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-rw-r--r--vendor/0xacab.org/leap/shapeshifter/README.md22
-rw-r--r--vendor/0xacab.org/leap/shapeshifter/shapeshifter.go182
2 files changed, 204 insertions, 0 deletions
diff --git a/vendor/0xacab.org/leap/shapeshifter/README.md b/vendor/0xacab.org/leap/shapeshifter/README.md
new file mode 100644
index 0000000..ae9bf8f
--- /dev/null
+++ b/vendor/0xacab.org/leap/shapeshifter/README.md
@@ -0,0 +1,22 @@
+ShapeShifter library
+--------------------
+
+Heavily based on the shapeshifter-dispatcher:
+https://github.com/OperatorFoundation/shapeshifter-dispatcher/
+
+
+To use it:
+```go
+ ss := ShapeShifter{
+ Cert: "cert",
+ Target: "ip:port",
+ SocksAddr: "127.0.0.1:4430",
+ }
+ err := ss.Open()
+ if err != nil {
+ return err
+ }
+ defer ss.Close()
+```
+
+And now you can tunnel your protocol into `127.0.0.1:4430`.
diff --git a/vendor/0xacab.org/leap/shapeshifter/shapeshifter.go b/vendor/0xacab.org/leap/shapeshifter/shapeshifter.go
new file mode 100644
index 0000000..f201e07
--- /dev/null
+++ b/vendor/0xacab.org/leap/shapeshifter/shapeshifter.go
@@ -0,0 +1,182 @@
+package shapeshifter
+
+import (
+ "encoding/base64"
+ "fmt"
+ "io"
+ "log"
+ "net"
+ "sync"
+
+ "github.com/OperatorFoundation/obfs4/common/ntor"
+ "github.com/OperatorFoundation/shapeshifter-transports/transports/obfs4"
+ "golang.org/x/net/proxy"
+)
+
+type Logger interface {
+ Log(msg string)
+}
+
+type ShapeShifter struct {
+ Cert string
+ IatMode int
+ Target string // remote ip:port obfs4 server
+ SocksAddr string // -proxylistenaddr in shapeshifter-dispatcher
+ Logger Logger
+ ln net.Listener
+ errChan chan error
+}
+
+func (ss *ShapeShifter) Open() error {
+ err := ss.checkOptions()
+ if err != nil {
+ return err
+ }
+
+ ss.ln, err = net.Listen("tcp", ss.SocksAddr)
+ if err != nil {
+ return fmt.Errorf("failed to listen: %s", err.Error())
+ }
+
+ go ss.clientAcceptLoop()
+ return nil
+}
+
+func (ss *ShapeShifter) Close() error {
+ if ss.ln != nil {
+ return ss.ln.Close()
+ }
+ if ss.errChan != nil {
+ close(ss.errChan)
+ }
+ return nil
+}
+
+func (ss *ShapeShifter) GetErrorChannel() chan error {
+ if ss.errChan == nil {
+ ss.errChan = make(chan error, 2)
+ }
+ return ss.errChan
+}
+
+func (ss ShapeShifter) clientAcceptLoop() error {
+ for {
+ conn, err := ss.ln.Accept()
+ if err != nil {
+ if e, ok := err.(net.Error); ok && !e.Temporary() {
+ return err
+ }
+ ss.sendError("Error accepting connection: %v", err)
+ continue
+ }
+ go ss.clientHandler(conn)
+ }
+}
+
+func (ss ShapeShifter) clientHandler(conn net.Conn) {
+ defer conn.Close()
+
+ dialer := proxy.Direct
+ transport, err := obfs4.NewObfs4Client(ss.Cert, ss.IatMode, dialer)
+ if err != nil {
+ ss.sendError("Can not create an obfs4 client (cert: %s, iat-mode: %d): %v", ss.Cert, ss.IatMode, err)
+ return
+ }
+ remote, err := transport.Dial(ss.Target)
+ if err != nil {
+ ss.sendError("outgoing connection failed %s: %v", ss.Target, err)
+ return
+ }
+ if remote == nil {
+ ss.sendError("outgoing connection failed %s", ss.Target)
+ return
+ }
+ defer remote.Close()
+
+ err = copyLoop(conn, remote)
+ if err != nil {
+ ss.sendError("%s - closed connection: %v", ss.Target, err)
+ } else {
+ log.Printf("%s - closed connection", ss.Target)
+ }
+
+ return
+}
+
+func copyLoop(a net.Conn, b net.Conn) error {
+ // Note: b is always the pt connection. a is the SOCKS/ORPort connection.
+ errChan := make(chan error, 2)
+
+ var wg sync.WaitGroup
+ wg.Add(2)
+
+ go func() {
+ defer wg.Done()
+ defer b.Close()
+ defer a.Close()
+ _, err := io.Copy(b, a)
+ errChan <- err
+ }()
+ go func() {
+ defer wg.Done()
+ defer a.Close()
+ defer b.Close()
+ _, err := io.Copy(a, b)
+ errChan <- err
+ }()
+
+ // Wait for both upstream and downstream to close. Since one side
+ // terminating closes the other, the second error in the channel will be
+ // something like EINVAL (though io.Copy() will swallow EOF), so only the
+ // first error is returned.
+ wg.Wait()
+ if len(errChan) > 0 {
+ return <-errChan
+ }
+
+ return nil
+}
+
+func (ss *ShapeShifter) checkOptions() error {
+ if ss.SocksAddr == "" {
+ ss.SocksAddr = "127.0.0.1:0"
+ }
+ return isCertValid(ss.Cert)
+}
+
+func (ss *ShapeShifter) sendError(format string, a ...interface{}) {
+ if ss.Logger != nil {
+ ss.Logger.Log(fmt.Sprintf(format, a...))
+ return
+ }
+
+ if ss.errChan == nil {
+ ss.errChan = make(chan error, 2)
+ }
+ select {
+ case ss.errChan <- fmt.Errorf(format, a...):
+ default:
+ log.Printf(format, a...)
+ }
+}
+
+func isCertValid(cert string) error {
+ // copied from github.com/OperatorFoundation/shapeshifter-transports/transports/obfs4/statefile.go
+ const certSuffix = "=="
+ const certLength = ntor.NodeIDLength + ntor.PublicKeyLength
+
+ if cert == "" {
+ return fmt.Errorf("obfs4 transport missing cert argument")
+ }
+
+ decoded, err := base64.StdEncoding.DecodeString(cert + certSuffix)
+ if err != nil {
+ return fmt.Errorf("failed to decode cert: %s", err)
+ }
+
+ if len(decoded) != certLength {
+ return fmt.Errorf("cert length %d is invalid", len(decoded))
+ }
+
+ return nil
+}