xref: /freebsd/crypto/openssl/crypto/cmp/cmp_server.c (revision e7be843b4a162e68651d3911f0357ed464915629)
1 /*
2  * Copyright 2007-2025 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 /* the context for the generic CMP server */
23 struct ossl_cmp_srv_ctx_st {
24     OSSL_CMP_CTX *ctx; /* CMP client context reused for transactionID etc. */
25     void *custom_ctx;  /* application-specific server context */
26     int certReqId;     /* of ir/cr/kur, OSSL_CMP_CERTREQID_NONE for p10cr */
27     int polling;       /* current transaction is in polling mode */
28 
29     OSSL_CMP_SRV_cert_request_cb_t process_cert_request;
30     OSSL_CMP_SRV_rr_cb_t process_rr;
31     OSSL_CMP_SRV_genm_cb_t process_genm;
32     OSSL_CMP_SRV_error_cb_t process_error;
33     OSSL_CMP_SRV_certConf_cb_t process_certConf;
34     OSSL_CMP_SRV_pollReq_cb_t process_pollReq;
35     OSSL_CMP_SRV_delayed_delivery_cb_t delayed_delivery;
36     OSSL_CMP_SRV_clean_transaction_cb_t clean_transaction;
37 
38     int sendUnprotectedErrors; /* Send error and rejection msgs unprotected */
39     int acceptUnprotected;     /* Accept requests with no/invalid prot. */
40     int acceptRAVerified;      /* Accept ir/cr/kur with POPO RAVerified */
41     int grantImplicitConfirm;  /* Grant implicit confirmation if requested */
42 
43 }; /* OSSL_CMP_SRV_CTX */
44 
OSSL_CMP_SRV_CTX_free(OSSL_CMP_SRV_CTX * srv_ctx)45 void OSSL_CMP_SRV_CTX_free(OSSL_CMP_SRV_CTX *srv_ctx)
46 {
47     if (srv_ctx == NULL)
48         return;
49 
50     OSSL_CMP_CTX_free(srv_ctx->ctx);
51     OPENSSL_free(srv_ctx);
52 }
53 
OSSL_CMP_SRV_CTX_new(OSSL_LIB_CTX * libctx,const char * propq)54 OSSL_CMP_SRV_CTX *OSSL_CMP_SRV_CTX_new(OSSL_LIB_CTX *libctx, const char *propq)
55 {
56     OSSL_CMP_SRV_CTX *ctx = OPENSSL_zalloc(sizeof(OSSL_CMP_SRV_CTX));
57 
58     if (ctx == NULL)
59         goto err;
60 
61     if ((ctx->ctx = OSSL_CMP_CTX_new(libctx, propq)) == NULL)
62         goto err;
63     ctx->certReqId = OSSL_CMP_CERTREQID_INVALID;
64     ctx->polling = 0;
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 
OSSL_CMP_SRV_CTX_init(OSSL_CMP_SRV_CTX * srv_ctx,void * custom_ctx,OSSL_CMP_SRV_cert_request_cb_t process_cert_request,OSSL_CMP_SRV_rr_cb_t process_rr,OSSL_CMP_SRV_genm_cb_t process_genm,OSSL_CMP_SRV_error_cb_t process_error,OSSL_CMP_SRV_certConf_cb_t process_certConf,OSSL_CMP_SRV_pollReq_cb_t process_pollReq)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         ERR_raise(ERR_LIB_CMP, 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 
OSSL_CMP_SRV_CTX_init_trans(OSSL_CMP_SRV_CTX * srv_ctx,OSSL_CMP_SRV_delayed_delivery_cb_t delay,OSSL_CMP_SRV_clean_transaction_cb_t clean)95 int OSSL_CMP_SRV_CTX_init_trans(OSSL_CMP_SRV_CTX *srv_ctx,
96                                 OSSL_CMP_SRV_delayed_delivery_cb_t delay,
97                                 OSSL_CMP_SRV_clean_transaction_cb_t clean)
98 {
99     if (srv_ctx == NULL) {
100         ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
101         return 0;
102     }
103     srv_ctx->delayed_delivery = delay;
104     srv_ctx->clean_transaction = clean;
105     return 1;
106 }
107 
OSSL_CMP_SRV_CTX_get0_cmp_ctx(const OSSL_CMP_SRV_CTX * srv_ctx)108 OSSL_CMP_CTX *OSSL_CMP_SRV_CTX_get0_cmp_ctx(const OSSL_CMP_SRV_CTX *srv_ctx)
109 {
110     if (srv_ctx == NULL) {
111         ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
112         return NULL;
113     }
114     return srv_ctx->ctx;
115 }
116 
