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mirror of https://github.com/v2fly/v2ray-core.git synced 2024-11-04 09:17:32 -05:00
v2fly/proxy/shadowsocks/config.go
2017-11-27 10:42:34 +01:00

286 lines
7.0 KiB
Go

package shadowsocks
import (
"bytes"
"crypto/aes"
"crypto/cipher"
"crypto/md5"
"crypto/sha1"
"io"
"golang.org/x/crypto/chacha20poly1305"
"golang.org/x/crypto/hkdf"
"v2ray.com/core/common"
"v2ray.com/core/common/buf"
"v2ray.com/core/common/crypto"
"v2ray.com/core/common/protocol"
)
type ShadowsocksAccount struct {
Cipher Cipher
Key []byte
OneTimeAuth Account_OneTimeAuth
}
func (v *ShadowsocksAccount) Equals(another protocol.Account) bool {
if account, ok := another.(*ShadowsocksAccount); ok {
return bytes.Equal(v.Key, account.Key)
}
return false
}
func createAesGcm(key []byte) cipher.AEAD {
block, err := aes.NewCipher(key)
common.Must(err)
gcm, err := cipher.NewGCM(block)
common.Must(err)
return gcm
}
func createChacha20Poly1305(key []byte) cipher.AEAD {
chacha20, err := chacha20poly1305.New(key)
common.Must(err)
return chacha20
}
func (v *Account) GetCipher() (Cipher, error) {
switch v.CipherType {
case CipherType_AES_128_CFB:
return &AesCfb{KeyBytes: 16}, nil
case CipherType_AES_256_CFB:
return &AesCfb{KeyBytes: 32}, nil
case CipherType_CHACHA20:
return &ChaCha20{IVBytes: 8}, nil
case CipherType_CHACHA20_IETF:
return &ChaCha20{IVBytes: 12}, nil
case CipherType_AES_128_GCM:
return &AEADCipher{
KeyBytes: 16,
IVBytes: 16,
AEADAuthCreator: createAesGcm,
}, nil
case CipherType_AES_256_GCM:
return &AEADCipher{
KeyBytes: 32,
IVBytes: 32,
AEADAuthCreator: createAesGcm,
}, nil
case CipherType_CHACHA20_POLY1305:
return &AEADCipher{
KeyBytes: 32,
IVBytes: 32,
AEADAuthCreator: createChacha20Poly1305,
}, nil
default:
return nil, newError("Unsupported cipher.")
}
}
func (v *Account) AsAccount() (protocol.Account, error) {
cipher, err := v.GetCipher()
if err != nil {
return nil, newError("failed to get cipher").Base(err)
}
return &ShadowsocksAccount{
Cipher: cipher,
Key: v.GetCipherKey(),
OneTimeAuth: v.Ota,
}, nil
}
func (v *Account) GetCipherKey() []byte {
ct, err := v.GetCipher()
if err != nil {
return nil
}
return PasswordToCipherKey(v.Password, ct.KeySize())
}
type Cipher interface {
KeySize() int
IVSize() int
NewEncryptionWriter(key []byte, iv []byte, writer io.Writer) (buf.Writer, error)
NewDecryptionReader(key []byte, iv []byte, reader io.Reader) (buf.Reader, error)
IsAEAD() bool
EncodePacket(key []byte, b *buf.Buffer) error
DecodePacket(key []byte, b *buf.Buffer) error
}
type AesCfb struct {
KeyBytes int
}
func (*AesCfb) IsAEAD() bool {
return false
}
func (v *AesCfb) KeySize() int {
return v.KeyBytes
}
func (v *AesCfb) IVSize() int {
return 16
}
func (v *AesCfb) NewEncryptionWriter(key []byte, iv []byte, writer io.Writer) (buf.Writer, error) {
stream := crypto.NewAesEncryptionStream(key, iv)
return buf.NewWriter(crypto.NewCryptionWriter(stream, writer)), nil
}
func (v *AesCfb) NewDecryptionReader(key []byte, iv []byte, reader io.Reader) (buf.Reader, error) {
stream := crypto.NewAesDecryptionStream(key, iv)
return buf.NewReader(crypto.NewCryptionReader(stream, reader)), nil
}
func (v *AesCfb) EncodePacket(key []byte, b *buf.Buffer) error {
iv := b.BytesTo(v.IVSize())
stream := crypto.NewAesEncryptionStream(key, iv)
stream.XORKeyStream(b.BytesFrom(v.IVSize()), b.BytesFrom(v.IVSize()))
return nil
}
func (v *AesCfb) DecodePacket(key []byte, b *buf.Buffer) error {
iv := b.BytesTo(v.IVSize())
stream := crypto.NewAesDecryptionStream(key, iv)
