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mirror of https://github.com/v2fly/v2ray-core.git synced 2024-12-22 01:57:12 -05:00
v2fly/proxy/vmess/encoding/client.go
2016-12-15 11:05:32 +01:00

281 lines
8.6 KiB
Go

package encoding
import (
"crypto/aes"
"crypto/cipher"
"crypto/md5"
"crypto/rand"
"hash/fnv"
"io"
"golang.org/x/crypto/chacha20poly1305"
"v2ray.com/core/common/buf"
"v2ray.com/core/common/crypto"
"v2ray.com/core/common/dice"
"v2ray.com/core/common/errors"
"v2ray.com/core/common/log"
v2net "v2ray.com/core/common/net"
"v2ray.com/core/common/protocol"
"v2ray.com/core/common/serial"
"v2ray.com/core/proxy/vmess"
)
func hashTimestamp(t protocol.Timestamp) []byte {
bytes := make([]byte, 0, 32)
bytes = t.Bytes(bytes)
bytes = t.Bytes(bytes)
bytes = t.Bytes(bytes)
bytes = t.Bytes(bytes)
return bytes
}
// ClientSession stores connection session info for VMess client.
type ClientSession struct {
requestBodyKey []byte
requestBodyIV []byte
responseHeader byte
responseBodyKey []byte
responseBodyIV []byte
responseReader io.Reader
idHash protocol.IDHash
}
// NewClientSession creates a new ClientSession.
func NewClientSession(idHash protocol.IDHash) *ClientSession {
randomBytes := make([]byte, 33) // 16 + 16 + 1
rand.Read(randomBytes)
session := &ClientSession{}
session.requestBodyKey = randomBytes[:16]
session.requestBodyIV = randomBytes[16:32]
session.responseHeader = randomBytes[32]
responseBodyKey := md5.Sum(session.requestBodyKey)
responseBodyIV := md5.Sum(session.requestBodyIV)
session.responseBodyKey = responseBodyKey[:]
session.responseBodyIV = responseBodyIV[:]
session.idHash = idHash
return session
}
func (v *ClientSession) EncodeRequestHeader(header *protocol.RequestHeader, writer io.Writer) {
timestamp := protocol.NewTimestampGenerator(protocol.NowTime(), 30)()
account, err := header.User.GetTypedAccount()
if err != nil {
log.Error("VMess: Failed to get user account: ", err)
return
}
idHash := v.idHash(account.(*vmess.InternalAccount).AnyValidID().Bytes())
idHash.Write(timestamp.Bytes(nil))
writer.Write(idHash.Sum(nil))
buffer := make([]byte, 0, 512)
buffer = append(buffer, Version)
buffer = append(buffer, v.requestBodyIV...)
buffer = append(buffer, v.requestBodyKey...)
buffer = append(buffer, v.responseHeader, byte(header.Option))
padingLen := dice.Roll(16)
if header.Security.Is(protocol.SecurityType_LEGACY) {
// Disable padding in legacy mode for a smooth transition.
padingLen = 0
}
security := byte(padingLen<<4) | byte(header.Security)
buffer = append(buffer, security, byte(0), byte(header.Command))
buffer = header.Port.Bytes(buffer)
switch header.Address.Family() {
case v2net.AddressFamilyIPv4:
buffer = append(buffer, AddrTypeIPv4)
buffer = append(buffer, header.Address.IP()...)
case v2net.AddressFamilyIPv6:
buffer = append(buffer, AddrTypeIPv6)
buffer = append(buffer, header.Address.IP()...)
case v2net.AddressFamilyDomain:
buffer = append(buffer, AddrTypeDomain, byte(len(header.Address.Domain())))
buffer = append(buffer, header.Address.Domain()...)
}
if padingLen > 0 {
pading := make([]byte, padingLen)
rand.Read(pading)
buffer = append(buffer, pading...)