OSSL_CMP_SRV_CTX_get0_custom_ctx(const OSSL_CMP_SRV_CTX * srv_ctx)117 void *OSSL_CMP_SRV_CTX_get0_custom_ctx(const OSSL_CMP_SRV_CTX *srv_ctx)
118 {
119     if (srv_ctx == NULL) {
120         ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
121         return NULL;
122     }
123     return srv_ctx->custom_ctx;
124 }
125 
OSSL_CMP_SRV_CTX_set_send_unprotected_errors(OSSL_CMP_SRV_CTX * srv_ctx,int val)126 int OSSL_CMP_SRV_CTX_set_send_unprotected_errors(OSSL_CMP_SRV_CTX *srv_ctx,
127                                                  int val)
128 {
129     if (srv_ctx == NULL) {
130         ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
131         return 0;
132     }
133     srv_ctx->sendUnprotectedErrors = val != 0;
134     return 1;
135 }
136 
OSSL_CMP_SRV_CTX_set_accept_unprotected(OSSL_CMP_SRV_CTX * srv_ctx,int val)137 int OSSL_CMP_SRV_CTX_set_accept_unprotected(OSSL_CMP_SRV_CTX *srv_ctx, int val)
138 {
139     if (srv_ctx == NULL) {
140         ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
141         return 0;
142     }
143     srv_ctx->acceptUnprotected = val != 0;
144     return 1;
145 }
146 
OSSL_CMP_SRV_CTX_set_accept_raverified(OSSL_CMP_SRV_CTX * srv_ctx,int val)147 int OSSL_CMP_SRV_CTX_set_accept_raverified(OSSL_CMP_SRV_CTX *srv_ctx, int val)
148 {
149     if (srv_ctx == NULL) {
150         ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
151         return 0;
152     }
153     srv_ctx->acceptRAVerified = val != 0;
154     return 1;
155 }
156 
OSSL_CMP_SRV_CTX_set_grant_implicit_confirm(OSSL_CMP_SRV_CTX * srv_ctx,int val)157 int OSSL_CMP_SRV_CTX_set_grant_implicit_confirm(OSSL_CMP_SRV_CTX *srv_ctx,
158                                                 int val)
159 {
160     if (srv_ctx == NULL) {
161         ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
162         return 0;
163     }
164     srv_ctx->grantImplicitConfirm = val != 0;
165     return 1;
166 }
167 
168 /* return error msg with waiting status if polling is initiated, else NULL */
delayed_delivery(OSSL_CMP_SRV_CTX * srv_ctx,const OSSL_CMP_MSG * req)169 static OSSL_CMP_MSG *delayed_delivery(OSSL_CMP_SRV_CTX *srv_ctx,
170                                       const OSSL_CMP_MSG *req)
171 {
172     int ret;
173     unsigned long err;
174     int status = OSSL_CMP_PKISTATUS_waiting,
175         fail_info = 0, errorCode = 0;
176     const char *txt = NULL, *details = NULL;
177     OSSL_CMP_PKISI *si;
178     OSSL_CMP_MSG *msg;
179 
180     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL
181                      && srv_ctx->delayed_delivery != NULL))
182         return NULL;
183 
184     ret = srv_ctx->delayed_delivery(srv_ctx, req);
185     if (ret == 0)
186         return NULL;
187     if (ret == 1) {
188         srv_ctx->polling = 1;
189     } else {
190         status = OSSL_CMP_PKISTATUS_rejection;
191         fail_info = 1 << OSSL_CMP_PKIFAILUREINFO_systemFailure;
192         txt = "server application error";
193         err = ERR_peek_error();
194         errorCode = ERR_GET_REASON(err);
195         details = ERR_reason_error_string(err);
196     }
197 
198     si = OSSL_CMP_STATUSINFO_new(status, fail_info, txt);
199     if (si == NULL)
200         return NULL;
201 
202     msg = ossl_cmp_error_new(srv_ctx->ctx, si, errorCode, details,
203                              srv_ctx->sendUnprotectedErrors);
204     OSSL_CMP_PKISI_free(si);
205     return msg;
206 }
207 
208 /*
209  * Processes an ir/cr/p10cr/kur and returns a certification response.
