Botan 2.19.3
Crypto and TLS for C&
Functions
Botan::PKIX Namespace Reference

Functions

Certificate_Status_Code build_all_certificate_paths (std::vector< std::vector< std::shared_ptr< const X509_Certificate > > > &cert_paths, const std::vector< Certificate_Store * > &trusted_certstores, const std::shared_ptr< const X509_Certificate > &end_entity, const std::vector< std::shared_ptr< const X509_Certificate > > &end_entity_extra)
 
Certificate_Status_Code build_certificate_path (std::vector< std::shared_ptr< const X509_Certificate > > &cert_path_out, const std::vector< Certificate_Store * > &trusted_certstores, const std::shared_ptr< const X509_Certificate > &end_entity, const std::vector< std::shared_ptr< const X509_Certificate > > &end_entity_extra)
 
CertificatePathStatusCodes check_chain (const std::vector< std::shared_ptr< const X509_Certificate > > &cert_path, std::chrono::system_clock::time_point ref_time, const std::string &hostname, Usage_Type usage, size_t min_signature_algo_strength, const std::set< std::string > &trusted_hashes)
 
CertificatePathStatusCodes check_crl (const std::vector< std::shared_ptr< const X509_Certificate > > &cert_path, const std::vector< Certificate_Store * > &certstores, std::chrono::system_clock::time_point ref_time)
 
CertificatePathStatusCodes check_crl (const std::vector< std::shared_ptr< const X509_Certificate > > &cert_path, const std::vector< std::shared_ptr< const X509_CRL > > &crls, std::chrono::system_clock::time_point ref_time)
 
CertificatePathStatusCodes check_ocsp (const std::vector< std::shared_ptr< const X509_Certificate > > &cert_path, const std::vector< std::shared_ptr< const OCSP::Response > > &ocsp_responses, const std::vector< Certificate_Store * > &certstores, std::chrono::system_clock::time_point ref_time, std::chrono::seconds max_ocsp_age=std::chrono::seconds::zero())
 
void merge_revocation_status (CertificatePathStatusCodes &chain_status, const CertificatePathStatusCodes &crl_status, const CertificatePathStatusCodes &ocsp_status, bool require_rev_on_end_entity, bool require_rev_on_intermediates)
 
Certificate_Status_Code overall_status (const CertificatePathStatusCodes &cert_status)
 

Detailed Description

namespace PKIX holds the building blocks that are called by x509_path_validate. This allows custom validation logic to be written by applications and makes for easier testing, but unless you're positive you know what you're doing you probably want to just call x509_path_validate instead.

Function Documentation

◆ build_all_certificate_paths()

Certificate_Status_Code Botan::PKIX::build_all_certificate_paths ( std::vector< std::vector< std::shared_ptr< const X509_Certificate > > > &  cert_paths_out,
const std::vector< Certificate_Store * > &  trusted_certstores,
const std::shared_ptr< const X509_Certificate > &  end_entity,
const std::vector< std::shared_ptr< const X509_Certificate > > &  end_entity_extra 
)

Build all possible certificate paths from the end certificate to self-signed trusted roots.

All potentially valid paths are put into the cert_paths vector. If no potentially valid paths are found, one of the encountered errors is returned arbitrarily.

todo add a path building function that returns detailed information on errors encountered while building the potentially numerous path candidates.

Basically, a DFS is performed starting from the end certificate. A stack (vector) serves to control the DFS. At the beginning of each iteration, a pair is popped from the stack that contains (1) the next certificate to add to the path (2) a bool that indicates if the certificate is part of a trusted certstore. Ideally, we follow the unique issuer of the current certificate until a trusted root is reached. However, the issuer DN + authority key id need not be unique among the certificates used for building the path. In such a case, we consider all the matching issuers by pushing <IssuerCert, trusted?> on the stack for each of them.

Definition at line 633 of file x509path.cpp.

