mirror of
https://github.com/XTLS/Xray-core.git
synced 2025-08-22 01:26:49 +08:00
84 lines
1.5 KiB
Go
84 lines
1.5 KiB
Go
package encryption
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import (
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"bytes"
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"crypto/aes"
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"crypto/cipher"
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"crypto/sha256"
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"fmt"
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"io"
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"net"
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"github.com/xtls/xray-core/common/errors"
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"golang.org/x/crypto/chacha20poly1305"
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"golang.org/x/crypto/hkdf"
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)
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var MaxNonce = bytes.Repeat([]byte{255}, 12)
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func EncodeHeader(h []byte, t byte, l int) {
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switch t {
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case 1:
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h[0] = 1
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h[1] = 1
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h[2] = 1
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case 0:
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h[0] = 0
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h[1] = 0
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h[2] = 0
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case 23:
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h[0] = 23
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h[1] = 3
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h[2] = 3
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}
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h[3] = byte(l >> 8)
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h[4] = byte(l)
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}
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func DecodeHeader(h []byte) (t byte, l int, err error) {
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l = int(h[3])<<8 | int(h[4])
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if h[0] == 23 && h[1] == 3 && h[2] == 3 {
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t = 23
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} else if h[0] == 0 && h[1] == 0 && h[2] == 0 {
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t = 0
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} else if h[0] == 1 && h[1] == 1 && h[2] == 1 {
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t = 1
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} else {
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h = nil
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}
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if h == nil || l < 17 || l > 17000 { // TODO: TLSv1.3 max length
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err = errors.New("invalid header: ", fmt.Sprintf("%v", h[:5]))
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}
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return
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}
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func ReadAndDecodeHeader(conn net.Conn) (h []byte, t byte, l int, err error) {
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h = make([]byte, 5)
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if _, err = io.ReadFull(conn, h); err != nil {
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return
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}
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t, l, err = DecodeHeader(h)
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return
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}
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func NewAead(c byte, secret, salt, info []byte) (aead cipher.AEAD) {
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key := make([]byte, 32)
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hkdf.New(sha256.New, secret, salt, info).Read(key)
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if c&1 == 1 {
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block, _ := aes.NewCipher(key)
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aead, _ = cipher.NewGCM(block)
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} else {
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aead, _ = chacha20poly1305.New(key)
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}
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return
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}
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func IncreaseNonce(nonce []byte) {
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for i := range 12 {
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nonce[11-i]++
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if nonce[11-i] != 0 {
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break
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}
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}
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}
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