goto err;
 231     }
 232
 233     msg = ossl_cmp_certrep_new(srv_ctx->ctx, bodytype, certReqId, si,
 234                                certOut, chainOut, caPubs, 0 /* encrypted */,
 235                                srv_ctx->sendUnprotectedErrors);
 236     /*
 237      * TODO when implemented in ossl_cmp_certrep_new():
 238      * in case OSSL_CRMF_POPO_KEYENC, set encrypted
 239      */
 240     if (msg == NULL)
 241         CMPerr(0, CMP_R_ERROR_CREATING_CERTREP);
 242
 243  err:
 244     OSSL_CMP_PKISI_free(si);
 245     X509_free(certOut);
 246     sk_X509_pop_free(chainOut, X509_free);
 247     sk_X509_pop_free(caPubs, X509_free);
 248     return msg;
 249 }
 250
 251 static OSSL_CMP_MSG *process_rr(OSSL_CMP_SRV_CTX *srv_ctx,
 252                                 const OSSL_CMP_MSG *req)
 253 {
 254     OSSL_CMP_MSG *msg = NULL;
 255     OSSL_CMP_REVDETAILS *details;
 256     OSSL_CRMF_CERTID *certId;
 257     OSSL_CRMF_CERTTEMPLATE *tmpl;
 258     const X509_NAME *issuer;
 259     ASN1_INTEGER *serial;
 260     OSSL_CMP_PKISI *si;
 261
 262     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 263         return NULL;
 264
 265     if (sk_OSSL_CMP_REVDETAILS_num(req->body->value.rr) != 1) {
 266         /* TODO: handle multiple elements if multiple requests have been sent */
 267         CMPerr(0, CMP_R_MULTIPLE_REQUESTS_NOT_SUPPORTED);
 268         return NULL;
 269     }
 270
 271     if ((details = sk_OSSL_CMP_REVDETAILS_value(req->body->value.rr,
 272                                                 OSSL_CMP_REVREQSID)) == NULL) {
 273         CMPerr(0, CMP_R_ERROR_PROCESSING_MESSAGE);
 274         return NULL;
 275     }
 276
 277     tmpl = details->certDetails;
 278     issuer = OSSL_CRMF_CERTTEMPLATE_get0_issuer(tmpl);
 279     serial = OSSL_CRMF_CERTTEMPLATE_get0_serialNumber(tmpl);
 280     /* here issuer and serial may safely be NULL */
 281     if ((certId = OSSL_CRMF_CERTID_gen(issuer, serial)) == NULL)
 282         return NULL;
 283     if ((si = srv_ctx->process_rr(srv_ctx, req, issuer, serial)) == NULL)
 284         goto err;
 285
 286     if ((msg = ossl_cmp_rp_new(srv_ctx->ctx, si, certId,
 287                                srv_ctx->sendUnprotectedErrors)) == NULL)
 288         CMPerr(0, CMP_R_ERROR_CREATING_RR);
 289
 290  err:
 291     OSSL_CRMF_CERTID_free(certId);
 292     OSSL_CMP_PKISI_free(si);
 293     return msg;
 294 }
 295
 296 /*
 297  * Processes genm and creates a genp message mirroring the contents of the
 298  * incoming message
 299  */
 300 static OSSL_CMP_MSG *process_genm(OSSL_CMP_SRV_CTX *srv_ctx,
 301                                   const OSSL_CMP_MSG *req)
 302 {
 303     OSSL_CMP_GENMSGCONTENT *itavs;
 304     OSSL_CMP_MSG *msg;
 305
 306     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 307         return NULL;
 308
 309     if (!srv_ctx->process_genm(srv_ctx, req, req->body->value.genm, &itavs))
 310         return NULL;
 311
 312     msg = ossl_cmp_genp_new(srv_ctx->ctx, itavs);
 313     sk_OSSL_CMP_ITAV_pop_free(itavs, OSSL_CMP_ITAV_free);
 314     return msg;
 315 }
 316
 317 static OSSL_CMP_MSG *process_error(OSSL_CMP_SRV_CTX *srv_ctx,
 318                                    const OSSL_CMP_MSG *req)
 319 {
 320     OSSL_CMP_ERRORMSGCONTENT *errorContent;
 321     OSSL_CMP_MSG *msg;
 322
 323     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 324         return NULL;
 325     errorContent = req->body->value.error;
 326     srv_ctx->process_error(srv_ctx, req, errorContent->pKIStatusInfo,
 327                            errorContent->errorCode, errorContent->errorDetails);
 328
 329     if ((msg = ossl_cmp_pkiconf_new(srv_ctx->ctx)) == NULL)