210  * Only handles the first certification request contained in req
211  * returns an ip/cp/kup on success and NULL on error
212  */
process_cert_request(OSSL_CMP_SRV_CTX * srv_ctx,const OSSL_CMP_MSG * req)213 static OSSL_CMP_MSG *process_cert_request(OSSL_CMP_SRV_CTX *srv_ctx,
214                                           const OSSL_CMP_MSG *req)
215 {
216     OSSL_CMP_MSG *msg = NULL;
217     OSSL_CMP_PKISI *si = NULL;
218     X509 *certOut = NULL;
219     EVP_PKEY *keyOut = NULL;
220     STACK_OF(X509) *chainOut = NULL, *caPubs = NULL;
221     const OSSL_CRMF_MSG *crm = NULL;
222     const X509_REQ *p10cr = NULL;
223     int bodytype;
224     int certReqId, central_keygen;
225 
226     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
227         return NULL;
228 
229     switch (OSSL_CMP_MSG_get_bodytype(req)) {
230     case OSSL_CMP_PKIBODY_P10CR:
231     case OSSL_CMP_PKIBODY_CR:
232         bodytype = OSSL_CMP_PKIBODY_CP;
233         break;
234     case OSSL_CMP_PKIBODY_IR:
235         bodytype = OSSL_CMP_PKIBODY_IP;
236         break;
237     case OSSL_CMP_PKIBODY_KUR:
238         bodytype = OSSL_CMP_PKIBODY_KUP;
239         break;
240     default:
241         ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
242         return NULL;
243     }
244 
245     if (OSSL_CMP_MSG_get_bodytype(req) == OSSL_CMP_PKIBODY_P10CR) {
246         certReqId = OSSL_CMP_CERTREQID_NONE; /* p10cr does not include an Id */
247         p10cr = req->body->value.p10cr;
248     } else {
249         OSSL_CRMF_MSGS *reqs = req->body->value.ir; /* same for cr and kur */
250 
251         if (sk_OSSL_CRMF_MSG_num(reqs) != 1) {
252             ERR_raise(ERR_LIB_CMP, CMP_R_MULTIPLE_REQUESTS_NOT_SUPPORTED);
253             return NULL;
254         }
255         if ((crm = sk_OSSL_CRMF_MSG_value(reqs, 0)) == NULL) {
256             ERR_raise(ERR_LIB_CMP, CMP_R_CERTREQMSG_NOT_FOUND);
257             return NULL;
258         }
259         certReqId = OSSL_CRMF_MSG_get_certReqId(crm);
260         if (certReqId != OSSL_CMP_CERTREQID) { /* so far, only possible value */
261             ERR_raise(ERR_LIB_CMP, CMP_R_BAD_REQUEST_ID);
262             return NULL;
263         }
264     }
265     srv_ctx->certReqId = certReqId;
266 
267     central_keygen = OSSL_CRMF_MSG_centralkeygen_requested(crm, p10cr);
268     if (central_keygen < 0)
269         return NULL;
270     if (central_keygen == 0
271         && !ossl_cmp_verify_popo(srv_ctx->ctx, req, srv_ctx->acceptRAVerified)) {
272         /* Proof of possession could not be verified */
273         si = OSSL_CMP_STATUSINFO_new(OSSL_CMP_PKISTATUS_rejection,
274                                      1 << OSSL_CMP_PKIFAILUREINFO_badPOP,
275                                      ERR_reason_error_string(ERR_peek_error()));
276         if (si == NULL)
277             return NULL;
278     } else {
279         OSSL_CMP_PKIHEADER *hdr = OSSL_CMP_MSG_get0_header(req);
280 
281         si = srv_ctx->process_cert_request(srv_ctx, req, certReqId, crm, p10cr,
282                                            &certOut, &chainOut, &caPubs);
283         if (si == NULL)
284             goto err;
285         if (ossl_cmp_pkisi_get_status(si) == OSSL_CMP_PKISTATUS_waiting)
286             srv_ctx->polling = 1;
287         /* set OSSL_CMP_OPT_IMPLICIT_CONFIRM if and only if transaction ends */
288         if (!OSSL_CMP_CTX_set_option(srv_ctx->ctx,
289                                      OSSL_CMP_OPT_IMPLICIT_CONFIRM,
290                                      ossl_cmp_hdr_has_implicitConfirm(hdr)
291                                          && srv_ctx->grantImplicitConfirm
292                                          /* do not set if polling starts: */
293                                          && certOut != NULL))
294             goto err;
295         if (central_keygen == 1
296             && srv_ctx->ctx->newPkey_priv && srv_ctx->ctx->newPkey != NULL)
297             keyOut = srv_ctx->ctx->newPkey;
298     }
299 
300     msg = ossl_cmp_certrep_new(srv_ctx->ctx, bodytype, certReqId, si,
