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(void)
  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()) == 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(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, OSSL_CMP_OPT_IMPLICIT_CONFIRM,
 225                                      ossl_cmp_hdr_has_implicitConfirm(hdr)
 226                                          && srv_ctx->grantImplicitConfirm
 227                                          /* do not set if polling starts: */
 228                                          && certOut != NULL))
 229             goto err;
 230     }
 231
 232     msg = ossl_cmp_certRep_new(srv_ctx->ctx, bodytype, certReqId, si,
 233                                certOut, chainOut, caPubs, 0 /* encrypted */,
 234                                srv_ctx->sendUnprotectedErrors);
 235     /*
 236      * TODO when implemented in ossl_cmp_certrep_new():
 237      * in case OSSL_CRMF_POPO_KEYENC, set encrypted
 238      */
 239     if (msg == NULL)
 240         CMPerr(0, CMP_R_ERROR_CREATING_CERTREP);
 241
 242  err:
 243     OSSL_CMP_PKISI_free(si);
 244     X509_free(certOut);
 245     sk_X509_pop_free(chainOut, X509_free);
 246     sk_X509_pop_free(caPubs, X509_free);
 247     return msg;
 248 }
 249
 250 static OSSL_CMP_MSG *process_rr(OSSL_CMP_SRV_CTX *srv_ctx,
 251                                 const OSSL_CMP_MSG *req)
 252 {
 253     OSSL_CMP_MSG *msg = NULL;
 254     OSSL_CMP_REVDETAILS *details;
 255     OSSL_CRMF_CERTID *certId;
 256     OSSL_CRMF_CERTTEMPLATE *tmpl;
 257     const X509_NAME *issuer;
 258     ASN1_INTEGER *serial;
 259     OSSL_CMP_PKISI *si;
 260
 261     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 262         return NULL;
 263
 264     if (sk_OSSL_CMP_REVDETAILS_num(req->body->value.rr) != 1) {
 265         /* TODO: handle multiple elements if multiple requests have been sent */
 266         CMPerr(0, CMP_R_MULTIPLE_REQUESTS_NOT_SUPPORTED);
 267         return NULL;
 268     }
 269
 270     if ((details = sk_OSSL_CMP_REVDETAILS_value(req->body->value.rr,
 271                                                 OSSL_CMP_REVREQSID)) == NULL) {
 272         CMPerr(0, CMP_R_ERROR_PROCESSING_MESSAGE);
 273         return NULL;
 274     }
 275
 276     tmpl = details->certDetails;
 277     issuer = OSSL_CRMF_CERTTEMPLATE_get0_issuer(tmpl);
 278     serial = OSSL_CRMF_CERTTEMPLATE_get0_serialNumber(tmpl);
 279     /* here issuer and serial may safely be NULL */
 280     if ((certId = OSSL_CRMF_CERTID_gen(issuer, serial)) == NULL)
 281         return NULL;
 282     if ((si = srv_ctx->process_rr(srv_ctx, req, issuer, serial)) == NULL)
 283         goto err;
 284
 285     if ((msg = ossl_cmp_rp_new(srv_ctx->ctx, si, certId,
 286                                srv_ctx->sendUnprotectedErrors)) == NULL)
 287         CMPerr(0, CMP_R_ERROR_CREATING_RR);
 288
 289  err:
 290     OSSL_CRMF_CERTID_free(certId);
 291     OSSL_CMP_PKISI_free(si);
 292     return msg;
 293 }
 294
 295 /*
 296  * Processes genm and creates a genp message mirroring the contents of the
 297  * incoming message
 298  */
 299 static OSSL_CMP_MSG *process_genm(OSSL_CMP_SRV_CTX *srv_ctx,
 300                                   const OSSL_CMP_MSG *req)
 301 {
 302     OSSL_CMP_GENMSGCONTENT *itavs;
 303     OSSL_CMP_MSG *msg;
 304
 305     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 306         return NULL;
 307
 308     if (!srv_ctx->process_genm(srv_ctx, req, req->body->value.genm, &itavs))
 309         return NULL;
 310
 311     msg = ossl_cmp_genp_new(srv_ctx->ctx, itavs);
 312     sk_OSSL_CMP_ITAV_pop_free(itavs, OSSL_CMP_ITAV_free);
 313     return msg;
 314 }
 315
 316 static OSSL_CMP_MSG *process_error(OSSL_CMP_SRV_CTX *srv_ctx,
 317                                    const OSSL_CMP_MSG *req)
 318 {
 319     OSSL_CMP_ERRORMSGCONTENT *errorContent;
 320     OSSL_CMP_MSG *msg;
 321
