Added a certificate validation hook to the credential manager

src/libstrongswan/credentials/cert_validator.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2010 Martin Willi
+ * Copyright (C) 2010 revosec AG
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+/**
+ * @defgroup cert_validator cert_validator
+ * @{ @ingroup ccredentials
+ */
+
+#ifndef CERT_VALIDATOR_H_
+#define CERT_VALIDATOR_H_
+
+typedef struct cert_validator_t cert_validator_t;
+
+/**
+ * Certificate validator interface.
+ *
+ * A certificate validator checks constraints or revocation in a certificate
+ * or its issuing CA certificate. The interface allows plugins to do
+ * revocation checking or similar tasks.
+ */
+struct cert_validator_t {
+
+	/**
+	 * Validate a subject certificate in relation to its issuer.
+	 *
+	 * @param subject		subject certificate to check
+	 * @param issuer		issuer of subject
+	 * @param online		wheter to do online revocation checking
+	 * @param pathlen		the current length of the path up to the root CA
+	 * @param auth			container for resulting authentication info
+	 */
+	bool (*validate)(cert_validator_t *this, certificate_t *subject,
+					 certificate_t *issuer, bool online, int pathlen,
+					 auth_cfg_t *auth);
+};
+
+#endif /** CERT_VALIDATOR_H_ @}*/

src/libstrongswan/credentials/credential_manager.c

@@ -67,6 +67,11 @@ struct private_credential_manager_t {
 	 */
 	linked_list_t *cache_queue;
 
+	/**
+	 * list of certificate validators, cert_validator_t
+	 */
+	linked_list_t *validators;
+
 	/**
 	 * read-write lock to sets list
 	 */
@@ -1000,6 +1005,8 @@ static bool check_certificate(private_credential_manager_t *this,
 							  bool online, int pathlen, auth_cfg_t *auth)
 {
 	time_t not_before, not_after;
+	cert_validator_t *validator;
+	enumerator_t *enumerator;
 
 	if (!subject->get_validity(subject, NULL, &not_before, &not_after))
 	{
@@ -1075,6 +1082,18 @@ static bool check_certificate(private_credential_manager_t *this,
 			}
 		}
 	}
+
+	enumerator = this->validators->create_enumerator(this->validators);
+	while (enumerator->enumerate(enumerator, &validator))
+	{
+		if (!validator->validate(validator, subject, issuer,
+								 online, pathlen, auth))
+		{
+			enumerator->destroy(enumerator);
+			return FALSE;
+		}
+	}
+	enumerator->destroy(enumerator);
 	return TRUE;
 }
 
@@ -1595,6 +1614,22 @@ METHOD(credential_manager_t, remove_set, void,
 	this->lock->unlock(this->lock);
 }
 
+METHOD(credential_manager_t, add_validator, void,
+	private_credential_manager_t *this, cert_validator_t *vdtr)
+{
+	this->lock->write_lock(this->lock);
+	this->sets->insert_last(this->validators, vdtr);
+	this->lock->unlock(this->lock);
+}
+
+METHOD(credential_manager_t, remove_validator, void,
+	private_credential_manager_t *this, cert_validator_t *vdtr)
+{
+	this->lock->write_lock(this->lock);
+	this->validators->remove(this->validators, vdtr, NULL);
+	this->lock->unlock(this->lock);
+}
+
 METHOD(credential_manager_t, destroy, void,
 	private_credential_manager_t *this)
 {
@@ -1604,6 +1639,7 @@ METHOD(credential_manager_t, destroy, void,
 	this->sets->destroy(this->sets);
 	this->local_sets->destroy(this->local_sets);
 	this->cache->destroy(this->cache);
+	this->validators->destroy(this->validators);
 	this->lock->destroy(this->lock);
 	this->queue_mutex->destroy(this->queue_mutex);
 	free(this);
@@ -1629,9 +1665,12 @@ credential_manager_t *credential_manager_create()
 			.cache_cert = _cache_cert,
 			.add_set = _add_set,
 			.remove_set = _remove_set,
+			.add_validator = _add_validator,
+			.remove_validator = _remove_validator,
 			.destroy = _destroy,
 		},
 		.sets = linked_list_create(),
+		.validators = linked_list_create(),
 		.cache = cert_cache_create(),
 		.cache_queue = linked_list_create(),
 		.lock = rwlock_create(RWLOCK_TYPE_DEFAULT),

src/libstrongswan/credentials/credential_manager.h

@@ -30,6 +30,7 @@ typedef struct credential_manager_t credential_manager_t;
 #include <credentials/keys/private_key.h>
 #include <credentials/keys/shared_key.h>
 #include <credentials/certificates/certificate.h>
+#include <credentials/cert_validator.h>
 
 /**
  * Manages credentials using credential_sets.
@@ -189,6 +190,20 @@ struct credential_manager_t {
 	 */
 	void (*remove_set)(credential_manager_t *this, credential_set_t *set);
 
+	/**
+	 * Register a certificate validator to the manager.
+	 *
+	 * @param vdtr		validator to register
+	 */
+	void (*add_validator)(credential_manager_t *this, cert_validator_t *vdtr);
+
+	/**
+	 * Remove a certificate validator from the manager.
+	 *
+	 * @param vdtr		validator to unregister
+	 */
+	void (*remove_validator)(credential_manager_t *this, cert_validator_t *vdtr);
+
 	/**
 	 * Destroy a credential_manager instance.
 	 */