301                                certOut, keyOut, NULL /* enc */, chainOut, caPubs,
302                                srv_ctx->sendUnprotectedErrors);
303     /* When supporting OSSL_CRMF_POPO_KEYENC, "enc" will need to be set */
304     if (msg == NULL)
305         ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_CREATING_CERTREP);
306 
307  err:
308     OSSL_CMP_PKISI_free(si);
309     X509_free(certOut);
310     OSSL_CMP_CTX_set0_newPkey(srv_ctx->ctx, 0, NULL);
311     OSSL_STACK_OF_X509_free(chainOut);
312     OSSL_STACK_OF_X509_free(caPubs);
313     return msg;
314 }
315 
process_rr(OSSL_CMP_SRV_CTX * srv_ctx,const OSSL_CMP_MSG * req)316 static OSSL_CMP_MSG *process_rr(OSSL_CMP_SRV_CTX *srv_ctx,
317                                 const OSSL_CMP_MSG *req)
318 {
319     OSSL_CMP_MSG *msg = NULL;
320     OSSL_CMP_REVDETAILS *details;
321     OSSL_CRMF_CERTID *certId = NULL;
322     OSSL_CRMF_CERTTEMPLATE *tmpl;
323     const X509_NAME *issuer;
324     const ASN1_INTEGER *serial;
325     OSSL_CMP_PKISI *si;
326 
327     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
328         return NULL;
329 
330     if (sk_OSSL_CMP_REVDETAILS_num(req->body->value.rr) != 1) {
331         ERR_raise(ERR_LIB_CMP, CMP_R_MULTIPLE_REQUESTS_NOT_SUPPORTED);
332         return NULL;
333     }
334     details = sk_OSSL_CMP_REVDETAILS_value(req->body->value.rr, 0);
335     if (details == NULL) {
336         ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_PROCESSING_MESSAGE);
337         return NULL;
338     }
339 
340     tmpl = details->certDetails;
341     issuer = OSSL_CRMF_CERTTEMPLATE_get0_issuer(tmpl);
342     serial = OSSL_CRMF_CERTTEMPLATE_get0_serialNumber(tmpl);
343     if (issuer != NULL && serial != NULL
344             && (certId = OSSL_CRMF_CERTID_gen(issuer, serial)) == NULL)
345         return NULL;
346     if ((si = srv_ctx->process_rr(srv_ctx, req, issuer, serial)) == NULL)
347         goto err;
348 
349     if ((msg = ossl_cmp_rp_new(srv_ctx->ctx, si, certId,
350                                srv_ctx->sendUnprotectedErrors)) == NULL)
351         ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_CREATING_RR);
352 
353  err:
354     OSSL_CRMF_CERTID_free(certId);
355     OSSL_CMP_PKISI_free(si);
356     return msg;
357 }
358 
359 /*
360  * Processes genm and creates a genp message mirroring the contents of the
361  * incoming message
362  */
process_genm(OSSL_CMP_SRV_CTX * srv_ctx,const OSSL_CMP_MSG * req)363 static OSSL_CMP_MSG *process_genm(OSSL_CMP_SRV_CTX *srv_ctx,
364                                   const OSSL_CMP_MSG *req)
365 {
366     OSSL_CMP_GENMSGCONTENT *itavs;
367     OSSL_CMP_MSG *msg;
368 
369     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
370         return NULL;
371 
372     if (!srv_ctx->process_genm(srv_ctx, req, req->body->value.genm, &itavs))
373         return NULL;
374 
375     msg = ossl_cmp_genp_new(srv_ctx->ctx, itavs);
376     sk_OSSL_CMP_ITAV_pop_free(itavs, OSSL_CMP_ITAV_free);
377     return msg;
378 }
379 
process_error(OSSL_CMP_SRV_CTX * srv_ctx,const OSSL_CMP_MSG * req)380 static OSSL_CMP_MSG *process_error(OSSL_CMP_SRV_CTX *srv_ctx,
381                                    const OSSL_CMP_MSG *req)
382 {
383     OSSL_CMP_ERRORMSGCONTENT *errorContent;
384     OSSL_CMP_MSG *msg;
385 
386     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
387         return NULL;
388     errorContent = req->body->value.error;
389     srv_ctx->process_error(srv_ctx, req, errorContent->pKIStatusInfo,
390                            errorContent->errorCode, errorContent->errorDetails);
391 
392     if ((msg = ossl_cmp_pkiconf_new(srv_ctx->ctx)) == NULL)
393         ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_CREATING_PKICONF);
394     return msg;
395 }
396 
process_certConf(OSSL_CMP_SRV_CTX * srv_ctx,const OSSL_CMP_MSG * req)397 static OSSL_CMP_MSG *process_certConf(OSSL_CMP_SRV_CTX *srv_ctx,
398                                       const OSSL_CMP_MSG *req)
399 {
400     OSSL_CMP_CTX *ctx;
401     OSSL_CMP_CERTCONFIRMCONTENT *ccc;
