Massive refactoring for better code structure

common/io/encryption.go

@@ -0,0 +1,60 @@
+package io
+
+import (
+	"crypto/cipher"
+	"io"
+
+	"github.com/v2ray/v2ray-core/log"
+)
+
+// CryptionReader is a general purpose reader that applies
+// block cipher on top of a regular reader.
+type CryptionReader struct {
+	stream cipher.Stream
+	reader io.Reader
+}
+
+func NewCryptionReader(stream cipher.Stream, reader io.Reader) *CryptionReader {
+	return &CryptionReader{
+		stream: stream,
+		reader: reader,
+	}
+}
+
+// Read reads blocks from underlying reader, the length of blocks must be
+// a multiply of BlockSize()
+func (reader CryptionReader) Read(blocks []byte) (int, error) {
+	nBytes, err := reader.reader.Read(blocks)
+	if nBytes > 0 {
+		reader.stream.XORKeyStream(blocks[:nBytes], blocks[:nBytes])
+	}
+	if err != nil && err != io.EOF {
+		log.Error("Error reading blocks: %v", err)
+	}
+	return nBytes, err
+}
+
+// Cryption writer is a general purpose of byte stream writer that applies
+// block cipher on top of a regular writer.
+type CryptionWriter struct {
+	stream cipher.Stream
+	writer io.Writer
+}
+
+func NewCryptionWriter(stream cipher.Stream, writer io.Writer) *CryptionWriter {
+	return &CryptionWriter{
+		stream: stream,
+		writer: writer,
+	}
+}
+
+func (writer CryptionWriter) Crypt(blocks []byte) {
+	writer.stream.XORKeyStream(blocks, blocks)
+}
+
+// Write writes the give blocks to underlying writer. The length of the blocks
+// must be a multiply of BlockSize()
+func (writer CryptionWriter) Write(blocks []byte) (int, error) {
+	writer.Crypt(blocks)
+	return writer.writer.Write(blocks)
+}