stream.XORKeyStream(b.BytesFrom(v.IVSize()), b.BytesFrom(v.IVSize()))
b.SliceFrom(v.IVSize())
return nil
}
type AEADCipher struct {
KeyBytes int
IVBytes int
AEADAuthCreator func(key []byte) cipher.AEAD
}
func (*AEADCipher) IsAEAD() bool {
return true
}
func (c *AEADCipher) KeySize() int {
return c.KeyBytes
}
func (c *AEADCipher) IVSize() int {
return c.IVBytes
}
func (c *AEADCipher) createAuthenticator(key []byte, iv []byte) *crypto.AEADAuthenticator {
nonce := crypto.NewIncreasingAEADNonceGenerator()
subkey := make([]byte, c.KeyBytes)
hkdfSHA1(key, iv, subkey)
return &crypto.AEADAuthenticator{
AEAD: c.AEADAuthCreator(subkey),
NonceGenerator: nonce,
}
}
func (c *AEADCipher) NewEncryptionWriter(key []byte, iv []byte, writer io.Writer) (buf.Writer, error) {
auth := c.createAuthenticator(key, iv)
return crypto.NewAuthenticationWriter(auth, &crypto.AEADChunkSizeParser{
Auth: auth,
}, writer, protocol.TransferTypeStream), nil
}
func (c *AEADCipher) NewDecryptionReader(key []byte, iv []byte, reader io.Reader) (buf.Reader, error) {
auth := c.createAuthenticator(key, iv)
return crypto.NewAuthenticationReader(auth, &crypto.AEADChunkSizeParser{
Auth: auth,
}, reader, protocol.TransferTypeStream), nil
}
func (c *AEADCipher) EncodePacket(key []byte, b *buf.Buffer) error {
ivLen := c.IVSize()
payloadLen := b.Len()
auth := c.createAuthenticator(key, b.BytesTo(ivLen))
return b.Reset(func(bb []byte) (int, error) {
bbb, err := auth.Seal(bb[:ivLen], bb[ivLen:payloadLen])
if err != nil {
return 0, err
}
return len(bbb), nil
})
}
func (c *AEADCipher) DecodePacket(key []byte, b *buf.Buffer) error {
ivLen := c.IVSize()
payloadLen := b.Len()
auth := c.createAuthenticator(key, b.BytesTo(ivLen))
if err := b.Reset(func(bb []byte) (int, error) {
bbb, err := auth.Open(bb[:ivLen], bb[ivLen:payloadLen])
if err != nil {
return 0, err
}
return len(bbb), nil
}); err != nil {
return err
}
b.SliceFrom(ivLen)
return nil
}
type ChaCha20 struct {
IVBytes int
}
func (*ChaCha20) IsAEAD() bool {
return false
}
func (v *ChaCha20) KeySize() int {
return 32
}
func (v *ChaCha20) IVSize() int {
return v.IVBytes
}
func (v *ChaCha20) NewEncryptionWriter(key []byte, iv []byte, writer io.Writer) (buf.Writer, error) {
stream := crypto.NewChaCha20Stream(key, iv)
return buf.NewWriter(crypto.NewCryptionWriter(stream, writer)), nil
}
func (v *ChaCha20) NewDecryptionReader(key []byte, iv []byte, reader io.Reader) (buf.Reader, error) {
stream := crypto.NewChaCha20Stream(key, iv)
return buf.NewReader(crypto.NewCryptionReader(stream, reader)), nil
}
func (v *ChaCha20) EncodePacket(key []byte, b *buf.Buffer) error {
iv := b.BytesTo(v.IVSize())
stream := crypto.NewChaCha20Stream(key, iv)
stream.XORKeyStream(b.BytesFrom(v.IVSize()), b.BytesFrom(v.IVSize()))
return nil
}
func (v *ChaCha20) DecodePacket(key []byte, b *buf.Buffer) error {
iv := b.BytesTo(v.IVSize())
stream := crypto.NewChaCha20Stream(key, iv)
stream.XORKeyStream(b.BytesFrom(v.IVSize()), b.BytesFrom(v.IVSize()))
b.SliceFrom(v.IVSize())
return nil
}
func PasswordToCipherKey(password string, keySize int) []byte {
pwdBytes := []byte(password)
key := make([]byte, 0, keySize)
md5Sum := md5.Sum(pwdBytes)
key = append(key, md5Sum[:]...)
for len(key) < keySize {
md5Hash := md5.New()
md5Hash.Write(md5Sum[:])
md5Hash.Write(pwdBytes)
md5Hash.Sum(md5Sum[:0])
key = append(key, md5Sum[:]...)
}
return key
}
func hkdfSHA1(secret, salt, outkey []byte) {
r := hkdf.New(sha1.New, secret, salt, []byte("ss-subkey"))
common.Must2(io.ReadFull(r, outkey))
}