 322     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 323         return NULL;
 324     errorContent = req->body->value.error;
 325     srv_ctx->process_error(srv_ctx, req, errorContent->pKIStatusInfo,
 326                            errorContent->errorCode, errorContent->errorDetails);
 327
 328     if ((msg = ossl_cmp_pkiconf_new(srv_ctx->ctx)) == NULL)
 329         CMPerr(0, CMP_R_ERROR_CREATING_PKICONF);
 330     return msg;
 331 }
 332
 333 static OSSL_CMP_MSG *process_certConf(OSSL_CMP_SRV_CTX *srv_ctx,
 334                                       const OSSL_CMP_MSG *req)
 335 {
 336     OSSL_CMP_CTX *ctx;
 337     OSSL_CMP_CERTCONFIRMCONTENT *ccc;
 338     int num;
 339     OSSL_CMP_MSG *msg = NULL;
 340     OSSL_CMP_CERTSTATUS *status = NULL;
 341
 342     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 343         return NULL;
 344
 345     ctx = srv_ctx->ctx;
 346     ccc = req->body->value.certConf;
 347     num = sk_OSSL_CMP_CERTSTATUS_num(ccc);
 348
 349     if (OSSL_CMP_CTX_get_option(ctx, OSSL_CMP_OPT_IMPLICIT_CONFIRM) == 1) {
 350         CMPerr(0, CMP_R_ERROR_UNEXPECTED_CERTCONF);
 351         return NULL;
 352     }
 353
 354     if (num == 0) {
 355         ossl_cmp_err(ctx, "certificate rejected by client");
 356     } else {
 357         if (num > 1)
 358             ossl_cmp_warn(ctx, "All CertStatus but the first will be ignored");
 359         status = sk_OSSL_CMP_CERTSTATUS_value(ccc, OSSL_CMP_CERTREQID);
 360     }
 361
 362     if (status != NULL) {
 363         int certReqId = ossl_cmp_asn1_get_int(status->certReqId);
 364         ASN1_OCTET_STRING *certHash = status->certHash;
 365         OSSL_CMP_PKISI *si = status->statusInfo;
 366
 367         if (!srv_ctx->process_certConf(srv_ctx, req, certReqId, certHash, si))
 368             return NULL; /* reason code may be: CMP_R_CERTHASH_UNMATCHED */
 369
 370         if (si != NULL && ossl_cmp_pkisi_get_status(si)
 371             != OSSL_CMP_PKISTATUS_accepted) {
 372             int pki_status = ossl_cmp_pkisi_get_status(si);
 373             const char *str = ossl_cmp_PKIStatus_to_string(pki_status);
 374
 375             ossl_cmp_log2(INFO, ctx, "certificate rejected by client %s %s",
 376                           str == NULL ? "without" : "with",
 377                           str == NULL ? "PKIStatus" : str);
 378         }
 379     }
 380
 381     if ((msg = ossl_cmp_pkiconf_new(ctx)) == NULL)
 382         CMPerr(0, CMP_R_ERROR_CREATING_PKICONF);
 383     return msg;
 384 }
 385
 386 static OSSL_CMP_MSG *process_pollReq(OSSL_CMP_SRV_CTX *srv_ctx,
 387                                      const OSSL_CMP_MSG *req)
 388 {
 389     OSSL_CMP_POLLREQCONTENT *prc;
 390     OSSL_CMP_POLLREQ *pr;
 391     int certReqId;
 392     OSSL_CMP_MSG *certReq;
 393     int64_t check_after = 0;
 394     OSSL_CMP_MSG *msg = NULL;
 395
 396     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
 397         return NULL;
 398
 399     prc = req->body->value.pollReq;
 400     if (sk_OSSL_CMP_POLLREQ_num(prc) != 1) { /* TODO: handle case > 1 */
 401         CMPerr(0, CMP_R_MULTIPLE_REQUESTS_NOT_SUPPORTED);
 402         return NULL;
 403     }
 404
 405     pr = sk_OSSL_CMP_POLLREQ_value(prc, 0);
 406     certReqId = ossl_cmp_asn1_get_int(pr->certReqId);
 407     if (!srv_ctx->process_pollReq(srv_ctx, req, certReqId,
 408                                   &certReq, &check_after))
 409         return NULL;
 410
 411     if (certReq != NULL) {
 412         msg = process_cert_request(srv_ctx, certReq);
 413         OSSL_CMP_MSG_free(certReq);
 414     } else {
 415         if ((msg = ossl_cmp_pollRep_new(srv_ctx->ctx, certReqId,
 416                                         check_after)) == NULL)
 417             CMPerr(0, CMP_R_ERROR_CREATING_POLLREP);
 418     }
 419     return msg;
 420 }
 421
 422 /*
 423  * Determine whether missing/invalid protection of request message is allowed.
