Refactor: Add Shadowsocks Validator (#233)

proxy/shadowsocks/validator.go

@@ -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
+}