73 lines
1.7 KiB
Go
73 lines
1.7 KiB
Go
|
package wsutil
|
||
|
|
|
||
|
|
import (
|
||
|
|
"io"
|
||
|
|
|
||
|
|
"github.com/gobwas/pool/pbytes"
|
||
|
|
"github.com/gobwas/ws"
|
||
|
|
)
|
||
|
|
|
||
|
|
// CipherReader implements io.Reader that applies xor-cipher to the bytes read
|
||
|
|
// from source.
|
||
|
|
// It could help to unmask WebSocket frame payload on the fly.
|
||
|
|
type CipherReader struct {
|
||
|
|
r io.Reader
|
||
|
|
mask [4]byte
|
||
|
|
pos int
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewCipherReader creates xor-cipher reader from r with given mask.
|
||
|
|
func NewCipherReader(r io.Reader, mask [4]byte) *CipherReader {
|
||
|
|
return &CipherReader{r, mask, 0}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Reset resets CipherReader to read from r with given mask.
|
||
|
|
func (c *CipherReader) Reset(r io.Reader, mask [4]byte) {
|
||
|
|
c.r = r
|
||
|
|
c.mask = mask
|
||
|
|
c.pos = 0
|
||
|
|
}
|
||
|
|
|
||
|
|
// Read implements io.Reader interface. It applies mask given during
|
||
|
|
// initialization to every read byte.
|
||
|
|
func (c *CipherReader) Read(p []byte) (n int, err error) {
|
||
|
|
n, err = c.r.Read(p)
|
||
|
|
ws.Cipher(p[:n], c.mask, c.pos)
|
||
|
|
c.pos += n
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
// CipherWriter implements io.Writer that applies xor-cipher to the bytes
|
||
|
|
// written to the destination writer. It does not modify the original bytes.
|
||
|
|
type CipherWriter struct {
|
||
|
|
w io.Writer
|
||
|
|
mask [4]byte
|
||
|
|
pos int
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewCipherWriter creates xor-cipher writer to w with given mask.
|
||
|
|
func NewCipherWriter(w io.Writer, mask [4]byte) *CipherWriter {
|
||
|
|
return &CipherWriter{w, mask, 0}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Reset reset CipherWriter to write to w with given mask.
|
||
|
|
func (c *CipherWriter) Reset(w io.Writer, mask [4]byte) {
|
||
|
|
c.w = w
|
||
|
|
c.mask = mask
|
||
|
|
c.pos = 0
|
||
|
|
}
|
||
|
|
|
||
|
|
// Write implements io.Writer interface. It applies masking during
|
||
|
|
// initialization to every sent byte. It does not modify original slice.
|
||
|
|
func (c *CipherWriter) Write(p []byte) (n int, err error) {
|
||
|
|
cp := pbytes.GetLen(len(p))
|
||
|
|
defer pbytes.Put(cp)
|
||
|
|
|
||
|
|
copy(cp, p)
|
||
|
|
ws.Cipher(cp, c.mask, c.pos)
|
||
|
|
n, err = c.w.Write(cp)
|
||
|
|
c.pos += n
|
||
|
|
|
||
|
|
return
|
||
|
|
}
|