 424  * Return 1 on acceptance, 0 on rejection, or -1 on (internal) error.
 425  */
 426 static int unprotected_exception(const OSSL_CMP_CTX *ctx,
 427                                  const OSSL_CMP_MSG *req,
 428                                  int invalid_protection,
 429                                  int accept_unprotected_requests)
 430 {
 431     if (!ossl_assert(ctx != NULL && req != NULL))
 432         return -1;
 433
 434     if (accept_unprotected_requests) {
 435         ossl_cmp_log1(WARN, ctx, "ignoring %s protection of request message",
 436                       invalid_protection ? "invalid" : "missing");
 437         return 1;
 438     }
 439     if (ossl_cmp_msg_get_bodytype(req) == OSSL_CMP_PKIBODY_ERROR
 440         && OSSL_CMP_CTX_get_option(ctx, OSSL_CMP_OPT_UNPROTECTED_ERRORS) == 1) {
 441         ossl_cmp_warn(ctx, "ignoring missing protection of error message");
 442         return 1;
 443     }
 444     return 0;
 445 }
 446
 447 /*
 448  * returns created message and NULL on internal error
 449  */
 450 OSSL_CMP_MSG *OSSL_CMP_SRV_process_request(OSSL_CMP_SRV_CTX *srv_ctx,
 451                                            const OSSL_CMP_MSG *req)
 452 {
 453     OSSL_CMP_CTX *ctx;
 454     OSSL_CMP_PKIHEADER *hdr;
 455     int req_type, rsp_type;
 456     OSSL_CMP_MSG *rsp = NULL;
 457
 458     if (srv_ctx == NULL || srv_ctx->ctx == NULL
 459             || req == NULL || req->body == NULL
 460             || (hdr = OSSL_CMP_MSG_get0_header(req)) == NULL) {
 461         CMPerr(0, CMP_R_NULL_ARGUMENT);
 462         return 0;
 463     }
 464     ctx = srv_ctx->ctx;
 465
 466     if (hdr->sender->type != GEN_DIRNAME) {
 467         CMPerr(0, CMP_R_SENDER_GENERALNAME_TYPE_NOT_SUPPORTED);
 468         goto err;
 469     }
 470     if (!OSSL_CMP_CTX_set1_recipient(ctx, hdr->sender->d.directoryName))
 471         goto err;
 472
 473     req_type = ossl_cmp_msg_get_bodytype(req);
 474     switch (req_type) {
 475     case OSSL_CMP_PKIBODY_IR:
 476     case OSSL_CMP_PKIBODY_CR:
 477     case OSSL_CMP_PKIBODY_P10CR:
 478     case OSSL_CMP_PKIBODY_KUR:
 479     case OSSL_CMP_PKIBODY_RR:
 480     case OSSL_CMP_PKIBODY_GENM:
 481     case OSSL_CMP_PKIBODY_ERROR:
 482         if (ctx->transactionID != NULL) {
 483             char *tid;
 484
 485             tid = OPENSSL_buf2hexstr(ctx->transactionID->data,
 486                                      ctx->transactionID->length);
 487             ossl_cmp_log1(WARN, ctx,
 488                           "Assuming that last transaction with ID=%s got aborted",
 489                           tid);
 490             OPENSSL_free(tid);
 491         }
 492         /* start of a new transaction, set transactionID and senderNonce */
 493         if (!OSSL_CMP_CTX_set1_transactionID(ctx, hdr->transactionID)
 494                 || !ossl_cmp_ctx_set1_recipNonce(ctx, hdr->senderNonce))
 495             goto err;
 496         break;
 497     default:
 498         /* transactionID should be already initialized */
 499         if (ctx->transactionID == NULL) {
 500 #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
 501             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 502             /* ignore any (extra) error in next two function calls: */
 503             (void)OSSL_CMP_CTX_set1_transactionID(ctx, hdr->transactionID);
 504             (void)ossl_cmp_ctx_set1_recipNonce(ctx, hdr->senderNonce);
 505             goto err;
 506 #endif
 507         }
 508     }
 509
 510     if (ossl_cmp_msg_check_received(ctx, req, unprotected_exception,
 511                                     srv_ctx->acceptUnprotected) < 0)
 512         goto err;
 513
 514     switch (req_type) {
 515     case OSSL_CMP_PKIBODY_IR:
 516     case OSSL_CMP_PKIBODY_CR:
 517     case OSSL_CMP_PKIBODY_P10CR:
 518     case OSSL_CMP_PKIBODY_KUR:
 519         if (srv_ctx->process_cert_request == NULL)
 520             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 521         else
 522             rsp = process_cert_request(srv_ctx, req);
 523         break;
 524     case OSSL_CMP_PKIBODY_RR:
