func getRequest(conn *ss.Conn) (host string, extra []byte, err error) { const ( idType = 0 // address type index idIP0 = 1 // ip addres start index idDmLen = 1 // domain address length index idDm0 = 2 // domain address start index typeIP = 1 // type is ip address typeDm = 3 // type is domain address lenIP = 1 + 4 + 2 // 1addrType + 4ip + 2port lenDmBase = 1 + 1 + 2 // 1addrType + 1addrLen + 2port, plus addrLen ) // buf size should at least have the same size with the largest possible // request size (when addrType is 3, domain name has at most 256 bytes) // 1(addrType) + 1(lenByte) + 256(max length address) + 2(port) buf := make([]byte, 260, 260) var n int // read till we get possible domain length field ss.SetReadTimeout(conn) if n, err = io.ReadAtLeast(conn, buf, idDmLen+1); err != nil { return } reqLen := lenIP if buf[idType] == typeDm { reqLen = int(buf[idDmLen]) + lenDmBase } else if buf[idType] != typeIP { err = errAddrType return } if n < reqLen { // rare case ss.SetReadTimeout(conn) if _, err = io.ReadFull(conn, buf[n:reqLen]); err != nil { return } } else if n > reqLen { // it's possible to read more than just the request head extra = buf[reqLen:n] } // TODO add ipv6 support if buf[idType] == typeDm { host = string(buf[idDm0 : idDm0+buf[idDmLen]]) } else if buf[idType] == typeIP { addrIp := make(net.IP, 4) copy(addrIp, buf[idIP0:idIP0+4]) host = addrIp.String() } // parse port var port int16 sb := bytes.NewBuffer(buf[reqLen-2 : reqLen]) binary.Read(sb, binary.BigEndian, &port) host += ":" + strconv.Itoa(int(port)) return }
func getRequest(conn *ss.Conn) (host string, extra []byte, err error) { const ( idType = 0 // address type index idIP0 = 1 // ip addres start index idDmLen = 1 // domain address length index idDm0 = 2 // domain address start index typeIPv4 = 1 // type is ipv4 address typeDm = 3 // type is domain address typeIPv6 = 4 // type is ipv6 address lenIP = 1 + 4 + 2 // 1addrType + 4ip + 2port lenDmBase = 1 + 1 + 2 // 1addrType + 1addrLen + 2port, plus addrLen ) // buf size should at least have the same size with the largest possible // request size (when addrType is 3, domain name has at most 256 bytes) // 1(addrType) + 1(lenByte) + 256(max length address) + 2(port) buf := make([]byte, 260, 260) var n int // read till we get possible domain length field ss.SetReadTimeout(conn) if n, err = io.ReadAtLeast(conn, buf, idDmLen+1); err != nil { return } // Currently the client will not send request with ipv6 address. reqLen := lenIP if buf[idType] == typeDm { reqLen = int(buf[idDmLen]) + lenDmBase } else if buf[idType] != typeIPv4 { err = errAddrType return } if n < reqLen { // rare case ss.SetReadTimeout(conn) if _, err = io.ReadFull(conn, buf[n:reqLen]); err != nil { return } } else if n > reqLen { // it's possible to read more than just the request head extra = buf[reqLen:n] } if buf[idType] == typeDm { host = string(buf[idDm0 : idDm0+buf[idDmLen]]) } else if buf[idType] == typeIPv4 { addrIp := net.IPv4(buf[idIP0], buf[idIP0+1], buf[idIP0+2], buf[idIP0+3]) host = addrIp.String() } // parse port port := binary.BigEndian.Uint16(buf[reqLen-2 : reqLen]) host = net.JoinHostPort(host, strconv.Itoa(int(port))) return }
