added a facility to hand out fingerprinting/key encoding to the pkcs1/pgp/... plugins

src/libstrongswan/credentials/keys/key_encoding.c

@@ -0,0 +1,256 @@
+/*
+ * Copyright (C) 2009 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 "key_encoding.h"
+
+#include <stdint.h>
+
+#include <utils/linked_list.h>
+#include <utils/hashtable.h>
+#include <utils/mutex.h>
+
+typedef struct private_key_encoding_t private_key_encoding_t;
+
+/**
+ * Private data of an key_encoding_t object.
+ */
+struct private_key_encoding_t {
+	
+	/**
+	 * Public key_encoding_t interface.
+	 */
+	key_encoding_t public;
+	
+	/**
+	 * cached encodings, a table for each encoding_type_t, containing chunk_t*
+	 */
+	hashtable_t *cache[KEY_ENCODING_MAX];
+	
+	/**
+	 * Registered encoding fuctions, key_encoder_t
+	 */
+	linked_list_t *encoders;
+	
+	/**
+	 * lock to access cache/encoders
+	 */
+	rwlock_t *lock;
+};
+
+/**
+ * See header.
+ */
+bool key_encoding_args(va_list args, ...)
+{
+	va_list parts, copy;
+	bool failed = FALSE;
+	
+	va_start(parts, args);
+	
+	while (!failed)
+	{
+		key_encoding_part_t current, target;
+		chunk_t *out, data;
+		
+		/* get the part we are looking for */
+		target = va_arg(parts, key_encoding_part_t);
+		if (target == KEY_PART_END)
+		{
+			break;
+		}
+		out = va_arg(parts, chunk_t*);
+		
+		va_copy(copy, args);
+		while (!failed)
+		{
+			current = va_arg(copy, key_encoding_part_t);
+			if (current == KEY_PART_END)
+			{
+				failed = TRUE;
+				break;
+			}
+			data = va_arg(copy, chunk_t);
+			if (current == target)
+			{
+				*out = data;
+				break;
+			}
+		}
+		va_end(copy);
+	}
+	va_end(parts);
+	return !failed;
+}
+
+/**
+ * hashtable hash() function
+ */
+static u_int hash(void *key)
+{
+	return (uintptr_t)key;
+}
+
+/**
+ * hashtable equals() function
+ */
+static bool equals(void *key1, void *key2)
+{
+	return key1 == key2;
+}
+
+/**
+ * Implementation of key_encoding_t.encode
+ */
+static bool encode(private_key_encoding_t *this, key_encoding_type_t type,
+				   void *cache, chunk_t *encoding, ...)
+{
+	enumerator_t *enumerator;
+	va_list args, copy;
+	key_encoder_t encode;
+	bool success = FALSE;
+	chunk_t *chunk;
+	
+	if (type >= KEY_ENCODING_MAX || type < 0)
+	{
+		return FALSE;
+	}
+	this->lock->read_lock(this->lock);
+	if (cache)
+	{
+		chunk = this->cache[type]->get(this->cache[type], cache);
+		if (chunk)
+		{
+			*encoding = *chunk;
+			this->lock->unlock(this->lock);
+			return TRUE;
+		}
+	}
+	va_start(args, encoding);
+	enumerator = this->encoders->create_enumerator(this->encoders);
+	while (enumerator->enumerate(enumerator, &encode))
+	{
+		va_copy(copy, args);
+		success = encode(type, encoding, copy);
+		va_end(copy);
+		if (success)
+		{
+			if (cache)
+			{
+				chunk = malloc_thing(chunk_t);
+				*chunk = *encoding;
+				this->lock->unlock(this->lock);
+				this->lock->write_lock(this->lock);
+				this->cache[type]->put(this->cache[type], cache, chunk);
+			}
+			break;
+		}
+	}
+	enumerator->destroy(enumerator);
+	va_end(args);
+	this->lock->unlock(this->lock);
+	return success;
+}
+
+/**
+ * Implementation of key_encoding_t.clear_cache
+ */
+static void clear_cache(private_key_encoding_t *this, void *cache)
+{
+	key_encoding_type_t type;
+	chunk_t *chunk;
+	
+	this->lock->write_lock(this->lock);
+	for (type = 0; type < KEY_ENCODING_MAX; type++)
+	{
+		chunk = this->cache[type]->remove(this->cache[type], cache);
+		if (chunk)
+		{
+			chunk_free(chunk);
+			free(chunk);
+		}
+	}
+	this->lock->unlock(this->lock);
+}
+
+/**
+ * Implementation of key_encoding_t.add_encoder
+ */
+static void add_encoder(private_key_encoding_t *this, key_encoder_t encoder)
+{
+	this->lock->write_lock(this->lock);
+	this->encoders->insert_last(this->encoders, encoder);
+	this->lock->unlock(this->lock);
+}
+
+/**
+ * Implementation of key_encoding_t.remove_encoder
+ */
+static void remove_encoder(private_key_encoding_t *this, key_encoder_t encoder)
+{
+	this->lock->write_lock(this->lock);
+	this->encoders->remove(this->encoders, encoder, NULL);
+	this->lock->unlock(this->lock);
+}
+
+/**
+ * Implementation of key_encoder_t.destroy.
+ */
+static void destroy(private_key_encoding_t *this)
+{
+	enumerator_t *enumerator;
+	key_encoding_type_t type;
+	chunk_t *chunk;
+	void *key;
+	
+	for (type = 0; type < KEY_ENCODING_MAX; type++)
+	{
+		enumerator = this->cache[type]->create_enumerator(this->cache[type]);
+		while (enumerator->enumerate(enumerator, &key, &chunk))
+		{
+			chunk_free(chunk);
+			free(chunk);
+		}
+		enumerator->destroy(enumerator);
+		this->cache[type]->destroy(this->cache[type]);
+	}
+	this->encoders->destroy(this->encoders);
+	this->lock->destroy(this->lock);
+	free(this);
+}
+
+/**
+ * See header
+ */
+key_encoding_t *key_encoding_create()
+{
+	private_key_encoding_t *this = malloc_thing(private_key_encoding_t);
+	key_encoding_type_t type;
+	
+	this->public.encode = (bool(*)(key_encoding_t*, key_encoding_type_t type, void *cache, chunk_t *encoding, ...))encode;
+	this->public.clear_cache = (void(*)(key_encoding_t*, void *cache))clear_cache;
+	this->public.add_encoder = (void(*)(key_encoding_t*, key_encoder_t encoder))add_encoder;
+	this->public.remove_encoder = (void(*)(key_encoding_t*, key_encoder_t encoder))remove_encoder;
+	this->public.destroy = (void(*)(key_encoding_t*))destroy;
+	
+	for (type = 0; type < KEY_ENCODING_MAX; type++)
+	{
+		this->cache[type] = hashtable_create(hash, equals, 8);
+	}
+	this->encoders = linked_list_create();
+	this->lock = rwlock_create(RWLOCK_TYPE_DEFAULT);
+	
+	return &this->public;
+}
+