1 files changed, 76 insertions, 388 deletions

diff --git a/src/libcharon/plugins/eap_radius/radius_client.c b/src/libcharon/plugins/eap_radius/radius_client.c
index 1d1f21742..232b9135e 100644
--- a/src/libcharon/plugins/eap_radius/radius_client.c
+++ b/src/libcharon/plugins/eap_radius/radius_client.c
@@ -15,6 +15,9 @@
 
 #include "radius_client.h"
 
+#include "eap_radius_plugin.h"
+#include "radius_server.h"
+
 #include <unistd.h>
 #include <errno.h>
 
@@ -24,42 +27,8 @@
 #include <threading/condvar.h>
 #include <threading/mutex.h>
 
-/**
- * Default RADIUS server port, when not configured
- */
-#define RADIUS_PORT 1812
-
-/**
- * Vendor-Id of Microsoft specific attributes
- */
-#define VENDOR_ID_MICROSOFT 311
-
-/**
- * Microsoft specific vendor attributes
- */
-#define MS_MPPE_SEND_KEY 16
-#define MS_MPPE_RECV_KEY 17
-
 typedef struct private_radius_client_t private_radius_client_t;
 
-typedef struct entry_t entry_t;
-
-/**
- * A socket pool entry.
- */
-struct entry_t {
-	/** socket file descriptor */
-	int fd;
-	/** 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;
-};
-
 /**
  * Private data of an radius_client_t object.
  */
@@ -71,170 +40,20 @@ struct private_radius_client_t {
 	radius_client_t public;
 
 	/**
+	 * Selected RADIUS server
+	 */
+	radius_server_t *server;
+
+	/**
 	 * RADIUS servers State attribute
 	 */
 	chunk_t state;
-};
 
