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22 * PKIXPathValidator.cpp
24 * A path validator based on PKIX support in OpenSSL.
29 #include "security/OpenSSLPathValidator.h"
30 #include "security/OpenSSLCryptoX509CRL.h"
31 #include "security/PKIXPathValidatorParams.h"
32 #include "security/SecurityHelper.h"
34 #include "util/PathResolver.h"
35 #include "util/Threads.h"
36 #include "util/XMLHelper.h"
40 #include <openssl/x509_vfy.h>
41 #include <openssl/x509v3.h>
42 #include <xsec/enc/OpenSSL/OpenSSLCryptoX509.hpp>
44 using namespace xmltooling::logging;
45 using namespace xmltooling;
50 static int XMLTOOL_DLLLOCAL error_callback(int ok, X509_STORE_CTX* ctx)
53 Category::getInstance("OpenSSL").error("path validation failure: %s", X509_verify_cert_error_string(ctx->error));
57 static string XMLTOOL_DLLLOCAL X509_NAME_to_string(X509_NAME* n)
60 BIO* b = BIO_new(BIO_s_mem());
61 X509_NAME_print_ex(b,n,0,XN_FLAG_RFC2253);
63 BUF_MEM* bptr=nullptr;
64 BIO_get_mem_ptr(b, &bptr);
65 if (bptr && bptr->length > 0) {
66 s.append(bptr->data, bptr->length);
72 static time_t XMLTOOL_DLLLOCAL getCRLTime(const ASN1_TIME *a)
75 memset(&t, 0, sizeof(t));
76 // RFC 5280, sections 5.1.2.4 and 5.1.2.5 require thisUpdate and nextUpdate
77 // to be encoded as UTCTime until 2049, and RFC 5280 section 4.1.2.5.1
78 // further restricts the format to "YYMMDDHHMMSSZ" ("even where the number
79 // of seconds is zero").
80 // As long as OpenSSL doesn't provide any API to convert ASN1_TIME values
81 // time_t, we therefore have to parse it ourselves, unfortunately.
82 if (sscanf((const char*)a->data, "%2d%2d%2d%2d%2d%2dZ",
83 &t.tm_year, &t.tm_mon, &t.tm_mday,
84 &t.tm_hour, &t.tm_min, &t.tm_sec) == 6) {
85 if (t.tm_year <= 50) {
86 // RFC 5280, section 4.1.2.5.1
90 #if defined(HAVE_TIMEGM)
93 // Windows, and hopefully most others...?
94 return mktime(&t) - timezone;
100 static const XMLCh minRefreshDelay[] = UNICODE_LITERAL_15(m,i,n,R,e,f,r,e,s,h,D,e,l,a,y);
101 static const XMLCh minSecondsRemaining[] = UNICODE_LITERAL_19(m,i,n,S,e,c,o,n,d,s,R,e,m,a,i,n,i,n,g);
102 static const XMLCh minPercentRemaining[] = UNICODE_LITERAL_19(m,i,n,P,e,r,c,e,n,t,R,e,m,a,i,n,i,n,g);
105 namespace xmltooling {
107 class XMLTOOL_DLLLOCAL PKIXPathValidator : public OpenSSLPathValidator
110 PKIXPathValidator(const xercesc::DOMElement* e)
111 : m_log(Category::getInstance(XMLTOOLING_LOGCAT".PathValidator.PKIX")),
112 m_lock(XMLToolingConfig::getConfig().getNamedMutex(XMLTOOLING_LOGCAT".PathValidator.PKIX")),
113 m_minRefreshDelay(XMLHelper::getAttrInt(e, 60, minRefreshDelay)),
114 m_minSecondsRemaining(XMLHelper::getAttrInt(e, 86400, minSecondsRemaining)),
115 m_minPercentRemaining(XMLHelper::getAttrInt(e, 10, minPercentRemaining)) {
118 virtual ~PKIXPathValidator() {}
121 XSECCryptoX509* certEE, const vector<XSECCryptoX509*>& certChain, const PathValidatorParams& params
124 X509* certEE, STACK_OF(X509)* certChain, const PathValidatorParams& params
128 XSECCryptoX509CRL* getRemoteCRLs(const char* cdpuri) const;
129 bool isFreshCRL(XSECCryptoX509CRL *c, Category* log=nullptr) const;
133 time_t m_minRefreshDelay,m_minSecondsRemaining;
134 unsigned short m_minPercentRemaining;
136 static map<string,time_t> m_crlUpdateMap;
139 PathValidator* XMLTOOL_DLLLOCAL PKIXPathValidatorFactory(const xercesc::DOMElement* const & e)
141 return new PKIXPathValidator(e);
146 map<string,time_t> PKIXPathValidator::m_crlUpdateMap;
148 void XMLTOOL_API xmltooling::registerPathValidators()
