1 files changed, 312 insertions, 0 deletions
diff --git a/src/libcharon/plugins/eap_radius/eap_radius.c b/src/libcharon/plugins/eap_radius/eap_radius.c
new file mode 100644
index 000000000..f041fda54
--- /dev/null
+++ b/src/libcharon/plugins/eap_radius/eap_radius.c
@@ -0,0 +1,312 @@
+/*
+ * 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 "eap_radius.h"
+
+#include "radius_message.h"
+#include "radius_client.h"
+
+#include <daemon.h>
+
+typedef struct private_eap_radius_t private_eap_radius_t;
+
+/**
+ * Private data of an eap_radius_t object.
+ */
+struct private_eap_radius_t {
+
+	/**
+	 * Public authenticator_t interface.
+	 */
+	eap_radius_t public;
+
+	/**
+	 * ID of the server
+	 */
+	identification_t *server;
+
+	/**
+	 * ID of the peer
+	 */
+	identification_t *peer;
+
+	/**
+	 * EAP method type we are proxying
+	 */
+	eap_type_t type;
+
+	/**
+	 * EAP vendor, if any
+	 */
+	u_int32_t vendor;
+
+	/**
+	 * EAP MSK, if method established one
+	 */
+	chunk_t msk;
+
+	/**
+	 * RADIUS client instance
+	 */
+	radius_client_t *client;
+
+	/**
+	 * TRUE to use EAP-Start, FALSE to send EAP-Identity Response directly
+	 */
+	bool eap_start;
+
+	/**
+	 * Prefix to prepend to EAP identity
+	 */
+	char *id_prefix;
+};
+
+/**
+ * Add EAP-Identity to RADIUS message
+ */
+static void add_eap_identity(private_eap_radius_t *this,
+							 radius_message_t *request)
+{
+	struct {
+		/** EAP code (REQUEST/RESPONSE) */
+		u_int8_t code;
+		/** unique message identifier */
+		u_int8_t identifier;
+		/** length of whole message */
+		u_int16_t length;
+		/** EAP type */
+		u_int8_t type;
+		/** identity data */
+		u_int8_t data[];
+	} __attribute__((__packed__)) *hdr;
+	chunk_t id, prefix;
+	size_t len;
+
+	id = this->peer->get_encoding(this->peer);
+	prefix = chunk_create(this->id_prefix, strlen(this->id_prefix));
+	len = sizeof(*hdr) + prefix.len + id.len;
+
+	hdr = alloca(len);
+	hdr->code = EAP_RESPONSE;
+	hdr->identifier = 0;
+	hdr->length = htons(len);
+	hdr->type = EAP_IDENTITY;
+	memcpy(hdr->data, prefix.ptr, prefix.len);
+	memcpy(hdr->data + prefix.len, id.ptr, id.len);
+
+	request->add(request, RAT_EAP_MESSAGE, chunk_create((u_char*)hdr, len));
+}
+
+/**
+ * Copy EAP-Message attribute from RADIUS message to an new EAP payload
+ */
+static bool radius2ike(private_eap_radius_t *this,
+					   radius_message_t *msg, eap_payload_t **out)
+{
+	enumerator_t *enumerator;
+	eap_payload_t *payload;
+	chunk_t data, message = chunk_empty;
+	int type;
+
+	enumerator = msg->create_enumerator(msg);
+	while (enumerator->enumerate(enumerator, &type, &data))
+	{
+		if (type == RAT_EAP_MESSAGE && data.len)
+		{
+			message = chunk_cat("mc", message, data);
+		}
+	}
+	enumerator->destroy(enumerator);
+	if (message.len)
+	{
+		*out = payload = eap_payload_create_data(message);
+		free(message.ptr);
+		/* apply EAP method selected by RADIUS server */
+		this->type = payload->get_type(payload, &this->vendor);
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * Implementation of eap_method_t.initiate
+ */
+static status_t initiate(private_eap_radius_t *this, eap_payload_t **out)
+{
+	radius_message_t *request, *response;
+	status_t status = FAILED;
+	chunk_t username;
+
+	request = radius_message_create_request();
+	username = chunk_create(this->id_prefix, strlen(this->id_prefix));
+	username = chunk_cata("cc", username, this->peer->get_encoding(this->peer));
+	request->add(request, RAT_USER_NAME, username);
+
+	if (this->eap_start)
+	{
+		request->add(request, RAT_EAP_MESSAGE, chunk_empty);
+	}
+	else
+	{
+		add_eap_identity(this, request);
+	}
+
+	response = this->client->request(this->client, request);
+	if (response)
+	{
+		if (radius2ike(this, response, out))
