Refactor: Add Shadowsocks Validator (#233)

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秋のかえで 2021-02-12 23:17:31 +08:00 committed by GitHub
parent 1b87264c53
commit df39991bb3
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
5 changed files with 230 additions and 93 deletions

View file

@ -7,6 +7,8 @@ import (
"crypto/md5"
"crypto/sha1"
"io"
"reflect"
"strconv"
"golang.org/x/crypto/chacha20poly1305"
"golang.org/x/crypto/hkdf"
@ -31,6 +33,31 @@ func (a *MemoryAccount) Equals(another protocol.Account) bool {
return false
}
func (a *MemoryAccount) GetCipherName() string {
switch a.Cipher.(type) {
case *AesCfb:
keyBytes := a.Cipher.(*AesCfb).KeyBytes
return "AES_" + strconv.FormatInt(int64(keyBytes*8), 10) + "_CFB"
case *ChaCha20:
if a.Cipher.(*ChaCha20).IVBytes == 8 {
return "CHACHA20"
}
return "CHACHA20_IETF"
case *AEADCipher:
switch reflect.ValueOf(a.Cipher.(*AEADCipher).AEADAuthCreator).Pointer() {
case reflect.ValueOf(createAesGcm).Pointer():
keyBytes := a.Cipher.(*AEADCipher).KeyBytes
return "AES_" + strconv.FormatInt(int64(keyBytes*8), 10) + "_GCM"
case reflect.ValueOf(createChacha20Poly1305).Pointer():
return "CHACHA20_POLY1305"
}
case *NoneCipher:
return "NONE"
}
return ""
}
func createAesGcm(key []byte) cipher.AEAD {
block, err := aes.NewCipher(key)
common.Must(err)

