freebsd-nq/contrib/hostapd/radius_server.c

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2005-06-05 22:35:03 +00:00
/*
* hostapd / RADIUS authentication server
* Copyright (c) 2005, Jouni Malinen <jkmaline@cc.hut.fi>
*
* 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.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*/
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <net/if.h>
#include "common.h"
#include "radius.h"
#include "eloop.h"
#include "config.h"
#include "eap.h"
#include "radius_server.h"
#define RADIUS_SESSION_TIMEOUT 60
#define RADIUS_MAX_SESSION 100
#define RADIUS_MAX_MSG_LEN 3000
static struct eapol_callbacks radius_server_eapol_cb;
struct radius_client;
struct radius_server_data;
struct radius_session {
struct radius_session *next;
struct radius_client *client;
struct radius_server_data *server;
unsigned int sess_id;
struct eap_sm *eap;
u8 *eapKeyData, *eapReqData;
size_t eapKeyDataLen, eapReqDataLen;
Boolean eapSuccess, eapRestart, eapFail, eapResp, eapReq, eapNoReq;
Boolean portEnabled, eapTimeout;
};
struct radius_client {
struct radius_client *next;
struct in_addr addr;
struct in_addr mask;
char *shared_secret;
int shared_secret_len;
struct radius_session *sessions;
};
struct radius_server_data {
int auth_sock;
struct radius_client *clients;
struct radius_server_session *sessions;
unsigned int next_sess_id;
void *hostapd_conf;
int num_sess;
void *eap_sim_db_priv;
void *ssl_ctx;
};
extern int wpa_debug_level;
#define RADIUS_DEBUG(args...) \
wpa_printf(MSG_DEBUG, "RADIUS SRV: " args)
#define RADIUS_ERROR(args...) \
wpa_printf(MSG_ERROR, "RADIUS SRV: " args)
#define RADIUS_DUMP(args...) \
wpa_hexdump(MSG_MSGDUMP, "RADIUS SRV: " args)
#define RADIUS_DUMP_ASCII(args...) \
wpa_hexdump_ascii(MSG_MSGDUMP, "RADIUS SRV: " args)
static void radius_server_session_timeout(void *eloop_ctx, void *timeout_ctx);
static struct radius_client *
radius_server_get_client(struct radius_server_data *data, struct in_addr *addr)
{
struct radius_client *client = data->clients;
while (client) {
if ((client->addr.s_addr & client->mask.s_addr) ==
(addr->s_addr & client->mask.s_addr)) {
break;
}
client = client->next;
}
return client;
}
static struct radius_session *
radius_server_get_session(struct radius_client *client, unsigned int sess_id)
{
struct radius_session *sess = client->sessions;
while (sess) {
if (sess->sess_id == sess_id) {
break;
}
sess = sess->next;
}
return sess;
}
static void radius_server_session_free(struct radius_server_data *data,
struct radius_session *sess)
{
eloop_cancel_timeout(radius_server_session_timeout, data, sess);
free(sess->eapKeyData);
free(sess->eapReqData);
eap_sm_deinit(sess->eap);
free(sess);
data->num_sess--;
}
static void radius_server_session_remove(struct radius_server_data *data,
struct radius_session *sess)
{
struct radius_client *client = sess->client;
struct radius_session *session, *prev;
prev = NULL;
session = client->sessions;
while (session) {
if (session == sess) {
if (prev == NULL) {
client->sessions = sess->next;
} else {
prev->next = sess->next;
}
radius_server_session_free(data, sess);
break;
}
prev = session;
session = session->next;
}
}
static void radius_server_session_timeout(void *eloop_ctx, void *timeout_ctx)