402     int num;
403     OSSL_CMP_MSG *msg = NULL;
404     OSSL_CMP_CERTSTATUS *status = NULL;
405 
406     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
407         return NULL;
408 
409     ctx = srv_ctx->ctx;
410     ccc = req->body->value.certConf;
411     num = sk_OSSL_CMP_CERTSTATUS_num(ccc);
412 
413     if (OSSL_CMP_CTX_get_option(ctx, OSSL_CMP_OPT_IMPLICIT_CONFIRM) == 1
414             || ctx->status != OSSL_CMP_PKISTATUS_trans) {
415         ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_UNEXPECTED_CERTCONF);
416         return NULL;
417     }
418 
419     if (num == 0) {
420         ossl_cmp_err(ctx, "certificate rejected by client");
421     } else {
422         if (num > 1)
423             ossl_cmp_warn(ctx, "All CertStatus but the first will be ignored");
424         status = sk_OSSL_CMP_CERTSTATUS_value(ccc, 0);
425     }
426 
427     if (status != NULL) {
428         int certReqId = ossl_cmp_asn1_get_int(status->certReqId);
429         ASN1_OCTET_STRING *certHash = status->certHash;
430         OSSL_CMP_PKISI *si = status->statusInfo;
431 
432         if (certReqId != srv_ctx->certReqId) {
433             ERR_raise(ERR_LIB_CMP, CMP_R_BAD_REQUEST_ID);
434             return NULL;
435         }
436         if (!srv_ctx->process_certConf(srv_ctx, req, certReqId, certHash, si))
437             return NULL; /* reason code may be: CMP_R_CERTHASH_UNMATCHED */
438 
439         if (si != NULL
440             && ossl_cmp_pkisi_get_status(si) != OSSL_CMP_PKISTATUS_accepted) {
441             int pki_status = ossl_cmp_pkisi_get_status(si);
442             const char *str = ossl_cmp_PKIStatus_to_string(pki_status);
443 
444             ossl_cmp_log2(INFO, ctx, "certificate rejected by client %s %s",
445                           str == NULL ? "without" : "with",
446                           str == NULL ? "PKIStatus" : str);
447         }
448     }
449 
450     if ((msg = ossl_cmp_pkiconf_new(ctx)) == NULL)
451         ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_CREATING_PKICONF);
452     return msg;
453 }
454 
455 /* pollReq is handled separately, to avoid recursive call */
process_non_polling_request(OSSL_CMP_SRV_CTX * srv_ctx,const OSSL_CMP_MSG * req)456 static OSSL_CMP_MSG *process_non_polling_request(OSSL_CMP_SRV_CTX *srv_ctx,
457                                                  const OSSL_CMP_MSG *req)
458 {
459     OSSL_CMP_MSG *rsp = NULL;
460 
461     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL
462                      && req->body != NULL))
463         return NULL;
464 
465     switch (OSSL_CMP_MSG_get_bodytype(req)) {
466     case OSSL_CMP_PKIBODY_IR:
467     case OSSL_CMP_PKIBODY_CR:
468     case OSSL_CMP_PKIBODY_P10CR:
469     case OSSL_CMP_PKIBODY_KUR:
470         if (srv_ctx->process_cert_request == NULL)
471             ERR_raise(ERR_LIB_CMP, CMP_R_UNSUPPORTED_PKIBODY);
472         else
473             rsp = process_cert_request(srv_ctx, req);
474         break;
475     case OSSL_CMP_PKIBODY_RR:
476         if (srv_ctx->process_rr == NULL)
477             ERR_raise(ERR_LIB_CMP, CMP_R_UNSUPPORTED_PKIBODY);
478         else
479             rsp = process_rr(srv_ctx, req);
480         break;
481     case OSSL_CMP_PKIBODY_GENM:
482         if (srv_ctx->process_genm == NULL)
483             ERR_raise(ERR_LIB_CMP, CMP_R_UNSUPPORTED_PKIBODY);
484         else
485             rsp = process_genm(srv_ctx, req);
486         break;
487     case OSSL_CMP_PKIBODY_ERROR:
488         if (srv_ctx->process_error == NULL)
489             ERR_raise(ERR_LIB_CMP, CMP_R_UNSUPPORTED_PKIBODY);
490         else
491             rsp = process_error(srv_ctx, req);
492         break;
493     case OSSL_CMP_PKIBODY_CERTCONF:
494         if (srv_ctx->process_certConf == NULL)
495             ERR_raise(ERR_LIB_CMP, CMP_R_UNSUPPORTED_PKIBODY);
496         else
497             rsp = process_certConf(srv_ctx, req);
498         break;
499 
500     case OSSL_CMP_PKIBODY_POLLREQ:
501         ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
502         break;