+		{
+			status = NEED_MORE;
+		}
+		response->destroy(response);
+	}
+	request->destroy(request);
+	return status;
+}
+
+/**
+ * Implementation of eap_method_t.process
+ */
+static status_t process(private_eap_radius_t *this,
+						eap_payload_t *in, eap_payload_t **out)
+{
+	radius_message_t *request, *response;
+	status_t status = FAILED;
+	chunk_t data;
+
+	request = radius_message_create_request();
+	request->add(request, RAT_USER_NAME, this->peer->get_encoding(this->peer));
+	data = in->get_data(in);
+	/* fragment data suitable for RADIUS (not more than 253 bytes) */
+	while (data.len > 253)
+	{
+		request->add(request, RAT_EAP_MESSAGE, chunk_create(data.ptr, 253));
+		data = chunk_skip(data, 253);
+	}
+	request->add(request, RAT_EAP_MESSAGE, data);
+
+	response = this->client->request(this->client, request);
+	if (response)
+	{
+		switch (response->get_code(response))
+		{
+			case RMC_ACCESS_CHALLENGE:
+				if (radius2ike(this, response, out))
+				{
+					status = NEED_MORE;
+					break;
+				}
+				status = FAILED;
+				break;
+			case RMC_ACCESS_ACCEPT:
+				this->msk = this->client->decrypt_msk(this->client,
+													  response, request);
+				status = SUCCESS;
+				break;
+			case RMC_ACCESS_REJECT:
+			default:
+				DBG1(DBG_CFG, "received %N from RADIUS server",
+					 radius_message_code_names, response->get_code(response));
+				status = FAILED;
+				break;
+		}
+		response->destroy(response);
+	}
+	request->destroy(request);
+	return status;
+}
+
+/**
+ * Implementation of eap_method_t.get_type.
+ */
+static eap_type_t get_type(private_eap_radius_t *this, u_int32_t *vendor)
+{
+	*vendor = this->vendor;
+	return this->type;
+}
+
+/**
+ * Implementation of eap_method_t.get_msk.
+ */
+static status_t get_msk(private_eap_radius_t *this, chunk_t *msk)
+{
+	if (this->msk.ptr)
+	{
+		*msk = this->msk;
+		return SUCCESS;
+	}
+	return FAILED;
+}
+
+/**
+ * Implementation of eap_method_t.is_mutual.
+ */
+static bool is_mutual(private_eap_radius_t *this)
+{
+	switch (this->type)
+	{
+		case EAP_AKA:
+		case EAP_SIM:
+			return TRUE;
+		default:
+			return FALSE;
+	}
+}
+
+/**
+ * Implementation of eap_method_t.destroy.
+ */
+static void destroy(private_eap_radius_t *this)
+{
+	this->peer->destroy(this->peer);
+	this->server->destroy(this->server);
+	this->client->destroy(this->client);
+	chunk_clear(&this->msk);
+	free(this);
+}
+
+/**
+ * Generic constructor
+ */
+eap_radius_t *eap_radius_create(identification_t *server, identification_t *peer)
+{
+	private_eap_radius_t *this = malloc_thing(private_eap_radius_t);
+
+	this->public.eap_method_interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))initiate;
+	this->public.eap_method_interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))process;
+	this->public.eap_method_interface.get_type = (eap_type_t(*)(eap_method_t*,u_int32_t*))get_type;
+	this->public.eap_method_interface.is_mutual = (bool(*)(eap_method_t*))is_mutual;
+	this->public.eap_method_interface.get_msk = (status_t(*)(eap_method_t*,chunk_t*))get_msk;
+	this->public.eap_method_interface.destroy = (void(*)(eap_method_t*))destroy;
+
+	this->client = radius_client_create();
+	if (!this->client)
+	{
+		free(this);
+		return NULL;
+	}
+	this->peer = peer->clone(peer);
+	this->server = server->clone(server);
+	/* initially EAP_RADIUS, but is set to the method selected by RADIUS */
+	this->type = EAP_RADIUS;
+	this->vendor = 0;
+	this->msk = chunk_empty;
+	this->eap_start = lib->settings->get_bool(lib->settings,
+								"charon.plugins.eap-radius.eap_start", FALSE);
+	this->id_prefix = lib->settings->get_str(lib->settings,
+								"charon.plugins.eap-radius.id_prefix", "");
+	return &this->public;
+}
+