 525         if (srv_ctx->process_rr == NULL)
 526             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 527         else
 528             rsp = process_rr(srv_ctx, req);
 529         break;
 530     case OSSL_CMP_PKIBODY_GENM:
 531         if (srv_ctx->process_genm == NULL)
 532             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 533         else
 534             rsp = process_genm(srv_ctx, req);
 535         break;
 536     case OSSL_CMP_PKIBODY_ERROR:
 537         if (srv_ctx->process_error == NULL)
 538             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 539         else
 540             rsp = process_error(srv_ctx, req);
 541         break;
 542     case OSSL_CMP_PKIBODY_CERTCONF:
 543         if (srv_ctx->process_certConf == NULL)
 544             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 545         else
 546             rsp = process_certConf(srv_ctx, req);
 547         break;
 548     case OSSL_CMP_PKIBODY_POLLREQ:
 549         if (srv_ctx->process_pollReq == NULL)
 550             CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 551         else
 552             rsp = process_pollReq(srv_ctx, req);
 553         break;
 554     default:
 555         /* TODO possibly support further request message types */
 556         CMPerr(0, CMP_R_UNEXPECTED_PKIBODY);
 557         break;
 558     }
 559
 560  err:
 561     if (rsp == NULL) {
 562         /* on error, try to respond with CMP error message to client */
 563         const char *data = NULL;
 564         int flags = 0;
 565         unsigned long err = ERR_peek_error_data(&data, &flags);
 566         int fail_info = 1 << OSSL_CMP_PKIFAILUREINFO_badRequest;
 567         /* TODO fail_info could be more specific */
 568         OSSL_CMP_PKISI *si = NULL;
 569
 570         if ((si = OSSL_CMP_STATUSINFO_new(OSSL_CMP_PKISTATUS_rejection,
 571                                           fail_info, NULL)) == NULL)
 572             return 0;
 573         if (err != 0 && (flags & ERR_TXT_STRING) != 0)
 574             data = ERR_reason_error_string(err);
 575         rsp = ossl_cmp_error_new(srv_ctx->ctx, si,
 576                                  err != 0 ? ERR_GET_REASON(err) : -1,
 577                                  data, srv_ctx->sendUnprotectedErrors);
 578         OSSL_CMP_PKISI_free(si);
 579     }
 580
 581     /* possibly close the transaction */
 582     rsp_type =
 583         rsp != NULL ? ossl_cmp_msg_get_bodytype(rsp) : OSSL_CMP_PKIBODY_ERROR;
 584     switch (rsp_type) {
 585     case OSSL_CMP_PKIBODY_IP:
 586     case OSSL_CMP_PKIBODY_CP:
 587     case OSSL_CMP_PKIBODY_KUP:
 588     case OSSL_CMP_PKIBODY_RP:
 589         if (OSSL_CMP_CTX_get_option(ctx, OSSL_CMP_OPT_IMPLICIT_CONFIRM) == 0)
 590             break;
 591         /* fall through */
 592
 593     case OSSL_CMP_PKIBODY_PKICONF:
 594     case OSSL_CMP_PKIBODY_GENP:
 595     case OSSL_CMP_PKIBODY_ERROR:
 596         /* TODO possibly support further terminating response message types */
 597         (void)OSSL_CMP_CTX_set1_transactionID(ctx, NULL); /* ignore any error */
 598
 599     default: /* not closing transaction in other cases */
 600         break;
 601     }
 602     return rsp;
 603 }
 604
 605 /*
 606  * Server interface that may substitute OSSL_CMP_MSG_http_perform at the client.
 607  * The OSSL_CMP_SRV_CTX must be set as client_ctx->transfer_cb_arg.
 608  * returns received message on success, else NULL and pushes an element on the
 609  * error stack.
 610  */
 611 OSSL_CMP_MSG * OSSL_CMP_CTX_server_perform(OSSL_CMP_CTX *client_ctx,
 612                                            const OSSL_CMP_MSG *req)
 613 {
 614     OSSL_CMP_SRV_CTX *srv_ctx = NULL;
 615
 616     if (client_ctx == NULL || req == NULL) {
 617         CMPerr(0, CMP_R_NULL_ARGUMENT);
 618         return 0;
 619     }
 620
 621     if ((srv_ctx = OSSL_CMP_CTX_get_transfer_cb_arg(client_ctx)) == NULL) {
 622         CMPerr(0, CMP_R_TRANSFER_ERROR);
 623         return 0;
 624     }
 625
 626     return OSSL_CMP_SRV_process_request(srv_ctx, req);
 627 }