150 XMLToolingConfig& conf=XMLToolingConfig::getConfig();
151 conf.PathValidatorManager.registerFactory(PKIX_PATHVALIDATOR, PKIXPathValidatorFactory);
154 PathValidator::PathValidator()
158 PathValidator::~PathValidator()
162 PathValidator::PathValidatorParams::PathValidatorParams()
166 PathValidator::PathValidatorParams::~PathValidatorParams()
170 PKIXPathValidatorParams::PKIXPathValidatorParams()
174 PKIXPathValidatorParams::~PKIXPathValidatorParams()
178 OpenSSLPathValidator::OpenSSLPathValidator()
182 OpenSSLPathValidator::~OpenSSLPathValidator()
186 bool PKIXPathValidator::validate(
187 XSECCryptoX509* certEE, const vector<XSECCryptoX509*>& certChain, const PathValidatorParams& params
190 if (certEE->getProviderName()!=DSIGConstants::s_unicodeStrPROVOpenSSL) {
191 m_log.error("only the OpenSSL XSEC provider is supported");
195 STACK_OF(X509)* untrusted=sk_X509_new_null();
196 for (vector<XSECCryptoX509*>::const_iterator i=certChain.begin(); i!=certChain.end(); ++i)
197 sk_X509_push(untrusted,static_cast<OpenSSLCryptoX509*>(*i)->getOpenSSLX509());
199 bool ret = validate(static_cast<OpenSSLCryptoX509*>(certEE)->getOpenSSLX509(), untrusted, params);
200 sk_X509_free(untrusted);
204 bool PKIXPathValidator::validate(X509* EE, STACK_OF(X509)* untrusted, const PathValidatorParams& params) const
210 const PKIXPathValidatorParams* pkixParams = dynamic_cast<const PKIXPathValidatorParams*>(¶ms);
212 m_log.error("input parameters were of incorrect type");
216 // First we build a stack of CA certs. These objects are all referenced in place.
217 m_log.debug("supplying PKIX Validation information");
219 // We need this for CRL support.
220 X509_STORE* store=X509_STORE_new();
226 // PKIX policy checking (cf. RFCs 3280/5280 section 6)
227 if (pkixParams->isPolicyMappingInhibited() || pkixParams->isAnyPolicyInhibited() || (!pkixParams->getPolicies().empty())) {
228 #if (OPENSSL_VERSION_NUMBER < 0x00908000L)
229 m_log.error("PKIX policy checking option is configured, but OpenSSL version is less than 0.9.8");
230 X509_STORE_free(store);
233 unsigned long pflags = 0;
234 X509_VERIFY_PARAM *vpm = X509_VERIFY_PARAM_new();
237 X509_STORE_free(store);
241 // populate the "user-initial-policy-set" input variable
242 const set<string>& policies = pkixParams->getPolicies();
243 if (!policies.empty()) {
244 for (set<string>::const_iterator o=policies.begin(); o!=policies.end(); o++) {
245 ASN1_OBJECT *oid = OBJ_txt2obj(o->c_str(), 1);
246 if (oid && X509_VERIFY_PARAM_add0_policy(vpm, oid)) {
247 m_log.debug("OID (%s) added to set of acceptable policies", o->c_str());
251 m_log.error("unable to parse/configure policy OID value (%s)", o->c_str());
253 ASN1_OBJECT_free(oid);
254 X509_VERIFY_PARAM_free(vpm);
255 X509_STORE_free(store);
259 // when the user has supplied at least one policy OID, he obviously wants to check
260 // for an explicit policy ("initial-explicit-policy")
261 pflags |= X509_V_FLAG_EXPLICIT_POLICY;
264 // "initial-policy-mapping-inhibit" input variable
265 if (pkixParams->isPolicyMappingInhibited())
266 pflags |= X509_V_FLAG_INHIBIT_MAP;
267 // "initial-any-policy-inhibit" input variable
268 if (pkixParams->isAnyPolicyInhibited())
269 pflags |= X509_V_FLAG_INHIBIT_ANY;
271 if (!X509_VERIFY_PARAM_set_flags(vpm, pflags) || !X509_STORE_set1_param(store, vpm)) {
273 m_log.error("unable to set PKIX policy checking parameters");
274 X509_VERIFY_PARAM_free(vpm);
275 X509_STORE_free(store);
279 X509_VERIFY_PARAM_free(vpm);
283 // This contains the state of the validate operation.
