Commit d8f74cc4 authored by George Kadianakis's avatar George Kadianakis Committed by Nick Mathewson
Browse files

Move Extended ORPort code to its own module.

Move the code from the connection_or module to ext_orport.

This commit only moves code: it shouldn't modify anything.
parent 2207525a
......@@ -19,6 +19,7 @@
#include "connection_or.h"
#include "control.h"
#include "reasons.h"
#include "ext_orport.h"
#include "../common/util.h"
#include "../common/torlog.h"
#ifdef HAVE_UNISTD_H
......
......@@ -45,6 +45,7 @@
#include "routerset.h"
#include "statefile.h"
#include "transports.h"
#include "ext_orport.h"
#ifdef _WIN32
#include <shlobj.h>
#endif
......
......@@ -33,6 +33,7 @@
#include "dns.h"
#include "dnsserv.h"
#include "entrynodes.h"
#include "ext_orport.h"
#include "geoip.h"
#include "main.h"
#include "policies.h"
......
......@@ -37,7 +37,7 @@
#include "rephist.h"
#include "router.h"
#include "routerlist.h"
#include "ext_orport.h"
#ifdef USE_BUFFEREVENTS
#include <event2/bufferevent_ssl.h>
#endif
......@@ -482,24 +482,6 @@ var_cell_free(var_cell_t *cell)
tor_free(cell);
}
/** Allocate and return a structure capable of holding an Extended
* ORPort message of body length <b>len</b>. */
ext_or_cmd_t *
ext_or_cmd_new(uint16_t len)
{
size_t size = STRUCT_OFFSET(ext_or_cmd_t, body) + len;
ext_or_cmd_t *cmd = tor_malloc(size);
cmd->len = len;
return cmd;
}
/** Deallocate the Extended ORPort message in <b>cmd</b>. */
void
ext_or_cmd_free(ext_or_cmd_t *cmd)
{
tor_free(cmd);
}
/** We've received an EOF from <b>conn</b>. Mark it for close and return. */
int
connection_or_reached_eof(or_connection_t *conn)
......@@ -2442,507 +2424,3 @@ connection_or_send_authenticate_cell(or_connection_t *conn, int authtype)
return 0;
}
/** Get an Extended ORPort message from <b>conn</b>, and place it in
* <b>out</b>. Return -1 on fail, 0 if we need more data, and 1 if we
* successfully extracted an Extended ORPort command from the
* buffer. */
static int
connection_fetch_ext_or_cmd_from_buf(connection_t *conn, ext_or_cmd_t **out)
{
IF_HAS_BUFFEREVENT(conn, {
struct evbuffer *input = bufferevent_get_input(conn->bufev);
return fetch_ext_or_command_from_evbuffer(input, out);
}) ELSE_IF_NO_BUFFEREVENT {
return fetch_ext_or_command_from_buf(conn->inbuf, out);
}
}
/** Write an Extended ORPort message to <b>conn</b>. Use
* <b>command</b> as the command type, <b>bodylen</b> as the body
* length, and <b>body</b>, if it's present, as the body of the
* message. */
static int
connection_write_ext_or_command(connection_t *conn,
uint16_t command,
const char *body,
size_t bodylen)
{
char header[4];
if (bodylen > UINT16_MAX)
return -1;
set_uint16(header, htons(command));
set_uint16(header+2, htons(bodylen));
connection_write_to_buf(header, 4, conn);
if (bodylen) {
tor_assert(body);
connection_write_to_buf(body, bodylen, conn);
}
return 0;
}
/** Transition from an Extended ORPort which accepts Extended ORPort
* messages, to an Extended ORport which accepts OR traffic. */
static void
connection_ext_or_transition(or_connection_t *conn)
{
tor_assert(conn->base_.type == CONN_TYPE_EXT_OR);
conn->base_.type = CONN_TYPE_OR;
control_event_or_conn_status(conn, OR_CONN_EVENT_NEW, 0);
connection_tls_start_handshake(conn, 1);
}
/** Length of authentication cookie. */
#define EXT_OR_PORT_AUTH_COOKIE_LEN 32
/** Length of the header of the cookie file. */
#define EXT_OR_PORT_AUTH_COOKIE_HEADER_LEN 32
/** Total length of the cookie file. */
#define EXT_OR_PORT_AUTH_COOKIE_FILE_LEN \
EXT_OR_PORT_AUTH_COOKIE_LEN+EXT_OR_PORT_AUTH_COOKIE_HEADER_LEN
/** Static cookie file header. */
#define EXT_OR_PORT_AUTH_COOKIE_HEADER "! Extended ORPort Auth Cookie !\x0a"
/** Length of safe-cookie protocol hashes. */
#define EXT_OR_PORT_AUTH_HASH_LEN DIGEST256_LEN
/** Length of safe-cookie protocol nonces. */
#define EXT_OR_PORT_AUTH_NONCE_LEN 32
/** Safe-cookie protocol constants. */
