// Write writes data to connection.
func (c *Conn) Write(b []byte) (n int, err error) {
// buf = [iv] + [encrypt data]
// [iv] exists only at beginning of connection, else [iv] is empty.
var buf = c.writeBuf
var encryptData = buf
dataLen := len(b)
if c.iv == nil {
utils.Debugf("Write iv")
c.writeStart = true
dataLen += c.info.ivLen
if dataLen > len(buf) {
buf = make([]byte, dataLen)
}
iv := c.initEncStream()
copy(buf, iv)
encryptData = buf[c.info.ivLen:]
} else if !c.writeStart {
c.initEncStream()
utils.Debugf("init enc")
c.writeStart = true
}
if dataLen > len(buf) {
buf = make([]byte, dataLen)
encryptData = buf
}
c.encrypt(encryptData, b)
return c.Conn.Write(buf[:dataLen])
}
func (c *Mika) Read(b []byte) (n int, err error) {
// recover() avoid panic
var buf = c.readBuf
// dataLen := len(b)
if c.serverSide {
// ------------------------------
// | dataLen | hmac | user data |
// ------------------------------
// | 2 | 10 | Variable |
// ------------------------------
const datePos = 12
if _, err := io.ReadFull(c.Conn, buf[:datePos]); err != nil {
return 0, err
}
dataLen := int(binary.BigEndian.Uint16(buf[:2]))
expectedhmac := make([]byte, 10)
copy(expectedhmac, buf[2:datePos])
utils.Debugf("dataLen %d expected len %d", dataLen, len(b))
if dataLen > len(b) {
utils.Errorf("Date len %d large than b %d", dataLen, len(b))
return 0, fmt.Errorf("Too large data")
}
if _, err := io.ReadFull(c.Conn, b[:dataLen]); err != nil {
utils.Errorf("Read error %s", err)
return 0, err
}
c.header.ChunkID++
utils.Debugf("ChunkID %d, receive %d datas, expectedhmac %#v ", c.header.ChunkID, dataLen, expectedhmac)
_, hmac := otaReqChunkAuth(c.iv, c.header.ChunkID, b[:dataLen])
if !bytes.Equal(hmac, expectedhmac) {
utils.Errorf("Hmac %#v mismatch with %#v, remote addr %s", hmac, expectedhmac, c.RemoteAddr())
return 0, fmt.Errorf("Hmac mismatch")
}
// if dataLen > b
// we should buffer remains.
return dataLen, nil
}
return c.Conn.Read(b)
}
// Read reads data from connection.
func (c *Conn) Read(b []byte) (n int, err error) {
if c.iv == nil {
utils.Debugf("Read iv")
iv := make([]byte, c.info.ivLen)
if _, err := io.ReadFull(c.Conn, iv); err != nil {
return 0, err
}
c.initDecStream(iv)
c.readStart = true
} else if !c.readStart {
c.initDecStream(c.iv)
c.readStart = true
}
var buf = c.readBuf
n, err = c.Conn.Read(buf[:len(b)])
if err != nil {
return
}
c.decrypt(b, buf[:n])
return
}
// Write writes data to connection.
func (c *Mika) Write(b []byte) (n int, err error) {
buf := b
dataLen := len(b)
if !c.serverSide {
// ------------------------------
// | dataLen | hmac | user data |
// ------------------------------
// | 2 | 10 | Variable |
// ------------------------------
c.header.ChunkID++
// hmac := HmacSha1(append(c.iv, c.key...), b)
// len(hmac)+dataLen = 12
dataLen += 12
// utils.Debugf("Send %d hmac %#v", dataLen-12, hmac)
// utils.Debugf("Data write %#v", b)
var hmac []byte
buf, hmac = otaReqChunkAuth(c.iv, c.header.ChunkID, b)
utils.Debugf("Send %d data, chunkID %d, hmac %#v", dataLen-12, c.header.ChunkID, hmac)
// utils.Debugf("Data after write %#v", buf[12:dataLen])
}
return c.Conn.Write(buf[:dataLen])
}
// Close closes connection and releases buf.
// TODO check close state to avoid close twice.
func (c *Conn) Close() error {
leakyBuf.Put(c.writeBuf)
leakyBuf.Put(c.readBuf)
utils.Debugf("Connection %s closed", c.RemoteAddr())
return c.Conn.Close()
}