View file

@ -54,12 +54,9 @@ func (r *FullReader) Read(p []byte) (n int, err error) {
}
// ReadTCPSession reads a Shadowsocks TCP session from the given reader, returns its header and remaining parts.
func ReadTCPSession(users []*protocol.MemoryUser, reader io.Reader) (*protocol.RequestHeader, buf.Reader, error) {
user := users[0]
account := user.Account.(*MemoryAccount)
func ReadTCPSession(validator *Validator, reader io.Reader) (*protocol.RequestHeader, buf.Reader, error) {
hashkdf := hmac.New(sha256.New, []byte("SSBSKDF"))
hashkdf.Write(account.Key)
behaviorSeed := crc32.ChecksumIEEE(hashkdf.Sum(nil))
@ -71,10 +68,20 @@ func ReadTCPSession(users []*protocol.MemoryUser, reader io.Reader) (*protocol.R
readSizeRemain := DrainSize
var r2 buf.Reader
buffer := buf.New()
defer buffer.Release()
if len(users) > 1 {
buffer := buf.New()
defer buffer.Release()
var user *protocol.MemoryUser
var ivLen int32
var err error
count := validator.Count()
if count == 0 {
readSizeRemain -= int(buffer.Len())
DrainConnN(reader, readSizeRemain)
return nil, nil, newError("invalid user")
} else if count > 1 {
var aead cipher.AEAD
if _, err := buffer.ReadFullFrom(reader, 50); err != nil {
readSizeRemain -= int(buffer.Len())
@ -83,45 +90,26 @@ func ReadTCPSession(users []*protocol.MemoryUser, reader io.Reader) (*protocol.R
}
bs := buffer.Bytes()
user, aead, _, ivLen, err = validator.Get(bs, protocol.RequestCommandTCP)
var aeadCipher *AEADCipher
var ivLen int32
subkey := make([]byte, 32)
length := make([]byte, 16)
var aead cipher.AEAD
var err error
for _, user = range users {
account = user.Account.(*MemoryAccount)
aeadCipher = account.Cipher.(*AEADCipher)
ivLen = aeadCipher.IVSize()
subkey = subkey[:aeadCipher.KeyBytes]
hkdfSHA1(account.Key, bs[:ivLen], subkey)
aead = aeadCipher.AEADAuthCreator(subkey)
_, err = aead.Open(length[:0], length[4:16], bs[ivLen:ivLen+18], nil)
if err == nil {
reader = &FullReader{reader, bs[ivLen:]}
auth := &crypto.AEADAuthenticator{
AEAD: aead,
NonceGenerator: crypto.GenerateInitialAEADNonce(),
}
r2 = crypto.NewAuthenticationReader(auth, &crypto.AEADChunkSizeParser{
Auth: auth,
}, reader, protocol.TransferTypeStream, nil)
break
if user != nil {
reader = &FullReader{reader, bs[ivLen:]}
auth := &crypto.AEADAuthenticator{
AEAD: aead,
NonceGenerator: crypto.GenerateInitialAEADNonce(),
}
}
if err != nil {
r2 = crypto.NewAuthenticationReader(auth, &crypto.AEADChunkSizeParser{
Auth: auth,
}, reader, protocol.TransferTypeStream, nil)
} else {
readSizeRemain -= int(buffer.Len())
DrainConnN(reader, readSizeRemain)
return nil, nil, newError("failed to match an user").Base(err)
}
}
buffer := buf.New()
defer buffer.Release()
if r2 == nil {
ivLen := account.Cipher.IVSize()
} else {
user, ivLen = validator.GetOnlyUser()
account := user.Account.(*MemoryAccount)
hashkdf.Write(account.Key)
var iv []byte
if ivLen > 0 {
if _, err := buffer.ReadFullFrom(reader, ivLen); err != nil {
@ -261,40 +249,31 @@ func EncodeUDPPacket(request *protocol.RequestHeader, payload []byte) (*buf.Buff
return buffer, nil
}
func DecodeUDPPacket(users []*protocol.MemoryUser, payload *buf.Buffer) (*protocol.RequestHeader, *buf.Buffer, error) {
func DecodeUDPPacket(validator *Validator, payload *buf.Buffer) (*protocol.RequestHeader, *buf.Buffer, error) {
bs := payload.Bytes()
if len(bs) <= 32 {
return nil, nil, newError("len(bs) <= 32")
}
var user *protocol.MemoryUser
var account *MemoryAccount
var err error
if len(users) > 1 {
bs := payload.Bytes()
if len(bs) <= 32 {
return nil, nil, newError("len(bs) <= 32")
}
var aeadCipher *AEADCipher
var ivLen int32
subkey := make([]byte, 32)
data := make([]byte, 8192)
var aead cipher.AEAD
count := validator.Count()
if count == 0 {
return nil, nil, newError("invalid user")
} else if count > 1 {
var d []byte
for _, user = range users {
account = user.Account.(*MemoryAccount)
aeadCipher = account.Cipher.(*AEADCipher)
ivLen = aeadCipher.IVSize()
subkey = subkey[:aeadCipher.KeyBytes]
hkdfSHA1(account.Key, bs[:ivLen], subkey)
aead = aeadCipher.AEADAuthCreator(subkey)
d, err = aead.Open(data[:0], data[8180:8192], bs[ivLen:], nil)
if err == nil {
payload.Clear()
payload.Write(d)
break
}
user, _, d, _, err = validator.Get(bs, protocol.RequestCommandUDP)
if user != nil {
payload.Clear()
payload.Write(d)
} else {
return nil, nil, newError("failed to decrypt UDP payload").Base(err)
}
} else {
user = users[0]
account = user.Account.(*MemoryAccount)
user, _ = validator.GetOnlyUser()
account := user.Account.(*MemoryAccount)
var iv []byte
if !account.Cipher.IsAEAD() && account.Cipher.IVSize() > 0 {
@ -302,12 +281,9 @@ func DecodeUDPPacket(users []*protocol.MemoryUser, payload *buf.Buffer) (*protoc
iv = make([]byte, account.Cipher.IVSize())
copy(iv, payload.BytesTo(account.Cipher.IVSize()))
}
err = account.Cipher.DecodePacket(account.Key, payload)
}
if err != nil {
return nil, nil, newError("failed to decrypt UDP payload").Base(err)
if err = account.Cipher.DecodePacket(account.Key, payload); err != nil {
return nil, nil, newError("failed to decrypt UDP payload").Base(err)
}
}
request := &protocol.RequestHeader{
@ -341,7 +317,10 @@ func (v *UDPReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
buffer.Release()
return nil, err
}
u, payload, err := DecodeUDPPacket([]*protocol.MemoryUser{v.User}, buffer)
validator := new(Validator)
validator.Add(v.User)
u, payload, err := DecodeUDPPacket(validator, buffer)
if err != nil {
buffer.Release()
return nil, err