{
struct radius_server_data *data = eloop_ctx;
struct radius_session *sess = timeout_ctx;
RADIUS_DEBUG("Timing out authentication session 0x%x", sess->sess_id);
radius_server_session_remove(data, sess);
}
static struct radius_session *
radius_server_new_session(struct radius_server_data *data,
struct radius_client *client)
{
struct radius_session *sess;
if (data->num_sess >= RADIUS_MAX_SESSION) {
RADIUS_DEBUG("Maximum number of existing session - no room "
"for a new session");
return NULL;
}
sess = malloc(sizeof(*sess));
if (sess == NULL) {
return NULL;
}
memset(sess, 0, sizeof(*sess));
sess->server = data;
sess->client = client;
sess->sess_id = data->next_sess_id++;
sess->next = client->sessions;
client->sessions = sess;
eloop_register_timeout(RADIUS_SESSION_TIMEOUT, 0,
radius_server_session_timeout, data, sess);
data->num_sess++;
return sess;
}
static struct radius_session *
radius_server_get_new_session(struct radius_server_data *data,
struct radius_client *client,
struct radius_msg *msg)
{
u8 *user;
size_t user_len;
const struct hostapd_eap_user *eap_user;
int res;
struct radius_session *sess;
struct eap_config eap_conf;
RADIUS_DEBUG("Creating a new session");
user = malloc(256);
if (user == NULL) {
return NULL;
}
res = radius_msg_get_attr(msg, RADIUS_ATTR_USER_NAME, user, 256);
if (res < 0 || res > 256) {
RADIUS_DEBUG("Could not get User-Name");
free(user);
return NULL;
}
user_len = res;
RADIUS_DUMP_ASCII("User-Name", user, user_len);
eap_user = hostapd_get_eap_user(data->hostapd_conf, user, user_len, 0);
free(user);
if (eap_user) {
RADIUS_DEBUG("Matching user entry found");
sess = radius_server_new_session(data, client);
if (sess == NULL) {
RADIUS_DEBUG("Failed to create a new session");
return NULL;
}
} else {
RADIUS_DEBUG("User-Name not found from user database");
return NULL;
}
memset(&eap_conf, 0, sizeof(eap_conf));
eap_conf.ssl_ctx = data->ssl_ctx;
eap_conf.eap_sim_db_priv = data->eap_sim_db_priv;
eap_conf.backend_auth = TRUE;
sess->eap = eap_sm_init(sess, &radius_server_eapol_cb, &eap_conf);
if (sess->eap == NULL) {
RADIUS_DEBUG("Failed to initialize EAP state machine for the "
"new session");
radius_server_session_free(data, sess);
return NULL;
}
sess->eapRestart = TRUE;
sess->portEnabled = TRUE;
RADIUS_DEBUG("New session 0x%x initialized", sess->sess_id);
return sess;
}
static struct radius_msg *
radius_server_encapsulate_eap(struct radius_server_data *data,
struct radius_client *client,
struct radius_session *sess,
struct radius_msg *request)
{
struct radius_msg *msg;
int code;
unsigned int sess_id;
if (sess->eapFail) {
code = RADIUS_CODE_ACCESS_REJECT;
} else if (sess->eapSuccess) {
code = RADIUS_CODE_ACCESS_ACCEPT;
} else {
code = RADIUS_CODE_ACCESS_CHALLENGE;
}
msg = radius_msg_new(code, request->hdr->identifier);
if (msg == NULL) {
return NULL;
}
sess_id = htonl(sess->sess_id);
if (code == RADIUS_CODE_ACCESS_CHALLENGE &&
!radius_msg_add_attr(msg, RADIUS_ATTR_STATE,
(u8 *) &sess_id, sizeof(sess_id))) {
RADIUS_DEBUG("Failed to add State attribute");
}
if (sess->eapReqData &&
!radius_msg_add_eap(msg, sess->eapReqData, sess->eapReqDataLen)) {
RADIUS_DEBUG("Failed to add EAP-Message attribute");
}
if (code == RADIUS_CODE_ACCESS_ACCEPT && sess->eapKeyData) {
