[svn-upgrade] new version strongswan (4.4.1)

1 files changed, 389 insertions, 0 deletions

diff --git a/src/libstrongswan/credentials/sets/cert_cache.c b/src/libstrongswan/credentials/sets/cert_cache.c
new file mode 100644
index 000000000..7161ac9ac
--- /dev/null
+++ b/src/libstrongswan/credentials/sets/cert_cache.c
@@ -0,0 +1,389 @@
+/*
+ * Copyright (C) 2008 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.
+ */
+
+#include "cert_cache.h"
+
+#include <time.h>
+#include <sched.h>
+
+#include <library.h>
+#include <threading/rwlock.h>
+#include <utils/linked_list.h>
+
+/** cache size, a power of 2 for fast modulo */
+#define CACHE_SIZE 32
+
+/** attempts to acquire a cache lock */
+#define REPLACE_TRIES 5
+
+typedef struct private_cert_cache_t private_cert_cache_t;
+typedef struct relation_t relation_t;
+
+/**
+ * A trusted relation between subject and issuer
+ */
+struct relation_t {
+
+	/**
+	 * subject of this relation
+	 */
+	certificate_t *subject;
+
+	/**
+	 * issuer of this relation
+	 */
+	certificate_t *issuer;
+
+	/**
+	 * Cache hits
+	 */
+	u_int hits;
+
+	/**
+	 * Lock for this relation
+	 */
+	rwlock_t *lock;
+};
+
+/**
+ * private data of cert_cache
+ */
+struct private_cert_cache_t {
+
+	/**
+	 * public functions
+	 */
+	cert_cache_t public;
+
+	/**
+	 * array of trusted subject-issuer relations
+	 */
+	relation_t relations[CACHE_SIZE];
+};
+
+/**
+ * Cache relation in a free slot/replace an other
+ */
+static void cache(private_cert_cache_t *this,
+				  certificate_t *subject, certificate_t *issuer)
+{
+	relation_t *rel;
+	int i, offset, try;
+	u_int total_hits = 0;
+
+	/* check for a unused relation slot first */
+	for (i = 0; i < CACHE_SIZE; i++)
+	{
+		rel = &this->relations[i];
+
+		if (!rel->subject && rel->lock->try_write_lock(rel->lock))
+		{
+			/* double-check having lock */
+			if (!rel->subject)
+			{
+				rel->subject = subject->get_ref(subject);
+				rel->issuer = issuer->get_ref(issuer);
+				return rel->lock->unlock(rel->lock);
+			}
+			rel->lock->unlock(rel->lock);
+		}
+		total_hits += rel->hits;
+	}
+	/* run several attempts to replace a random slot, never block. */
+	for (try = 0; try < REPLACE_TRIES; try++)
+	{
+		/* replace a random relation */
+		offset = random();
+		for (i = 0; i < CACHE_SIZE; i++)
+		{
+			rel = &this->relations[(i + offset) % CACHE_SIZE];
+
+			if (rel->hits > total_hits / CACHE_SIZE)
+			{	/* skip often used slots */
+				continue;
+			}
+			if (rel->lock->try_write_lock(rel->lock))
+			{
+				if (rel->subject)
+				{
+					rel->subject->destroy(rel->subject);
+					rel->issuer->destroy(rel->issuer);
+				}
+				rel->subject = subject->get_ref(subject);
+				rel->issuer = issuer->get_ref(issuer);
+				rel->hits = 0;
+				return rel->lock->unlock(rel->lock);
+			}
+		}
+		/* give other threads a chance to release locks */
+		sched_yield();
+	}
+}
+
+/**
+ * Implementation of cert_cache_t.issued_by.
+ */
+static bool issued_by(private_cert_cache_t *this,
+					  certificate_t *subject, certificate_t *issuer)
+{
+	relation_t *found = NULL, *current;
+	int i;
+
+	for (i = 0; i < CACHE_SIZE; i++)
+	{
+		current = &this->relations[i];
+
+		current->lock->read_lock(current->lock);
+		if (current->subject)
+		{
+			/* check for equal issuer */
+			if (issuer->equals(issuer, current->issuer))
+			{
+				/* reuse issuer instance in cache() */
+				issuer = current->issuer;
+				if (subject->equals(subject, current->subject))
+				{
+					/* write hit counter is not locked, but not critical */
+					current->hits++;
+					found = current;
+				}
+			}
+		}
+		current->lock->unlock(current->lock);
+		if (found)
+		{
+			return TRUE;
+		}
+	}
+	/* no cache hit, check and cache signature */
+	if (subject->issued_by(subject, issuer))
+	{
+		cache(this, subject, issuer);
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * certificate enumerator implemenation
+ */
+typedef struct {
+	/** implements enumerator_t interface */
+	enumerator_t public;
+	/** type of requested certificate */
+	certificate_type_t cert;
+	/** type of requested key */
+	key_type_t key;
+	/** ID to get a cert for */
+	identification_t *id;
+	/** cache */
+	relation_t *relations;
+	/** current position in array cache */
+	int index;
+	/** currently locked relation */
+	int locked;
+} cert_enumerator_t;
+
+/**
+ * filter function for certs enumerator
+ */
+static bool cert_enumerate(cert_enumerator_t *this, certificate_t **out)
+{
+	public_key_t *public;
+	relation_t *rel;
