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113 lines
2.5 KiB
Go
113 lines
2.5 KiB
Go
package common
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import (
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"encoding/binary"
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"errors"
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"io"
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"net"
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"sync"
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"time"
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)
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const (
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VersionTLS11 = 0x0301
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VersionTLS13 = 0x0303
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recordLayerLength = 5
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Handshake = 22
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ApplicationData = 23
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initialWriteBufSize = 14336
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)
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func AddRecordLayer(input []byte, typ byte, ver uint16) []byte {
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msgLen := len(input)
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retLen := msgLen + recordLayerLength
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var ret []byte
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ret = make([]byte, retLen)
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copy(ret[recordLayerLength:], input)
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ret[0] = typ
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ret[1] = byte(ver >> 8)
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ret[2] = byte(ver)
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ret[3] = byte(msgLen >> 8)
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ret[4] = byte(msgLen)
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return ret
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}
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type TLSConn struct {
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net.Conn
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writeBufPool sync.Pool
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}
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func NewTLSConn(conn net.Conn) *TLSConn {
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return &TLSConn{
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Conn: conn,
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writeBufPool: sync.Pool{New: func() interface{} {
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b := make([]byte, 0, initialWriteBufSize)
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b = append(b, ApplicationData, byte(VersionTLS13>>8), byte(VersionTLS13&0xFF))
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return &b
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}},
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}
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}
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func (tls *TLSConn) LocalAddr() net.Addr {
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return tls.Conn.LocalAddr()
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}
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func (tls *TLSConn) RemoteAddr() net.Addr {
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return tls.Conn.RemoteAddr()
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}
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func (tls *TLSConn) SetDeadline(t time.Time) error {
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return tls.Conn.SetDeadline(t)
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}
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func (tls *TLSConn) SetReadDeadline(t time.Time) error {
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return tls.Conn.SetReadDeadline(t)
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}
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func (tls *TLSConn) SetWriteDeadline(t time.Time) error {
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return tls.Conn.SetWriteDeadline(t)
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}
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func (tls *TLSConn) Read(buffer []byte) (n int, err error) {
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// TCP is a stream. Multiple TLS messages can arrive at the same time,
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// a single message can also be segmented due to MTU of the IP layer.
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// This function guareentees a single TLS message to be read and everything
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// else is left in the buffer.
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if len(buffer) < recordLayerLength {
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return 0, io.ErrShortBuffer
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}
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_, err = io.ReadFull(tls.Conn, buffer[:recordLayerLength])
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if err != nil {
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return
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}
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dataLength := int(binary.BigEndian.Uint16(buffer[3:5]))
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if dataLength > len(buffer) {
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err = io.ErrShortBuffer
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return
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}
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// we overwrite the record layer here
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return io.ReadFull(tls.Conn, buffer[:dataLength])
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}
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func (tls *TLSConn) Write(in []byte) (n int, err error) {
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msgLen := len(in)
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if msgLen > 1<<14+256 { // https://tools.ietf.org/html/rfc8446#section-5.2
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return 0, errors.New("message is too long")
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}
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writeBuf := tls.writeBufPool.Get().(*[]byte)
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*writeBuf = append(*writeBuf, byte(msgLen>>8), byte(msgLen&0xFF))
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*writeBuf = append(*writeBuf, in...)
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n, err = tls.Conn.Write(*writeBuf)
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*writeBuf = (*writeBuf)[:3]
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tls.writeBufPool.Put(writeBuf)
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return n - recordLayerLength, err
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}
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func (tls *TLSConn) Close() error {
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return tls.Conn.Close()
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}
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