503     default:
504         ERR_raise(ERR_LIB_CMP, CMP_R_UNSUPPORTED_PKIBODY);
505         break;
506     }
507 
508     return rsp;
509 }
510 
process_pollReq(OSSL_CMP_SRV_CTX * srv_ctx,const OSSL_CMP_MSG * req)511 static OSSL_CMP_MSG *process_pollReq(OSSL_CMP_SRV_CTX *srv_ctx,
512                                      const OSSL_CMP_MSG *req)
513 {
514     OSSL_CMP_POLLREQCONTENT *prc;
515     OSSL_CMP_POLLREQ *pr;
516     int certReqId;
517     OSSL_CMP_MSG *orig_req;
518     int64_t check_after = 0;
519     OSSL_CMP_MSG *msg = NULL;
520 
521     if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL))
522         return NULL;
523 
524     if (!srv_ctx->polling) {
525         ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
526         return NULL;
527     }
528 
529     prc = req->body->value.pollReq;
530     if (sk_OSSL_CMP_POLLREQ_num(prc) != 1) {
531         ERR_raise(ERR_LIB_CMP, CMP_R_MULTIPLE_REQUESTS_NOT_SUPPORTED);
532         return NULL;
533     }
534 
535     pr = sk_OSSL_CMP_POLLREQ_value(prc, 0);
536     certReqId = ossl_cmp_asn1_get_int(pr->certReqId);
537     if (!srv_ctx->process_pollReq(srv_ctx, req, certReqId,
538                                   &orig_req, &check_after))
539         return NULL;
540 
541     if (orig_req != NULL) {
542         srv_ctx->polling = 0;
543         msg = process_non_polling_request(srv_ctx, orig_req);
544         OSSL_CMP_MSG_free(orig_req);
545     } else {
546         if ((msg = ossl_cmp_pollRep_new(srv_ctx->ctx, certReqId,
547                                         check_after)) == NULL)
548             ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_CREATING_POLLREP);
549     }
550     return msg;
551 }
552 
553 /*
554  * Determine whether missing/invalid protection of request message is allowed.
555  * Return 1 on acceptance, 0 on rejection, or -1 on (internal) error.
556  */
unprotected_exception(const OSSL_CMP_CTX * ctx,const OSSL_CMP_MSG * req,int invalid_protection,int accept_unprotected_requests)557 static int unprotected_exception(const OSSL_CMP_CTX *ctx,
558                                  const OSSL_CMP_MSG *req,
559                                  int invalid_protection,
560                                  int accept_unprotected_requests)
561 {
562     if (!ossl_assert(ctx != NULL && req != NULL))
563         return -1;
564 
565     if (accept_unprotected_requests) {
566         ossl_cmp_log1(WARN, ctx, "ignoring %s protection of request message",
567                       invalid_protection ? "invalid" : "missing");
568         return 1;
569     }
570     if (OSSL_CMP_MSG_get_bodytype(req) == OSSL_CMP_PKIBODY_ERROR
571         && OSSL_CMP_CTX_get_option(ctx, OSSL_CMP_OPT_UNPROTECTED_ERRORS) == 1) {
572         ossl_cmp_warn(ctx, "ignoring missing protection of error message");
573         return 1;
574     }
575     return 0;
576 }
577 
578 /*
579  * returns created message and NULL on internal error
580  */
OSSL_CMP_SRV_process_request(OSSL_CMP_SRV_CTX * srv_ctx,const OSSL_CMP_MSG * req)581 OSSL_CMP_MSG *OSSL_CMP_SRV_process_request(OSSL_CMP_SRV_CTX *srv_ctx,
582                                            const OSSL_CMP_MSG *req)
583 {
584     OSSL_CMP_CTX *ctx;
585     ASN1_OCTET_STRING *backup_secret;
586     OSSL_CMP_PKIHEADER *hdr;
587     int req_type, rsp_type;
588     int req_verified = 0;
589     OSSL_CMP_MSG *rsp = NULL;
590 
591     if (srv_ctx == NULL || srv_ctx->ctx == NULL
592             || req == NULL || req->body == NULL
593             || (hdr = OSSL_CMP_MSG_get0_header(req)) == NULL) {
594         ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
595         return 0;
596     }
597     ctx = srv_ctx->ctx;
598     backup_secret = ctx->secretValue;
599     req_type = OSSL_CMP_MSG_get_bodytype(req);
600     ossl_cmp_log1(DEBUG, ctx,
601                   "received %s", ossl_cmp_bodytype_to_string(req_type));
602 
603     /*
604      * Some things need to be done already before validating the message in
605      * order to be able to send an error message as far as needed and possible.
