UDP noises: Add base64 and multi-packet support

infra/conf/freedom.go

@@ -1,6 +1,7 @@
 package conf
 
 import (
+	"encoding/base64"
 	"net"
 	"strconv"
 	"strings"
@@ -19,6 +20,7 @@ type FreedomConfig struct {
 	UserLevel      uint32    `json:"userLevel"`
 	Fragment       *Fragment `json:"fragment"`
 	Noise          *Noise    `json:"noise"`
+	Noises         []*Noise  `json:"noises"`
 	ProxyProtocol  uint32    `json:"proxyProtocol"`
 }
 
@@ -29,8 +31,9 @@ type Fragment struct {
 }
 
 type Noise struct {
-	Packet string `json:"packet"`
-	Delay  string `json:"delay"`
+	Type   string      `json:"type"`
+	Packet string      `json:"packet"`
+	Delay  *Int32Range `json:"delay"`
 }
 
 // Build implements Buildable
@@ -149,74 +152,18 @@ func (c *FreedomConfig) Build() (proto.Message, error) {
 			}
 		}
 	}
-	if c.Noise != nil {
-		config.Noise = new(freedom.Noise)
-		var err, err2 error
-		p := strings.Split(strings.ToLower(c.Noise.Packet), ":")
-		if len(p) != 2 {
-			return nil, errors.New("invalid type for packet")
-		}
-		switch p[0] {
-		case "rand":
-			randValue := strings.Split(p[1], "-")
-			if len(randValue) > 2 {
-				return nil, errors.New("Only 2 values are allowed for rand")
-			}
-			if len(randValue) == 2 {
-				config.Noise.LengthMin, err = strconv.ParseUint(randValue[0], 10, 64)
-				config.Noise.LengthMax, err2 = strconv.ParseUint(randValue[1], 10, 64)
-			}
-			if len(randValue) == 1 {
-				config.Noise.LengthMin, err = strconv.ParseUint(randValue[0], 10, 64)
-				config.Noise.LengthMax = config.Noise.LengthMin
-			}
-			if err != nil {
-				return nil, errors.New("invalid value for rand LengthMin").Base(err)
-			}
-			if err2 != nil {
-				return nil, errors.New("invalid value for rand LengthMax").Base(err2)
-			}
-			if config.Noise.LengthMin > config.Noise.LengthMax {
-				config.Noise.LengthMin, config.Noise.LengthMax = config.Noise.LengthMax, config.Noise.LengthMin
-			}
-			if config.Noise.LengthMin == 0 {
-				return nil, errors.New("rand lengthMin or lengthMax cannot be 0")
-			}
-
-		case "str":
-			//user input string
-			config.Noise.StrNoise = strings.TrimSpace(p[1])
 
-		default:
-			return nil, errors.New("Invalid packet,only rand and str are supported")
-		}
-		if c.Noise.Delay != "" {
-			d := strings.Split(strings.ToLower(c.Noise.Delay), "-")
-			if len(d) > 2 {
-				return nil, errors.New("Invalid delay value")
-			}
-			if len(d) == 2 {
-				config.Noise.DelayMin, err = strconv.ParseUint(d[0], 10, 64)
-				config.Noise.DelayMax, err2 = strconv.ParseUint(d[1], 10, 64)
+	if c.Noise != nil {
+		return nil, errors.PrintRemovedFeatureError("noise = { ... }", "noises = [ { ... } ]")
+	}
 
-			} else {
-				config.Noise.DelayMin, err = strconv.ParseUint(d[0], 10, 64)
-				config.Noise.DelayMax = config.Noise.DelayMin
-			}
+	if c.Noises != nil {
+		for _, n := range c.Noises {
+			NConfig, err := ParseNoise(n)
 			if err != nil {
-				return nil, errors.New("Invalid value for DelayMin").Base(err)
-			}
-			if err2 != nil {
-				return nil, errors.New("Invalid value for DelayMax").Base(err2)
+				return nil, err
 			}
-			if config.Noise.DelayMin > config.Noise.DelayMax {
-				config.Noise.DelayMin, config.Noise.DelayMax = config.Noise.DelayMax, config.Noise.DelayMin
-			}
-			if config.Noise.DelayMin == 0 {
-				return nil, errors.New("DelayMin or DelayMax cannot be 0")
-			}
-		} else {
-			config.Noise.DelayMin = 0
+			config.Noises = append(config.Noises, NConfig)
 		}
 	}
 