func handShake(conn net.Conn) (err error) { const ( idVer = 0 idNmethod = 1 ) // version identification and method selection message in theory can have // at most 256 methods, plus version and nmethod field in total 258 bytes // the current rfc defines only 3 authentication methods (plus 2 reserved), // so it won't be such long in practice buf := make([]byte, 258) var n int ss.SetReadTimeout(conn) // make sure we get the nmethod field if n, err = io.ReadAtLeast(conn, buf, idNmethod+1); err != nil { return } if buf[idVer] != socksVer5 { return errVer } nmethod := int(buf[idNmethod]) msgLen := nmethod + 2 if debug { debug.Printf("nmethod = %d, msgLen = %d.\n", nmethod, msgLen) ss.DumpMemory(buf, msgLen) } if n == msgLen { // handshake done, common case // do nothing, jump directly to send confirmation } else if n < msgLen { // has more methods to read, rare case if _, err = io.ReadFull(conn, buf[n:msgLen]); err != nil { return } if debug { ss.DumpMemory(buf, msgLen) } } else { // error, should not get extra data return errAuthExtraData } // send confirmation: version 5, no authentication required _, err = conn.Write([]byte{socksVer5, 0}) return }
func getRequest(conn net.Conn) (rawaddr []byte, host string, err error) { const ( idVer = 0 idCmd = 1 idType = 3 // address type index idIP0 = 4 // ip addres start index idDmLen = 4 // domain address length index idDm0 = 5 // domain address start index typeIPv4 = 1 // type is ipv4 address typeDm = 3 // type is domain address typeIPv6 = 4 // type is ipv6 address lenIPv4 = 3 + 1 + net.IPv4len + 2 // 3(ver+cmd+rsv) + 1addrType + ipv4 + 2port lenIPv6 = 3 + 1 + net.IPv6len + 2 // 3(ver+cmd+rsv) + 1addrType + ipv6 + 2port lenDmBase = 3 + 1 + 1 + 2 // 3 + 1addrType + 1addrLen + 2port, plus addrLen ) // refer to getRequest in server.go for why set buffer size to 263 buf := make([]byte, 263) var n int ss.SetReadTimeout(conn) // read till we get possible domain length field if n, err = io.ReadAtLeast(conn, buf, idDmLen+1); err != nil { return } // check version and cmd if buf[idVer] != socksVer5 { err = errVer return } if buf[idCmd] != socksCmdConnect { err = errCmd return } reqLen := -1 switch buf[idType] { case typeIPv4: reqLen = lenIPv4 case typeIPv6: reqLen = lenIPv6 case typeDm: reqLen = int(buf[idDmLen]) + lenDmBase default: err = errAddrType return } if n == reqLen { // common case, do nothing } else if n < reqLen { // rare case if _, err = io.ReadFull(conn, buf[n:reqLen]); err != nil { return } } else { err = errReqExtraData return } rawaddr = buf[idType:reqLen] if debug { switch buf[idType] { case typeIPv4: host = net.IP(buf[idIP0 : idIP0+net.IPv4len]).String() case typeIPv6: host = net.IP(buf[idIP0 : idIP0+net.IPv6len]).String() case typeDm: host = string(buf[idDm0 : idDm0+buf[idDmLen]]) } port := binary.BigEndian.Uint16(buf[reqLen-2 : reqLen]) host = net.JoinHostPort(host, strconv.Itoa(int(port))) } return }
func getRequest(conn *ss.Conn) (host string, extra []byte, err error) { const ( idType = 0 // address type index idIP0 = 1 // ip addres start index idDmLen = 1 // domain address length index idDm0 = 2 // domain address start index typeIPv4 = 1 // type is ipv4 address typeDm = 3 // type is domain address typeIPv6 = 4 // type is ipv6 address lenIPv4 = 1 + net.IPv4len + 2 // 1addrType + ipv4 + 2port lenIPv6 = 1 + net.IPv6len + 2 // 1addrType + ipv6 + 2port lenDmBase = 1 + 1 + 2 // 1addrType + 1addrLen + 2port, plus addrLen ) // buf size should at least have