606      */
607     if (hdr->sender->type != GEN_DIRNAME) {
608         ERR_raise(ERR_LIB_CMP, CMP_R_SENDER_GENERALNAME_TYPE_NOT_SUPPORTED);
609         goto err;
610     }
611     if (!OSSL_CMP_CTX_set1_recipient(ctx, hdr->sender->d.directoryName))
612         goto err;
613 
614     if (srv_ctx->polling && req_type != OSSL_CMP_PKIBODY_POLLREQ
615             && req_type != OSSL_CMP_PKIBODY_ERROR) {
616         ERR_raise(ERR_LIB_CMP, CMP_R_EXPECTED_POLLREQ);
617         goto err;
618     }
619 
620     switch (req_type) {
621     case OSSL_CMP_PKIBODY_IR:
622     case OSSL_CMP_PKIBODY_CR:
623     case OSSL_CMP_PKIBODY_P10CR:
624     case OSSL_CMP_PKIBODY_KUR:
625     case OSSL_CMP_PKIBODY_RR:
626     case OSSL_CMP_PKIBODY_GENM:
627     case OSSL_CMP_PKIBODY_ERROR:
628         if (ctx->transactionID != NULL) {
629             char *tid = i2s_ASN1_OCTET_STRING(NULL, ctx->transactionID);
630 
631             if (tid != NULL)
632                 ossl_cmp_log1(WARN, ctx,
633                               "Assuming that last transaction with ID=%s got aborted",
634                               tid);
635             OPENSSL_free(tid);
636         }
637         /* start of a new transaction, reset transactionID and senderNonce */
638         if (!OSSL_CMP_CTX_set1_transactionID(ctx, NULL)
639                 || !OSSL_CMP_CTX_set1_senderNonce(ctx, NULL))
640             goto err;
641 
642         if (srv_ctx->clean_transaction != NULL
643                 && !srv_ctx->clean_transaction(srv_ctx, NULL)) {
644             ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_PROCESSING_MESSAGE);
645             goto err;
646         }
647 
648         break;
649     default:
650         /* transactionID should be already initialized */
651         if (ctx->transactionID == NULL) {
652 #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
653             ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
654             goto err;
655 #endif
656         }
657     }
658 
659     req_verified = ossl_cmp_msg_check_update(ctx, req, unprotected_exception,
660                                              srv_ctx->acceptUnprotected);
661     if (ctx->secretValue != NULL && ctx->pkey != NULL
662             && ossl_cmp_hdr_get_protection_nid(hdr) != NID_id_PasswordBasedMAC)
663         ctx->secretValue = NULL; /* use MSG_SIG_ALG when protecting rsp */
664     if (!req_verified)
665         goto err;
666 
667     if (req_type == OSSL_CMP_PKIBODY_POLLREQ) {
668         if (srv_ctx->process_pollReq == NULL)
669             ERR_raise(ERR_LIB_CMP, CMP_R_UNSUPPORTED_PKIBODY);
670         else
671             rsp = process_pollReq(srv_ctx, req);
672     } else {
673         if (srv_ctx->delayed_delivery != NULL
674             && (rsp = delayed_delivery(srv_ctx, req)) != NULL) {
675             goto err;
676         }
677         rsp = process_non_polling_request(srv_ctx, req);
678     }
679 
680  err:
681     if (rsp == NULL) {
682         /* on error, try to respond with CMP error message to client */
683         const char *data = NULL, *reason = NULL;
684         int flags = 0;
685         unsigned long err = ERR_peek_error_data(&data, &flags);
686         int fail_info = 1 << OSSL_CMP_PKIFAILUREINFO_badRequest;
687         /* fail_info is not very specific */
688         OSSL_CMP_PKISI *si = NULL;
689 
690         if (!req_verified) {
691             /*
692              * Above ossl_cmp_msg_check_update() was not successfully executed,
693              * which normally would set ctx->transactionID and ctx->recipNonce.