#define EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST \
"ExtORPort authentication server-to-client hash"
#define EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST \
"ExtORPort authentication client-to-server hash"
/** If true, we've set ext_or_auth_cookie to a secret code and stored
* it to disk. */
static int ext_or_auth_cookie_is_set = 0;
/** If ext_or_auth_cookie_is_set, a secret cookie that we've stored to disk
* and which we're using to authenticate controllers. (If the controller can
* read it off disk, it has permission to connect.) */
static char ext_or_auth_cookie[EXT_OR_PORT_AUTH_COOKIE_LEN] = {0};
/** Helper: Return a newly allocated string containing a path to the
* file where we store our authentication cookie. */
char *
get_ext_or_auth_cookie_file(void)
{
const or_options_t *options = get_options();
if (options->ExtORPortCookieAuthFile &&
strlen(options->ExtORPortCookieAuthFile)) {
return tor_strdup(options->ExtORPortCookieAuthFile);
} else {
return get_datadir_fname("extended_orport_auth_cookie");
}
}
/** Choose a random authentication cookie and write it to disk.
* Anybody who can read the cookie from disk will be considered
* authorized to use the control connection. Return -1 if we can't
* write the file, or 0 on success. */
int
init_ext_or_auth_cookie_authentication(int is_enabled)
{
char *fname;
char cookie_file_string[EXT_OR_PORT_AUTH_COOKIE_FILE_LEN];
if (!is_enabled) {
ext_or_auth_cookie_is_set = 0;
return 0;
}
/* We don't want to generate a new cookie every time we call
* options_act(). One should be enough. */
if (ext_or_auth_cookie_is_set)
return 0; /* all set */
if (crypto_rand(ext_or_auth_cookie, EXT_OR_PORT_AUTH_COOKIE_LEN) < 0)
return -1;
ext_or_auth_cookie_is_set = 1;
memcpy(cookie_file_string, EXT_OR_PORT_AUTH_COOKIE_HEADER,
EXT_OR_PORT_AUTH_COOKIE_HEADER_LEN);
memcpy(cookie_file_string+EXT_OR_PORT_AUTH_COOKIE_HEADER_LEN,
ext_or_auth_cookie, EXT_OR_PORT_AUTH_COOKIE_LEN);
fname = get_ext_or_auth_cookie_file();
if (write_bytes_to_file(fname, cookie_file_string,
EXT_OR_PORT_AUTH_COOKIE_FILE_LEN, 1)) {
log_warn(LD_FS,"Error writing authentication cookie to %s.",
escaped(fname));
tor_free(fname);
return -1;
}
log_warn(LD_GENERAL, "Generated Extended ORPort cookie file in '%s'.",
fname);
tor_free(fname);
return 0;
}
/** Read data from <b>conn</b> and see if the client sent us the
* authentication type that she prefers to use in this session.
*
* Return -1 if we received corrupted data or if we don't support the
* authentication type. Return 0 if we need more data in
* <b>conn</b>. Return 1 if the authentication type negotiation was
* successful. */
static int
connection_ext_or_auth_neg_auth_type(connection_t *conn)
{
char authtype[1] = {0};
if (connection_get_inbuf_len(conn) < 1)
return 0;
if (connection_fetch_from_buf(authtype, 1, conn) < 0)
return -1;
log_warn(LD_GENERAL, "Client wants us to use %d auth type", authtype[0]);
if (authtype[0] != 1) /* '1' is the only auth type supported atm */
return -1;
conn->state = EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_NONCE;
return 1;
}
/** Read the client's nonce out of <b>conn</b>, setup the safe-cookie
* crypto, and then send our own hash and nonce to the client
*
* Return -1 if there was an error; return 0 if we need more data in
* <b>conn</b>, and return 1 if we successfully retrieved the
* client's nonce and sent our own. */
static int
connection_ext_or_auth_handle_client_nonce(connection_t *conn)
{
char server_hash[EXT_OR_PORT_AUTH_HASH_LEN] = {0};
char client_nonce[EXT_OR_PORT_AUTH_NONCE_LEN] = {0};
char server_nonce[EXT_OR_PORT_AUTH_NONCE_LEN] = {0};
char reply[EXT_OR_PORT_AUTH_COOKIE_LEN+EXT_OR_PORT_AUTH_NONCE_LEN] = {0};
if (!ext_or_auth_cookie_is_set) { /* this should not happen */
log_warn(LD_BUG, "Extended ORPort authentication cookie was not set. "
