Drop support for go 1.20

[btrtrc.git] / handshake.go

diff --git a/handshake.go b/handshake.go
index 25730f31e5475565a883decd26adb9fb2f0292ab..b38a7086e83227003b7c5f7b5ef0af120dc76986 100644 (file)
--- a/handshake.go
+++ b/handshake.go
@@ -27,22 +27,26 @@ func (r deadlineReader) Read(b []byte) (int, error) {
        return r.r.Read(b)
 }
 
+// Handles stream encryption for inbound connections.
 func handleEncryption(
        rw io.ReadWriter,
        skeys mse.SecretKeyIter,
-       policy EncryptionPolicy,
+       policy HeaderObfuscationPolicy,
+       selector mse.CryptoSelector,
 ) (
        ret io.ReadWriter,
        headerEncrypted bool,
        cryptoMethod mse.CryptoMethod,
        err error,
 ) {
-       if !policy.ForceEncryption {
+       // Tries to start an unencrypted stream.
+       if !policy.RequirePreferred || !policy.Preferred {
                var protocol [len(pp.Protocol)]byte
                _, err = io.ReadFull(rw, protocol[:])
                if err != nil {
                        return
                }
+               // Put the protocol back into the stream.
                rw = struct {
                        io.Reader
                        io.Writer
@@ -54,21 +58,15 @@ func handleEncryption(
                        ret = rw
                        return
                }
+               if policy.RequirePreferred {
+                       // We are here because we require unencrypted connections.
+                       err = fmt.Errorf("unexpected protocol string %q and header obfuscation disabled", protocol)
+                       return
+               }
        }
        headerEncrypted = true
-       ret, cryptoMethod, err = mse.ReceiveHandshake(rw, skeys, func(provides mse.CryptoMethod) mse.CryptoMethod {
-               switch {
-               case policy.ForceEncryption:
-                       return mse.CryptoMethodRC4
-               case policy.DisableEncryption:
-                       return mse.CryptoMethodPlaintext
-               case policy.PreferNoEncryption && provides&mse.CryptoMethodPlaintext != 0:
-                       return mse.CryptoMethodPlaintext
-               default:
-                       return mse.DefaultCryptoSelector(provides)
-               }
-       })
+       ret, cryptoMethod, err = mse.ReceiveHandshake(rw, skeys, selector)
        return
 }
 
-type PeerExtensionBits=pp.PeerExtensionBits
\ No newline at end of file
+type PeerExtensionBits = pp.PeerExtensionBits