1 files changed, 327 insertions, 0 deletions
diff --git a/src/libcharon/plugins/eap_gtc/eap_gtc.c b/src/libcharon/plugins/eap_gtc/eap_gtc.c
new file mode 100644
index 000000000..c7f55fa70
--- /dev/null
+++ b/src/libcharon/plugins/eap_gtc/eap_gtc.c
@@ -0,0 +1,327 @@
+/*
+ * Copyright (C) 2007 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_gtc.h"
+
+#include <daemon.h>
+#include <library.h>
+#include <crypto/hashers/hasher.h>
+
+#include <security/pam_appl.h>
+
+#define GTC_REQUEST_MSG "password"
+#define GTC_PAM_SERVICE "login"
+
+typedef struct private_eap_gtc_t private_eap_gtc_t;
+
+/**
+ * Private data of an eap_gtc_t object.
+ */
+struct private_eap_gtc_t {
+
+	/**
+	 * Public authenticator_t interface.
+	 */
+	eap_gtc_t public;
+
+	/**
+	 * ID of the server
+	 */
+	identification_t *server;
+
+	/**
+	 * ID of the peer
+	 */
+	identification_t *peer;
+
+	/**
+	 * EAP message identififier
+	 */
+	u_int8_t identifier;
+};
+
+typedef struct eap_gtc_header_t eap_gtc_header_t;
+
+/**
+ * packed eap GTC header struct
+ */
+struct eap_gtc_header_t {
+	/** 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;
+	/** type data */
+	u_int8_t data[];
+} __attribute__((__packed__));
+
+/**
+ * Implementation of eap_method_t.initiate for the peer
+ */
+static status_t initiate_peer(private_eap_gtc_t *this, eap_payload_t **out)
+{
+	/* peer never initiates */
+	return FAILED;
+}
+
+/**
+ * PAM conv callback function
+ */
+static int auth_conv(int num_msg, const struct pam_message **msg,
+					 struct pam_response **resp, char *password)
+{
+	struct pam_response *response;
+
+	if (num_msg != 1)
+	{
+		return PAM_CONV_ERR;
+	}
+	response = malloc(sizeof(struct pam_response));
+	response->resp = strdup(password);
+	response->resp_retcode = 0;
+	*resp = response;
+	return PAM_SUCCESS;
+}
+
+/**
+ * Authenticate a username/password using PAM
+ */
+static bool authenticate(char *service, char *user, char *password)
+{
+	pam_handle_t *pamh = NULL;
+	static struct pam_conv conv;
+	int ret;
+
+	conv.conv = (void*)auth_conv;
+	conv.appdata_ptr = password;
+
+	ret = pam_start(service, user, &conv, &pamh);
+	if (ret != PAM_SUCCESS)
+	{
+		DBG1(DBG_IKE, "EAP-GTC pam_start failed: %s",
+			 pam_strerror(pamh, ret));
+		return FALSE;
+	}
+	ret = pam_authenticate(pamh, 0);
+	if (ret == PAM_SUCCESS)
+	{
+		ret = pam_acct_mgmt(pamh, 0);
+		if (ret != PAM_SUCCESS)
+		{
+			DBG1(DBG_IKE, "EAP-GTC pam_acct_mgmt failed: %s",
+				 pam_strerror(pamh, ret));
+		}
+	}
+	else
+	{
+		DBG1(DBG_IKE, "EAP-GTC pam_authenticate failed: %s",
+			 pam_strerror(pamh, ret));
+	}
+	pam_end(pamh, ret);
+	return ret == PAM_SUCCESS;
+}
+
+/**
+ * Implementation of eap_method_t.initiate for the server
+ */
+static status_t initiate_server(private_eap_gtc_t *this, eap_payload_t **out)
+{
+	eap_gtc_header_t *req;
+	size_t len;
+
+	len = strlen(GTC_REQUEST_MSG);
+	req = alloca(sizeof(eap_gtc_header_t) + len);
+	req->length = htons(sizeof(eap_gtc_header_t) + len);
+	req->code = EAP_REQUEST;
+	req->identifier = this->identifier;
+	req->type = EAP_GTC;
+	memcpy(req->data, GTC_REQUEST_MSG, len);
+
+	*out = eap_payload_create_data(chunk_create((void*)req,
+								   sizeof(eap_gtc_header_t) + len));
+	return NEED_MORE;
+}
+
+/**
+ * Implementation of eap_method_t.process for the peer
+ */
+static status_t process_peer(private_eap_gtc_t *this,
+							 eap_payload_t *in, eap_payload_t **out)
+{
+	eap_gtc_header_t *res;
+	shared_key_t *shared;
+	chunk_t key;
+	size_t len;
+
+	shared = charon->credentials->get_shared(charon->credentials, SHARED_EAP,
+											 this->peer, this->server);
+	if (shared == NULL)
+	{
+		DBG1(DBG_IKE, "no EAP key found for '%Y' - '%Y'",
+			 this->peer, this->server);
+		return FAILED;
