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/*
* Copyright (c) 2015, Yawning Angel <yawning at torproject dot org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
// Package scramblesuit provides an implementation of the ScrambleSuit
// obfuscation protocol. The implementation is client only.
package scramblesuit
import (
"fmt"
"net"
"git.torproject.org/pluggable-transports/goptlib.git"
"github.com/OperatorFoundation/obfs4/transports/base"
)
const transportName = "scramblesuit"
// Transport is the ScrambleSuit implementation of the base.Transport interface.
type Transport struct{}
// Name returns the name of the ScrambleSuit transport protocol.
func (t *Transport) Name() string {
return transportName
}
// ClientFactory returns a new ssClientFactory instance.
func (t *Transport) ClientFactory(stateDir string) (base.ClientFactory, error) {
tStore, err := loadTicketStore(stateDir)
if err != nil {
return nil, err
}
cf := &ssClientFactory{transport: t, ticketStore: tStore}
return cf, nil
}
// ServerFactory will one day return a new ssServerFactory instance.
func (t *Transport) ServerFactory(stateDir string, args *pt.Args) (base.ServerFactory, error) {
// TODO: Fill this in eventually, though obfs4 is better.
return nil, fmt.Errorf("server not supported")
}
type ssClientFactory struct {
transport base.Transport
ticketStore *ssTicketStore
}
func (cf *ssClientFactory) Transport() base.Transport {
return cf.transport
}
func (cf *ssClientFactory) ParseArgs(args *pt.Args) (interface{}, error) {
return newClientArgs(args)
}
func (cf *ssClientFactory) Dial(network, addr string, dialFn base.DialFunc, args interface{}) (net.Conn, error) {
// Validate args before opening outgoing connection.
ca, ok := args.(*ssClientArgs)
if !ok {
return nil, fmt.Errorf("invalid argument type for args")
}
conn, err := dialFn(network, addr)
if err != nil {
return nil, err
}
dialConn := conn
if conn, err = newScrambleSuitClientConn(conn, cf.ticketStore, ca); err != nil {
dialConn.Close()
return nil, err
}
return conn, nil
}
var _ base.ClientFactory = (*ssClientFactory)(nil)
var _ base.Transport = (*Transport)(nil)
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