343 lines
7.4 KiB
C
343 lines
7.4 KiB
C
/*
|
|
* Copyright (C) 2010 Martin Willi
|
|
* Copyright (C) 2010 revosec AG
|
|
*
|
|
* 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 "radius_socket.h"
|
|
#include "radius_mppe.h"
|
|
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
|
|
#include <pen/pen.h>
|
|
#include <utils/debug.h>
|
|
|
|
typedef struct private_radius_socket_t private_radius_socket_t;
|
|
|
|
/**
|
|
* Private data of an radius_socket_t object.
|
|
*/
|
|
struct private_radius_socket_t {
|
|
|
|
/**
|
|
* Public radius_socket_t interface.
|
|
*/
|
|
radius_socket_t public;
|
|
|
|
/**
|
|
* Server port for authentication
|
|
*/
|
|
u_int16_t auth_port;
|
|
|
|
/**
|
|
* socket file descriptor for authentication
|
|
*/
|
|
int auth_fd;
|
|
|
|
/**
|
|
* Server port for accounting
|
|
*/
|
|
u_int16_t acct_port;
|
|
|
|
/**
|
|
* socket file descriptor for accounting
|
|
*/
|
|
int acct_fd;
|
|
|
|
/**
|
|
* Server address
|
|
*/
|
|
char *address;
|
|
|
|
/**
|
|
* current RADIUS identifier
|
|
*/
|
|
u_int8_t identifier;
|
|
|
|
/**
|
|
* hasher to use for response verification
|
|
*/
|
|
hasher_t *hasher;
|
|
|
|
/**
|
|
* HMAC-MD5 signer to build Message-Authenticator attribute
|
|
*/
|
|
signer_t *signer;
|
|
|
|
/**
|
|
* random number generator for RADIUS request authenticator
|
|
*/
|
|
rng_t *rng;
|
|
|
|
/**
|
|
* RADIUS secret
|
|
*/
|
|
chunk_t secret;
|
|
};
|
|
|
|
/**
|
|
* Check or establish RADIUS connection
|
|
*/
|
|
static bool check_connection(private_radius_socket_t *this,
|
|
int *fd, u_int16_t port)
|
|
{
|
|
if (*fd == -1)
|
|
{
|
|
host_t *server;
|
|
|
|
server = host_create_from_dns(this->address, AF_UNSPEC, port);
|
|
if (!server)
|
|
{
|
|
DBG1(DBG_CFG, "resolving RADIUS server address '%s' failed",
|
|
this->address);
|
|
return FALSE;
|
|
}
|
|
*fd = socket(server->get_family(server), SOCK_DGRAM, IPPROTO_UDP);
|
|
if (*fd == -1)
|
|
{
|
|
DBG1(DBG_CFG, "opening RADIUS socket for %#H failed: %s",
|
|
server, strerror(errno));
|
|
server->destroy(server);
|
|
return FALSE;
|
|
}
|
|
if (connect(*fd, server->get_sockaddr(server),
|
|
*server->get_sockaddr_len(server)) < 0)
|
|
{
|
|
DBG1(DBG_CFG, "connecting RADIUS socket to %#H failed: %s",
|
|
server, strerror(errno));
|
|
server->destroy(server);
|
|
close(*fd);
|
|
*fd = -1;
|
|
return FALSE;
|
|
}
|
|
server->destroy(server);
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
METHOD(radius_socket_t, request, radius_message_t*,
|
|
private_radius_socket_t *this, radius_message_t *request)
|
|
{
|
|
chunk_t data;
|
|
int i, *fd;
|
|
u_int16_t port;
|
|
rng_t *rng = NULL;
|
|
|
|
if (request->get_code(request) == RMC_ACCOUNTING_REQUEST)
|
|
{
|
|
fd = &this->acct_fd;
|
|
port = this->acct_port;
|
|
}
|
|
else
|
|
{
|
|
fd = &this->auth_fd;
|
|
port = this->auth_port;
|
|
rng = this->rng;
|
|
}
|
|
|
|
/* set Message Identifier */
|
|
request->set_identifier(request, this->identifier++);
|
|
/* sign the request */
|
|
if (!request->sign(request, NULL, this->secret, this->hasher, this->signer,
|
|
rng, rng != NULL))
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
if (!check_connection(this, fd, port))
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
data = request->get_encoding(request);
|
|
DBG3(DBG_CFG, "%B", &data);
|
|
|
|
/* timeout after 2, 3, 4, 5 seconds */
|
|
for (i = 2; i <= 5; i++)
|
|
{
|
|
radius_message_t *response;
|
|
bool retransmit = FALSE;
|
|
struct timeval tv;
|
|
char buf[4096];
|
|
fd_set fds;
|
|
int res;
|
|
|
|
if (send(*fd, data.ptr, data.len, 0) != data.len)
|
|
{
|
|
DBG1(DBG_CFG, "sending RADIUS message failed: %s", strerror(errno));
|
|
return NULL;
|
|
}
|
|
tv.tv_sec = i;
|
|
tv.tv_usec = 0;
|
|
|
|
while (TRUE)
|
|
{
|
|
FD_ZERO(&fds);
|
|
FD_SET(*fd, &fds);
|
|
res = select((*fd) + 1, &fds, NULL, NULL, &tv);
|
|
/* TODO: updated tv to time not waited. Linux does this for us. */
|
|
if (res < 0)
|
|
{ /* failed */
|
|
DBG1(DBG_CFG, "waiting for RADIUS message failed: %s",
|
|