View file

@ -38,7 +38,9 @@ func TestUDPEncoding(t *testing.T) {
encodedData, err := EncodeUDPPacket(request, data.Bytes())
common.Must(err)
decodedRequest, decodedData, err := DecodeUDPPacket([]*protocol.MemoryUser{request.User}, encodedData)
validator := new(Validator)
validator.Add(request.User)
decodedRequest, decodedData, err := DecodeUDPPacket(validator, encodedData)
common.Must(err)
if r := cmp.Diff(decodedData.Bytes(), data.Bytes()); r != "" {
@ -117,7 +119,9 @@ func TestTCPRequest(t *testing.T) {
common.Must(writer.WriteMultiBuffer(buf.MultiBuffer{data}))
decodedRequest, reader, err := ReadTCPSession([]*protocol.MemoryUser{request.User}, cache)
validator := new(Validator)
validator.Add(request.User)
decodedRequest, reader, err := ReadTCPSession(validator, cache)
common.Must(err)
if r := cmp.Diff(decodedRequest, request, cmp.Comparer(func(a1, a2 protocol.Account) bool { return a1.Equals(a2) })); r != "" {
t.Error("request: ", r)

View file

@ -22,35 +22,46 @@ import (
type Server struct {
config *ServerConfig
users []*protocol.MemoryUser
validator *Validator
policyManager policy.Manager
cone bool
}
// NewServer create a new Shadowsocks server.
func NewServer(ctx context.Context, config *ServerConfig) (*Server, error) {
if config.Users == nil {
return nil, newError("empty users")
validator := new(Validator)
for _, user := range config.Users {
u, err := user.ToMemoryUser()
if err != nil {
return nil, newError("failed to get shadowsocks user").Base(err).AtError()
}
if err := validator.Add(u); err != nil {
return nil, newError("failed to add user").Base(err).AtError()
}
}
v := core.MustFromContext(ctx)
s := &Server{
config: config,
validator: validator,
policyManager: v.GetFeature(policy.ManagerType()).(policy.Manager),
cone: ctx.Value("cone").(bool),
}
for _, user := range config.Users {
u, err := user.ToMemoryUser()
if err != nil {
return nil, newError("failed to parse user account").Base(err)
}
s.users = append(s.users, u)
}
return s, nil
}
// AddUser implements proxy.UserManager.AddUser().
func (s *Server) AddUser(ctx context.Context, u *protocol.MemoryUser) error {
return s.validator.Add(u)
}
// RemoveUser implements proxy.UserManager.RemoveUser().
func (s *Server) RemoveUser(ctx context.Context, e string) error {
return s.validator.Del(e)
}
func (s *Server) Network() []net.Network {
list := s.config.Network
if len(list) == 0 {
@ -102,8 +113,9 @@ func (s *Server) handleUDPPayload(ctx context.Context, conn internet.Connection,
if inbound == nil {
panic("no inbound metadata")
}
if len(s.users) == 1 {
inbound.User = s.users[0]
if s.validator.Count() == 1 {
inbound.User, _ = s.validator.GetOnlyUser()
}
var dest *net.Destination
@ -121,9 +133,11 @@ func (s *Server) handleUDPPayload(ctx context.Context, conn internet.Connection,
var err error
if inbound.User != nil {
request, data, err = DecodeUDPPacket([]*protocol.MemoryUser{inbound.User}, payload)
validator := new(Validator)
validator.Add(inbound.User)
request, data, err = DecodeUDPPacket(validator, payload)
} else {
request, data, err = DecodeUDPPacket(s.users, payload)
request, data, err = DecodeUDPPacket(s.validator, payload)
if err == nil {
inbound.User = request.User
}
@ -178,7 +192,7 @@ func (s *Server) handleConnection(ctx context.Context, conn internet.Connection,
}
bufferedReader := buf.BufferedReader{Reader: buf.NewReader(conn)}
request, bodyReader, err := ReadTCPSession(s.users, &bufferedReader)
request, bodyReader, err := ReadTCPSession(s.validator, &bufferedReader)
if err != nil {
log.Record(&log.AccessMessage{
From: conn.RemoteAddr(),