637 {
638 if(!cert_paths_out.empty())
639 {
640 throw Invalid_Argument("PKIX::build_all_certificate_paths: cert_paths_out must be empty");
641 }
642
643 if(end_entity->is_self_signed())
644 {
645 return Certificate_Status_Code::CANNOT_ESTABLISH_TRUST;
646 }
647
648 /*
649 * Pile up error messages
650 */
651 std::vector<Certificate_Status_Code> stats;
652
653 Certificate_Store_In_Memory ee_extras;
654 for(size_t i = 0; i != end_entity_extra.size(); ++i)
655 {
656 ee_extras.add_certificate(end_entity_extra[i]);
657 }
658
659 /*
660 * This is an inelegant but functional way of preventing path loops
661 * (where C1 -> C2 -> C3 -> C1). We store a set of all the certificate
662 * fingerprints in the path. If there is a duplicate, we error out.
663 * TODO: save fingerprints in result struct? Maybe useful for blacklists, etc.
664 */
665 std::set<std::string> certs_seen;
666
667 // new certs are added and removed from the path during the DFS
668 // it is copied into cert_paths_out when we encounter a trusted root
669 std::vector<std::shared_ptr<const X509_Certificate>> path_so_far;
670
671 // todo can we assume that the end certificate is not trusted?
672 std::vector<cert_maybe_trusted> stack = { {end_entity, false} };
673
674 while(!stack.empty())
675 {
676 // found a deletion marker that guides the DFS, backtracing
677 if(stack.back().first == nullptr)
678 {
679 stack.pop_back();
680 std::string fprint = path_so_far.back()->fingerprint("SHA-256");
681 certs_seen.erase(fprint);
682 path_so_far.pop_back();
683 }
684 // process next cert on the path
685 else
686 {
687 std::shared_ptr<const X509_Certificate> last = stack.back().first;
688 bool trusted = stack.back().second;
689 stack.pop_back();
690
691 // certificate already seen?
692 const std::string fprint = last->fingerprint("SHA-256");
693 if(certs_seen.count(fprint) == 1)
694 {
695 stats.push_back(Certificate_Status_Code::CERT_CHAIN_LOOP);
696 // the current path ended in a loop
697 continue;
698 }
699
700 // the current path ends here
701 if(last->is_self_signed())
702 {
703 // found a trust anchor
704 if(trusted)
705 {
706 cert_paths_out.push_back(path_so_far);
707 cert_paths_out.back().push_back(last);
708
709 continue;
710 }
711 // found an untrustworthy root
712 else
713 {
714 stats.push_back(Certificate_Status_Code::CANNOT_ESTABLISH_TRUST);
715 continue;
716 }
717 }
718
719 const X509_DN issuer_dn = last->issuer_dn();
720 const std::vector<uint8_t> auth_key_id = last->authority_key_id();
721
722 // search for trusted issuers
723 std::vector<std::shared_ptr<const X509_Certificate>> trusted_issuers;
724 for(Certificate_Store* store : trusted_certstores)
725 {
726 auto new_issuers = store->find_all_certs(issuer_dn, auth_key_id);
727 trusted_issuers.insert(trusted_issuers.end(), new_issuers.begin(), new_issuers.end());
728 }
729
730 // search the supplemental certs
731 std::vector<std::shared_ptr<const X509_Certificate>> misc_issuers =
732 ee_extras.find_all_certs(issuer_dn, auth_key_id);
733
734 // if we could not find any issuers, the current path ends here
735 if(trusted_issuers.size() + misc_issuers.size() == 0)
736 {
737 stats.push_back(Certificate_Status_Code::CERT_ISSUER_NOT_FOUND);
738 continue;
739 }
740
741 // push the latest certificate onto the path_so_far
742 path_so_far.push_back(last);
743 certs_seen.emplace(fprint);
744
745 // push a deletion marker on the stack for backtracing later
746 stack.push_back({std::shared_ptr<const X509_Certificate>(nullptr),false});
747
748 for(const auto& trusted_cert : trusted_issuers)
749 {
750 stack.push_back({trusted_cert,true});
751 }
752
753 for(const auto& misc : misc_issuers)
754 {
755 stack.push_back({misc,false});
756 }
757 }
758 }
759
760 // could not construct any potentially valid path
761 if(cert_paths_out.empty())
762 {
763 if(stats.empty())
764 throw Internal_Error("X509 path building failed for unknown reasons");
765 else
766 // arbitrarily return the first error
767 return stats[0];
768 }
769 else
770 {
771 return Certificate_Status_Code::OK;
772 }
773 }

References Botan::Certificate_Store_In_Memory::add_certificate(), Botan::CANNOT_ESTABLISH_TRUST, Botan::CERT_CHAIN_LOOP, Botan::CERT_ISSUER_NOT_FOUND, Botan::Certificate_Store_In_Memory::find_all_certs(), and Botan::OK.