int len;
if (sess->eapKeyDataLen > 64) {
len = 32;
} else {
len = sess->eapKeyDataLen / 2;
}
if (!radius_msg_add_mppe_keys(msg, request->hdr->authenticator,
(u8 *) client->shared_secret,
client->shared_secret_len,
sess->eapKeyData + len, len,
sess->eapKeyData, len)) {
RADIUS_DEBUG("Failed to add MPPE key attributes");
}
}
if (radius_msg_finish_srv(msg, (u8 *) client->shared_secret,
client->shared_secret_len,
request->hdr->authenticator) < 0) {
RADIUS_DEBUG("Failed to add Message-Authenticator attribute");
}
return msg;
}
static int radius_server_reject(struct radius_server_data *data,
struct radius_client *client,
struct radius_msg *request,
struct sockaddr_in *from)
{
struct radius_msg *msg;
int ret = 0;
struct eap_hdr eapfail;
2005-06-05 22:35:03 +00:00
RADIUS_DEBUG("Reject invalid request from %s:%d",
inet_ntoa(from->sin_addr), ntohs(from->sin_port));
msg = radius_msg_new(RADIUS_CODE_ACCESS_REJECT,
request->hdr->identifier);
if (msg == NULL) {
return -1;
}
memset(&eapfail, 0, sizeof(eapfail));
eapfail.code = EAP_CODE_FAILURE;
eapfail.identifier = 0;
eapfail.length = htons(sizeof(eapfail));
if (!radius_msg_add_eap(msg, (u8 *) &eapfail, sizeof(eapfail))) {
RADIUS_DEBUG("Failed to add EAP-Message attribute");
}
2005-06-05 22:35:03 +00:00
if (radius_msg_finish_srv(msg, (u8 *) client->shared_secret,
client->shared_secret_len,
request->hdr->authenticator) < 0) {
RADIUS_DEBUG("Failed to add Message-Authenticator attribute");
}
if (wpa_debug_level <= MSG_MSGDUMP) {
radius_msg_dump(msg);
}
if (sendto(data->auth_sock, msg->buf, msg->buf_used, 0,
(struct sockaddr *) from, sizeof(*from)) < 0) {
perror("sendto[RADIUS SRV]");
ret = -1;
}
radius_msg_free(msg);
free(msg);
return ret;
}
static int radius_server_request(struct radius_server_data *data,
struct radius_msg *msg,
struct sockaddr_in *from,
struct radius_client *client)
{
u8 *eap = NULL;
size_t eap_len;
int res, state_included;
u8 statebuf[4], resp_id;
unsigned int state;
struct radius_session *sess;
struct radius_msg *reply;
struct eap_hdr *hdr;
/* TODO: Implement duplicate packet processing */
res = radius_msg_get_attr(msg, RADIUS_ATTR_STATE, statebuf,
sizeof(statebuf));
state_included = res >= 0;
if (res == sizeof(statebuf)) {
state = (statebuf[0] << 24) | (statebuf[1] << 16) |
(statebuf[2] << 8) | statebuf[3];
sess = radius_server_get_session(client, state);
} else {
sess = NULL;
}
if (sess) {
RADIUS_DEBUG("Request for session 0x%x", sess->sess_id);
} else if (state_included) {
RADIUS_DEBUG("State attribute included but no session found");
radius_server_reject(data, client, msg, from);
return -1;
} else {
sess = radius_server_get_new_session(data, client, msg);
if (sess == NULL) {
RADIUS_DEBUG("Could not create a new session");
radius_server_reject(data, client, msg, from);
2005-06-05 22:35:03 +00:00
return -1;
}
}
eap = radius_msg_get_eap(msg, &eap_len);
if (eap == NULL) {
RADIUS_DEBUG("No EAP-Message in RADIUS packet from %s",
inet_ntoa(from->sin_addr));
return -1;
}
RADIUS_DUMP("Received EAP data", eap, eap_len);
if (eap_len >= sizeof(*hdr)) {
hdr = (struct eap_hdr *) eap;
resp_id = hdr->identifier;
} else {
resp_id = 0;
}
eap_set_eapRespData(sess->eap, eap, eap_len);
free(eap);
eap = NULL;
sess->eapResp = TRUE;