"That's weird since we should have done that on startup. "
"This might be a Tor bug, please file a bug report. ");
return -1;
}
if (connection_get_inbuf_len(conn) < EXT_OR_PORT_AUTH_NONCE_LEN)
return 0;
if (connection_fetch_from_buf(client_nonce,
EXT_OR_PORT_AUTH_NONCE_LEN, conn) < 0) /* XXX check-spaces */
return -1;
/* Get our nonce */
if (crypto_rand(server_nonce, EXT_OR_PORT_AUTH_NONCE_LEN) < 0)
return -1;
{ /* set up macs */
size_t hmac_s_msg_len = strlen(EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST) +
2*EXT_OR_PORT_AUTH_NONCE_LEN;
size_t hmac_c_msg_len = strlen(EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST) +
2*EXT_OR_PORT_AUTH_NONCE_LEN;
char *hmac_s_msg = tor_malloc_zero(hmac_s_msg_len);
char *hmac_c_msg = tor_malloc_zero(hmac_c_msg_len);
char *correct_client_hash = tor_malloc_zero(EXT_OR_PORT_AUTH_HASH_LEN);
memcpy(hmac_s_msg,
EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST,
strlen(EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST));
memcpy(hmac_s_msg + strlen(EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST),
client_nonce, EXT_OR_PORT_AUTH_NONCE_LEN);
memcpy(hmac_s_msg + strlen(EXT_OR_PORT_AUTH_SERVER_TO_CLIENT_CONST) +
EXT_OR_PORT_AUTH_NONCE_LEN,
server_nonce, EXT_OR_PORT_AUTH_NONCE_LEN);
memcpy(hmac_c_msg,
EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST,
strlen(EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST));
memcpy(hmac_c_msg + strlen(EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST),
client_nonce, EXT_OR_PORT_AUTH_NONCE_LEN);
memcpy(hmac_c_msg + strlen(EXT_OR_PORT_AUTH_CLIENT_TO_SERVER_CONST) +
EXT_OR_PORT_AUTH_NONCE_LEN,
server_nonce, EXT_OR_PORT_AUTH_NONCE_LEN);
crypto_hmac_sha256(server_hash,
ext_or_auth_cookie,
EXT_OR_PORT_AUTH_COOKIE_LEN,
hmac_s_msg,
hmac_s_msg_len);
crypto_hmac_sha256(correct_client_hash,
ext_or_auth_cookie,
EXT_OR_PORT_AUTH_COOKIE_LEN,
hmac_c_msg,
hmac_c_msg_len);
/* Store the client hash we generated. We will need to compare it
with the hash sent by the client. */
TO_OR_CONN(conn)->ext_or_auth_correct_client_hash = correct_client_hash;
tor_free(hmac_s_msg);
tor_free(hmac_c_msg);
}
{ /* debug logging */ /* XXX disable this codepath if not logging on debug?*/
char server_hash_encoded[(2*EXT_OR_PORT_AUTH_HASH_LEN) + 1];
char server_nonce_encoded[(2*EXT_OR_PORT_AUTH_NONCE_LEN) + 1];
char client_nonce_encoded[(2*EXT_OR_PORT_AUTH_NONCE_LEN) + 1];
base16_encode(server_hash_encoded, sizeof(server_hash_encoded),
server_hash, sizeof(server_hash));
base16_encode(server_nonce_encoded, sizeof(server_nonce_encoded),
server_nonce, sizeof(server_nonce));
base16_encode(client_nonce_encoded, sizeof(client_nonce_encoded),
client_nonce, sizeof(client_nonce));
log_warn(LD_GENERAL,
"server_hash: '%s'\nserver_nonce: '%s'\nclient_nonce: '%s'",
server_hash_encoded, server_nonce_encoded, client_nonce_encoded);
}
{ /* write reply: (server_hash, server_nonce) */
memcpy(reply, server_hash, EXT_OR_PORT_AUTH_HASH_LEN);
memcpy(reply + EXT_OR_PORT_AUTH_HASH_LEN, server_nonce,
EXT_OR_PORT_AUTH_NONCE_LEN);
connection_write_to_buf(reply, sizeof(reply), conn);
}
log_warn(LD_GENERAL, "Got client nonce, and sent our own nonce and hash.");
conn->state = EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_HASH;
return 1;
}
#define connection_ext_or_auth_send_result_success(c) \
connection_ext_or_auth_send_result(c, 1)
#define connection_ext_or_auth_send_result_fail(c) \
connection_ext_or_auth_send_result(c, 0)
/** Send authentication results to <b>conn</b>. Successful results if
* <b>success</b> is set; failure results otherwise. */
static void
connection_ext_or_auth_send_result(connection_t *conn, int success)
{
if (success)
connection_write_to_buf("\x01", 1, conn);
else
connection_write_to_buf("\x00", 1, conn);
}
/** Receive the client's hash from <b>conn</b>, validate that it's
* correct, and then send the authentication results to the client.