Referenced by Botan::x509_path_validate().

◆ build_certificate_path()

Certificate_Status_Code Botan::PKIX::build_certificate_path ( std::vector< std::shared_ptr< const X509_Certificate > > &  cert_path_out,
const std::vector< Certificate_Store * > &  trusted_certstores,
const std::shared_ptr< const X509_Certificate > &  end_entity,
const std::vector< std::shared_ptr< const X509_Certificate > > &  end_entity_extra 
)

Build certificate path

Parameters
cert_path_outoutput parameter, cert_path will be appended to this vector
trusted_certstoreslist of certificate stores that contain trusted certificates
end_entitythe cert to be validated
end_entity_extraoptional list of additional untrusted certs for path building
Returns
result of the path building operation (OK or error)

Definition at line 528 of file x509path.cpp.

532 {
533 if(end_entity->is_self_signed())
534 {
535 return Certificate_Status_Code::CANNOT_ESTABLISH_TRUST;
536 }
537
538 /*
539 * This is an inelegant but functional way of preventing path loops
540 * (where C1 -> C2 -> C3 -> C1). We store a set of all the certificate
541 * fingerprints in the path. If there is a duplicate, we error out.
542 * TODO: save fingerprints in result struct? Maybe useful for blacklists, etc.
543 */
544 std::set<std::string> certs_seen;
545
546 cert_path.push_back(end_entity);
547 certs_seen.insert(end_entity->fingerprint("SHA-256"));
548
550 for(size_t i = 0; i != end_entity_extra.size(); ++i)
551 ee_extras.add_certificate(end_entity_extra[i]);
552
553 // iterate until we reach a root or cannot find the issuer
554 for(;;)
555 {
556 const X509_Certificate& last = *cert_path.back();
557 const X509_DN issuer_dn = last.issuer_dn();
558 const std::vector<uint8_t> auth_key_id = last.authority_key_id();
559
560 std::shared_ptr<const X509_Certificate> issuer;
561 bool trusted_issuer = false;
562
563 for(Certificate_Store* store : trusted_certstores)
564 {
565 issuer = store->find_cert(issuer_dn, auth_key_id);
566 if(issuer)
567 {
568 trusted_issuer = true;
569 break;
570 }
571 }
572
573 if(!issuer)
574 {
575 // fall back to searching supplemental certs
576 issuer = ee_extras.find_cert(issuer_dn, auth_key_id);
577 }
578
579 if(!issuer)
580 return Certificate_Status_Code::CERT_ISSUER_NOT_FOUND;
581
582 const std::string fprint = issuer->fingerprint("SHA-256");
583
584 if(certs_seen.count(fprint) > 0) // already seen?
585 {
586 return Certificate_Status_Code::CERT_CHAIN_LOOP;
587 }
588
589 certs_seen.insert(fprint);
590 cert_path.push_back(issuer);
591
592 if(issuer->is_self_signed())
593 {
594 if(trusted_issuer)
595 {
596 return Certificate_Status_Code::OK;
597 }
598 else
599 {
600 return Certificate_Status_Code::CANNOT_ESTABLISH_TRUST;
601 }
602 }
603 }
604 }
std::shared_ptr< const X509_Certificate > find_cert(const X509_DN &subject_dn, const std::vector< uint8_t > &key_id) const override
Definition certstor.cpp:65
void add_certificate(const X509_Certificate &cert)
Definition certstor.cpp:38
const std::vector< uint8_t > & authority_key_id() const
Definition x509cert.cpp:450
const X509_DN & issuer_dn() const
Definition x509cert.cpp:471

References Botan::Certificate_Store_In_Memory::add_certificate(), Botan::X509_Certificate::authority_key_id(), Botan::CANNOT_ESTABLISH_TRUST, Botan::CERT_CHAIN_LOOP, Botan::CERT_ISSUER_NOT_FOUND, Botan::Certificate_Store_In_Memory::find_cert(), Botan::X509_Certificate::issuer_dn(), and Botan::OK.

