Moved TLS stack to its own library

src/libtls/tls_fragmentation.c

@@ -0,0 +1,256 @@
+/*
+ * 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.
+ */
+
+#include "tls_fragmentation.h"
+
+#include "tls_reader.h"
+
+#include <debug.h>
+
+typedef struct private_tls_fragmentation_t private_tls_fragmentation_t;
+
+/**
+ * Private data of an tls_fragmentation_t object.
+ */
+struct private_tls_fragmentation_t {
+
+	/**
+	 * Public tls_fragmentation_t interface.
+	 */
+	tls_fragmentation_t public;
+
+	/**
+	 * Upper layer handshake protocol
+	 */
+	tls_handshake_t *handshake;
+
+	/**
+	 * Handshake input buffer
+	 */
+	chunk_t input;
+
+	/**
+	 * Position in input buffer
+	 */
+	size_t inpos;
+
+	/**
+	 * Currently processed handshake message type
+	 */
+	tls_handshake_type_t type;
+
+	/**
+	 * Handshake output buffer
+	 */
+	chunk_t output;
+};
+
+/**
+ * Maximum size of a TLS fragment
+ */
+#define MAX_TLS_FRAGMENT_LEN 16384
+
+/**
+ * Maximum size of a TLS handshake message we accept
+ */
+#define MAX_TLS_HANDSHAKE_LEN 65536
+
+/**
+ * Process TLS handshake protocol data
+ */
+static status_t process_handshake(private_tls_fragmentation_t *this,
+								  tls_reader_t *reader)
+{
+	while (reader->remaining(reader))
+	{
+		tls_reader_t *msg;
+		u_int8_t type;
+		u_int32_t len;
+		status_t status;
+		chunk_t data;
+
+		if (reader->remaining(reader) > MAX_TLS_FRAGMENT_LEN)
+		{
+			DBG1(DBG_IKE, "TLS fragment has invalid length");
+			return FAILED;
+		}
+
+		if (this->input.len == 0)
+		{	/* new handshake message */
+			if (!reader->read_uint8(reader, &type) ||
+				!reader->read_uint24(reader, &len))
+			{
+				return FAILED;
+			}
+			this->type = type;
+			if (len > MAX_TLS_HANDSHAKE_LEN)
+			{
+				DBG1(DBG_IKE, "TLS handshake message exceeds maximum length");
+				return FAILED;
+			}
+			chunk_free(&this->input);
+			this->inpos = 0;
+			if (len)
+			{
+				this->input = chunk_alloc(len);
+			}
+		}
+
+		len = min(this->input.len - this->inpos, reader->remaining(reader));
+		if (!reader->read_data(reader, len, &data))
+		{
+			return FAILED;
+		}
+		memcpy(this->input.ptr + this->inpos, data.ptr, len);
+		this->inpos += len;
+
+		if (this->input.len == this->inpos)
+		{	/* message completely defragmented, process */
+			msg = tls_reader_create(this->input);
+			status = this->handshake->process(this->handshake, this->type, msg);
+			msg->destroy(msg);
+			chunk_free(&this->input);
+			if (status != NEED_MORE)
+			{
+				return status;
+			}
+		}
+	}
+	return NEED_MORE;
+}
+
+METHOD(tls_fragmentation_t, process, status_t,
+	private_tls_fragmentation_t *this, tls_content_type_t type, chunk_t data)
+{
+	tls_reader_t *reader;
+	status_t status;
+
+	reader = tls_reader_create(data);
+	switch (type)
+	{
+		case TLS_CHANGE_CIPHER_SPEC:
+			if (this->handshake->change_cipherspec(this->handshake))
+			{
+				status = NEED_MORE;
+				break;
+			}
+			status = FAILED;
+			break;
+		case TLS_ALERT:
+			/* TODO: handle Alert */
+			status = FAILED;
+			break;
+		case TLS_HANDSHAKE:
+			status = process_handshake(this, reader);
+			break;
+		case TLS_APPLICATION_DATA:
+			/* skip application data */
+			status = NEED_MORE;
+			break;
+		default:
+			DBG1(DBG_IKE, "received unknown TLS content type %d, ignored", type);
+			status = NEED_MORE;
+			break;
+	}
+	reader->destroy(reader);
+	return status;
+}
+
+METHOD(tls_fragmentation_t, build, status_t,
+	private_tls_fragmentation_t *this, tls_content_type_t *type, chunk_t *data)
+{
+	tls_handshake_type_t hs_type;
+	tls_writer_t *writer, *msg;
+	status_t status;
+
+	if (this->handshake->cipherspec_changed(this->handshake))
+	{
+		*type = TLS_CHANGE_CIPHER_SPEC;
+		*data = chunk_clone(chunk_from_chars(0x01));
+		return NEED_MORE;
+	}
+
+	if (!this->output.len)
+	{
+		msg = tls_writer_create(64);
+		do
+		{
+			writer = tls_writer_create(64);
+			status = this->handshake->build(this->handshake, &hs_type, writer);
+			switch (status)
+			{
+				case NEED_MORE:
+					msg->write_uint8(msg, hs_type);
+					msg->write_data24(msg, writer->get_buf(writer));
+					break;
+				case INVALID_STATE:
+					this->output = chunk_clone(msg->get_buf(msg));
+					break;
+				default:
+					break;
+			}
+			writer->destroy(writer);
+		}
+		while (status == NEED_MORE);
+
+		msg->destroy(msg);
+		if (status != INVALID_STATE)
+		{
+			return status;
+		}
+	}
+
+	if (this->output.len)
+	{
+		*type = TLS_HANDSHAKE;
+		if (this->output.len <= MAX_TLS_FRAGMENT_LEN)
+		{
+			*data = this->output;
+			this->output = chunk_empty;
+			return NEED_MORE;
+		}
+		*data = chunk_create(this->output.ptr, MAX_TLS_FRAGMENT_LEN);
+		this->output = chunk_clone(chunk_skip(this->output, MAX_TLS_FRAGMENT_LEN));
+		return NEED_MORE;
+	}
+	return status;
+}
+
+METHOD(tls_fragmentation_t, destroy, void,
+	private_tls_fragmentation_t *this)
+{
+	free(this->input.ptr);
+	free(this->output.ptr);
+	free(this);
+}
+
+/**
+ * See header
+ */
+tls_fragmentation_t *tls_fragmentation_create(tls_handshake_t *handshake)
+{
+	private_tls_fragmentation_t *this;
+
+	INIT(this,
+		.public = {
+			.process = _process,
+			.build = _build,
+			.destroy = _destroy,
+		},
+		.handshake = handshake,
+	);
+
+	return &this->public;
+}