diff --git a/io/vmess/vmess.go b/io/vmess/vmess.go
index d597b19a8..cbfb6f6a2 100644
--- a/io/vmess/vmess.go
+++ b/io/vmess/vmess.go
@@ -2,36 +2,328 @@
 package vmess
 
 import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/binary"
+	"errors"
 	"fmt"
 	"io"
+	_ "log"
+	mrand "math/rand"
+	"net"
+
+	"github.com/v2ray/v2ray-core"
+	v2io "github.com/v2ray/v2ray-core/io"
 )
 
-// VMessInput implements the input message of VMess protocol. It only contains
-// the header of a input message. The data part will be handled by conection
+const (
+	addrTypeIPv4   = byte(0x01)
+	addrTypeIPv6   = byte(0x03)
+	addrTypeDomain = byte(0x02)
+
+	vMessVersion = byte(0x01)
+)
+
+var (
+	ErrorInvalidUser = errors.New("Invalid User")
+)
+
+// VMessRequest implements the request message of VMess protocol. It only contains
+// the header of a request message. The data part will be handled by conection
 // handler directly, in favor of data streaming.
-type VMessInput struct {
-	version  byte
-	userHash [16]byte
-	respKey  [16]byte
-	iv       [16]byte
-	respHead [4]byte
-	command  byte
-	port     uint16
-	target   [256]byte
+// 1 Version
+// 16 UserHash
+// 16 Request IV
+// 16 Request Key
+// 4 Response Header
+// 1 Command
+// 2 Port
+// 1 Address Type
+// 256 Target Address
+
+type VMessRequest [312]byte
+
+func (r *VMessRequest) Version() byte {
+	return r[0]
 }
 
-func Read(reader io.Reader) (input *VMessInput, err error) {
-	buffer := make([]byte, 17 /* version + user hash */)
-	nBytes, err := reader.Read(buffer)
-	if err != nil {
-		return
+func (r *VMessRequest) SetVersion(version byte) *VMessRequest {
+	r[0] = version
+	return r
+}
+
+func (r *VMessRequest) UserHash() []byte {
+	return r[1:17]
+}
+
+func (r *VMessRequest) RequestIV() []byte {
+	return r[17:33]
+}
+
+func (r *VMessRequest) RequestKey() []byte {
+	return r[33:49]
+}
+
+func (r *VMessRequest) ResponseHeader() []byte {
+	return r[49:53]
+}
+
+func (r *VMessRequest) Command() byte {
+	return r[53]
+}
+
+func (r *VMessRequest) SetCommand(command byte) *VMessRequest {
+	r[53] = command
+	return r
+}
+
+func (r *VMessRequest) Port() uint16 {
+	return binary.BigEndian.Uint16(r.portBytes())
+}
+
+func (r *VMessRequest) portBytes() []byte {
+	return r[54:56]
+}
+
+func (r *VMessRequest) SetPort(port uint16) *VMessRequest {
+	binary.BigEndian.PutUint16(r.portBytes(), port)
+	return r
+}
+
+func (r *VMessRequest) targetAddressType() byte {
+	return r[56]
+}
+
+func (r *VMessRequest) TargetAddress() string {
+	switch r.targetAddressType() {
+	case addrTypeIPv4:
+		return string(net.IPv4(r[57], r[58], r[59], r[60]))
+	case addrTypeIPv6:
+		return string(net.IP(r[57:73]))
+	case addrTypeDomain:
+		domainLength := int(r[57])
+		return string(r[58 : 58+domainLength])
+	default:
+		panic("Unexpected address type")
 	}
-	if nBytes != len(buffer) {
+}
+
+func (r *VMessRequest) targetAddressBytes() []byte {
+	switch r.targetAddressType() {
+	case addrTypeIPv4:
+		return r[57:61]
+	case addrTypeIPv6:
+		return r[57:73]
+	case addrTypeDomain:
+		domainLength := int(r[57])
+		return r[57 : 58+domainLength]
+	default:
+		panic("Unexpected address type")
+	}
+}
+
+func (r *VMessRequest) SetIPv4(ipv4 []byte) *VMessRequest {
+	r[56] = addrTypeIPv4
+	copy(r[57:], ipv4)
+	return r
+}
+
+func (r *VMessRequest) SetIPv6(ipv6 []byte) *VMessRequest {
+	r[56] = addrTypeIPv6
+	copy(r[57:], ipv6)
+	return r
+}
+
+func (r *VMessRequest) SetDomain(domain string) *VMessRequest {
+	r[56] = addrTypeDomain
+	r[57] = byte(len(domain))
+	copy(r[58:], []byte(domain))
+	return r
+}
+
+type VMessRequestReader struct {
+	vUserSet *core.VUserSet
+}
+
+func NewVMessRequestReader(vUserSet *core.VUserSet) *VMessRequestReader {
+	reader := new(VMessRequestReader)
+	reader.vUserSet = vUserSet
+	return reader
+}
+
+func (r *VMessRequestReader) Read(reader io.Reader) (*VMessRequest, error) {
+	request := new(VMessRequest)
+
+	nBytes, err := reader.Read(request[0:17] /* version + user hash */)
+	if err != nil {
+		return nil, err
+	}
+	if nBytes != 17 {
 		err = fmt.Errorf("Unexpected length of header %d", nBytes)
-		return
+		return nil, err
+	}
+	// TODO: verify version number
+	userId, valid := r.vUserSet.IsValidUserId(request.UserHash())
+	if !valid {
+		return nil, ErrorInvalidUser
 	}
 