eap_sm_step(sess->eap);
if (sess->eapReqData) {
RADIUS_DUMP("EAP data from the state machine",
sess->eapReqData, sess->eapReqDataLen);
} else if (sess->eapFail) {
RADIUS_DEBUG("No EAP data from the state machine, but eapFail "
"set - generate EAP-Failure");
hdr = malloc(sizeof(*hdr));
if (hdr) {
memset(hdr, 0, sizeof(*hdr));
hdr->identifier = resp_id;
hdr->length = htons(sizeof(*hdr));
sess->eapReqData = (u8 *) hdr;
sess->eapReqDataLen = sizeof(*hdr);
}
} else {
RADIUS_DEBUG("No EAP data from the state machine - ignore this"
" Access-Request silently (assuming it was a "
"duplicate)");
return -1;
}
reply = radius_server_encapsulate_eap(data, client, sess, msg);
free(sess->eapReqData);
sess->eapReqData = NULL;
sess->eapReqDataLen = 0;
if (reply) {
RADIUS_DEBUG("Reply to %s:%d", inet_ntoa(from->sin_addr),
ntohs(from->sin_port));
if (wpa_debug_level <= MSG_MSGDUMP) {
radius_msg_dump(reply);
}
res = sendto(data->auth_sock, reply->buf, reply->buf_used, 0,
(struct sockaddr *) from, sizeof(*from));
if (res < 0) {
perror("sendto[RADIUS SRV]");
}
radius_msg_free(reply);
free(reply);
}
if (sess->eapSuccess || sess->eapFail) {
RADIUS_DEBUG("Removing completed session 0x%x", sess->sess_id);
radius_server_session_remove(data, sess);
}
return 0;
}
static void radius_server_receive_auth(int sock, void *eloop_ctx,
void *sock_ctx)
{
struct radius_server_data *data = eloop_ctx;
u8 *buf = NULL;
struct sockaddr_in from;
socklen_t fromlen;
int len;
struct radius_client *client;
struct radius_msg *msg = NULL;
buf = malloc(RADIUS_MAX_MSG_LEN);
if (buf == NULL) {
goto fail;
}
fromlen = sizeof(from);
len = recvfrom(sock, buf, RADIUS_MAX_MSG_LEN, 0,
(struct sockaddr *) &from, &fromlen);
if (len < 0) {
perror("recvfrom[radius_server]");
goto fail;
}
RADIUS_DEBUG("Received %d bytes from %s:%d",
len, inet_ntoa(from.sin_addr), ntohs(from.sin_port));
RADIUS_DUMP("Received data", buf, len);
client = radius_server_get_client(data, &from.sin_addr);
if (client == NULL) {
RADIUS_DEBUG("Unknown client %s - packet ignored",
inet_ntoa(from.sin_addr));
goto fail;
}
msg = radius_msg_parse(buf, len);
if (msg == NULL) {
RADIUS_DEBUG("Parsing incoming RADIUS frame failed");
goto fail;
}
free(buf);
buf = NULL;
if (wpa_debug_level <= MSG_MSGDUMP) {
radius_msg_dump(msg);
}
if (msg->hdr->code != RADIUS_CODE_ACCESS_REQUEST) {
RADIUS_DEBUG("Unexpected RADIUS code %d", msg->hdr->code);
goto fail;
}
if (radius_msg_verify_msg_auth(msg, (u8 *) client->shared_secret,
client->shared_secret_len, NULL)) {
RADIUS_DEBUG("Invalid Message-Authenticator from %s",
inet_ntoa(from.sin_addr));
goto fail;
}
radius_server_request(data, msg, &from, client);
fail:
if (msg) {
radius_msg_free(msg);
free(msg);
}
free(buf);
}
static int radius_server_open_socket(int port)
{
int s;
struct sockaddr_in addr;
s = socket(PF_INET, SOCK_DGRAM, 0);
if (s < 0) {
perror("socket");
return -1;
}
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
perror("bind");
close(s);
return -1;
}
return s;
}
static void radius_server_free_sessions(struct radius_server_data *data,
struct radius_session *sessions)
{
struct radius_session *session, *prev;
session = sessions;
while (session) {
prev = session;
session = session->next;
radius_server_session_free(data, prev);
}
}