287 // AFAICT, EE and untrusted are passed in but not owned by the ctx.
288 #if (OPENSSL_VERSION_NUMBER >= 0x00907000L)
289 if (X509_STORE_CTX_init(&ctx,store,EE,untrusted)!=1) {
291 m_log.error("unable to initialize X509_STORE_CTX");
292 X509_STORE_free(store);
296 X509_STORE_CTX_init(&ctx,store,EE,untrusted);
299 STACK_OF(X509)* CAstack = sk_X509_new_null();
300 const vector<XSECCryptoX509*>& CAcerts = pkixParams->getTrustAnchors();
301 for (vector<XSECCryptoX509*>::const_iterator i=CAcerts.begin(); i!=CAcerts.end(); ++i) {
302 if ((*i)->getProviderName()==DSIGConstants::s_unicodeStrPROVOpenSSL) {
303 sk_X509_push(CAstack,static_cast<OpenSSLCryptoX509*>(*i)->getOpenSSLX509());
307 m_log.debug("supplied (%d) CA certificate(s)", count);
309 // Seems to be most efficient to just pass in the CA stack.
310 X509_STORE_CTX_trusted_stack(&ctx,CAstack);
311 X509_STORE_CTX_set_depth(&ctx,100); // we check the depth down below
312 X509_STORE_CTX_set_verify_cb(&ctx,error_callback);
314 // Do a first pass verify. If CRLs aren't used, this is the only pass.
315 int ret=X509_verify_cert(&ctx);
317 // Now see if the depth was acceptable by counting the number of intermediates.
318 int depth=sk_X509_num(ctx.chain)-2;
319 if (pkixParams->getVerificationDepth() < depth) {
321 "certificate chain was too long (%d intermediates, only %d allowed)",
322 (depth==-1) ? 0 : depth,
323 pkixParams->getVerificationDepth()
329 if (pkixParams->getRevocationChecking() != PKIXPathValidatorParams::REVOCATION_OFF) {
330 #if (OPENSSL_VERSION_NUMBER >= 0x00907000L)
331 // When we add CRLs, we have to be sure the nextUpdate hasn't passed, because OpenSSL won't accept
332 // the CRL in that case. If we end up not adding a CRL for a particular link in the chain, the
333 // validation will fail (if the fullChain option was set).
334 set<string> crlissuers;
335 time_t now = time(nullptr);
337 const vector<XSECCryptoX509CRL*>& crls = pkixParams->getCRLs();
338 for (vector<XSECCryptoX509CRL*>::const_iterator j=crls.begin(); j!=crls.end(); ++j) {
339 if ((*j)->getProviderName()==DSIGConstants::s_unicodeStrPROVOpenSSL &&
340 (X509_cmp_time(X509_CRL_get_nextUpdate(static_cast<OpenSSLCryptoX509CRL*>(*j)->getOpenSSLX509CRL()), &now) > 0)) {
342 X509_STORE_add_crl(store, X509_CRL_dup(static_cast<OpenSSLCryptoX509CRL*>(*j)->getOpenSSLX509CRL()));
343 string crlissuer(X509_NAME_to_string(X509_CRL_get_issuer(static_cast<OpenSSLCryptoX509CRL*>(*j)->getOpenSSLX509CRL())));
344 if (!crlissuer.empty()) {
345 m_log.debug("added CRL issued by (%s)", crlissuer.c_str());
346 crlissuers.insert(crlissuer);
351 for (int i = 0; i < sk_X509_num(untrusted); ++i) {
352 X509 *cert = sk_X509_value(untrusted, i);
353 string crlissuer(X509_NAME_to_string(X509_get_issuer_name(cert)));
354 if (crlissuers.count(crlissuer)) {
355 // We already have a CRL for this cert, so skip CRLDP processing for this one.