-	return
+	decryptor, err := NewDecryptionReader(reader, userId.Hash([]byte("PWD")), make([]byte, blockSize))
+	if err != nil {
+		return nil, err
+	}
+
+	buffer := make([]byte, 300)
+	nBytes, err = decryptor.Read(buffer[0:1])
+	if err != nil {
+		return nil, err
+	}
+
+	randomLength := buffer[0]
+	if randomLength <= 0 || randomLength > 32 {
+		return nil, fmt.Errorf("Unexpected random length %d", randomLength)
+	}
+	_, err = decryptor.Read(buffer[:randomLength])
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: check number of bytes returned
+	_, err = decryptor.Read(request.RequestIV())
+	if err != nil {
+		return nil, err
+	}
+	_, err = decryptor.Read(request.RequestKey())
+	if err != nil {
+		return nil, err
+	}
+	_, err = decryptor.Read(request.ResponseHeader())
+	if err != nil {
+		return nil, err
+	}
+	_, err = decryptor.Read(buffer[0:1])
+	if err != nil {
+		return nil, err
+	}
+	request.SetCommand(buffer[0])
+
+	_, err = decryptor.Read(buffer[0:2])
+	if err != nil {
+		return nil, err
+	}
+	request.SetPort(binary.BigEndian.Uint16(buffer[0:2]))
+
+	_, err = decryptor.Read(buffer[0:1])
+	if err != nil {
+		return nil, err
+	}
+	switch buffer[0] {
+	case addrTypeIPv4:
+		_, err = decryptor.Read(buffer[1:5])
+		if err != nil {
+			return nil, err
+		}
+		request.SetIPv4(buffer[1:5])
+	case addrTypeIPv6:
+		_, err = decryptor.Read(buffer[1:17])
+		if err != nil {
+			return nil, err
+		}
+		request.SetIPv6(buffer[1:17])
+	case addrTypeDomain:
+		_, err = decryptor.Read(buffer[1:2])
+		if err != nil {
+			return nil, err
+		}
+		domainLength := buffer[1]
+		_, err = decryptor.Read(buffer[2 : 2+domainLength])
+		if err != nil {
+			return nil, err
+		}
+		request.SetDomain(string(buffer[2 : 2+domainLength]))
+	}
+	_, err = decryptor.Read(buffer[0:1])
+	if err != nil {
+		return nil, err
+	}
+	randomLength = buffer[0]
+	_, err = decryptor.Read(buffer[:randomLength])
+	if err != nil {
+		return nil, err
+	}
+
+	return request, nil
+}
+
+type VMessRequestWriter struct {
+	vUserSet *core.VUserSet
+}
+
+func NewVMessRequestWriter(vUserSet *core.VUserSet) *VMessRequestWriter {
+	writer := new(VMessRequestWriter)
+	writer.vUserSet = vUserSet
+	return writer
+}
+
+func (w *VMessRequestWriter) Write(writer io.Writer, request *VMessRequest) error {
+	buffer := make([]byte, 0, 300)
+	buffer = append(buffer, request.Version())
+	buffer = append(buffer, request.UserHash()...)
+
+	encryptionBegin := len(buffer)
+
+	randomLength := mrand.Intn(32) + 1
+	randomContent := make([]byte, randomLength)
+	_, err := rand.Read(randomContent)
+	if err != nil {
+		return err
+	}
+	buffer = append(buffer, byte(randomLength))
+	buffer = append(buffer, randomContent...)
+
+	buffer = append(buffer, request.RequestIV()...)
+	buffer = append(buffer, request.RequestKey()...)
+	buffer = append(buffer, request.ResponseHeader()...)
+	buffer = append(buffer, request.Command())
+	buffer = append(buffer, request.portBytes()...)
+	buffer = append(buffer, request.targetAddressType())
+	buffer = append(buffer, request.targetAddressBytes()...)
+
+	paddingLength := blockSize - 1 - (len(buffer)-encryptionBegin)%blockSize
+	if paddingLength == 0 {
+		paddingLength = blockSize
+	}
+	paddingBuffer := make([]byte, paddingLength)
+	_, err = rand.Read(paddingBuffer)
+	if err != nil {
+		return err
+	}
+	buffer = append(buffer, byte(paddingLength))
+	buffer = append(buffer, paddingBuffer...)
+	encryptionEnd := len(buffer)
+
+	userId, valid := w.vUserSet.IsValidUserId(request.UserHash())
+	if !valid {
+		return ErrorInvalidUser
+	}
+	aesCipher, err := aes.NewCipher(userId.Hash([]byte("PWD")))
+	if err != nil {
+		return err
+	}
+	aesMode := cipher.NewCBCEncrypter(aesCipher, make([]byte, blockSize))
+	cWriter := v2io.NewCryptionWriter(aesMode, writer)
+
+	_, err = writer.Write(buffer[0:encryptionBegin])
+	if err != nil {
+		return err
+	}
+	_, err = cWriter.Write(buffer[encryptionBegin:encryptionEnd])
+	if err != nil {
+		return err
+	}
+
+	return nil
 }
 