 330         CMPerr(0, CMP_R_ERROR_CREATING_PKICONF);
 331     return msg;
 332 }
 333
 334 static OSSL_CMP_MSG *process_certConf(OSSL_CMP_SRV_CTX *srv_ctx,
 335                                       const OSSL_CMP_MSG *req)
 336 {
 337     OSSL_CMP_CTX *ctx;
 338     OSSL_CMP_CERTCONFIRMCONTENT *ccc;
 339     int num;
 340     OSSL_CMP_MSG *msg = NULL;
 341     OSSL_CMP_CERTSTATUS *status = NULL;
 342
 343     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 344         return NULL;
 345
 346     ctx = srv_ctx->ctx;
 347     ccc = req->body->value.certConf;
 348     num = sk_OSSL_CMP_CERTSTATUS_num(ccc);
 349
 350     if (OSSL_CMP_CTX_get_option(ctx, OSSL_CMP_OPT_IMPLICIT_CONFIRM) == 1) {
 351         CMPerr(0, CMP_R_ERROR_UNEXPECTED_CERTCONF);
 352         return NULL;
 353     }
 354
 355     if (num == 0) {
 356         ossl_cmp_err(ctx, "certificate rejected by client");
 357     } else {
 358         if (num > 1)
 359             ossl_cmp_warn(ctx, "All CertStatus but the first will be ignored");
 360         status = sk_OSSL_CMP_CERTSTATUS_value(ccc, OSSL_CMP_CERTREQID);
 361     }
 362
 363     if (status != NULL) {
 364         int certReqId = ossl_cmp_asn1_get_int(status->certReqId);
 365         ASN1_OCTET_STRING *certHash = status->certHash;
 366         OSSL_CMP_PKISI *si = status->statusInfo;
 367
 368         if (!srv_ctx->process_certConf(srv_ctx, req, certReqId, certHash, si))
 369             return NULL; /* reason code may be: CMP_R_CERTHASH_UNMATCHED */
 370
 371         if (si != NULL && ossl_cmp_pkisi_get_status(si)
 372             != OSSL_CMP_PKISTATUS_accepted) {
 373             int pki_status = ossl_cmp_pkisi_get_status(si);
 374             const char *str = ossl_cmp_PKIStatus_to_string(pki_status);
 375
 376             ossl_cmp_log2(INFO, ctx, "certificate rejected by client %s %s",
 377                           str == NULL ? "without" : "with",
 378                           str == NULL ? "PKIStatus" : str);
 379         }
 380     }
 381
 382     if ((msg = ossl_cmp_pkiconf_new(ctx)) == NULL)
 383         CMPerr(0, CMP_R_ERROR_CREATING_PKICONF);
 384     return msg;
 385 }
 386
 387 static OSSL_CMP_MSG *process_pollReq(OSSL_CMP_SRV_CTX *srv_ctx,
 388                                      const OSSL_CMP_MSG *req)
 389 {
 390     OSSL_CMP_POLLREQCONTENT *prc;
 391     OSSL_CMP_POLLREQ *pr;
 392     int certReqId;
 393     OSSL_CMP_MSG *certReq;
 394     int64_t check_after = 0;
 395     OSSL_CMP_MSG *msg = NULL;
 396
 397     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 398         return NULL;
 399
 400     prc = req->body->value.pollReq;
 401     if (sk_OSSL_CMP_POLLREQ_num(prc) != 1) { /* TODO: handle case > 1 */
 402         CMPerr(0, CMP_R_MULTIPLE_REQUESTS_NOT_SUPPORTED);
 403         return NULL;
 404     }
 405
 406     pr = sk_OSSL_CMP_POLLREQ_value(prc, 0);
 407     certReqId = ossl_cmp_asn1_get_int(pr->certReqId);
 408     if (!srv_ctx->process_pollReq(srv_ctx, req, certReqId,
 409                                   &certReq, &check_after))
 410         return NULL;
 411
 412     if (certReq != NULL) {
 413         msg = process_cert_request(srv_ctx, certReq);
 414         OSSL_CMP_MSG_free(certReq);
 415     } else {
 416         if ((msg = ossl_cmp_pollRep_new(srv_ctx->ctx, certReqId,
 417                                         check_after)) == NULL)
 418             CMPerr(0, CMP_R_ERROR_CREATING_POLLREP);
 419     }
 420     return msg;
 421 }
 422
 423 /*
 424  * Determine whether missing/invalid protection of request message is allowed.
 425  * Return 1 on acceptance, 0 on rejection, or -1 on (internal) error.
