1 files changed, 394 insertions, 0 deletions
diff --git a/src/charon/plugins/eap_aka/eap_aka_server.c b/src/charon/plugins/eap_aka/eap_aka_server.c
new file mode 100644
index 000000000..6a2f970ab
--- /dev/null
+++ b/src/charon/plugins/eap_aka/eap_aka_server.c
@@ -0,0 +1,394 @@
+/*
+ * Copyright (C) 2006-2009 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_aka_server.h"
+
+#include <daemon.h>
+#include <library.h>
+
+#include <simaka_message.h>
+#include <simaka_crypto.h>
+
+typedef struct private_eap_aka_server_t private_eap_aka_server_t;
+
+/**
+ * Private data of an eap_aka_server_t object.
+ */
+struct private_eap_aka_server_t {
+
+	/**
+	 * Public authenticator_t interface.
+	 */
+	eap_aka_server_t public;
+
+	/**
+	 * EAP-AKA crypto helper
+	 */
+	simaka_crypto_t *crypto;
+
+	/**
+	 * ID of the peer
+	 */
+	identification_t *peer;
+
+	/**
+	 * EAP identifier value
+	 */
+	u_int8_t identifier;
+
+	/**
+	 * MSK
+	 */
+	chunk_t msk;
+
+	/**
+	 * Expected Result XRES
+	 */
+	chunk_t xres;
+
+	/**
+	 * Random value RAND
+	 */
+	chunk_t rand;
+};
+
+/**
+ * Check if an unknown attribute is skippable
+ */
+static bool attribute_skippable(simaka_attribute_t attribute)
+{
+	if (attribute >= 0 && attribute <= 127)
+	{
+		DBG1(DBG_IKE, "ignoring skippable attribute %N",
+			 simaka_attribute_names, attribute);
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * Implementation of eap_method_t.initiate
+ */
+static status_t initiate(private_eap_aka_server_t *this, eap_payload_t **out)
+{
+	simaka_message_t *message;
+	enumerator_t *enumerator;
+	sim_provider_t *provider;
+	char rand[AKA_RAND_LEN], xres[AKA_RES_LEN];
+	char ck[AKA_CK_LEN], ik[AKA_IK_LEN], autn[AKA_AUTN_LEN];
+	chunk_t data;
+	bool found = FALSE;
+
+	enumerator = charon->sim->create_provider_enumerator(charon->sim);
+	while (enumerator->enumerate(enumerator, &provider))
+	{
+		if (provider->get_quintuplet(provider, this->peer,
+									 rand, xres, ck, ik, autn))
+		{
+			found = TRUE;
+			break;
+		}
+	}
+	enumerator->destroy(enumerator);
+	if (!found)
+	{
+		DBG1(DBG_IKE, "no AKA provider found with quintuplets for '%Y'",
+			 this->peer);
+		return FAILED;
+	}
+
+	data = chunk_cata("cc", chunk_create(ik, AKA_IK_LEN),
+					  chunk_create(ck, AKA_CK_LEN));
+	free(this->msk.ptr);
+	this->msk = this->crypto->derive_keys_full(this->crypto, this->peer, data);
+	this->rand = chunk_clone(chunk_create(rand, AKA_RAND_LEN));
+	this->xres = chunk_clone(chunk_create(xres, AKA_RES_LEN));
+
+	message = simaka_message_create(TRUE, this->identifier++,
+									EAP_AKA, AKA_CHALLENGE);
+	message->add_attribute(message, AT_RAND, this->rand);
+	message->add_attribute(message, AT_AUTN, chunk_create(autn, AKA_AUTN_LEN));
+	*out = message->generate(message, this->crypto, chunk_empty);
+	message->destroy(message);
+	return NEED_MORE;
+}
+
+/**
+ * Process EAP-AKA/Response/Challenge message
+ */
+static status_t process_challenge(private_eap_aka_server_t *this,
+								  simaka_message_t *in)
+{
+	enumerator_t *enumerator;
+	simaka_attribute_t type;
+	chunk_t data, res = chunk_empty;
+
+	enumerator = in->create_attribute_enumerator(in);
+	while (enumerator->enumerate(enumerator, &type, &data))
+	{
+		switch (type)
+		{
+			case AT_RES:
+				res = data;
+				break;
+			default:
+				if (!attribute_skippable(type))
+				{
+					enumerator->destroy(enumerator);
+					DBG1(DBG_IKE, "found non skippable attribute %N",
+						 simaka_attribute_names, type);
+					return FAILED;
+				}
+				break;
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	/* verify MAC of EAP message, AT_MAC */
+	if (!in->verify(in, this->crypto, chunk_empty))
+	{
+		DBG1(DBG_IKE, "AT_MAC verification failed");
+		return FAILED;
+	}
+	/* compare received RES against stored XRES */
+	if (!chunk_equals(res, this->xres))
+	{
+		DBG1(DBG_IKE, "received RES does not match XRES");
+		return FAILED;
+	}
+	return SUCCESS;
+}
+
+/**
+ * Process EAP-AKA/Response/SynchronizationFailure message
+ */
+static status_t process_synchronize(private_eap_aka_server_t *this,
+									simaka_message_t *in, eap_payload_t **out)
+{
+	sim_provider_t *provider;
+	enumerator_t *enumerator;
+	simaka_attribute_t type;
+	chunk_t data, auts = chunk_empty;
+	bool found = FALSE;
+
+	DBG1(DBG_IKE, "received synchronization request, retrying...");
+
+	enumerator = in->create_attribute_enumerator(in);
+	while (enumerator->enumerate(enumerator, &type, &data))
+	{
+		switch (type)
+		{
+			case AT_AUTS:
+				auts = data;
+				break;
+			default:
+				if (!attribute_skippable(type))
+				{