 type VMessOutput [4]byte
diff --git a/io/vmess/vmess_test.go b/io/vmess/vmess_test.go
new file mode 100644
index 000000000..91af1651e
--- /dev/null
+++ b/io/vmess/vmess_test.go
@@ -0,0 +1,88 @@
+package vmess
+
+import (
+	"bytes"
+	"crypto/rand"
+	"testing"
+
+	"github.com/v2ray/v2ray-core"
+)
+
+func TestVMessSerialization(t *testing.T) {
+	userId, err := core.UUIDToVID("2b2966ac-16aa-4fbf-8d81-c5f172a3da51")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	userSet := core.NewVUserSet()
+	userSet.AddUser(core.VUser{userId})
+
+	request := new(VMessRequest)
+	request.SetVersion(byte(0x01))
+	userHash := userId.Hash([]byte("ASK"))
+	copy(request.UserHash(), userHash)
+
+	_, err = rand.Read(request.RequestIV())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = rand.Read(request.RequestKey())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = rand.Read(request.ResponseHeader())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	request.SetCommand(byte(0x01))
+	request.SetPort(80)
+	request.SetDomain("v2ray.com")
+
+	buffer := bytes.NewBuffer(make([]byte, 0, 300))
+	requestWriter := NewVMessRequestWriter(userSet)
+	err = requestWriter.Write(buffer, request)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	requestReader := NewVMessRequestReader(userSet)
+	actualRequest, err := requestReader.Read(buffer)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if actualRequest.Version() != byte(0x01) {
+		t.Errorf("Expected Version 1, but got %d", actualRequest.Version())
+	}
+
+	if !bytes.Equal(request.UserHash(), actualRequest.UserHash()) {
+		t.Errorf("Expected user hash %v, but got %v", request.UserHash(), actualRequest.UserHash())
+	}
+
+	if !bytes.Equal(request.RequestIV(), actualRequest.RequestIV()) {
+		t.Errorf("Expected request IV %v, but got %v", request.RequestIV(), actualRequest.RequestIV())
+	}
+
+	if !bytes.Equal(request.RequestKey(), actualRequest.RequestKey()) {
+		t.Errorf("Expected request Key %v, but got %v", request.RequestKey(), actualRequest.RequestKey())
+	}
+
+	if !bytes.Equal(request.ResponseHeader(), actualRequest.ResponseHeader()) {
+		t.Errorf("Expected response header %v, but got %v", request.ResponseHeader(), actualRequest.ResponseHeader())
+	}
+
+	if actualRequest.Command() != byte(0x01) {
+		t.Errorf("Expected command 1, but got %d", actualRequest.Command())
+	}
+
+	if actualRequest.Port() != 80 {
+		t.Errorf("Expected port 80, but got %d", actualRequest.Port())
+	}
+
+	if actualRequest.TargetAddress() != "v2ray.com" {
+		t.Errorf("Expected target address v2ray.com, but got %s", actualRequest.TargetAddress())
+	}
+}
diff --git a/vuserset.go b/vuserset.go
index 18ffb9cae..6f7f3db55 100644
--- a/vuserset.go
+++ b/vuserset.go
@@ -12,6 +12,7 @@ type VUserSet struct {
 func NewVUserSet() *VUserSet {
 	vuSet := new(VUserSet)
 	vuSet.validUserIds = make([]VID, 0, 16)
+	vuSet.userIdsAskHash = make(map[string]int)
 	return vuSet
 }