+	}
+	key = shared->get_key(shared);
+	len = key.len;
+
+	/* TODO: According to the draft we should "SASLprep" password, RFC4013. */
+
+	res = alloca(sizeof(eap_gtc_header_t) + len);
+	res->length = htons(sizeof(eap_gtc_header_t) + len);
+	res->code = EAP_RESPONSE;
+	res->identifier = in->get_identifier(in);
+	res->type = EAP_GTC;
+	memcpy(res->data, key.ptr, len);
+
+	shared->destroy(shared);
+
+	*out = eap_payload_create_data(chunk_create((void*)res,
+								   sizeof(eap_gtc_header_t) + len));
+	return NEED_MORE;
+}
+
+/**
+ * Implementation of eap_method_t.process for the server
+ */
+static status_t process_server(private_eap_gtc_t *this,
+							   eap_payload_t *in, eap_payload_t **out)
+{
+	chunk_t data, encoding;
+	char *user, *password, *service, *pos;
+
+	data = chunk_skip(in->get_data(in), 5);
+	if (this->identifier != in->get_identifier(in) || !data.len)
+	{
+		DBG1(DBG_IKE, "received invalid EAP-GTC message");
+		return FAILED;
+	}
+
+	encoding = this->peer->get_encoding(this->peer);
+	/* if a RFC822_ADDR id is provided, we use the username part only */
+	pos = memchr(encoding.ptr, '@', encoding.len);
+	if (pos)
+	{
+		encoding.len = (u_char*)pos - encoding.ptr;
+	}
+	user = alloca(encoding.len + 1);
+	memcpy(user, encoding.ptr, encoding.len);
+	user[encoding.len] = '\0';
+
+	password = alloca(data.len + 1);
+	memcpy(password, data.ptr, data.len);
+	password[data.len] = '\0';
+
+	service = lib->settings->get_str(lib->settings,
+						"charon.plugins.eap-gtc.pam_service", GTC_PAM_SERVICE);
+
+	if (!authenticate(service, user, password))
+	{
+		return FAILED;
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implementation of eap_method_t.get_type.
+ */
+static eap_type_t get_type(private_eap_gtc_t *this, u_int32_t *vendor)
+{
+	*vendor = 0;
+	return EAP_GTC;
+}
+
+/**
+ * Implementation of eap_method_t.get_msk.
+ */
+static status_t get_msk(private_eap_gtc_t *this, chunk_t *msk)
+{
+	return FAILED;
+}
+
+/**
+ * Implementation of eap_method_t.is_mutual.
+ */
+static bool is_mutual(private_eap_gtc_t *this)
+{
+	return FALSE;
+}
+
+/**
+ * Implementation of eap_method_t.destroy.
+ */
+static void destroy(private_eap_gtc_t *this)
+{
+	this->peer->destroy(this->peer);
+	this->server->destroy(this->server);
+	free(this);
+}
+
+/**
+ * Generic constructor
+ */
+static private_eap_gtc_t *eap_gtc_create_generic(identification_t *server,
+												 identification_t *peer)
+{
+	private_eap_gtc_t *this = malloc_thing(private_eap_gtc_t);
+
+	this->public.eap_method_interface.initiate = NULL;
+	this->public.eap_method_interface.process = NULL;
+	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;
+
+	/* private data */
+	this->peer = peer->clone(peer);
+	this->server = server->clone(server);
+	this->identifier = 0;
+
+	return this;
+}
+
+/*
+ * see header
+ */
+eap_gtc_t *eap_gtc_create_server(identification_t *server, identification_t *peer)
+{
+	private_eap_gtc_t *this = eap_gtc_create_generic(server, peer);
+
+	this->public.eap_method_interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))initiate_server;
+	this->public.eap_method_interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))process_server;
+
+	/* generate a non-zero identifier */
+	do {
+		this->identifier = random();
+	} while (!this->identifier);
+
+	return &this->public;
+}
+
+/*
+ * see header
+ */
+eap_gtc_t *eap_gtc_create_peer(identification_t *server, identification_t *peer)
+{
+	private_eap_gtc_t *this = eap_gtc_create_generic(server, peer);
+
+	this->public.eap_method_interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))initiate_peer;
+	this->public.eap_method_interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))process_peer;
+
+	return &this->public;
+}
+