conn: Send auth plugin name (#4177)

Author: breezewish

server/conn.go

@@ -59,7 +59,8 @@ import (
 var defaultCapability = mysql.ClientLongPassword | mysql.ClientLongFlag |
 	mysql.ClientConnectWithDB | mysql.ClientProtocol41 |
 	mysql.ClientTransactions | mysql.ClientSecureConnection | mysql.ClientFoundRows |
-	mysql.ClientMultiResults | mysql.ClientLocalFiles | mysql.ClientConnectAtts
+	mysql.ClientMultiResults | mysql.ClientLocalFiles |
+	mysql.ClientConnectAtts | mysql.ClientPluginAuth
 
 // clientConn represents a connection between server and client, it maintains connection specific state,
 // handles client query.
@@ -161,6 +162,9 @@ func (cc *clientConn) writeInitialHandshake() error {
 	data = append(data, cc.salt[8:]...)
 	// filler [00]
 	data = append(data, 0)
+	// auth-plugin name
+	data = append(data, []byte("mysql_native_password")...)
+	data = append(data, 0)
 	err := cc.writePacket(data)
 	if err != nil {
 		return errors.Trace(err)

server/conn_test.go

@@ -14,6 +14,10 @@
 package server
 
 import (
+	"bufio"
+	"bytes"
+	"encoding/binary"
+
 	. "github.com/pingcap/check"
 	"github.com/pingcap/tidb/mysql"
 )
@@ -97,6 +101,37 @@ func (ts ConnTestSuite) TestIssue1768(c *C) {
 	c.Assert(len(p.Auth) > 0, IsTrue)
 }
 
+func (ts ConnTestSuite) TestInitialHandshake(c *C) {
+	c.Parallel()
+	var outBuffer bytes.Buffer
+	cc := &clientConn{
+		connectionID: 1,
+		salt:         []byte{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10},
+		pkt: &packetIO{
+			wb: bufio.NewWriter(&outBuffer),
+		},
+	}
+	err := cc.writeInitialHandshake()
+	c.Assert(err, IsNil)
+
+	expected := new(bytes.Buffer)
+	expected.WriteByte(0x0a)                                                           // Protocol
+	expected.WriteString(mysql.ServerVersion)                                          // Version
+	expected.WriteByte(0x00)                                                           // NULL
+	binary.Write(expected, binary.LittleEndian, int32(1))                              // Connection ID
+	expected.Write([]byte{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x00})       // Salt
+	binary.Write(expected, binary.LittleEndian, int16(defaultCapability&0xFFFF))       // Server Capability
+	expected.WriteByte(uint8(mysql.DefaultCollationID))                                // Server Language
+	binary.Write(expected, binary.LittleEndian, mysql.ServerStatusAutocommit)          // Server Status
+	binary.Write(expected, binary.LittleEndian, int16((defaultCapability>>16)&0xFFFF)) // Extended Server Capability
+	expected.WriteByte(0x15)                                                           // Authentication Plugin Length
+	expected.Write([]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}) // Unused
+	expected.Write([]byte{0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x00})       // Salt
+	expected.WriteString("mysql_native_password")                                      // Authentication Plugin
+	expected.WriteByte(0x00)                                                           // NULL
+	c.Assert(outBuffer.Bytes()[4:], DeepEquals, expected.Bytes())
+}
+
 func mapIdentical(m1, m2 map[string]string) bool {
 	return mapBelong(m1, m2) && mapBelong(m2, m1)
 }