◆ check_chain()

CertificatePathStatusCodes Botan::PKIX::check_chain ( const std::vector< std::shared_ptr< const X509_Certificate > > &  cert_path,
std::chrono::system_clock::time_point  ref_time,
const std::string &  hostname,
Usage_Type  usage,
size_t  min_signature_algo_strength,
const std::set< std::string > &  trusted_hashes 
)

Check the certificate chain, but not any revocation data

Parameters
cert_pathpath built by build_certificate_path with OK result
ref_timewhatever time you want to perform the validation against (normally current system clock)
hostnamethe hostname
usageend entity usage checks
min_signature_algo_strength80 or 110 typically Note 80 allows 1024 bit RSA and SHA-1. 110 allows 2048 bit RSA and SHA-2. Using 128 requires ECC (P-256) or ~3000 bit RSA keys.
trusted_hashesset of trusted hash functions, empty means accept any hash we have an OID for
Returns
vector of results on per certificate in the path, each containing a set of results. If all codes in the set are < Certificate_Status_Code::FIRST_ERROR_STATUS, then the result for that certificate is successful. If all results are

Definition at line 32 of file x509path.cpp.

38 {
39 if(cert_path.empty())
40 throw Invalid_Argument("PKIX::check_chain cert_path empty");
41
42 const bool self_signed_ee_cert = (cert_path.size() == 1);
43
44 X509_Time validation_time(ref_time);
45
46 CertificatePathStatusCodes cert_status(cert_path.size());
47
48 if(!hostname.empty() && !cert_path[0]->matches_dns_name(hostname))
49 cert_status[0].insert(Certificate_Status_Code::CERT_NAME_NOMATCH);
50
51 if(!cert_path[0]->allowed_usage(usage))
52 cert_status[0].insert(Certificate_Status_Code::INVALID_USAGE);
53
54 if(cert_path[0]->is_CA_cert() == false &&
55 cert_path[0]->has_constraints(KEY_CERT_SIGN))
56 {
57 /*
58 "If the keyCertSign bit is asserted, then the cA bit in the
59 basic constraints extension (Section 4.2.1.9) MUST also be
60 asserted." - RFC 5280
61
62 We don't bother doing this check on the rest of the path since they
63 must have the cA bit asserted or the validation will fail anyway.
64 */
65 cert_status[0].insert(Certificate_Status_Code::INVALID_USAGE);
66 }
67
68 for(size_t i = 0; i != cert_path.size(); ++i)
69 {
70 std::set<Certificate_Status_Code>& status = cert_status.at(i);
71
72 const bool at_self_signed_root = (i == cert_path.size() - 1);
73
74 const std::shared_ptr<const X509_Certificate>& subject = cert_path[i];
75
76 const std::shared_ptr<const X509_Certificate>& issuer = cert_path[at_self_signed_root ? (i) : (i + 1)];
77
78 if(at_self_signed_root && (issuer->is_self_signed() == false))
79 {
80 status.insert(Certificate_Status_Code::CHAIN_LACKS_TRUST_ROOT);
81 }
82
83 if(subject->issuer_dn() != issuer->subject_dn())
84 {
85 status.insert(Certificate_Status_Code::CHAIN_NAME_MISMATCH);
86 }
87
88 // Check the serial number
89 if(subject->is_serial_negative())
90 {
91 status.insert(Certificate_Status_Code::CERT_SERIAL_NEGATIVE);
92 }
93
94 // Check the subject's DN components' length
95
96 for(const auto& dn_pair : subject->subject_dn().dn_info())
97 {
98 const size_t dn_ub = X509_DN::lookup_ub(dn_pair.first);
99 // dn_pair = <OID,str>
100 if(dn_ub > 0 && dn_pair.second.size() > dn_ub)
101 {
102 status.insert(Certificate_Status_Code::DN_TOO_LONG);
103 }
104 }
105
106 // Check all certs for valid time range
107 if(validation_time < subject->not_before())
108 status.insert(Certificate_Status_Code::CERT_NOT_YET_VALID);