694              * So anyway try to provide the right transactionID and recipNonce,
695              * while ignoring any (extra) error in next two function calls.
696              */
697             if (ctx->transactionID == NULL)
698                 (void)OSSL_CMP_CTX_set1_transactionID(ctx, hdr->transactionID);
699             (void)ossl_cmp_ctx_set1_recipNonce(ctx, hdr->senderNonce);
700         }
701 
702         if ((flags & ERR_TXT_STRING) == 0 || *data == '\0')
703             data = NULL;
704         reason = ERR_reason_error_string(err);
705         if ((si = OSSL_CMP_STATUSINFO_new(OSSL_CMP_PKISTATUS_rejection,
706                                           fail_info, reason)) != NULL) {
707             rsp = ossl_cmp_error_new(srv_ctx->ctx, si, err,
708                                      data, srv_ctx->sendUnprotectedErrors);
709             OSSL_CMP_PKISI_free(si);
710         }
711     }
712     OSSL_CMP_CTX_print_errors(ctx);
713     ctx->secretValue = backup_secret;
714 
715     rsp_type =
716         rsp != NULL ? OSSL_CMP_MSG_get_bodytype(rsp) : OSSL_CMP_PKIBODY_ERROR;
717     if (rsp != NULL)
718         ossl_cmp_log1(DEBUG, ctx,
719                       "sending %s", ossl_cmp_bodytype_to_string(rsp_type));
720     else
721         ossl_cmp_log(ERR, ctx, "cannot send proper CMP response");
722 
723     /* determine whether to keep the transaction open or not */
724     ctx->status = OSSL_CMP_PKISTATUS_trans;
725     switch (rsp_type) {
726     case OSSL_CMP_PKIBODY_IP:
727     case OSSL_CMP_PKIBODY_CP:
728     case OSSL_CMP_PKIBODY_KUP:
729         if (OSSL_CMP_CTX_get_option(ctx, OSSL_CMP_OPT_IMPLICIT_CONFIRM) == 0)
730             break;
731         /* fall through */
732 
733     case OSSL_CMP_PKIBODY_ERROR:
734         if (rsp != NULL && ossl_cmp_is_error_with_waiting(rsp))
735             break;
736         /* fall through */
737 
738     case OSSL_CMP_PKIBODY_RP:
739     case OSSL_CMP_PKIBODY_PKICONF:
740     case OSSL_CMP_PKIBODY_GENP:
741         /* Other terminating response message types are not supported */
742         srv_ctx->certReqId = OSSL_CMP_CERTREQID_INVALID;
743         /* Prepare for next transaction, ignoring any errors here: */
744         if (srv_ctx->clean_transaction != NULL)
745             (void)srv_ctx->clean_transaction(srv_ctx, ctx->transactionID);
746         (void)OSSL_CMP_CTX_set1_transactionID(ctx, NULL);
747         (void)OSSL_CMP_CTX_set1_senderNonce(ctx, NULL);
748         ctx->status = OSSL_CMP_PKISTATUS_unspecified; /* transaction closed */
749 
750     default: /* not closing transaction in other cases */
751         break;
752     }
753     return rsp;
754 }
755 
756 /*
757  * Server interface that may substitute OSSL_CMP_MSG_http_perform at the client.
758  * The OSSL_CMP_SRV_CTX must be set as client_ctx->transfer_cb_arg.
759  * returns received message on success, else NULL and pushes an element on the
760  * error stack.
761  */
OSSL_CMP_CTX_server_perform(OSSL_CMP_CTX * client_ctx,const OSSL_CMP_MSG * req)762 OSSL_CMP_MSG *OSSL_CMP_CTX_server_perform(OSSL_CMP_CTX *client_ctx,
763                                           const OSSL_CMP_MSG *req)
764 {
765     OSSL_CMP_SRV_CTX *srv_ctx = NULL;
766 
767     if (client_ctx == NULL || req == NULL) {
768         ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
769         return NULL;
770     }
771 
772     if ((srv_ctx = OSSL_CMP_CTX_get_transfer_cb_arg(client_ctx)) == NULL) {
773         ERR_raise(ERR_LIB_CMP, CMP_R_TRANSFER_ERROR);
774         return NULL;
775     }
776 
777     return OSSL_CMP_SRV_process_request(srv_ctx, req);
778 }
779