strerror(errno));
|
|
break;
|
|
}
|
|
if (res == 0)
|
|
{ /* timeout */
|
|
DBG1(DBG_CFG, "retransmitting RADIUS message");
|
|
retransmit = TRUE;
|
|
break;
|
|
}
|
|
res = recv(*fd, buf, sizeof(buf), MSG_DONTWAIT);
|
|
if (res <= 0)
|
|
{
|
|
DBG1(DBG_CFG, "receiving RADIUS message failed: %s",
|
|
strerror(errno));
|
|
break;
|
|
}
|
|
response = radius_message_parse(chunk_create(buf, res));
|
|
if (response)
|
|
{
|
|
if (response->verify(response,
|
|
request->get_authenticator(request), this->secret,
|
|
this->hasher, this->signer))
|
|
{
|
|
return response;
|
|
}
|
|
response->destroy(response);
|
|
}
|
|
DBG1(DBG_CFG, "received invalid RADIUS message, ignored");
|
|
}
|
|
if (!retransmit)
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
DBG1(DBG_CFG, "RADIUS server is not responding");
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* Decrypt a MS-MPPE-Send/Recv-Key
|
|
*/
|
|
static chunk_t decrypt_mppe_key(private_radius_socket_t *this, u_int16_t salt,
|
|
chunk_t C, radius_message_t *request)
|
|
{
|
|
chunk_t decrypted;
|
|
|
|
decrypted = chunk_alloca(C.len);
|
|
if (!request->crypt(request, chunk_from_thing(salt), C, decrypted,
|
|
this->secret, this->hasher) ||
|
|
decrypted.ptr[0] >= decrypted.len)
|
|
{ /* decryption failed? */
|
|
return chunk_empty;
|
|
}
|
|
/* remove truncation, first byte is key length */
|
|
return chunk_clone(chunk_create(decrypted.ptr + 1, decrypted.ptr[0]));
|
|
}
|
|
|
|
METHOD(radius_socket_t, decrypt_msk, chunk_t,
|
|
private_radius_socket_t *this, radius_message_t *request,
|
|
radius_message_t *response)
|
|
{
|
|
mppe_key_t *mppe_key;
|
|
enumerator_t *enumerator;
|
|
chunk_t data, send = chunk_empty, recv = chunk_empty;
|
|
int type;
|
|
|
|
enumerator = response->create_enumerator(response);
|
|
while (enumerator->enumerate(enumerator, &type, &data))
|
|
{
|
|
if (type == RAT_VENDOR_SPECIFIC && data.len > sizeof(mppe_key_t))
|
|
{
|
|
mppe_key = (mppe_key_t*)data.ptr;
|
|
if (ntohl(mppe_key->id) == PEN_MICROSOFT &&
|
|
mppe_key->length == data.len - sizeof(mppe_key->id))
|
|
{
|
|
data = chunk_create(mppe_key->key, data.len - sizeof(mppe_key_t));
|
|
if (mppe_key->type == MS_MPPE_SEND_KEY)
|
|
{
|
|
send = decrypt_mppe_key(this, mppe_key->salt, data, request);
|
|
}
|
|
if (mppe_key->type == MS_MPPE_RECV_KEY)
|
|
{
|
|
recv = decrypt_mppe_key(this, mppe_key->salt, data, request);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
enumerator->destroy(enumerator);
|
|
if (send.ptr && recv.ptr)
|
|
{
|
|
return chunk_cat("mm", recv, send);
|
|
}
|
|
chunk_clear(&send);
|
|
chunk_clear(&recv);
|
|
return chunk_empty;
|
|
}
|
|
|
|
METHOD(radius_socket_t, destroy, void,
|
|
private_radius_socket_t *this)
|
|
{
|
|
DESTROY_IF(this->hasher);
|
|
DESTROY_IF(this->signer);
|
|
DESTROY_IF(this->rng);
|
|
if (this->auth_fd != -1)
|
|
{
|
|
close(this->auth_fd);
|
|
};
|
|
if (this->acct_fd != -1)
|
|
{
|
|
close(this->acct_fd);
|
|
}
|
|
free(this);
|
|
}
|
|
|
|
/**
|
|
* See header
|
|
*/
|
|
radius_socket_t *radius_socket_create(char *address, u_int16_t auth_port,
|
|
u_int16_t acct_port, chunk_t secret)
|
|
{
|
|
private_radius_socket_t *this;
|
|
|
|
INIT(this,
|
|
.public = {
|
|
.request = _request,
|
|
.decrypt_msk = _decrypt_msk,
|
|
.destroy = _destroy,
|
|
},
|
|
.address = address,
|
|
.auth_port = auth_port,
|
|
.auth_fd = -1,
|
|
.acct_port = acct_port,
|
|
.acct_fd = -1,
|
|
.hasher = lib->crypto->create_hasher(lib->crypto, HASH_MD5),
|
|
.signer = lib->crypto->create_signer(lib->crypto, AUTH_HMAC_MD5_128),
|
|
.rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK),
|
|
);
|
|
|
|
if (!this->hasher || !this->signer || !this->rng ||
|
|
!this->signer->set_key(this->signer, secret))
|
|
{
|
|
DBG1(DBG_CFG, "RADIUS initialization failed, HMAC/MD5/RNG required");
|
|
destroy(this);
|
|
return NULL;
|
|
}
|
|
this->secret = secret;
|
|
/* we use a random identifier, helps if we restart often */
|
|
this->identifier = random();
|
|
|
|
return &this->public;
|
|
}
|