109
110 if(validation_time > subject->not_after())
111 status.insert(Certificate_Status_Code::CERT_HAS_EXPIRED);
112
113 // Check issuer constraints
114 if(!issuer->is_CA_cert() && !self_signed_ee_cert)
115 status.insert(Certificate_Status_Code::CA_CERT_NOT_FOR_CERT_ISSUER);
116
117 std::unique_ptr<Public_Key> issuer_key(issuer->subject_public_key());
118
119 // Check the signature algorithm is known
120 if(OIDS::oid2str_or_empty(subject->signature_algorithm().get_oid()).empty())
121 {
122 status.insert(Certificate_Status_Code::SIGNATURE_ALGO_UNKNOWN);
123 }
124 else
125 {
126 // only perform the following checks if the signature algorithm is known
127 if(!issuer_key)
128 {
129 status.insert(Certificate_Status_Code::CERT_PUBKEY_INVALID);
130 }
131 else
132 {
133 const Certificate_Status_Code sig_status = subject->verify_signature(*issuer_key);
134
135 if(sig_status != Certificate_Status_Code::VERIFIED)
136 status.insert(sig_status);
137
138 if(issuer_key->estimated_strength() < min_signature_algo_strength)
139 status.insert(Certificate_Status_Code::SIGNATURE_METHOD_TOO_WEAK);
140 }
141
142 // Ignore untrusted hashes on self-signed roots
143 if(trusted_hashes.size() > 0 && !at_self_signed_root)
144 {
145 if(trusted_hashes.count(subject->hash_used_for_signature()) == 0)
146 status.insert(Certificate_Status_Code::UNTRUSTED_HASH);
147 }
148 }
149
150 // Check cert extensions
151
152 if(subject->x509_version() == 1)
153 {
154 if(subject->v2_issuer_key_id().empty() == false ||
155 subject->v2_subject_key_id().empty() == false)
156 {
157 status.insert(Certificate_Status_Code::V2_IDENTIFIERS_IN_V1_CERT);
158 }
159 }
160
161 Extensions extensions = subject->v3_extensions();
162 const auto& extensions_vec = extensions.extensions();
163 if(subject->x509_version() < 3 && !extensions_vec.empty())
164 {
165 status.insert(Certificate_Status_Code::EXT_IN_V1_V2_CERT);
166 }
167 for(auto& extension : extensions_vec)
168 {
169 extension.first->validate(*subject, *issuer, cert_path, cert_status, i);
170 }
171 if(extensions.extensions().size() != extensions.get_extension_oids().size())
172 {
173 status.insert(Certificate_Status_Code::DUPLICATE_CERT_EXTENSION);
174 }
175 }
176
177 // path len check
178 size_t max_path_length = cert_path.size();
179 for(size_t i = cert_path.size() - 1; i > 0 ; --i)
180 {
181 std::set<Certificate_Status_Code>& status = cert_status.at(i);
182 const std::shared_ptr<const X509_Certificate>& subject = cert_path[i];
183
184 /*
185 * If the certificate was not self-issued, verify that max_path_length is
186 * greater than zero and decrement max_path_length by 1.
187 */
188 if(subject->subject_dn() != subject->issuer_dn())
189 {
190 if(max_path_length > 0)
191 {
192 --max_path_length;
193 }
194 else
195 {
196 status.insert(Certificate_Status_Code::CERT_CHAIN_TOO_LONG);
197 }
198 }
199
200 /*
201 * If pathLenConstraint is present in the certificate and is less than max_path_length,
202 * set max_path_length to the value of pathLenConstraint.
203 */
204 if(subject->path_limit() != Cert_Extension::NO_CERT_PATH_LIMIT && subject->path_limit() < max_path_length)
205 {
206 max_path_length = subject->path_limit();
207 }
208 }
209
210 return cert_status;
211 }
@ KEY_CERT_SIGN
Definition ffi.h:1571
std::vector< std::set< Certificate_Status_Code > > CertificatePathStatusCodes
Definition x509path.h:29
Certificate_Status_Code
Definition pkix_enums.h:17