static void radius_server_free_clients(struct radius_server_data *data,
struct radius_client *clients)
{
struct radius_client *client, *prev;
client = clients;
while (client) {
prev = client;
client = client->next;
radius_server_free_sessions(data, prev->sessions);
free(prev->shared_secret);
free(prev);
}
}
static struct radius_client *
radius_server_read_clients(const char *client_file)
{
FILE *f;
const int buf_size = 1024;
char *buf, *pos;
struct radius_client *clients, *tail, *entry;
int line = 0, mask, failed = 0, i;
struct in_addr addr;
unsigned int val;
f = fopen(client_file, "r");
if (f == NULL) {
RADIUS_ERROR("Could not open client file '%s'", client_file);
return NULL;
}
buf = malloc(buf_size);
if (buf == NULL) {
fclose(f);
return NULL;
}
clients = tail = NULL;
while (fgets(buf, buf_size, f)) {
/* Configuration file format:
* 192.168.1.0/24 secret
* 192.168.1.2 secret
*/
line++;
buf[buf_size - 1] = '\0';
pos = buf;
while (*pos != '\0' && *pos != '\n')
pos++;
if (*pos == '\n')
*pos = '\0';
if (*buf == '\0' || *buf == '#')
continue;
pos = buf;
while ((*pos >= '0' && *pos <= '9') || *pos == '.') {
pos++;
}
if (*pos == '\0') {
failed = 1;
break;
}
if (*pos == '/') {
char *end;
*pos++ = '\0';
mask = strtol(pos, &end, 10);
if ((pos == end) || (mask < 0 || mask > 32)) {
failed = 1;
break;
}
pos = end;
} else {
mask = 32;
*pos++ = '\0';
}
if (inet_aton(buf, &addr) == 0) {
failed = 1;
break;
}
while (*pos == ' ' || *pos == '\t') {
pos++;
}
if (*pos == '\0') {
failed = 1;
break;
}
entry = malloc(sizeof(*entry));
if (entry == NULL) {
failed = 1;
break;
}
memset(entry, 0, sizeof(*entry));
entry->shared_secret = strdup(pos);
if (entry->shared_secret == NULL) {
failed = 1;
free(entry);
break;
}
entry->shared_secret_len = strlen(entry->shared_secret);
entry->addr.s_addr = addr.s_addr;
val = 0;
for (i = 0; i < mask; i++)
val |= 1 << (31 - i);
entry->mask.s_addr = htonl(val);
if (tail == NULL) {
clients = tail = entry;
} else {
tail->next = entry;
tail = entry;
}
}
if (failed) {
RADIUS_ERROR("Invalid line %d in '%s'", line, client_file);
radius_server_free_clients(NULL, clients);
clients = NULL;
}
free(buf);
fclose(f);
return clients;
}
struct radius_server_data *
radius_server_init(struct radius_server_conf *conf)
{
struct radius_server_data *data;
data = malloc(sizeof(*data));
if (data == NULL) {
return NULL;
}
memset(data, 0, sizeof(*data));
data->hostapd_conf = conf->hostapd_conf;
data->eap_sim_db_priv = conf->eap_sim_db_priv;
data->ssl_ctx = conf->ssl_ctx;
data->clients = radius_server_read_clients(conf->client_file);
if (data->clients == NULL) {
printf("No RADIUS clients configured.\n");
radius_server_deinit(data);
return NULL;
}
data->auth_sock = radius_server_open_socket(conf->auth_port);
if (data->auth_sock < 0) {
printf("Failed to open UDP socket for RADIUS authentication "
"server\n");
radius_server_deinit(data);
return NULL;
}
if (eloop_register_read_sock(data->auth_sock,
radius_server_receive_auth,
data, NULL)) {
radius_server_deinit(data);
return NULL;
}
return data;
}
void radius_server_deinit(struct radius_server_data *data)
{
if (data == NULL)
return;
if (data->auth_sock >= 0) {
eloop_unregister_read_sock(data->auth_sock);
close(data->auth_sock);
}
