mirror of
https://github.com/cbeuw/Cloak.git
synced 2024-11-17 15:25:30 +00:00
92 lines
2.5 KiB
Go
92 lines
2.5 KiB
Go
package util
|
|
|
|
import (
|
|
"crypto/aes"
|
|
"crypto/cipher"
|
|
"encoding/binary"
|
|
"errors"
|
|
"io"
|
|
prand "math/rand"
|
|
"net"
|
|
"strconv"
|
|
)
|
|
|
|
func AESEncrypt(iv []byte, key []byte, plaintext []byte) []byte {
|
|
block, _ := aes.NewCipher(key)
|
|
ciphertext := make([]byte, len(plaintext))
|
|
stream := cipher.NewCTR(block, iv)
|
|
stream.XORKeyStream(ciphertext, plaintext)
|
|
return ciphertext
|
|
}
|
|
|
|
func AESDecrypt(iv []byte, key []byte, ciphertext []byte) []byte {
|
|
ret := make([]byte, len(ciphertext))
|
|
copy(ret, ciphertext) // Because XORKeyStream is inplace, but we don't want the input to be changed
|
|
block, _ := aes.NewCipher(key)
|
|
stream := cipher.NewCTR(block, iv)
|
|
stream.XORKeyStream(ret, ret)
|
|
return ret
|
|
}
|
|
|
|
// PsudoRandBytes returns a byte slice filled with psudorandom bytes generated by the seed
|
|
func PsudoRandBytes(length int, seed int64) []byte {
|
|
r := prand.New(prand.NewSource(seed))
|
|
ret := make([]byte, length)
|
|
r.Read(ret)
|
|
return ret
|
|
}
|
|
|
|
// ReadTLS reads TLS data according to its record layer
|
|
func ReadTLS(conn net.Conn, buffer []byte) (n int, err error) {
|
|
// TCP is a stream. Multiple TLS messages can arrive at the same time,
|
|
// a single message can also be segmented due to MTU of the IP layer.
|
|
// This function guareentees a single TLS message to be read and everything
|
|
// else is left in the buffer.
|
|
i, err := io.ReadFull(conn, buffer[:5])
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
dataLength := int(binary.BigEndian.Uint16(buffer[3:5]))
|
|
if dataLength > len(buffer) {
|
|
err = errors.New("Reading TLS message: message size greater than buffer. message size: " + strconv.Itoa(dataLength))
|
|
return
|
|
}
|
|
left := dataLength
|
|
readPtr := 5
|
|
|
|
for left != 0 {
|
|
// If left > buffer size (i.e. our message got segmented), the entire MTU is read
|
|
// if left = buffer size, the entire buffer is all there left to read
|
|
// if left < buffer size (i.e. multiple messages came together),
|
|
// only the message we want is read
|
|
i, err = io.ReadFull(conn, buffer[readPtr:readPtr+left])
|
|
if err != nil {
|
|
return
|
|
}
|
|
left -= i
|
|
readPtr += i
|
|
}
|
|
|
|
n = 5 + dataLength
|
|
return
|
|
}
|
|
|
|
// AddRecordLayer adds record layer to data
|
|
func AddRecordLayer(input []byte, typ []byte, ver []byte) []byte {
|
|
length := make([]byte, 2)
|
|
binary.BigEndian.PutUint16(length, uint16(len(input)))
|
|
ret := make([]byte, 5+len(input))
|
|
copy(ret[0:1], typ)
|
|
copy(ret[1:3], ver)
|
|
copy(ret[3:5], length)
|
|
copy(ret[5:], input)
|
|
return ret
|
|
}
|
|
|
|
// PeelRecordLayer peels off the record layer
|
|
func PeelRecordLayer(data []byte) []byte {
|
|
ret := data[5:]
|
|
return ret
|
|
}
|