@@ -248,3 +195,67 @@ func (c *FreedomConfig) Build() (proto.Message, error) {
 	}
 	return config, nil
 }
+
+func ParseNoise(noise *Noise) (*freedom.Noise, error) {
+	var err, err2 error
+	NConfig := new(freedom.Noise)
+
+	switch strings.ToLower(noise.Type) {
+	case "rand":
+		randValue := strings.Split(noise.Packet, "-")
+		if len(randValue) > 2 {
+			return nil, errors.New("Only 2 values are allowed for rand")
+		}
+		if len(randValue) == 2 {
+			NConfig.LengthMin, err = strconv.ParseUint(randValue[0], 10, 64)
+			NConfig.LengthMax, err2 = strconv.ParseUint(randValue[1], 10, 64)
+		}
+		if len(randValue) == 1 {
+			NConfig.LengthMin, err = strconv.ParseUint(randValue[0], 10, 64)
+			NConfig.LengthMax = NConfig.LengthMin
+		}
+		if err != nil {
+			return nil, errors.New("invalid value for rand LengthMin").Base(err)
+		}
+		if err2 != nil {
+			return nil, errors.New("invalid value for rand LengthMax").Base(err2)
+		}
+		if NConfig.LengthMin > NConfig.LengthMax {
+			NConfig.LengthMin, NConfig.LengthMax = NConfig.LengthMax, NConfig.LengthMin
+		}
+		if NConfig.LengthMin == 0 {
+			return nil, errors.New("rand lengthMin or lengthMax cannot be 0")
+		}
+
+	case "str":
+		//user input string
+		NConfig.StrNoise = []byte(strings.TrimSpace(noise.Packet))
+
+	case "base64":
+		//user input base64
+		NConfig.StrNoise, err = base64.StdEncoding.DecodeString(strings.TrimSpace(noise.Packet))
+		if err != nil {
+			return nil, errors.New("Invalid base64 string")
+		}
+
+	default:
+		return nil, errors.New("Invalid packet,only rand,str,base64 are supported")
+	}
+
+	if noise.Delay != nil {
+		if noise.Delay.From != 0 && noise.Delay.To != 0 {
+			NConfig.DelayMin = uint64(noise.Delay.From)
+			NConfig.DelayMax = uint64(noise.Delay.To)
+			if NConfig.DelayMin > NConfig.LengthMax {
+				NConfig.DelayMin, NConfig.DelayMax = NConfig.LengthMax, NConfig.DelayMin
+			}
+		} else {
+			return nil, errors.New("DelayMin or DelayMax cannot be zero")
+		}
+
+	} else {
+		NConfig.DelayMin = 0
+		NConfig.DelayMax = 0
+	}
+	return NConfig, nil
+}

proxy/freedom/config.proto

@@ -25,7 +25,7 @@ message Noise {
   uint64 length_max = 2;
   uint64 delay_min = 3;
   uint64 delay_max = 4;
-  string str_noise = 5;
+  bytes str_noise = 5;
 }
 
 message Config {
@@ -48,5 +48,5 @@ message Config {
   uint32 user_level = 4;
   Fragment fragment = 5;
   uint32 proxy_protocol = 6;
-  Noise noise = 7;
+  repeated Noise noises = 7;
 }

proxy/freedom/freedom.go

@@ -208,12 +208,11 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 			}
 		} else {
 			writer = NewPacketWriter(conn, h, ctx, UDPOverride)
-			if h.config.Noise != nil {
-				errors.LogDebug(ctx, "NOISE", h.config.Noise.StrNoise, h.config.Noise.LengthMin, h.config.Noise.LengthMax,
-					h.config.Noise.DelayMin, h.config.Noise.DelayMax)
+			if h.config.Noises != nil {
+				errors.LogDebug(ctx, "NOISE", h.config.Noises)
 				writer = &NoisePacketWriter{
 					Writer:      writer,
-					noise:       h.config.Noise,
+					noises:      h.config.Noises,
 					firstWrite:  true,
 					UDPOverride: UDPOverride,
 				}
@@ -396,12 +395,12 @@ func (w *PacketWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
 
 type NoisePacketWriter struct {
 	buf.Writer
-	noise       *Noise
+	noises      []*Noise
 	firstWrite  bool
 	UDPOverride net.Destination
 }
 
-// MultiBuffer writer with Noise in first packet
+// MultiBuffer writer with Noise before first packet
 func (w *NoisePacketWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
 	if w.firstWrite {
 		w.firstWrite = false
@@ -411,22 +410,23 @@ func (w *NoisePacketWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
 		}
 		var noise []byte
 		var err error
-		//User input string
-		if w.noise.StrNoise != "" {
-			noise = []byte(w.noise.StrNoise)
-		} else {
-			//Random noise
-			noise, err = GenerateRandomBytes(randBetween(int64(w.noise.LengthMin),
-				int64(w.noise.LengthMax)))
-		}
-
-		if err != nil {
-			return err
-		}
-		w.Writer.WriteMultiBuffer(buf.MultiBuffer{buf.FromBytes(noise)})
+		for _, n := range w.noises {
+			//User input string or base64 encoded string
+			if n.StrNoise != nil {
+				noise = n.StrNoise
+			} else {
+				//Random noise
+				noise, err = GenerateRandomBytes(randBetween(int64(n.LengthMin),
+					int64(n.LengthMax)))
+			}
+			if err != nil {
+				return err
+			}
+			w.Writer.WriteMultiBuffer(buf.MultiBuffer{buf.FromBytes(noise)})
 
-		if w.noise.DelayMin != 0 {
-			time.Sleep(time.Duration(randBetween(int64(w.noise.DelayMin), int64(w.noise.DelayMax))) * time.Millisecond)
+			if n.DelayMin != 0 {
+				time.Sleep(time.Duration(randBetween(int64(n.DelayMin), int64(n.DelayMax))) * time.Millisecond)
+			}
 		}
 
 	}