 426  */
 427 static int unprotected_exception(const OSSL_CMP_CTX *ctx,
 428                                  const OSSL_CMP_MSG *req,
 429                                  int invalid_protection,
 430                                  int accept_unprotected_requests)
 431 {
 432     if (!ossl_assert(ctx != NULL && req != NULL))
 433         return -1;
 434
 435     if (accept_unprotected_requests) {
 436         ossl_cmp_log1(WARN, ctx, "ignoring %s protection of request message",
 437                       invalid_protection ? "invalid" : "missing");
 438         return 1;
 439     }
 440     if (ossl_cmp_msg_get_bodytype(req) == OSSL_CMP_PKIBODY_ERROR
 441         && OSSL_CMP_CTX_get_option(ctx, OSSL_CMP_OPT_UNPROTECTED_ERRORS) == 1) {
 442         ossl_cmp_warn(ctx, "ignoring missing protection of error message");
 443         return 1;
 444     }
 445     return 0;
 446 }
 447
 448 /*
 449  * returns created message and NULL on internal error
 450  */
 451 OSSL_CMP_MSG *OSSL_CMP_SRV_process_request(OSSL_CMP_SRV_CTX *srv_ctx,
 452                                            const OSSL_CMP_MSG *req)
 453 {
 454     OSSL_CMP_CTX *ctx;
 455     ASN1_OCTET_STRING *backup_secret;
 456     OSSL_CMP_PKIHEADER *hdr;
 457     int req_type, rsp_type;
 458     int res;
 459     OSSL_CMP_MSG *rsp = NULL;
 460
 461     if (srv_ctx == NULL || srv_ctx->ctx == NULL
 462             || req == NULL || req->body == NULL
 463             || (hdr = OSSL_CMP_MSG_get0_header(req)) == NULL) {
 464         CMPerr(0, CMP_R_NULL_ARGUMENT);
 465         return 0;
 466     }
 467     ctx = srv_ctx->ctx;
 468     backup_secret = ctx->secretValue;
 469
 470     /*
 471      * Some things need to be done already before validating the message in
 472      * order to be able to send an error message as far as needed and possible.
 473      */
 474     if (hdr->sender->type != GEN_DIRNAME) {
 475         CMPerr(0, CMP_R_SENDER_GENERALNAME_TYPE_NOT_SUPPORTED);
 476         goto err;
 477     }
 478     if (!OSSL_CMP_CTX_set1_recipient(ctx, hdr->sender->d.directoryName))
 479         goto err;
 480
 481     req_type = ossl_cmp_msg_get_bodytype(req);
 482     switch (req_type) {
 483     case OSSL_CMP_PKIBODY_IR:
 484     case OSSL_CMP_PKIBODY_CR:
 485     case OSSL_CMP_PKIBODY_P10CR:
 486     case OSSL_CMP_PKIBODY_KUR:
 487     case OSSL_CMP_PKIBODY_RR:
 488     case OSSL_CMP_PKIBODY_GENM:
 489     case OSSL_CMP_PKIBODY_ERROR:
 490         if (ctx->transactionID != NULL) {
 491             char *tid;
 492
 493             tid = OPENSSL_buf2hexstr(ctx->transactionID->data,
 494                                      ctx->transactionID->length);
 495             if (tid != NULL)
 496                 ossl_cmp_log1(WARN, ctx,
 497                               "Assuming that last transaction with ID=%s got aborted",
 498                               tid);
 499             OPENSSL_free(tid);
 500         }
 501         /* start of a new transaction, reset transactionID and senderNonce */
 502         if (!OSSL_CMP_CTX_set1_transactionID(ctx, NULL)
 503                 || !OSSL_CMP_CTX_set1_senderNonce(ctx, NULL))
 504             goto err;
 505         break;
 506     default:
 507         /* transactionID should be already initialized */
 508         if (ctx->transactionID == NULL) {
 509 #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
 510             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 511             goto err;
 512 #endif
 513         }
 514     }
 515
 516     res = ossl_cmp_msg_check_update(ctx, req, unprotected_exception,
 517                                     srv_ctx->acceptUnprotected);
 518     if (ctx->secretValue != NULL && ctx->pkey != NULL
 519             && ossl_cmp_hdr_get_protection_nid(hdr) != NID_id_PasswordBasedMAC)
 520         ctx->secretValue = NULL; /* use MSG_SIG_ALG when protecting rsp */
 521     if (!res)
 522         goto err;
 523
 524     switch (req_type) {
 525     case OSSL_CMP_PKIBODY_IR:
 526     case OSSL_CMP_PKIBODY_CR:
 527     case OSSL_CMP_PKIBODY_P10CR:
 528     case OSSL_CMP_PKIBODY_KUR:
 529         if (srv_ctx->process_cert_request == NULL)
 530             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 531         else
 532             rsp = process_cert_request(srv_ctx, req);
 533         break;
 534     case OSSL_CMP_PKIBODY_RR:
 535         if (srv_ctx->process_rr == NULL)
 536             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 537         else