References Botan::CA_CERT_NOT_FOR_CERT_ISSUER, Botan::CERT_CHAIN_TOO_LONG, Botan::CERT_HAS_EXPIRED, Botan::CERT_NAME_NOMATCH, Botan::CERT_NOT_YET_VALID, Botan::CERT_PUBKEY_INVALID, Botan::CERT_SERIAL_NEGATIVE, Botan::CHAIN_LACKS_TRUST_ROOT, Botan::CHAIN_NAME_MISMATCH, Botan::DN_TOO_LONG, Botan::DUPLICATE_CERT_EXTENSION, Botan::EXT_IN_V1_V2_CERT, Botan::Extensions::extensions(), Botan::Extensions::get_extension_oids(), Botan::INVALID_USAGE, Botan::KEY_CERT_SIGN, Botan::X509_DN::lookup_ub(), Botan::OIDS::oid2str_or_empty(), Botan::SIGNATURE_ALGO_UNKNOWN, Botan::SIGNATURE_METHOD_TOO_WEAK, Botan::UNTRUSTED_HASH, Botan::V2_IDENTIFIERS_IN_V1_CERT, and Botan::VERIFIED.

Referenced by Botan::x509_path_validate().

◆ check_crl() [1/2]

CertificatePathStatusCodes Botan::PKIX::check_crl ( const std::vector< std::shared_ptr< const X509_Certificate > > &  cert_path,
const std::vector< Certificate_Store * > &  certstores,
std::chrono::system_clock::time_point  ref_time 
)

Check CRLs for revocation information

Parameters
cert_pathpath already validated by check_chain
certstoresa list of certificate stores to query for the CRL
ref_timewhatever time you want to perform the validation against (normally current system clock)
Returns
revocation status

Definition at line 339 of file x509path.cpp.

342 {
343 if(cert_path.empty())
344 throw Invalid_Argument("PKIX::check_crl cert_path empty");
345
346 if(certstores.empty())
347 throw Invalid_Argument("PKIX::check_crl certstores empty");
348
349 std::vector<std::shared_ptr<const X509_CRL>> crls(cert_path.size());
350
351 for(size_t i = 0; i != cert_path.size(); ++i)
352 {
353 BOTAN_ASSERT_NONNULL(cert_path[i]);
354 for(size_t c = 0; c != certstores.size(); ++c)
355 {
356 crls[i] = certstores[c]->find_crl_for(*cert_path[i]);
357 if(crls[i])
358 break;
359 }
360 }
361
362 return PKIX::check_crl(cert_path, crls, ref_time);
363 }
#define BOTAN_ASSERT_NONNULL(ptr)
Definition assert.h:107

References BOTAN_ASSERT_NONNULL, and check_crl().

◆ check_crl() [2/2]

CertificatePathStatusCodes Botan::PKIX::check_crl ( const std::vector< std::shared_ptr< const X509_Certificate > > &  cert_path,
const std::vector< std::shared_ptr< const X509_CRL > > &  crls,
std::chrono::system_clock::time_point  ref_time 
)

Check CRLs for revocation information

Parameters
cert_pathpath already validated by check_chain
crlsthe list of CRLs to check, it is assumed that crls[i] (if not null) is the associated CRL for the subject in cert_path[i].
ref_timewhatever time you want to perform the validation against (normally current system clock)
Returns
revocation status

Definition at line 269 of file x509path.cpp.

272 {
273 if(cert_path.empty())
274 throw Invalid_Argument("PKIX::check_crl cert_path empty");
275
276 CertificatePathStatusCodes cert_status(cert_path.size());
277 const X509_Time validation_time(ref_time);
278
279 for(size_t i = 0; i != cert_path.size() - 1; ++i)
280 {
281 std::set<Certificate_Status_Code>& status = cert_status.at(i);
282
283 if(i < crls.size() && crls.at(i))
284 {
285 std::shared_ptr<const X509_Certificate> subject = cert_path.at(i);
286 std::shared_ptr<const X509_Certificate> ca = cert_path.at(i+1);
287
288 if(!ca->allowed_usage(CRL_SIGN))
289 status.insert(Certificate_Status_Code::CA_CERT_NOT_FOR_CRL_ISSUER);
290
291 if(validation_time < crls[i]->this_update())
292 status.insert(Certificate_Status_Code::CRL_NOT_YET_VALID);
293
294 if(validation_time > crls[i]->next_update())
295 status.insert(Certificate_Status_Code::CRL_HAS_EXPIRED);
296
297 if(crls[i]->check_signature(ca->subject_public_key()) == false)
298 status.insert(Certificate_Status_Code::CRL_BAD_SIGNATURE);
299
300 status.insert(Certificate_Status_Code::VALID_CRL_CHECKED);
301
302 if(crls[i]->is_revoked(*subject))
303 status.insert(Certificate_Status_Code::CERT_IS_REVOKED);
304
305 std::string dp = subject->crl_distribution_point();
306 if(!dp.empty())
307 {
308 if(dp != crls[i]->crl_issuing_distribution_point())
309 {
310 status.insert(Certificate_Status_Code::NO_MATCHING_CRLDP);
311 }
312 }
313
314 for(const auto& extension : crls[i]->extensions().extensions())
315 {
316 // XXX this is wrong - the OID might be defined but the extention not full parsed
317 // for example see #1652
318
319 // is the extension critical and unknown?
320 if(extension.second && OIDS::oid2str_or_empty(extension.first->oid_of()) == "")
321 {
322 /* NIST Certificate Path Valiadation Testing document: "When an implementation does not recognize a critical extension in the
323 * crlExtensions field, it shall assume that identified certificates have been revoked and are no longer valid"
324 */
325 status.insert(Certificate_Status_Code::CERT_IS_REVOKED);
326 }
327 }
328
329 }
330 }
331
332 while(cert_status.size() > 0 && cert_status.back().empty())
333 cert_status.pop_back();
334
335 return cert_status;
336 }
@ CRL_SIGN
Definition ffi.h:1572