}
fnv1a := fnv.New32a()
fnv1a.Write(buffer)
buffer = fnv1a.Sum(buffer)
timestampHash := md5.New()
timestampHash.Write(hashTimestamp(timestamp))
iv := timestampHash.Sum(nil)
aesStream := crypto.NewAesEncryptionStream(account.(*vmess.InternalAccount).ID.CmdKey(), iv)
aesStream.XORKeyStream(buffer, buffer)
writer.Write(buffer)
return
}
func (v *ClientSession) EncodeRequestBody(request *protocol.RequestHeader, writer io.Writer) buf.Writer {
var authWriter io.Writer
if request.Security.Is(protocol.SecurityType_NONE) {
if request.Option.Has(protocol.RequestOptionChunkStream) {
auth := &crypto.AEADAuthenticator{
AEAD: new(FnvAuthenticator),
NonceGenerator: crypto.NoOpBytesGenerator{},
AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
}
authWriter = crypto.NewAuthenticationWriter(auth, writer)
} else {
authWriter = writer
}
} else if request.Security.Is(protocol.SecurityType_LEGACY) {
aesStream := crypto.NewAesEncryptionStream(v.requestBodyKey, v.requestBodyIV)
cryptionWriter := crypto.NewCryptionWriter(aesStream, writer)
if request.Option.Has(protocol.RequestOptionChunkStream) {
auth := &crypto.AEADAuthenticator{
AEAD: new(FnvAuthenticator),
NonceGenerator: crypto.NoOpBytesGenerator{},
AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
}
authWriter = crypto.NewAuthenticationWriter(auth, cryptionWriter)
} else {
authWriter = cryptionWriter
}
} else if request.Security.Is(protocol.SecurityType_AES128_GCM) {
block, _ := aes.NewCipher(v.requestBodyKey)
aead, _ := cipher.NewGCM(block)
auth := &crypto.AEADAuthenticator{
AEAD: aead,
NonceGenerator: &ChunkNonceGenerator{
Nonce: append([]byte(nil), v.requestBodyIV...),
Size: aead.NonceSize(),
},
AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
}
authWriter = crypto.NewAuthenticationWriter(auth, writer)
} else if request.Security.Is(protocol.SecurityType_CHACHA20_POLY1305) {
aead, _ := chacha20poly1305.New(GenerateChacha20Poly1305Key(v.requestBodyKey))
auth := &crypto.AEADAuthenticator{
AEAD: aead,
NonceGenerator: &ChunkNonceGenerator{
Nonce: append([]byte(nil), v.requestBodyIV...),
Size: aead.NonceSize(),
},
AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
}
authWriter = crypto.NewAuthenticationWriter(auth, writer)
}
return buf.NewWriter(authWriter)
}
func (v *ClientSession) DecodeResponseHeader(reader io.Reader) (*protocol.ResponseHeader, error) {
aesStream := crypto.NewAesDecryptionStream(v.responseBodyKey, v.responseBodyIV)
v.responseReader = crypto.NewCryptionReader(aesStream, reader)
buffer := make([]byte, 256)
_, err := io.ReadFull(v.responseReader, buffer[:4])
if err != nil {
log.Info("VMess|Client: Failed to read response header: ", err)
return nil, err
}
if buffer[0] != v.responseHeader {
return nil, errors.Format("VMess|Client: Unexpected response header. Expecting %d but actually %d", v.responseHeader, buffer[0])
}
header := &protocol.ResponseHeader{
Option: protocol.ResponseOption(buffer[1]),
}
if buffer[2] != 0 {
cmdID := buffer[2]
dataLen := int(buffer[3])
_, err := io.ReadFull(v.responseReader, buffer[:dataLen])
if err != nil {
log.Info("VMess|Client: Failed to read response command: ", err)
return nil, err
}
data := buffer[:dataLen]
command, err := UnmarshalCommand(cmdID, data)
if err == nil {
header.Command = command
}
}
return header, nil
}
func (v *ClientSession) DecodeResponseBody(request *protocol.RequestHeader, reader io.Reader) buf.Reader {
aggressive := (request.Command == protocol.RequestCommandTCP)
var authReader io.Reader
if request.Security.Is(protocol.SecurityType_NONE) {
if request.Option.Has(protocol.RequestOptionChunkStream) {
auth := &crypto.AEADAuthenticator{
AEAD: new(FnvAuthenticator),
NonceGenerator: crypto.NoOpBytesGenerator{},
AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
}
authReader = crypto.NewAuthenticationReader(auth, reader, aggressive)
} else {
authReader = reader
}
} else if request.Security.Is(protocol.SecurityType_LEGACY) {
if request.Option.Has(protocol.RequestOptionChunkStream) {
auth := &crypto.AEADAuthenticator{
AEAD: new(FnvAuthenticator),
NonceGenerator: crypto.NoOpBytesGenerator{},
AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
}
authReader = crypto.NewAuthenticationReader(auth, v.responseReader, aggressive)
} else {
authReader = v.responseReader
}
} else if request.Security.Is(protocol.SecurityType_AES128_GCM) {
block, _ := aes.NewCipher(v.responseBodyKey)
aead, _ := cipher.NewGCM(block)
auth := &crypto.AEADAuthenticator{
AEAD: aead,
NonceGenerator: &ChunkNonceGenerator{
Nonce: append([]byte(nil), v.responseBodyIV...),
Size: aead.NonceSize(),
},
AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
}
authReader = crypto.NewAuthenticationReader(auth, reader, aggressive)
} else if request.Security.Is(protocol.SecurityType_CHACHA20_POLY1305) {
aead, _ := chacha20poly1305.New(GenerateChacha20Poly1305Key(v.responseBodyKey))
auth := &crypto.AEADAuthenticator{
AEAD: aead,
NonceGenerator: &ChunkNonceGenerator{
Nonce: append([]byte(nil), v.responseBodyIV...),
Size: aead.NonceSize(),
},
AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
}
authReader = crypto.NewAuthenticationReader(auth, reader, aggressive)
}
return buf.NewReader(authReader)
}
type ChunkNonceGenerator struct {
Nonce []byte
Size int
count uint16
}
func (v *ChunkNonceGenerator) Next() []byte {
serial.Uint16ToBytes(v.count, v.Nonce[:0])
v.count++
return v.Nonce[:v.Size]
}