Add client and service

v2_hash.go

@@ -0,0 +1,74 @@
+package shadowtls
+
+import (
+	"crypto/hmac"
+	"crypto/sha1"
+	"hash"
+	"net"
+)
+
+type hashReadConn struct {
+	net.Conn
+	hmac hash.Hash
+}
+
+func newHashReadConn(conn net.Conn, password string) *hashReadConn {
+	return &hashReadConn{
+		conn,
+		hmac.New(sha1.New, []byte(password)),
+	}
+}
+
+func (c *hashReadConn) Read(b []byte) (n int, err error) {
+	n, err = c.Conn.Read(b)
+	if err != nil {
+		return
+	}
+	_, err = c.hmac.Write(b[:n])
+	return
+}
+
+func (c *hashReadConn) Sum() []byte {
+	return c.hmac.Sum(nil)[:8]
+}
+
+type hashWriteConn struct {
+	net.Conn
+	hmac       hash.Hash
+	hasContent bool
+	lastSum    []byte
+}
+
+func newHashWriteConn(conn net.Conn, password string) *hashWriteConn {
+	return &hashWriteConn{
+		Conn: conn,
+		hmac: hmac.New(sha1.New, []byte(password)),
+	}
+}
+
+func (c *hashWriteConn) Write(p []byte) (n int, err error) {
+	if c.hmac != nil {
+		if c.hasContent {
+			c.lastSum = c.Sum()
+		}
+		c.hmac.Write(p)
+		c.hasContent = true
+	}
+	return c.Conn.Write(p)
+}
+
+func (c *hashWriteConn) Sum() []byte {
+	return c.hmac.Sum(nil)[:8]
+}
+
+func (c *hashWriteConn) LastSum() []byte {
+	return c.lastSum
+}
+
+func (c *hashWriteConn) Fallback() {
+	c.hmac = nil
+}
+
+func (c *hashWriteConn) HasContent() bool {
+	return c.hasContent
+}