References Botan::CA_CERT_NOT_FOR_CRL_ISSUER, Botan::CERT_IS_REVOKED, Botan::CRL_BAD_SIGNATURE, Botan::CRL_HAS_EXPIRED, Botan::CRL_NOT_YET_VALID, Botan::CRL_SIGN, Botan::NO_MATCHING_CRLDP, Botan::OIDS::oid2str_or_empty(), and Botan::VALID_CRL_CHECKED.

Referenced by check_crl(), and Botan::x509_path_validate().

◆ check_ocsp()

CertificatePathStatusCodes Botan::PKIX::check_ocsp ( const std::vector< std::shared_ptr< const X509_Certificate > > &  cert_path,
const std::vector< std::shared_ptr< const OCSP::Response > > &  ocsp_responses,
const std::vector< Certificate_Store * > &  certstores,
std::chrono::system_clock::time_point  ref_time,
std::chrono::seconds  max_ocsp_age = std::chrono::seconds::zero() 
)

Check OCSP responses for revocation information

Parameters
cert_pathpath already validated by check_chain
ocsp_responsesthe OCSP responses to consider
certstorestrusted roots
ref_timewhatever time you want to perform the validation against (normally current system clock)
max_ocsp_agemaximum age of OCSP responses w/o next_update. If zero, there is no maximum age
Returns
revocation status

Definition at line 214 of file x509path.cpp.

219 {
220 if(cert_path.empty())
221 throw Invalid_Argument("PKIX::check_ocsp cert_path empty");
222
223 CertificatePathStatusCodes cert_status(cert_path.size() - 1);
224
225 for(size_t i = 0; i != cert_path.size() - 1; ++i)
226 {
227 std::set<Certificate_Status_Code>& status = cert_status.at(i);
228
229 std::shared_ptr<const X509_Certificate> subject = cert_path.at(i);
230 std::shared_ptr<const X509_Certificate> ca = cert_path.at(i+1);
231
232 if(i < ocsp_responses.size() && (ocsp_responses.at(i) != nullptr)
233 && (ocsp_responses.at(i)->status() == OCSP::Response_Status_Code::Successful))
234 {
235 try
236 {
237 // When verifying intermediate certificates we need to truncate the
238 // cert_path so that the intermediate under investigation becomes the
239 // last certificate in the chain.
240 std::vector<std::shared_ptr<const X509_Certificate>> ocsp_cert_path(cert_path.begin() + i, cert_path.end());
241 Certificate_Status_Code ocsp_signature_status = ocsp_responses.at(i)->check_signature(trusted_certstores, ocsp_cert_path);
242
243 if(ocsp_signature_status == Certificate_Status_Code::OCSP_SIGNATURE_OK)
244 {
245 // Signature ok, so check the claimed status
246 Certificate_Status_Code ocsp_status = ocsp_responses.at(i)->status_for(*ca, *subject, ref_time, max_ocsp_age);
247 status.insert(ocsp_status);
248 }
249 else
250 {
251 // Some signature problem
252 status.insert(ocsp_signature_status);
253 }
254 }
255 catch(Exception&)
256 {
257 status.insert(Certificate_Status_Code::OCSP_RESPONSE_INVALID);
258 }
259 }
260 }
261
262 while(cert_status.size() > 0 && cert_status.back().empty())
263 cert_status.pop_back();
264
265 return cert_status;
266 }

References Botan::OCSP_RESPONSE_INVALID, Botan::OCSP_SIGNATURE_OK, and Botan::OCSP::Successful.