*
* Return -1 if there was an error during validation; return 0 if we
* need more data in <b>conn</b>, and return 1 if we successfully
* validated the client's hash and sent a happy authentication
* result. */
static int
connection_ext_or_auth_handle_client_hash(connection_t *conn)
{
char provided_client_hash[EXT_OR_PORT_AUTH_HASH_LEN] = {0};
if (connection_get_inbuf_len(conn) < EXT_OR_PORT_AUTH_HASH_LEN)
return 0;
if (connection_fetch_from_buf(provided_client_hash,
EXT_OR_PORT_AUTH_HASH_LEN, conn) < 0)
return -1;
if (tor_memneq(TO_OR_CONN(conn)->ext_or_auth_correct_client_hash,
provided_client_hash, EXT_OR_PORT_AUTH_HASH_LEN)) {
log_warn(LD_GENERAL, "Incorrect client hash. Authentication failed.");
connection_ext_or_auth_send_result_fail(conn);
return -1;
}
log_warn(LD_GENERAL, "Got client's hash and it was legit.");
/* send positive auth result */
connection_ext_or_auth_send_result_success(conn);
conn->state = EXT_OR_CONN_STATE_OPEN;
return 1;
}
/** Handle data from <b>or_conn</b> received on Extended ORPort.
* Return -1 on error. 0 on unsufficient data. 1 on correct. */
static int
connection_ext_or_auth_process_inbuf(or_connection_t *or_conn)
{
connection_t *conn = TO_CONN(or_conn);
switch (conn->state) { /* Functionify */
case EXT_OR_CONN_STATE_AUTH_WAIT_AUTH_TYPE:
return connection_ext_or_auth_neg_auth_type(conn);
case EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_NONCE:
return connection_ext_or_auth_handle_client_nonce(conn);
case EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_HASH:
return connection_ext_or_auth_handle_client_hash(conn);
default:
log_warn(LD_BUG, "Encountered unexpected connection state %d while trying "
"to process Extended ORPort authentication data.", conn->state);
return -1;
}
}
/** Extended ORPort commands (Transport-to-Bridge) */
#define EXT_OR_CMD_TB_DONE 0x0000
#define EXT_OR_CMD_TB_USERADDR 0x0001
/** Extended ORPort commands (Bridge-to-Transport) */
#define EXT_OR_CMD_BT_OKAY 0x1000
#define EXT_OR_CMD_BT_DENY 0x1001
#define EXT_OR_CMD_BT_CONTROL 0x1002
/** Process a USERADDR command from the Extended
* ORPort. <b>payload</b> is a payload of size <b>len</b>.
*
* If the USERADDR command was well formed, change the address of
* <b>conn</b> to the address on the USERADDR command.
*
* Return 0 on success and -1 on error. */
static int
connection_ext_or_handle_useraddr(connection_t *conn,
char *payload, uint16_t len)
{
/* Copy address string. */
tor_addr_t addr;
uint16_t port;
char *addr_str;
char *address_part=NULL;
int res;
addr_str = tor_malloc(len + 1);
memcpy(addr_str, payload, len);
addr_str[len] = 0;
res = tor_addr_port_split(LOG_INFO, addr_str, &address_part, &port);
tor_free(addr_str);
if (res<0)
return -1;
res = tor_addr_parse(&addr, address_part);
tor_free(address_part);
if (res<0)
return -1;
{ /* do some logging */
char *old_address = tor_dup_addr(&conn->addr);
char *new_address = tor_dup_addr(&addr);
log_warn(LD_NET, "Received USERADDR." /* XXX Fix log severities/messages */
"We rewrite our address from '%s:%u' to '%s:%u'.",
safe_str(old_address), conn->port, safe_str(new_address), port);
tor_free(old_address);
tor_free(new_address);
}
/* record the address */
tor_addr_copy(&conn->addr, &addr);
conn->port = port;
return 0;
}
/** Process Extended ORPort messages from <b>or_conn</b>. */
int
connection_ext_or_process_inbuf(or_connection_t *or_conn)
{
connection_t *conn = TO_CONN(or_conn);
ext_or_cmd_t *command;
int r;
/* If we are still in the authentication stage, process traffic as
authentication data: */
while (conn->state <= EXT_OR_CONN_STATE_AUTH_MAX) {
log_warn(LD_GENERAL, "Got Extended ORPort authentication data (%u).",