-/**
- * Global list of radius sockets, contains entry_t's
- */
-static linked_list_t *sockets;
-
-/**
- * mutex to lock sockets list
- */
-static mutex_t *mutex;
-
-/**
- * condvar to wait for sockets
- */
-static condvar_t *condvar;
-
-/**
- * RADIUS secret
- */
-static chunk_t secret;
-
-/**
- * NAS-Identifier
- */
-static chunk_t nas_identifier;
-
-/**
- * Clean up socket list
- */
-void radius_client_cleanup()
-{
-	entry_t *entry;
-
-	mutex->destroy(mutex);
-	condvar->destroy(condvar);
-	while (sockets->remove_last(sockets, (void**)&entry) == SUCCESS)
-	{
-		entry->rng->destroy(entry->rng);
-		entry->hasher->destroy(entry->hasher);
-		entry->signer->destroy(entry->signer);
-		close(entry->fd);
-		free(entry);
-	}
-	sockets->destroy(sockets);
-}
-
-/**
- * Initialize the socket list
- */
-bool radius_client_init()
-{
-	int i, count, fd;
-	u_int16_t port;
-	entry_t *entry;
-	host_t *host;
-	char *server;
-
-	nas_identifier.ptr = lib->settings->get_str(lib->settings,
-					"charon.plugins.eap-radius.nas_identifier", "strongSwan");
-	nas_identifier.len = strlen(nas_identifier.ptr);
-
-	secret.ptr = lib->settings->get_str(lib->settings,
-					"charon.plugins.eap-radius.secret", NULL);
-	if (!secret.ptr)
-	{
-		DBG1(DBG_CFG, "no RADUIS secret defined");
-		return FALSE;
-	}
-	secret.len = strlen(secret.ptr);
-	server = lib->settings->get_str(lib->settings,
-					"charon.plugins.eap-radius.server", NULL);
-	if (!server)
-	{
-		DBG1(DBG_CFG, "no RADUIS server defined");
-		return FALSE;
-	}
-	port = lib->settings->get_int(lib->settings,
-					"charon.plugins.eap-radius.port", RADIUS_PORT);
-	host = host_create_from_dns(server, 0, port);
-	if (!host)
-	{
-		return FALSE;
-	}
-	count = lib->settings->get_int(lib->settings,
-					"charon.plugins.eap-radius.sockets", 1);
-
-	sockets = linked_list_create();
-	mutex = mutex_create(MUTEX_TYPE_DEFAULT);
-	condvar = condvar_create(CONDVAR_TYPE_DEFAULT);
-	for (i = 0; i < count; i++)
-	{
-		fd = socket(host->get_family(host), SOCK_DGRAM, IPPROTO_UDP);
-		if (fd < 0)
-		{
-			DBG1(DBG_CFG, "opening RADIUS socket failed");
-			host->destroy(host);
-			radius_client_cleanup();
-			return FALSE;
-		}
-		if (connect(fd, host->get_sockaddr(host),
-					*host->get_sockaddr_len(host)) < 0)
-		{
-			DBG1(DBG_CFG, "connecting RADIUS socket failed");
-			host->destroy(host);
-			radius_client_cleanup();
-			return FALSE;
-		}
-		entry = malloc_thing(entry_t);
-		entry->fd = fd;
-		/* we use per-socket crypto elements: this reduces overhead, but
-		 * is still thread-save. */
-		entry->hasher = lib->crypto->create_hasher(lib->crypto, HASH_MD5);
-		entry->signer = lib->crypto->create_signer(lib->crypto, AUTH_HMAC_MD5_128);
-		entry->rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
-		if (!entry->hasher || !entry->signer || !entry->rng)
-		{
-			DBG1(DBG_CFG, "RADIUS initialization failed, HMAC/MD5/RNG required");
-			DESTROY_IF(entry->hasher);
-			DESTROY_IF(entry->signer);
-			DESTROY_IF(entry->rng);
-			free(entry);
-			host->destroy(host);
-			radius_client_cleanup();
-			return FALSE;
-		}
-		entry->signer->set_key(entry->signer, secret);
-		/* we use a random identifier, helps if we restart often (testing) */
-		entry->identifier = random();
-		sockets->insert_last(sockets, entry);
-	}
-	host->destroy(host);
-	return TRUE;
-}
-
-/**
- * Get a socket from the pool, block if none available
- */
-static entry_t* get_socket()
-{
-	entry_t *entry;
-
-	mutex->lock(mutex);
-	while (sockets->remove_first(sockets, (void**)&entry) != SUCCESS)
-	{
-		condvar->wait(condvar, mutex);
-	}
-	mutex->unlock(mutex);
-	return entry;
-}
-
-/**
- * Release a socket to the pool
- */
-static void put_socket(entry_t *entry)
-{
-	mutex->lock(mutex);
-	sockets->insert_last(sockets, entry);
-	mutex->unlock(mutex);
-	condvar->signal(condvar);
-}
+	/**
+	 * EAP MSK, from MPPE keys
+	 */
+	chunk_t msk;
+};
 
 /**
  * Save the state attribute to include in further request
@@ -261,234 +80,103 @@ static void save_state(private_radius_client_t *this, radius_message_t *msg)
 	chunk_free(&this->state);
 }
 
-/**
- * Implementation of radius_client_t.request
- */
-static radius_message_t* request(private_radius_client_t *this,
-								 radius_message_t *req)
+METHOD(radius_client_t, request, radius_message_t*,
+	private_radius_client_t *this, radius_message_t *req)
 {
 	char virtual[] = {0x00,0x00,0x00,0x05};
-	entry_t *socket;
-	chunk_t data;
-	int i;
+	radius_socket_t *socket;
+	radius_message_t *res;
 
