Direct proxy works

_wrappers/blockcipher.go

@@ -0,0 +1,99 @@
+package wrappers
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"net"
+
+	"go.uber.org/zap"
+
+	"github.com/9seconds/mtg/utils"
+	"github.com/juju/errors"
+)
+
+// BlockCipher is a stream writer which encrypts/decrypts blocks of data
+// with AES CBC. This also is buffered reader. It means, that block
+// reading is transparent for it, you can assume you are working with
+// good old io.Reader.
+type BlockCipher struct {
+	buf *bytes.Buffer
+
+	logger    *zap.SugaredLogger
+	conn      StreamReadWriteCloser
+	encryptor cipher.BlockMode
+	decryptor cipher.BlockMode
+}
+
+func (b *BlockCipher) Read(p []byte) (int, error) {
+	if b.buf.Len() > 0 {
+		return b.flush(p)
+	}
+
+	buf := []byte{}
+	for len(buf) == 0 || len(buf)%aes.BlockSize != 0 {
+		rv, err := utils.ReadCurrentData(b.conn)
+		if err != nil {
+			return 0, errors.Annotate(err, "Cannot read from socket")
+		}
+		buf = append(buf, rv...)
+	}
+
+	b.decryptor.CryptBlocks(buf, buf)
+	b.buf.Write(buf) // nolint: gosec
+
+	return b.flush(p)
+}
+
+func (b *BlockCipher) flush(p []byte) (int, error) {
+	if b.buf.Len() <= len(p) {
+		sizeToReturn := b.buf.Len()
+		copy(p, b.buf.Bytes())
+		b.buf.Reset()
+		return sizeToReturn, nil
+	}
+
+	return b.buf.Read(p)
+}
+
+func (b *BlockCipher) Write(p []byte) (int, error) {
+	if len(p)%aes.BlockSize > 0 {
+		return 0, errors.Errorf("Incorrect block size %d", len(p))
+	}
+
+	encrypted := make([]byte, len(p))
+	b.encryptor.CryptBlocks(encrypted, p)
+
+	return b.conn.Write(encrypted)
+}
+
+// Logger returns an instance of the logger for this wrapper.
+func (b *BlockCipher) Logger() *zap.SugaredLogger {
+	return b.logger
+}
+
+// LocalAddr returns local address of the underlying net.Conn.
+func (b *BlockCipher) LocalAddr() *net.TCPAddr {
+	return b.conn.LocalAddr()
+}
+
+// RemoteAddr returns remote address of the underlying net.Conn.
+func (b *BlockCipher) RemoteAddr() *net.TCPAddr {
+	return b.conn.RemoteAddr()
+}
+
+// Close closes underlying net.Conn.
+func (b *BlockCipher) Close() error {
+	return b.conn.Close()
+}
+
+// NewBlockCipher creates new instance of BlockCipher based on given data.
+func NewBlockCipher(conn StreamReadWriteCloser, encryptor, decryptor cipher.BlockMode) StreamReadWriteCloser {
+	return &BlockCipher{
+		buf:       &bytes.Buffer{},
+		conn:      conn,
+		logger:    conn.Logger().Named("block-cipher"),
+		encryptor: encryptor,
+		decryptor: decryptor,
+	}
+}