359 bool foundUsableCDP = false;
360 STACK_OF(DIST_POINT)* dps = (STACK_OF(DIST_POINT)*)X509_get_ext_d2i(cert, NID_crl_distribution_points, nullptr, nullptr);
361 for (int ii = 0; !foundUsableCDP && ii < sk_DIST_POINT_num(dps); ++ii) {
362 DIST_POINT* dp = sk_DIST_POINT_value(dps, ii);
363 if (!dp->distpoint || dp->distpoint->type != 0)
365 for (int iii = 0; !foundUsableCDP && iii < sk_GENERAL_NAME_num(dp->distpoint->name.fullname); ++iii) {
366 GENERAL_NAME* gen = sk_GENERAL_NAME_value(dp->distpoint->name.fullname, iii);
367 // Only consider HTTP URIs, and stop after the first one we find.
368 #ifdef HAVE_STRCASECMP
369 if (gen->type == GEN_URI && (!strncasecmp((const char*)gen->d.ia5->data, "http:", 5))) {
371 if (gen->type == GEN_URI && (!strnicmp((const char*)gen->d.ia5->data, "http:", 5))) {
373 const char* cdpuri = (const char*)gen->d.ia5->data;
374 auto_ptr<XSECCryptoX509CRL> crl(getRemoteCRLs(cdpuri));
375 if (crl.get() && crl->getProviderName()==DSIGConstants::s_unicodeStrPROVOpenSSL &&
376 (isFreshCRL(crl.get()) || (ii == sk_DIST_POINT_num(dps)-1 && iii == sk_GENERAL_NAME_num(dp->distpoint->name.fullname)-1))) {
378 X509_STORE_add_crl(store, X509_CRL_dup(static_cast<OpenSSLCryptoX509CRL*>(crl.get())->getOpenSSLX509CRL()));
379 m_log.debug("added CRL issued by (%s)", crlissuer.c_str());
380 crlissuers.insert(crlissuer);
381 foundUsableCDP = true;
386 sk_DIST_POINT_free(dps);
389 // Do a second pass verify with CRLs in place.
390 if (pkixParams->getRevocationChecking() == PKIXPathValidatorParams::REVOCATION_FULLCHAIN)
391 X509_STORE_CTX_set_flags(&ctx, X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL);
393 X509_STORE_CTX_set_flags(&ctx, X509_V_FLAG_CRL_CHECK);
394 ret=X509_verify_cert(&ctx);
396 m_log.warn("CRL checking is enabled, but OpenSSL version is too old");
402 X509_STORE_CTX_cleanup(&ctx);
403 X509_STORE_free(store);
404 sk_X509_free(CAstack);
407 m_log.debug("successfully validated certificate chain");
414 XSECCryptoX509CRL* PKIXPathValidator::getRemoteCRLs(const char* cdpuri) const
416 // This is a filesystem-based CRL cache using a shared lock across all instances
419 // The filenames for the CRL cache are based on a hash of the CRL location.
420 string cdpfile = SecurityHelper::doHash("SHA1", cdpuri, strlen(cdpuri)) + ".crl";
421 XMLToolingConfig::getConfig().getPathResolver()->resolve(cdpfile, PathResolver::XMLTOOLING_RUN_FILE);
422 string cdpstaging = cdpfile + ".tmp";
424 time_t now = time(nullptr);
425 vector<XSECCryptoX509CRL*> crls;
428 // While holding the lock, check for a cached copy of the CRL, and remove "expired" ones.
431 struct _stat stat_buf;
432 if (_stat(cdpfile.c_str(), &stat_buf) == 0) {
434 struct stat stat_buf;
435 if (stat(cdpfile.c_str(), &stat_buf) == 0) {
437 SecurityHelper::loadCRLsFromFile(crls, cdpfile.c_str());
438 if (crls.empty() || crls.front()->getProviderName() != DSIGConstants::s_unicodeStrPROVOpenSSL ||
439 X509_cmp_time(X509_CRL_get_nextUpdate(static_cast<OpenSSLCryptoX509CRL*>(crls.front())->getOpenSSLX509CRL()), &now) < 0) {
440 for_each(crls.begin(), crls.end(), xmltooling::cleanup<XSECCryptoX509CRL>());
442 remove(cdpfile.c_str()); // may as well delete the local copy
443 m_crlUpdateMap.erase(cdpuri);
444 m_log.info("deleting cached CRL from %s with nextUpdate field in the past", cdpuri);
448 catch (exception& ex) {
449 m_log.error("exception loading cached copy of CRL from %s: %s", cdpuri, ex.what());
452 if (crls.empty() || !isFreshCRL(crls.front(), &m_log)) {
453 bool updateTimestamp = true;
455 // If we get here, the cached copy didn't exist yet, or it's time to refresh.
