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/*
*
* PPP library with GLib integration
*
* Copyright (C) 2009-2010 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <termios.h>
#include <arpa/inet.h>
#include <glib.h>
#include "gatppp.h"
#include "ppp.h"
struct chap_header {
guint8 code;
guint8 identifier;
guint16 length;
guint8 data[0];
} __attribute__((packed));
struct chap_data {
guint8 method;
struct auth_data *auth;
};
enum chap_code {
CHALLENGE=1,
RESPONSE,
SUCCESS,
FAILURE
};
void auth_set_credentials(struct auth_data *data, const char *username,
const char *password)
{
if (data == NULL)
return;
g_free(data->username);
data->username = g_strdup(username);
g_free(data->password);
data->password = g_strdup(password);
}
static void chap_process_challenge(struct auth_data *auth, guint8 *packet)
{
struct chap_header *header = (struct chap_header *) packet;
struct chap_header *response;
struct chap_data *data = auth->proto_data;
GChecksum *checksum;
gchar *secret = data->auth->password;
guint16 response_length;
struct ppp_header *ppp_packet;
gsize digest_len;
/* create a checksum over id, secret, and challenge */
checksum = g_checksum_new(data->method);
if (!checksum)
return;
g_checksum_update(checksum, &header->identifier, 1);
g_checksum_update(checksum, (guchar *) secret, strlen(secret));
g_checksum_update(checksum, &header->data[1], header->data[0]);
/* transmit a response packet */
/*
* allocate space for the header, the checksum, and the ppp header,
* and the value size byte
*/
digest_len = g_checksum_type_get_length(data->method);
response_length = digest_len + sizeof(*header) + 1;
ppp_packet = g_try_malloc0(response_length + 2);
if (!ppp_packet)
goto challenge_out;
/* add our protocol information */
ppp_packet->proto = htons(CHAP_PROTOCOL);
response = (struct chap_header *) &ppp_packet->info;
if (response) {
response->code = RESPONSE;
response->identifier = header->identifier;
response->length = htons(response_length);
response->data[0] = digest_len;
g_checksum_get_digest(checksum, &response->data[1],
(gsize *) &response->data[0]);
/* leave the name empty? */
}
/* transmit the packet */
ppp_transmit(auth->ppp, (guint8 *) ppp_packet, response_length);
challenge_out:
g_checksum_free(checksum);
}
static void chap_process_success(struct auth_data *data, guint8 *packet)
{
ppp_generate_event(data->ppp, PPP_SUCCESS);
}
static void chap_process_failure(struct auth_data *data, guint8 *packet)
{
struct chap_header *header = (struct chap_header *) packet;
g_print("Failed to authenticate, message %s\n", header->data);
}
/*
* parse the packet
*/
static void chap_process_packet(gpointer priv, guint8 *new_packet)
{
struct auth_data *data = priv;
guint8 code = new_packet[0];
switch (code) {
case CHALLENGE:
chap_process_challenge(data, new_packet);
break;
case RESPONSE:
g_print("Oops, received RESPONSE, but I've not implemented\n");
break;
case SUCCESS:
chap_process_success(data, new_packet);
break;
case FAILURE:
chap_process_failure(data, new_packet);
break;
default:
g_print("Unknown auth code\n");
break;
}
}
struct ppp_packet_handler chap_packet_handler = {
.proto = CHAP_PROTOCOL,
.handler = chap_process_packet,
};
static void chap_free(struct auth_data *auth)
{
/* TBD unregister protocol handler */
g_free(auth->proto_data);
}
static struct chap_data *chap_new(struct auth_data *auth, guint8 method)
{
struct chap_data *data;
data = g_try_malloc0(sizeof(*data));
if (!data)
return NULL;
data->auth = auth;
switch (method) {
case MD5:
data->method = G_CHECKSUM_MD5;
break;
default:
g_print("Unknown method\n");
}
/* register packet handler for CHAP protocol */
chap_packet_handler.priv = auth;
ppp_register_packet_handler(&chap_packet_handler);
return data;
}
void auth_set_proto(struct auth_data *data, guint16 proto, guint8 method)
{
if (data == NULL)
return;
switch (proto) {
case CHAP_PROTOCOL:
data->proto_data = (gpointer) chap_new(data, method);
break;
default:
g_print("Unknown auth protocol 0x%x\n", proto);
}
}
void auth_free(struct auth_data *data)
{
if (data == NULL)
return;
chap_free(data);
g_free(data);
}
struct auth_data *auth_new(GAtPPP *ppp)
{
struct auth_data *data;
data = g_try_malloc0(sizeof(*data));
if (!data)
return NULL;
data->ppp = ppp;
return data;
}
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