Add OpenVPN, TrustTunnel, Sudoku, inbound managers. Fixes

transport/openvpn/data.go

@@ -0,0 +1,91 @@
+package openvpn
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+)
+
+const (
+	PeerIDUnset uint32 = 0xffffff
+)
+
+type DataChannel struct {
+	cipher  DataCipher
+	keyID   uint8
+	peerID  uint32
+	compLZO bool
+	mu           sync.Mutex
+	sendPacketID uint32
+}
+
+func NewDataChannel(cipher DataCipher, peerID uint32, compLZO bool) *DataChannel {
+	return &DataChannel{
+		cipher:  cipher,
+		peerID:  peerID,
+		compLZO: compLZO,
+	}
+}
+
+func (d *DataChannel) Encrypt(packet []byte) ([]byte, error) {
+	if d.compLZO {
+		p := make([]byte, 1+len(packet))
+		p[0] = 0xFA
+		copy(p[1:], packet)
+		packet = p
+	}
+	d.mu.Lock()
+	d.sendPacketID++
+	packetID := d.sendPacketID
+	d.mu.Unlock()
+	return d.cipher.Encrypt(d.dataHeader(), packetID, packet)
+}
+
+func (d *DataChannel) Decrypt(packet []byte) ([]byte, error) {
+	if len(packet) < 1 {
+		return nil, errors.New("empty openvpn data packet")
+	}
+	opcode, _ := parseOpcodeKeyID(packet[0])
+	headerSize := 1
+	if opcode == PDataV2 {
+		headerSize = 4
+	}
+	plain, err := d.cipher.Decrypt(packet, headerSize)
+	if err != nil {
+		return nil, err
+	}
+	if d.compLZO {
+		if len(plain) < 1 {
+			return nil, errors.New("openvpn comp-lzo packet too short")
+		}
+		if plain[0] != 0xFA {
+			return nil, fmt.Errorf("openvpn compressed packet not supported (byte: 0x%02x)", plain[0])
+		}
+		plain = plain[1:]
+	}
+	return plain, nil
+}
+
+func (d *DataChannel) dataHeader() []byte {
+	if d.peerID != PeerIDUnset {
+		return []byte{
+			opcodeKeyID(PDataV2, d.keyID),
+			byte(d.peerID >> 16),
+			byte(d.peerID >> 8),
+			byte(d.peerID),
+		}
+	}
+	return []byte{opcodeKeyID(PDataV1, d.keyID)}
+}
+
+func ParsePeerID(options string) uint32 {
+	for _, field := range splitPushOptions(options) {
+		if len(field) > len("peer-id ") && field[:len("peer-id ")] == "peer-id " {
+			var id uint32
+			if _, err := fmt.Sscanf(field, "peer-id %d", &id); err == nil && id <= PeerIDUnset {
+				return id
+			}
+		}
+	}
+	return PeerIDUnset
+}