1 files changed, 159 insertions, 0 deletions
diff --git a/src/libtls/tls_aead_null.c b/src/libtls/tls_aead_null.c
new file mode 100644
index 000000000..595b64000
--- /dev/null
+++ b/src/libtls/tls_aead_null.c
@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2014 Martin Willi
+ * Copyright (C) 2014 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_aead.h"
+
+typedef struct private_tls_aead_t private_tls_aead_t;
+
+/**
+ * Private data of an tls_aead_t object.
+ */
+struct private_tls_aead_t {
+
+	/**
+	 * Public tls_aead_t interface.
+	 */
+	tls_aead_t public;
+
+	/**
+	 * traditional signer
+	 */
+	signer_t *signer;
+};
+
+/**
+ * Associated header data to create signature over
+ */
+typedef struct __attribute__((__packed__)) {
+	u_int64_t seq;
+	u_int8_t type;
+	u_int16_t version;
+	u_int16_t length;
+} sigheader_t;
+
+METHOD(tls_aead_t, encrypt, bool,
+	private_tls_aead_t *this, tls_version_t version,
+	tls_content_type_t type, u_int64_t seq, chunk_t *data)
+{
+	chunk_t assoc, mac;
+	sigheader_t hdr;
+
+	hdr.type = type;
+	htoun64(&hdr.seq, seq);
+	htoun16(&hdr.version, version);
+	htoun16(&hdr.length, data->len);
+
+	assoc = chunk_from_thing(hdr);
+	if (!this->signer->get_signature(this->signer, assoc, NULL) ||
+		!this->signer->allocate_signature(this->signer, *data, &mac))
+	{
+		return FALSE;
+	}
+	*data = chunk_cat("mm", *data, mac);
+	return TRUE;
+}
+
+METHOD(tls_aead_t, decrypt, bool,
+	private_tls_aead_t *this, tls_version_t version,
+	tls_content_type_t type, u_int64_t seq, chunk_t *data)
+{
+	chunk_t assoc, mac;
+	sigheader_t hdr;
+
+	mac.len = this->signer->get_block_size(this->signer);
+	if (data->len < mac.len)
+	{
+		return FALSE;
+	}
+	mac = chunk_skip(*data, data->len - mac.len);
+	data->len -= mac.len;
+
+	hdr.type = type;
+	htoun64(&hdr.seq, seq);
+	htoun16(&hdr.version, version);
+	htoun16(&hdr.length, data->len);
+
+	assoc = chunk_from_thing(hdr);
+	if (!this->signer->get_signature(this->signer, assoc, NULL) ||
+		!this->signer->verify_signature(this->signer, *data, mac))
+	{
+		return FALSE;
+	}
+	return TRUE;
+}
+
+METHOD(tls_aead_t, get_mac_key_size, size_t,
+	private_tls_aead_t *this)
+{
+	return this->signer->get_key_size(this->signer);
+}
+
+METHOD(tls_aead_t, get_encr_key_size, size_t,
+	private_tls_aead_t *this)
+{
+	return 0;
+}
+
+METHOD(tls_aead_t, get_iv_size, size_t,
+	private_tls_aead_t *this)
+{
+	return 0;
+}
+
+METHOD(tls_aead_t, set_keys, bool,
+	private_tls_aead_t *this, chunk_t mac, chunk_t encr, chunk_t iv)
+{
+	if (iv.len || encr.len)
+	{
+		return FALSE;
+	}
+	return this->signer->set_key(this->signer, mac);
+}
+
+METHOD(tls_aead_t, destroy, void,
+	private_tls_aead_t *this)
+{
+	this->signer->destroy(this->signer);
+	free(this);
+}
+
+/**
+ * See header
+ */
+tls_aead_t *tls_aead_create_null(integrity_algorithm_t alg)
+{
+	private_tls_aead_t *this;
+
+	INIT(this,
+		.public = {
+			.encrypt = _encrypt,
+			.decrypt = _decrypt,
+			.get_mac_key_size = _get_mac_key_size,
+			.get_encr_key_size = _get_encr_key_size,
+			.get_iv_size = _get_iv_size,
+			.set_keys = _set_keys,
+			.destroy = _destroy,
+		},
+		.signer = lib->crypto->create_signer(lib->crypto, alg),
+	);
+
+	if (!this->signer)
+	{
+		free(this);
+		return NULL;
+	}
+
+	return &this->public;
+}