radius_server_free_clients(data, data->clients);
free(data);
}
int radius_server_get_mib(struct radius_server_data *data, char *buf,
size_t buflen)
{
/* TODO: add support for RADIUS authentication server MIB */
return 0;
}
static Boolean radius_server_get_bool(void *ctx, enum eapol_bool_var variable)
{
struct radius_session *sess = ctx;
if (sess == NULL)
return FALSE;
switch (variable) {
case EAPOL_eapSuccess:
return sess->eapSuccess;
case EAPOL_eapRestart:
return sess->eapRestart;
case EAPOL_eapFail:
return sess->eapFail;
case EAPOL_eapResp:
return sess->eapResp;
case EAPOL_eapReq:
return sess->eapReq;
case EAPOL_eapNoReq:
return sess->eapNoReq;
case EAPOL_portEnabled:
return sess->portEnabled;
case EAPOL_eapTimeout:
return sess->eapTimeout;
}
return FALSE;
}
static void radius_server_set_bool(void *ctx, enum eapol_bool_var variable,
Boolean value)
{
struct radius_session *sess = ctx;
if (sess == NULL)
return;
switch (variable) {
case EAPOL_eapSuccess:
sess->eapSuccess = value;
break;
case EAPOL_eapRestart:
sess->eapRestart = value;
break;
case EAPOL_eapFail:
sess->eapFail = value;
break;
case EAPOL_eapResp:
sess->eapResp = value;
break;
case EAPOL_eapReq:
sess->eapReq = value;
break;
case EAPOL_eapNoReq:
sess->eapNoReq = value;
break;
case EAPOL_portEnabled:
sess->portEnabled = value;
break;
case EAPOL_eapTimeout:
sess->eapTimeout = value;
break;
}
}
static void radius_server_set_eapReqData(void *ctx, const u8 *eapReqData,
size_t eapReqDataLen)
{
struct radius_session *sess = ctx;
if (sess == NULL)
return;
free(sess->eapReqData);
sess->eapReqData = malloc(eapReqDataLen);
if (sess->eapReqData) {
memcpy(sess->eapReqData, eapReqData, eapReqDataLen);
sess->eapReqDataLen = eapReqDataLen;
} else {
sess->eapReqDataLen = 0;
}
}
static void radius_server_set_eapKeyData(void *ctx, const u8 *eapKeyData,
size_t eapKeyDataLen)
{
struct radius_session *sess = ctx;
if (sess == NULL)
return;
free(sess->eapKeyData);
if (eapKeyData) {
sess->eapKeyData = malloc(eapKeyDataLen);
if (sess->eapKeyData) {
memcpy(sess->eapKeyData, eapKeyData, eapKeyDataLen);
sess->eapKeyDataLen = eapKeyDataLen;
} else {
sess->eapKeyDataLen = 0;
}
} else {
sess->eapKeyData = NULL;
sess->eapKeyDataLen = 0;
}
}
static int radius_server_get_eap_user(void *ctx, const u8 *identity,
size_t identity_len, int phase2,
struct eap_user *user)
{
struct radius_session *sess = ctx;
const struct hostapd_eap_user *eap_user;
eap_user = hostapd_get_eap_user(sess->server->hostapd_conf, identity,
identity_len, phase2);
if (eap_user == NULL)
return -1;
memset(user, 0, sizeof(*user));
memcpy(user->methods, eap_user->methods,
EAP_USER_MAX_METHODS > EAP_MAX_METHODS ?
EAP_USER_MAX_METHODS : EAP_MAX_METHODS);
if (eap_user->password) {
user->password = malloc(eap_user->password_len);
if (user->password == NULL)
return -1;
memcpy(user->password, eap_user->password,
eap_user->password_len);
user->password_len = eap_user->password_len;
}
user->force_version = eap_user->force_version;
return 0;
}
static struct eapol_callbacks radius_server_eapol_cb =
{
.get_bool = radius_server_get_bool,
.set_bool = radius_server_set_bool,
.set_eapReqData = radius_server_set_eapReqData,
.set_eapKeyData = radius_server_set_eapKeyData,
.get_eap_user = radius_server_get_eap_user,
};