-	socket = get_socket();
-
-	/* set Message Identifier */
-	req->set_identifier(req, socket->identifier++);
 	/* we add the "Virtual" NAS-Port-Type, as we SHOULD include one */
 	req->add(req, RAT_NAS_PORT_TYPE, chunk_create(virtual, sizeof(virtual)));
 	/* add our NAS-Identifier */
-	req->add(req, RAT_NAS_IDENTIFIER, nas_identifier);
+	req->add(req, RAT_NAS_IDENTIFIER,
+			 this->server->get_nas_identifier(this->server));
 	/* add State attribute, if server sent one */
 	if (this->state.ptr)
 	{
 		req->add(req, RAT_STATE, this->state);
 	}
-	/* sign the request */
-	req->sign(req, socket->rng, socket->signer);
-
-	data = req->get_encoding(req);
-	/* timeout after 2, 3, 4, 5 seconds */
-	for (i = 2; i <= 5; i++)
+	socket = this->server->get_socket(this->server);
+	DBG1(DBG_CFG, "sending RADIUS %N to %#H", radius_message_code_names,
+		 req->get_code(req), this->server->get_address(this->server));
+	res = socket->request(socket, req);
+	if (res)
 	{
-		radius_message_t *response;
-		bool retransmit = FALSE;
-		struct timeval tv;
-		char buf[4096];
-		fd_set fds;
-		int res;
-
-		if (send(socket->fd, data.ptr, data.len, 0) != data.len)
-		{
-			DBG1(DBG_CFG, "sending RADIUS message failed: %s", strerror(errno));
-			put_socket(socket);
-			return NULL;
-		}
-		tv.tv_sec = i;
-		tv.tv_usec = 0;
-
-		while (TRUE)
+		DBG1(DBG_CFG, "received RADIUS %N from %#H", radius_message_code_names,
+			 res->get_code(res), this->server->get_address(this->server));
+		save_state(this, res);
+		if (res->get_code(res) == RMC_ACCESS_ACCEPT)
 		{
-			FD_ZERO(&fds);
-			FD_SET(socket->fd, &fds);
-			res = select(socket->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(socket->fd, buf, sizeof(buf), MSG_DONTWAIT);
-			if (res <= 0)
-			{
-				DBG1(DBG_CFG, "receiving RADIUS message failed: %s",
-					 strerror(errno));
-				break;
-			}
-			response = radius_message_parse_response(chunk_create(buf, res));
-			if (response)
-			{
-				if (response->verify(response, req->get_authenticator(req),
-							secret, socket->hasher, socket->signer))
-				{
-					save_state(this, response);
-					put_socket(socket);
-					return response;
-				}
-				response->destroy(response);
-			}
-			DBG1(DBG_CFG, "received invalid RADIUS message, ignored");
-		}
-		if (!retransmit)
-		{
-			break;
+			chunk_clear(&this->msk);
+			this->msk = socket->decrypt_msk(socket, req, res);
 		}
+		this->server->put_socket(this->server, socket, TRUE);
+		return res;
 	}
-	DBG1(DBG_CFG, "RADIUS server is not responding");
-	put_socket(socket);
+	this->server->put_socket(this->server, socket, FALSE);
 	charon->bus->alert(charon->bus, ALERT_RADIUS_NOT_RESPONDING);
 	return NULL;
 }
 
-/**
- * Decrypt a MS-MPPE-Send/Recv-Key
- */
-static chunk_t decrypt_mppe_key(private_radius_client_t *this, u_int16_t salt,
-								chunk_t C, radius_message_t *request)
+METHOD(radius_client_t, get_msk, chunk_t,
+	private_radius_client_t *this)
 {
-	chunk_t A, R, P, seed;
-	u_char *c, *p;
-	hasher_t *hasher;
-
-	/**
-	 * From RFC2548 (encryption):
-	 * b(1) = MD5(S + R + A)    c(1) = p(1) xor b(1)   C = c(1)
-	 * b(2) = MD5(S + c(1))     c(2) = p(2) xor b(2)   C = C + c(2)
-	 *      . . .
-	 * b(i) = MD5(S + c(i-1))   c(i) = p(i) xor b(i)   C = C + c(i)
-	 */
-
-	if (C.len % HASH_SIZE_MD5 || C.len < HASH_SIZE_MD5)
-	{
-		return chunk_empty;
-	}
-
-	hasher = lib->crypto->create_hasher(lib->crypto, HASH_MD5);
-	if (!hasher)
-	{
-		return chunk_empty;
-	}
-
-	A = chunk_create((u_char*)&salt, sizeof(salt));
-	R = chunk_create(request->get_authenticator(request), HASH_SIZE_MD5);
-	P = chunk_alloca(C.len);
-	p = P.ptr;
-	c = C.ptr;
-
-	seed = chunk_cata("cc", R, A);
-
-	while (c < C.ptr + C.len)
-	{
-		/* b(i) = MD5(S + c(i-1)) */
-		hasher->get_hash(hasher, secret, NULL);
-		hasher->get_hash(hasher, seed, p);
-
-		/* p(i) = b(i) xor c(1) */
-		memxor(p, c, HASH_SIZE_MD5);
-
-		/* prepare next round */
-		seed = chunk_create(c, HASH_SIZE_MD5);
-		c += HASH_SIZE_MD5;
-		p += HASH_SIZE_MD5;
-	}
-	hasher->destroy(hasher);
+	return this->msk;
+}
 
