glider/proxy/ssr/internal/cipher/cipher.go
2020-10-29 22:47:57 +08:00

343 lines
8.8 KiB
Go

package cipher
import (
"crypto/aes"
"crypto/cipher"
"crypto/des"
"crypto/md5"
"crypto/rc4"
"encoding/binary"
"errors"
"math/rand"
"github.com/aead/chacha20"
"github.com/dgryski/go-camellia"
"github.com/dgryski/go-idea"
"github.com/dgryski/go-rc2"
"golang.org/x/crypto/blowfish"
"golang.org/x/crypto/cast5"
"golang.org/x/crypto/salsa20/salsa"
"github.com/nadoo/glider/pool"
"github.com/nadoo/glider/proxy/ssr/internal/tools"
)
var errEmptyPassword = errors.New("empty key")
type DecOrEnc int
const (
Decrypt DecOrEnc = iota
Encrypt
)
func newCTRStream(block cipher.Block, err error, key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
if err != nil {
return nil, err
}
return cipher.NewCTR(block, iv), nil
}
func newAESCTRStream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
block, err := aes.NewCipher(key)
return newCTRStream(block, err, key, iv, doe)
}
func newOFBStream(block cipher.Block, err error, key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
if err != nil {
return nil, err
}
return cipher.NewCTR(block, iv), nil
}
func newAESOFBStream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
block, err := aes.NewCipher(key)
return newOFBStream(block, err, key, iv, doe)
}
func newCFBStream(block cipher.Block, err error, key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
if err != nil {
return nil, err
}
if doe == Encrypt {
return cipher.NewCFBEncrypter(block, iv), nil
} else {
return cipher.NewCFBDecrypter(block, iv), nil
}
}
func newAESCFBStream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
block, err := aes.NewCipher(key)
return newCFBStream(block, err, key, iv, doe)
}
func newDESStream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
block, err := des.NewCipher(key)
return newCFBStream(block, err, key, iv, doe)
}
func newBlowFishStream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
block, err := blowfish.NewCipher(key)
return newCFBStream(block, err, key, iv, doe)
}
func newCast5Stream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
block, err := cast5.NewCipher(key)
return newCFBStream(block, err, key, iv, doe)
}
func newRC4MD5Stream(key, iv []byte, _ DecOrEnc) (cipher.Stream, error) {
h := md5.New()
h.Write(key)
h.Write(iv)
rc4key := h.Sum(nil)
return rc4.NewCipher(rc4key)
}
func newChaCha20Stream(key, iv []byte, _ DecOrEnc) (cipher.Stream, error) {
return chacha20.NewCipher(iv, key)
}
func newChacha20IETFStream(key, iv []byte, _ DecOrEnc) (cipher.Stream, error) {
return chacha20.NewCipher(iv, key)
}
type salsaStreamCipher struct {
nonce [8]byte
key [32]byte
counter int
}
func (c *salsaStreamCipher) XORKeyStream(dst, src []byte) {
var buf []byte
padLen := c.counter % 64
dataSize := len(src) + padLen
if cap(dst) >= dataSize {
buf = dst[:dataSize]
// nadoo: comment out codes here to use pool buffer
// modify start -->
// } else if leakybuf.GlobalLeakyBufSize >= dataSize {
// buf = leakybuf.GlobalLeakyBuf.Get()
// defer leakybuf.GlobalLeakyBuf.Put(buf)
// buf = buf[:dataSize]
// } else {
// buf = make([]byte, dataSize)
// }
} else {
buf = pool.GetBuffer(dataSize)
defer pool.PutBuffer(buf)
}
// --> modify end
var subNonce [16]byte
copy(subNonce[:], c.nonce[:])
binary.LittleEndian.PutUint64(subNonce[len(c.nonce):], uint64(c.counter/64))
// It's difficult to avoid data copy here. src or dst maybe slice from
// Conn.Read/Write, which can't have padding.