 538             rsp = process_rr(srv_ctx, req);
 539         break;
 540     case OSSL_CMP_PKIBODY_GENM:
 541         if (srv_ctx->process_genm == NULL)
 542             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 543         else
 544             rsp = process_genm(srv_ctx, req);
 545         break;
 546     case OSSL_CMP_PKIBODY_ERROR:
 547         if (srv_ctx->process_error == NULL)
 548             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 549         else
 550             rsp = process_error(srv_ctx, req);
 551         break;
 552     case OSSL_CMP_PKIBODY_CERTCONF:
 553         if (srv_ctx->process_certConf == NULL)
 554             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 555         else
 556             rsp = process_certConf(srv_ctx, req);
 557         break;
 558     case OSSL_CMP_PKIBODY_POLLREQ:
 559         if (srv_ctx->process_pollReq == NULL)
 560             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 561         else
 562             rsp = process_pollReq(srv_ctx, req);
 563         break;
 564     default:
 565         /* TODO possibly support further request message types */
 566         CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 567         break;
 568     }
 569
 570  err:
 571     if (rsp == NULL) {
 572         /* on error, try to respond with CMP error message to client */
 573         const char *data = NULL;
 574         int flags = 0;
 575         unsigned long err = ERR_peek_error_data(&data, &flags);
 576         int fail_info = 1 << OSSL_CMP_PKIFAILUREINFO_badRequest;
 577         /* TODO fail_info could be more specific */
 578         OSSL_CMP_PKISI *si = NULL;
 579
 580         if (ctx->transactionID == NULL) {
 581             /* ignore any (extra) error in next two function calls: */
 582             (void)OSSL_CMP_CTX_set1_transactionID(ctx, hdr->transactionID);
 583             (void)ossl_cmp_ctx_set1_recipNonce(ctx, hdr->senderNonce);
 584         }
 585
 586         if ((si = OSSL_CMP_STATUSINFO_new(OSSL_CMP_PKISTATUS_rejection,
 587                                           fail_info, NULL)) != NULL) {
 588             if (err != 0 && (flags & ERR_TXT_STRING) != 0)
 589                 data = ERR_reason_error_string(err);
 590             rsp = ossl_cmp_error_new(srv_ctx->ctx, si,
 591                                      err != 0 ? ERR_GET_REASON(err) : -1,
 592                                      data, srv_ctx->sendUnprotectedErrors);
 593             OSSL_CMP_PKISI_free(si);
 594         }
 595     }
 596     ctx->secretValue = backup_secret;
 597
 598     /* possibly close the transaction */
 599     rsp_type =
 600         rsp != NULL ? ossl_cmp_msg_get_bodytype(rsp) : OSSL_CMP_PKIBODY_ERROR;
 601     switch (rsp_type) {
 602     case OSSL_CMP_PKIBODY_IP:
 603     case OSSL_CMP_PKIBODY_CP:
 604     case OSSL_CMP_PKIBODY_KUP:
 605     case OSSL_CMP_PKIBODY_RP:
 606         if (OSSL_CMP_CTX_get_option(ctx, OSSL_CMP_OPT_IMPLICIT_CONFIRM) == 0)
 607             break;
 608         /* fall through */
 609
 610     case OSSL_CMP_PKIBODY_PKICONF:
 611     case OSSL_CMP_PKIBODY_GENP:
 612     case OSSL_CMP_PKIBODY_ERROR:
 613         /* TODO possibly support further terminating response message types */
 614         /* prepare for next transaction, ignoring any errors here: */
 615         (void)OSSL_CMP_CTX_set1_transactionID(ctx, NULL);
 616         (void)OSSL_CMP_CTX_set1_senderNonce(ctx, NULL);
 617
 618     default: /* not closing transaction in other cases */
 619         break;
 620     }
 621     return rsp;
 622 }
 623
 624 /*
 625  * Server interface that may substitute OSSL_CMP_MSG_http_perform at the client.
 626  * The OSSL_CMP_SRV_CTX must be set as client_ctx->transfer_cb_arg.
 627  * returns received message on success, else NULL and pushes an element on the
 628  * error stack.
 629  */
 630 OSSL_CMP_MSG * OSSL_CMP_CTX_server_perform(OSSL_CMP_CTX *client_ctx,
 631                                            const OSSL_CMP_MSG *req)
 632 {
 633     OSSL_CMP_SRV_CTX *srv_ctx = NULL;
 634
 635     if (client_ctx == NULL || req == NULL) {
 636         CMPerr(0, CMP_R_NULL_ARGUMENT);
 637         return 0;
 638     }
 639
 640     if ((srv_ctx = OSSL_CMP_CTX_get_transfer_cb_arg(client_ctx)) == NULL) {
 641         CMPerr(0, CMP_R_TRANSFER_ERROR);
 642         return 0;
 643     }
 644
 645     return OSSL_CMP_SRV_process_request(srv_ctx, req);
 646 }