(unsigned int) connection_get_inbuf_len(conn));
r = connection_ext_or_auth_process_inbuf(or_conn);
if (r < 0) {
connection_mark_for_close(conn);
return -1;
} else if (r == 0) {
return 0;
}
/* if r > 0, loop and process more data (if any). */
}
while (1) {
log_warn(LD_GENERAL, "Got Extended ORPort data.");
command = NULL;
r = connection_fetch_ext_or_cmd_from_buf(conn, &command);
if (r < 0)
goto err;
else if (r == 0)
return 0; /* need to wait for more data */
/* Got a command! */
tor_assert(command);
if (command->cmd == EXT_OR_CMD_TB_DONE) {
if (connection_get_inbuf_len(conn)) {
/* The inbuf isn't empty; the client is misbehaving. */
goto err;
}
log_debug(LD_NET, "Received DONE.");
connection_write_ext_or_command(conn, EXT_OR_CMD_BT_OKAY, NULL, 0);
/* can't transition immediately; need to flush first. */
conn->state = EXT_OR_CONN_STATE_FLUSHING;
connection_stop_reading(conn);
} else if (command->cmd == EXT_OR_CMD_TB_USERADDR) {
if (connection_ext_or_handle_useraddr(conn,
command->body, command->len) < 0)
goto err;
} else {
log_notice(LD_NET,"Got Extended ORPort command we don't regognize (%u).",
command->cmd);
}
ext_or_cmd_free(command);
}
return 0;
err:
ext_or_cmd_free(command);
connection_mark_for_close(conn);
return -1;
}
/** <b>conn</b> finished flushing Extended ORPort messages to the
* network, and is now ready to accept OR traffic. This function
* does the transition. */
int
connection_ext_or_finished_flushing(or_connection_t *conn)
{
if (conn->base_.state == EXT_OR_CONN_STATE_FLUSHING) {
connection_start_reading(TO_CONN(conn));
connection_ext_or_transition(conn);
}
return 0;
}
/** Initiate Extended ORPort authentication, by sending the list of
* supported authentication types to the client. */
int
connection_ext_or_start_auth(or_connection_t *or_conn)
{
connection_t *conn = TO_CONN(or_conn);
char authtypes[2] = "\x01\x00"; /* We only support authtype '1' for now. */
log_warn(LD_GENERAL,
"ExtORPort authentication: Sending supported authentication types");
connection_write_to_buf(authtypes, sizeof(authtypes), conn);
conn->state = EXT_OR_CONN_STATE_AUTH_WAIT_AUTH_TYPE;
return 0;
}
......@@ -45,8 +45,6 @@ void connection_or_close_for_error(or_connection_t *orconn, int flush);
void connection_or_report_broken_states(int severity, int domain);
int connection_ext_or_start_auth(or_connection_t *or_conn);
int connection_tls_start_handshake(or_connection_t *conn, int receiving);
int connection_tls_continue_handshake(or_connection_t *conn);
......@@ -97,17 +95,5 @@ void var_cell_free(var_cell_t *cell);
/** DOCDOC */
#define MIN_LINK_PROTO_FOR_WIDE_CIRC_IDS 4
ext_or_cmd_t *ext_or_cmd_new(uint16_t len);
void ext_or_cmd_free(ext_or_cmd_t *cmd);
void connection_or_set_ext_or_identifier(or_connection_t *conn);
void connection_or_remove_from_ext_or_id_map(or_connection_t *conn);
void connection_or_clear_ext_or_id_map(void);
int connection_ext_or_finished_flushing(or_connection_t *conn);
int connection_ext_or_process_inbuf(or_connection_t *or_conn);
int init_ext_or_auth_cookie_authentication(int is_enabled);
char *get_ext_or_auth_cookie_file(void);
#endif
/* Copyright (c) 2012, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file ext_orport.c
* \brief Code implementing the Extended ORPort.
*/
#include "or.h"
#include "connection.h"
#include "connection_or.h"
#include "ext_orport.h"
#include "control.h"
#include "config.h"
#include "main.h"
/** Allocate and return a structure capable of holding an Extended
* ORPort message of body length <b>len</b>. */
ext_or_cmd_t *
ext_or_cmd_new(uint16_t len)
{
size_t size = STRUCT_OFFSET(ext_or_cmd_t, body) + len;
ext_or_cmd_t *cmd = tor_malloc(size);
cmd->len = len;
return cmd;