copy(buf[padLen:], src[:])
salsa.XORKeyStream(buf, buf, &subNonce, &c.key)
copy(dst, buf[padLen:])
c.counter += len(src)
}
func newSalsa20Stream(key, iv []byte, _ DecOrEnc) (cipher.Stream, error) {
var c salsaStreamCipher
copy(c.nonce[:], iv[:8])
copy(c.key[:], key[:32])
return &c, nil
}
func newCamelliaStream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
block, err := camellia.New(key)
return newCFBStream(block, err, key, iv, doe)
}
func newIdeaStream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
block, err := idea.NewCipher(key)
return newCFBStream(block, err, key, iv, doe)
}
func newRC2Stream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
block, err := rc2.New(key, 16)
return newCFBStream(block, err, key, iv, doe)
}
func newRC4Stream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
return rc4.NewCipher(key)
}
func newSeedStream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
// TODO: SEED block cipher implementation is required
block, err := rc2.New(key, 16)
return newCFBStream(block, err, key, iv, doe)
}
type NoneStream struct {
cipher.Stream
}
func (*NoneStream) XORKeyStream(dst, src []byte) {
copy(dst, src)
}
func newNoneStream(key, iv []byte, doe DecOrEnc) (cipher.Stream, error) {
return new(NoneStream), nil
}
type cipherInfo struct {
keyLen int
ivLen int
newStream func(key, iv []byte, doe DecOrEnc) (cipher.Stream, error)
}
var streamCipherMethod = map[string]*cipherInfo{
"aes-128-cfb": {16, 16, newAESCFBStream},
"aes-192-cfb": {24, 16, newAESCFBStream},
"aes-256-cfb": {32, 16, newAESCFBStream},
"aes-128-ctr": {16, 16, newAESCTRStream},
"aes-192-ctr": {24, 16, newAESCTRStream},
"aes-256-ctr": {32, 16, newAESCTRStream},
"aes-128-ofb": {16, 16, newAESOFBStream},
"aes-192-ofb": {24, 16, newAESOFBStream},
"aes-256-ofb": {32, 16, newAESOFBStream},
"des-cfb": {8, 8, newDESStream},
"bf-cfb": {16, 8, newBlowFishStream},
"cast5-cfb": {16, 8, newCast5Stream},
"rc4-md5": {16, 16, newRC4MD5Stream},
"rc4-md5-6": {16, 6, newRC4MD5Stream},
"chacha20": {32, 8, newChaCha20Stream},
"chacha20-ietf": {32, 12, newChacha20IETFStream},
"salsa20": {32, 8, newSalsa20Stream},
"camellia-128-cfb": {16, 16, newCamelliaStream},
"camellia-192-cfb": {24, 16, newCamelliaStream},
"camellia-256-cfb": {32, 16, newCamelliaStream},
"idea-cfb": {16, 8, newIdeaStream},
"rc2-cfb": {16, 8, newRC2Stream},
"seed-cfb": {16, 8, newSeedStream},
"rc4": {16, 0, newRC4Stream},
"none": {16, 0, newNoneStream},
}
func CheckCipherMethod(method string) error {
if method == "" {
method = "rc4-md5"
}
_, ok := streamCipherMethod[method]
if !ok {
return errors.New("Unsupported encryption method: " + method)
}
return nil
}
type StreamCipher struct {
enc cipher.Stream
dec cipher.Stream
key []byte
info *cipherInfo
iv []byte
}
// NewStreamCipher creates a cipher that can be used in Dial() etc.
// Use cipher.Copy() to create a new cipher with the same method and password
// to avoid the cost of repeated cipher initialization.
func NewStreamCipher(method, password string) (c *StreamCipher, err error) {
if password == "" {
return nil, errEmptyPassword
}
if method == "" {
method = "rc4-md5"
}
mi, ok := streamCipherMethod[method]
if !ok {
return nil, errors.New("Unsupported encryption method: " + method)
}
key := tools.EVPBytesToKey(password, mi.keyLen)
c = &StreamCipher{key: key, info: mi}
return c, nil
}
func (c *StreamCipher) EncryptInited() bool {
return c.enc != nil
}
func (c *StreamCipher) DecryptInited() bool {
return c.dec != nil
}
// Initializes the block cipher with CFB mode, returns IV.
func (c *StreamCipher) InitEncrypt() (iv []byte, err error) {
if c.iv == nil {
iv = make([]byte, c.info.ivLen)
rand.Read(iv)
c.iv = iv
} else {
iv = c.iv
}
c.enc, err = c.info.newStream(c.key, iv, Encrypt)
return
}
func (c *StreamCipher) InitDecrypt(iv []byte) (err error) {
c.dec, err = c.info.newStream(c.key, iv, Decrypt)
return
}
func (c *StreamCipher) Encrypt(dst, src []byte) {
c.enc.XORKeyStream(dst, src)
}
func (c *StreamCipher) Decrypt(dst, src []byte) {
c.dec.XORKeyStream(dst, src)
}
// Copy creates a new cipher at it's initial state.
func (c *StreamCipher) Copy() *StreamCipher {
// This optimization maybe not necessary. But without this function, we
// need to maintain a table cache for newTableCipher and use lock to
// protect concurrent access to that cache.
// AES and DES ciphers does not return specific types, so it's difficult
// to create copy. But their initialization time is less than 4000ns on my
// 2.26 GHz Intel Core 2 Duo processor. So no need to worry.
// Currently, blow-fish and cast5 initialization cost is an order of
// magnitude slower than other ciphers. (I'm not sure whether this is
// because the current implementation is not highly optimized, or this is
// the nature of the algorithm.)
nc := *c
nc.enc = nil
nc.dec = nil
return &nc
}
func (c *StreamCipher) Key() []byte {
return c.key
}
func (c *StreamCipher) IV() []byte {
return c.iv
}
func (c *StreamCipher) SetIV(iv []byte) {
c.iv = iv
}
func (c *StreamCipher) SetKey(key []byte) {
c.key = key
}
func (c *StreamCipher) InfoIVLen() int {
return c.info.ivLen
}
func (c *StreamCipher) InfoKeyLen() int {
return c.info.keyLen
}