+					enumerator->destroy(enumerator);
+					DBG1(DBG_IKE, "found non skippable attribute %N",
+						 simaka_attribute_names, type);
+					return FAILED;
+				}
+				break;
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	if (!auts.len)
+	{
+		DBG1(DBG_IKE, "synchronization request didn't contain usable AUTS");
+		return FAILED;
+	}
+
+	enumerator = charon->sim->create_provider_enumerator(charon->sim);
+	while (enumerator->enumerate(enumerator, &provider))
+	{
+		if (provider->resync(provider, this->peer, this->rand.ptr, auts.ptr))
+		{
+			found = TRUE;
+			break;
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	if (!found)
+	{
+		DBG1(DBG_IKE, "no AKA provider found supporting "
+			 "resynchronization for '%Y'", this->peer);
+		return FAILED;
+	}
+	return initiate(this, out);
+}
+
+/**
+ * Process EAP-AKA/Response/ClientErrorCode message
+ */
+static status_t process_client_error(private_eap_aka_server_t *this,
+									 simaka_message_t *in)
+{
+	enumerator_t *enumerator;
+	simaka_attribute_t type;
+	chunk_t data;
+
+	enumerator = in->create_attribute_enumerator(in);
+	while (enumerator->enumerate(enumerator, &type, &data))
+	{
+		if (type == AT_CLIENT_ERROR_CODE)
+		{
+			u_int16_t code;
+
+			memcpy(&code, data.ptr, sizeof(code));
+			DBG1(DBG_IKE, "received EAP-AKA client error '%N'",
+				 simaka_client_error_names, ntohs(code));
+		}
+		else if (!simaka_attribute_skippable(type))
+		{
+			break;
+		}
+	}
+	enumerator->destroy(enumerator);
+	return FAILED;
+}
+
+/**
+ * Process EAP-AKA/Response/AuthenticationReject message
+ */
+static status_t process_authentication_reject(private_eap_aka_server_t *this,
+											  simaka_message_t *in)
+{
+	DBG1(DBG_IKE, "received %N, authentication failed",
+		 simaka_subtype_names, in->get_subtype(in));
+	return FAILED;
+}
+
+/**
+ * Implementation of eap_method_t.process
+ */
+static status_t process(private_eap_aka_server_t *this,
+						eap_payload_t *in, eap_payload_t **out)
+{
+	simaka_message_t *message;
+	status_t status;
+
+	message = simaka_message_create_from_payload(in);
+	if (!message)
+	{
+		return FAILED;
+	}
+	if (!message->parse(message, this->crypto))
+	{
+		message->destroy(message);
+		return FAILED;
+	}
+	switch (message->get_subtype(message))
+	{
+		case AKA_CHALLENGE:
+			status = process_challenge(this, message);
+			break;
+		case AKA_SYNCHRONIZATION_FAILURE:
+			status = process_synchronize(this, message, out);
+			break;
+		case AKA_CLIENT_ERROR:
+			status = process_client_error(this, message);
+			break;
+		case AKA_AUTHENTICATION_REJECT:
+			status = process_authentication_reject(this, message);
+			break;
+		default:
+			DBG1(DBG_IKE, "unable to process EAP-AKA subtype %N",
+				 simaka_subtype_names, message->get_subtype(message));
+			status = FAILED;
+			break;
+	}
+	message->destroy(message);
+	return status;
+}
+
+/**
+ * Implementation of eap_method_t.get_type.
+ */
+static eap_type_t get_type(private_eap_aka_server_t *this, u_int32_t *vendor)
+{
+	*vendor = 0;
+	return EAP_AKA;
+}
+
+/**
+ * Implementation of eap_method_t.get_msk.
+ */
+static status_t get_msk(private_eap_aka_server_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_aka_server_t *this)
+{
+	return TRUE;
+}
+
+/**
+ * Implementation of eap_method_t.destroy.
+ */
+static void destroy(private_eap_aka_server_t *this)
+{
+	this->crypto->destroy(this->crypto);
+	this->peer->destroy(this->peer);
+	free(this->msk.ptr);
+	free(this->xres.ptr);
+	free(this->rand.ptr);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+eap_aka_server_t *eap_aka_server_create(identification_t *server,
+										identification_t *peer)
+{
+	private_eap_aka_server_t *this = malloc_thing(private_eap_aka_server_t);
+
+	this->public.interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))initiate;
+	this->public.interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))process;
+	this->public.interface.get_type = (eap_type_t(*)(eap_method_t*,u_int32_t*))get_type;
+	this->public.interface.is_mutual = (bool(*)(eap_method_t*))is_mutual;
+	this->public.interface.get_msk = (status_t(*)(eap_method_t*,chunk_t*))get_msk;
+	this->public.interface.destroy = (void(*)(eap_method_t*))destroy;
+
+	this->crypto = simaka_crypto_create();
+	if (!this->crypto)
+	{
+		free(this);
+		return NULL;
+	}
+	this->peer = peer->clone(peer);
+	this->msk = chunk_empty;
+	this->xres = chunk_empty;
+	this->rand = chunk_empty;
+	/* generate a non-zero identifier */
+	do {
+		this->identifier = random();
+	} while (!this->identifier);
+
+	return &this->public;
+}
+