View file

@ -0,0 +1,113 @@
package shadowsocks
import (
"crypto/cipher"
"strings"
"sync"
"github.com/xtls/xray-core/common/protocol"
)
// Validator stores valid Shadowsocks users.
type Validator struct {
// Considering email's usage here, map + sync.Mutex/RWMutex may have better performance.
email sync.Map
users sync.Map
}
// Add a Shadowsocks user, Email must be empty or unique.
func (v *Validator) Add(u *protocol.MemoryUser) error {
account := u.Account.(*MemoryAccount)
if !account.Cipher.IsAEAD() && v.Count() > 0 {
return newError("The cipher do not support Single-port Multi-user")
}
if u.Email != "" {
_, loaded := v.email.LoadOrStore(strings.ToLower(u.Email), u)
if loaded {
return newError("User ", u.Email, " already exists.")
}
}
v.users.Store(string(account.Key)+"&"+account.GetCipherName(), u)
return nil
}
// Del a Shadowsocks user with a non-empty Email.
func (v *Validator) Del(e string) error {
if e == "" {
return newError("Email must not be empty.")
}
le := strings.ToLower(e)
u, _ := v.email.Load(le)
if u == nil {
return newError("User ", e, " not found.")
}
account := u.(*protocol.MemoryUser).Account.(*MemoryAccount)
v.email.Delete(le)
v.users.Delete(string(account.Key) + "&" + account.GetCipherName())
return nil
}
// Count the number of Shadowsocks users
func (v *Validator) Count() int {
length := 0
v.users.Range(func(_, _ interface{}) bool {
length++
return true
})
return length
}
// Get a Shadowsocks user and the user's cipher.
func (v *Validator) Get(bs []byte, command protocol.RequestCommand) (u *protocol.MemoryUser, aead cipher.AEAD, ret []byte, ivLen int32, err error) {
var dataSize int
switch command {
case protocol.RequestCommandTCP:
dataSize = 16
case protocol.RequestCommandUDP:
dataSize = 8192
}
var aeadCipher *AEADCipher
subkey := make([]byte, 32)
data := make([]byte, dataSize)
v.users.Range(func(key, user interface{}) bool {
account := user.(*protocol.MemoryUser).Account.(*MemoryAccount)
aeadCipher = account.Cipher.(*AEADCipher)
ivLen = aeadCipher.IVSize()
subkey = subkey[:aeadCipher.KeyBytes]
hkdfSHA1(account.Key, bs[:ivLen], subkey)
aead = aeadCipher.AEADAuthCreator(subkey)
switch command {
case protocol.RequestCommandTCP:
ret, err = aead.Open(data[:0], data[4:16], bs[ivLen:ivLen+18], nil)
case protocol.RequestCommandUDP:
ret, err = aead.Open(data[:0], data[8180:8192], bs[ivLen:], nil)
}
if err == nil {
u = user.(*protocol.MemoryUser)
return false
}
return true
})
return
}
// Get the only user without authentication
func (v *Validator) GetOnlyUser() (u *protocol.MemoryUser, ivLen int32) {
v.users.Range(func(_, user interface{}) bool {
u = user.(*protocol.MemoryUser)
return false
})
ivLen = u.Account.(*MemoryAccount).Cipher.IVSize()
return
}