the same size with the largest possible // request size (when addrType is 3, domain name has at most 256 bytes) // 1(addrType) + 1(lenByte) + 256(max length address) + 2(port) buf := make([]byte, 260) var n int // read till we get possible domain length field ss.SetReadTimeout(conn) if n, err = io.ReadAtLeast(conn, buf, idDmLen+1); err != nil { return } reqLen := -1 switch buf[idType] { case typeIPv4: reqLen = lenIPv4 case typeIPv6: reqLen = lenIPv6 case typeDm: reqLen = int(buf[idDmLen]) + lenDmBase default: err = errors.New(fmt.Sprintf("addr type %d not supported", buf[idType])) return } if n < reqLen { // rare case ss.SetReadTimeout(conn) if _, err = io.ReadFull(conn, buf[n:reqLen]); err != nil { return } } else if n > reqLen { // it's possible to read more than just the request head extra = buf[reqLen:n] } // Return string for typeIP is not most efficient, but browsers (Chrome, // Safari, Firefox) all seems using typeDm exclusively. So this is not a // big problem. switch buf[idType] { case typeIPv4: host = net.IP(buf[idIP0 : idIP0+net.IPv4len]).String() case typeIPv6: host = net.IP(buf[idIP0 : idIP0+net.IPv6len]).String() case typeDm: host = string(buf[idDm0 : idDm0+buf[idDmLen]]) } // parse port port := binary.BigEndian.Uint16(buf[reqLen-2 : reqLen]) host = net.JoinHostPort(host, strconv.Itoa(int(port))) return }
func getRequest(conn *ss.Conn, auth bool) (host string, ota bool, err error) { ss.SetReadTimeout(conn) // buf size should at least have the same size with the largest possible // request size (when addrType is 3, domain name has at most 256 bytes) // 1(addrType) + 1(lenByte) + 256(max length address) + 2(port) + 10(hmac-sha1) buf := make([]byte, 270) // read till we get possible domain length field if _, err = io.ReadFull(conn, buf[:idType+1]); err != nil { return } var reqStart, reqEnd int addrType := buf[idType] switch addrType & ss.AddrMask { case typeIPv4: reqStart, reqEnd = idIP0, idIP0+lenIPv4 case typeIPv6: reqStart, reqEnd = idIP0, idIP0+lenIPv6 case typeDm: if _, err = io.ReadFull(conn, buf[idType+1:idDmLen+1]); err != nil { return } reqStart, reqEnd = idDm0, int(idDm0+buf[idDmLen]+lenDmBase) default: err = fmt.Errorf("addr type %d not supported", addrType&ss.AddrMask) return } if _, err = io.ReadFull(conn, buf[reqStart:reqEnd]); err != nil { return } // Return string for typeIP is not most efficient, but browsers (Chrome, // Safari, Firefox) all seems using typeDm exclusively. So this is not a // big problem. switch addrType & ss.AddrMask { case typeIPv4: host = net.IP(buf[idIP0 : idIP0+net.IPv4len]).String() case typeIPv6: host = net.IP(buf[idIP0 : idIP0+net.IPv6len]).String() case typeDm: host = string(buf[idDm0 : idDm0+buf[idDmLen]]) } // parse port port := binary.BigEndian.Uint16(buf[reqEnd-2 : reqEnd]) host = net.JoinHostPort(host, strconv.Itoa(int(port))) // if specified one time auth enabled, we should verify this if auth || addrType&ss.OneTimeAuthMask > 0 { ota = true if _, err = io.ReadFull(conn, buf[reqEnd:reqEnd+lenHmacSha1]); err != nil { return } iv := conn.GetIv() key := conn.GetKey() actualHmacSha1Buf := ss.HmacSha1(append(iv, key...), buf[:reqEnd]) if !bytes.Equal(buf[reqEnd:reqEnd+lenHmacSha1], actualHmacSha1Buf) { err = fmt.Errorf("verify one time auth failed, iv=%v key=%v data=%v", iv, key, buf[:reqEnd]) return } } return }