-	/* remove truncation, first byte is key length */
-	if (*P.ptr >= P.len)
-	{	/* decryption failed? */
-		return chunk_empty;
-	}
-	return chunk_clone(chunk_create(P.ptr + 1, *P.ptr));
+METHOD(radius_client_t, destroy, void,
+	private_radius_client_t *this)
+{
+	chunk_clear(&this->msk);
+	free(this->state.ptr);
+	free(this);
 }
 
 /**
- * Implementation of radius_client_t.decrypt_msk
+ * See header
  */
-static chunk_t decrypt_msk(private_radius_client_t *this,
-						   radius_message_t *response, radius_message_t *request)
+radius_client_t *radius_client_create()
 {
-	struct {
-		u_int32_t id;
-		u_int8_t type;
-		u_int8_t length;
-		u_int16_t salt;
-		u_int8_t key[];
-	} __attribute__((packed)) *mppe_key;
+	private_radius_client_t *this;
 	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))
+	radius_server_t *server;
+	int current, best = -1;
+
+	INIT(this,
+		.public = {
+			.request = _request,
+			.get_msk = _get_msk,
+			.destroy = _destroy,
+		},
+	);
+
+	enumerator = eap_radius_create_server_enumerator();
+	while (enumerator->enumerate(enumerator, &server))
 	{
-		if (type == RAT_VENDOR_SPECIFIC &&
-			data.len > sizeof(*mppe_key))
+		current = server->get_preference(server);
+		if (current > best ||
+			/* for two with equal preference, 50-50 chance */
+			(current == best && random() % 2 == 0))
+		{
+			DBG2(DBG_CFG, "RADIUS server %H is candidate: %d",
+				 server->get_address(server), current);
+			best = current;
+			this->server = server;
+		}
+		else
 		{
-			mppe_key = (void*)data.ptr;
-			if (ntohl(mppe_key->id) == VENDOR_ID_MICROSOFT &&
-				mppe_key->length == data.len - sizeof(mppe_key->id))
-			{
-				data = chunk_create(mppe_key->key, data.len - sizeof(*mppe_key));
-				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);
-				}
-			}
+			DBG2(DBG_CFG, "RADIUS server %H skipped: %d",
+				 server->get_address(server), current);
 		}
 	}
 	enumerator->destroy(enumerator);
-	if (send.ptr && recv.ptr)
+
+	if (!this->server)
 	{
-		return chunk_cat("mm", recv, send);
+		free(this);
+		return NULL;
 	}
-	chunk_clear(&send);
-	chunk_clear(&recv);
-	return chunk_empty;
-}
-
-/**
- * Implementation of radius_client_t.destroy.
- */
-static void destroy(private_radius_client_t *this)
-{
-	free(this->state.ptr);
-	free(this);
-}
-
-/**
- * See header
- */
-radius_client_t *radius_client_create()
-{
-	private_radius_client_t *this = malloc_thing(private_radius_client_t);
-
-	this->public.request = (radius_message_t*(*)(radius_client_t*, radius_message_t *msg))request;
-	this->public.decrypt_msk = (chunk_t(*)(radius_client_t*, radius_message_t *, radius_message_t *))decrypt_msk;
-	this->public.destroy = (void(*)(radius_client_t*))destroy;
-
-	this->state = chunk_empty;
 
 	return &this->public;
 }