Referenced by Botan::x509_path_validate().

◆ merge_revocation_status()

void Botan::PKIX::merge_revocation_status ( CertificatePathStatusCodes chain_status,
const CertificatePathStatusCodes crl_status,
const CertificatePathStatusCodes ocsp_status,
bool  require_rev_on_end_entity,
bool  require_rev_on_intermediates 
)

Merge the results from CRL and/or OCSP checks into chain_status

Parameters
chain_statusthe certificate status
crl_statusresults from check_crl
ocsp_statusresults from check_ocsp
require_rev_on_end_entityrequire valid CRL or OCSP on end-entity cert
require_rev_on_intermediatesrequire valid CRL or OCSP on all intermediate certificates

Definition at line 776 of file x509path.cpp.

781 {
782 if(chain_status.empty())
783 throw Invalid_Argument("PKIX::merge_revocation_status chain_status was empty");
784
785 for(size_t i = 0; i != chain_status.size() - 1; ++i)
786 {
787 bool had_crl = false, had_ocsp = false;
788
789 if(i < crl.size() && crl[i].size() > 0)
790 {
791 for(auto&& code : crl[i])
792 {
793 if(code == Certificate_Status_Code::VALID_CRL_CHECKED)
794 {
795 had_crl = true;
796 }
797 chain_status[i].insert(code);
798 }
799 }
800
801 if(i < ocsp.size() && ocsp[i].size() > 0)
802 {
803 for(auto&& code : ocsp[i])
804 {
805 if(code == Certificate_Status_Code::OCSP_RESPONSE_GOOD ||
806 code == Certificate_Status_Code::OCSP_NO_REVOCATION_URL || // softfail
807 code == Certificate_Status_Code::OCSP_SERVER_NOT_AVAILABLE) // softfail
808 {
809 had_ocsp = true;
810 }
811
812 chain_status[i].insert(code);
813 }
814 }
815
816 if(had_crl == false && had_ocsp == false)
817 {
818 if((require_rev_on_end_entity && i == 0) ||
819 (require_rev_on_intermediates && i > 0))
820 {
821 chain_status[i].insert(Certificate_Status_Code::NO_REVOCATION_DATA);
822 }
823 }
824 }
825 }

References Botan::NO_REVOCATION_DATA, Botan::OCSP_NO_REVOCATION_URL, Botan::OCSP_RESPONSE_GOOD, Botan::OCSP_SERVER_NOT_AVAILABLE, and Botan::VALID_CRL_CHECKED.

Referenced by Botan::x509_path_validate().

◆ overall_status()

Certificate_Status_Code Botan::PKIX::overall_status ( const CertificatePathStatusCodes cert_status)

Find overall status (OK, error) of a validation

Parameters
cert_statusresult of merge_revocation_status or check_chain

Definition at line 827 of file x509path.cpp.

828 {
829 if(cert_status.empty())
830 throw Invalid_Argument("PKIX::overall_status empty cert status");
831
832 Certificate_Status_Code overall_status = Certificate_Status_Code::OK;
833
834 // take the "worst" error as overall
835 for(const std::set<Certificate_Status_Code>& s : cert_status)
836 {
837 if(!s.empty())
838 {
839 auto worst = *s.rbegin();
840 // Leave informative OCSP/CRL confirmations on cert-level status only
841 if(worst >= Certificate_Status_Code::FIRST_ERROR_STATUS && worst > overall_status)
842 {
843 overall_status = worst;
844 }
845 }
846 }
847 return overall_status;
848 }
Certificate_Status_Code overall_status(const CertificatePathStatusCodes &cert_status)
Definition x509path.cpp:827

References Botan::FIRST_ERROR_STATUS, Botan::OK, and overall_status().

Referenced by overall_status().