456 // To limit the rate of unsuccessful attempts when a CRLDP is unreachable,
457 // we remember the timestamp of the last attempt (both successful/unsuccessful).
460 map<string,time_t>::const_iterator tsit = m_crlUpdateMap.find(cdpuri);
461 if (tsit != m_crlUpdateMap.end())
465 if (difftime(now, ts) > m_minRefreshDelay) {
466 SOAPTransport::Address addr("AbstractPKIXTrustEngine", cdpuri, cdpuri);
467 string scheme(addr.m_endpoint, strchr(addr.m_endpoint,':') - addr.m_endpoint);
468 auto_ptr<SOAPTransport> soap(XMLToolingConfig::getConfig().SOAPTransportManager.newPlugin(scheme.c_str(), addr));
470 istream& msg = soap->receive();
472 ofstream out(cdpstaging.c_str(), fstream::trunc|fstream::binary);
475 SecurityHelper::loadCRLsFromFile(crls, cdpstaging.c_str());
476 if (crls.empty() || crls.front()->getProviderName() != DSIGConstants::s_unicodeStrPROVOpenSSL ||
477 X509_cmp_time(X509_CRL_get_nextUpdate(static_cast<OpenSSLCryptoX509CRL*>(crls.front())->getOpenSSLX509CRL()), &now) < 0) {
478 // The "new" CRL wasn't usable, so get rid of it.
479 for_each(crls.begin(), crls.end(), xmltooling::cleanup<XSECCryptoX509CRL>());
481 remove(cdpstaging.c_str());
482 m_log.error("ignoring CRL retrieved from %s with nextUpdate field in the past", cdpuri);
485 // "Commit" the new CRL. Note that we might add a CRL which doesn't pass
486 // isFreshCRL, but that's preferrable over adding none at all.
487 m_log.info("CRL refreshed from %s", cdpuri);
488 remove(cdpfile.c_str());
489 if (rename(cdpstaging.c_str(), cdpfile.c_str()) != 0)
490 m_log.error("unable to rename CRL staging file");
494 updateTimestamp = false; // don't update if we're within the backoff window
497 catch (exception& ex) {
498 m_log.error("exception downloading/caching CRL from %s: %s", cdpuri, ex.what());
501 if (updateTimestamp) {
503 m_crlUpdateMap[cdpuri] = now;
509 for_each(crls.begin() + 1, crls.end(), xmltooling::cleanup<XSECCryptoX509CRL>());
513 bool PKIXPathValidator::isFreshCRL(XSECCryptoX509CRL *c, Category* log) const
516 const X509_CRL* crl = static_cast<OpenSSLCryptoX509CRL*>(c)->getOpenSSLX509CRL();
517 time_t thisUpdate = getCRLTime(X509_CRL_get_lastUpdate(crl));
518 time_t nextUpdate = getCRLTime(X509_CRL_get_nextUpdate(crl));
519 time_t now = time(nullptr);
521 if (thisUpdate < 0 || nextUpdate < 0) {
522 // we failed to parse at least one of the fields (they were not encoded
523 // as required by RFC 5280, actually)
524 time_t exp = now + m_minSecondsRemaining;
526 log->warn("isFreshCRL (issuer '%s'): improperly encoded thisUpdate or nextUpdate field - falling back to simple time comparison",
527 (X509_NAME_to_string(X509_CRL_get_issuer(crl))).c_str());
529 return (X509_cmp_time(X509_CRL_get_nextUpdate(crl), &exp) > 0) ? true : false;
532 if (log && log->isDebugEnabled()) {
533 log->debug("isFreshCRL (issuer '%s'): %.0f seconds until nextUpdate (%3.2f%% elapsed since thisUpdate)",
534 (X509_NAME_to_string(X509_CRL_get_issuer(crl))).c_str(),
535 difftime(nextUpdate, now), (difftime(now, thisUpdate) * 100) / difftime(nextUpdate, thisUpdate));
538 // consider it recent enough if there are at least MIN_SECS_REMAINING
539 // to the nextUpdate, and at least MIN_PERCENT_REMAINING of its
540 // overall "validity" are remaining to the nextUpdate
541 return (now + m_minSecondsRemaining < nextUpdate) &&
542 ((difftime(nextUpdate, now) * 100) / difftime(nextUpdate, thisUpdate) > m_minPercentRemaining);