+
+	if (this->locked >= 0)
+	{
+		rel = &this->relations[this->locked];
+		rel->lock->unlock(rel->lock);
+		this->locked = -1;
+	}
+
+	while (++this->index < CACHE_SIZE)
+	{
+		rel = &this->relations[this->index];
+		rel->lock->read_lock(rel->lock);
+		this->locked = this->index;
+		if (rel->subject)
+		{
+			/* CRL lookup is done using issuer/authkeyidentifier */
+			if (this->key == KEY_ANY && this->id &&
+				(this->cert == CERT_ANY || this->cert == CERT_X509_CRL) &&
+				rel->subject->get_type(rel->subject) == CERT_X509_CRL &&
+				rel->subject->has_issuer(rel->subject, this->id))
+			{
+				*out = rel->subject;
+				return TRUE;
+			}
+			if ((this->cert == CERT_ANY ||
+				 rel->subject->get_type(rel->subject) == this->cert) &&
+				(!this->id || rel->subject->has_subject(rel->subject, this->id)))
+			{
+				if (this->key == KEY_ANY)
+				{
+					*out = rel->subject;
+					return TRUE;
+				}
+				public = rel->subject->get_public_key(rel->subject);
+				if (public)
+				{
+					if (public->get_type(public) == this->key)
+					{
+						public->destroy(public);
+						*out = rel->subject;
+						return TRUE;
+					}
+					public->destroy(public);
+				}
+			}
+		}
+		this->locked = -1;
+		rel->lock->unlock(rel->lock);
+	}
+	return FALSE;
+}
+
+/**
+ * clean up enumeration data
+ */
+static void cert_enumerator_destroy(cert_enumerator_t *this)
+{
+	relation_t *rel;
+
+	if (this->locked >= 0)
+	{
+		rel = &this->relations[this->locked];
+		rel->lock->unlock(rel->lock);
+	}
+	free(this);
+}
+
+/**
+ * implementation of credential_set_t.create_cert_enumerator
+ */
+static enumerator_t *create_enumerator(private_cert_cache_t *this,
+									   certificate_type_t cert, key_type_t key,
+									   identification_t *id, bool trusted)
+{
+	cert_enumerator_t *enumerator;
+
+	if (trusted)
+	{
+		return NULL;
+	}
+	enumerator = malloc_thing(cert_enumerator_t);
+	enumerator->public.enumerate = (void*)cert_enumerate;
+	enumerator->public.destroy = (void*)cert_enumerator_destroy;
+	enumerator->cert = cert;
+	enumerator->key = key;
+	enumerator->id = id;
+	enumerator->relations = this->relations;
+	enumerator->index = -1;
+	enumerator->locked = -1;
+
+	return &enumerator->public;
+}
+
+/**
+ * Implementation of cert_cache_t.flush.
+ */
+static void flush(private_cert_cache_t *this, certificate_type_t type)
+{
+	relation_t *rel;
+	int i;
+
+	for (i = 0; i < CACHE_SIZE; i++)
+	{
+		rel = &this->relations[i];
+		if (!rel->subject)
+		{
+			continue;
+		}
+		/* check with cheap read lock first */
+		if (type != CERT_ANY)
+		{
+			rel->lock->read_lock(rel->lock);
+			if (!rel->subject || type != rel->subject->get_type(rel->subject))
+			{
+				rel->lock->unlock(rel->lock);
+				continue;
+			}
+			rel->lock->unlock(rel->lock);
+		}
+		/* double check in write lock */
+		rel->lock->write_lock(rel->lock);
+		if (rel->subject)
+		{
+			if (type == CERT_ANY || type == rel->subject->get_type(rel->subject))
+			{
+				rel->subject->destroy(rel->subject);
+				rel->issuer->destroy(rel->issuer);
+				rel->subject = NULL;
+				rel->issuer = NULL;
+				rel->hits = 0;
+			}
+		}
+		rel->lock->unlock(rel->lock);
+	}
+}
+
+/**
+ * Implementation of cert_cache_t.destroy
+ */
+static void destroy(private_cert_cache_t *this)
+{
+	relation_t *rel;
+	int i;
+
+	for (i = 0; i < CACHE_SIZE; i++)
+	{
+		rel = &this->relations[i];
+		if (rel->subject)
+		{
+			rel->subject->destroy(rel->subject);
+			rel->issuer->destroy(rel->issuer);
+		}
+		rel->lock->destroy(rel->lock);
+	}
+	free(this);
+}
+
+/*
+ * see header file
+ */
+cert_cache_t *cert_cache_create()
+{
+	private_cert_cache_t *this;
+	int i;
+
+	this = malloc_thing(private_cert_cache_t);
+	this->public.set.create_private_enumerator = (void*)return_null;
+	this->public.set.create_cert_enumerator = (void*)create_enumerator;
+	this->public.set.create_shared_enumerator = (void*)return_null;
+	this->public.set.create_cdp_enumerator = (void*)return_null;
+	this->public.set.cache_cert = (void*)nop;
+	this->public.issued_by = (bool(*)(cert_cache_t*, certificate_t *subject, certificate_t *issuer))issued_by;
+	this->public.flush = (void(*)(cert_cache_t*, certificate_type_t type))flush;
+	this->public.destroy = (void(*)(cert_cache_t*))destroy;
+
+	for (i = 0; i < CACHE_SIZE; i++)
+	{
+		this->relations[i].subject = NULL;
+		this->relations[i].issuer = NULL;
+		this->relations[i].hits = 0;
+		this->relations[i].lock = rwlock_create(RWLOCK_TYPE_DEFAULT);
+	}
+	return &this->public;
+}