Cleartext authentication plugin support

Author: joshuaprunier

AUTHORS

@@ -23,6 +23,7 @@ Henri Yandell <flamefew at gmail.com>
 INADA Naoki <songofacandy at gmail.com>
 James Harr <james.harr at gmail.com>
 Jian Zhen <zhenjl at gmail.com>
+Joshua Prunier <joshua.prunier at gmail.com>
 Julien Schmidt <go-sql-driver at julienschmidt.com>
 Kamil Dziedzic <kamil at klecza.pl>
 Leonardo YongUk Kim <dalinaum at gmail.com>

README.md

@@ -123,6 +123,15 @@ Default:        false
 `allowAllFiles=true` disables the file Whitelist for `LOAD DATA LOCAL INFILE` and allows *all* files.
 [*Might be insecure!*](http://dev.mysql.com/doc/refman/5.7/en/load-data-local.html)
 
+##### `allowClearPasswords`
+
+```
+Type:           bool
+Valid Values:   true, false
+Default:        false
+```
+`allowClearPasswords=true` allows the usage of the cleartext client side plugin. This can be insecure but is required by the [PAM authentication plugin](http://dev.mysql.com/doc/refman/5.5/en/pam-authentication-plugin.html).
+
 ##### `allowOldPasswords`
 
 ```

connection.go

@@ -34,21 +34,22 @@ type mysqlConn struct {
 }
 
 type config struct {
-	user              string
-	passwd            string
-	net               string
-	addr              string
-	dbname            string
-	params            map[string]string
-	loc               *time.Location
-	tls               *tls.Config
-	timeout           time.Duration
-	collation         uint8
-	allowAllFiles     bool
-	allowOldPasswords bool
-	clientFoundRows   bool
-	columnsWithAlias  bool
-	interpolateParams bool
+	user                string
+	passwd              string
+	net                 string
+	addr                string
+	dbname              string
+	params              map[string]string
+	loc                 *time.Location
+	tls                 *tls.Config
+	timeout             time.Duration
+	collation           uint8
+	allowAllFiles       bool
+	allowOldPasswords   bool
+	allowClearPasswords bool
+	clientFoundRows     bool
+	columnsWithAlias    bool
+	interpolateParams   bool
 }
 
 // Handles parameters set in DSN after the connection is established

const.go

@@ -45,6 +45,8 @@ const (
 	clientSecureConn
 	clientMultiStatements
 	clientMultiResults
+	clientPSMultiResults
+	clientPluginAuth
 )
 
 const (

driver.go

@@ -107,6 +107,15 @@ func (d MySQLDriver) Open(dsn string) (driver.Conn, error) {
 				mc.Close()
 				return nil, err
 			}
+		} else if mc.cfg != nil && mc.cfg.allowClearPasswords && err == ErrClearPassword {
+			if err = mc.writeClearAuthPacket(); err != nil {
+				mc.Close()
+				return nil, err
+			}
+			if err = mc.readResultOK(); err != nil {
+				mc.Close()
+				return nil, err
+			}
 		} else {
 			mc.Close()
 			return nil, err

errors.go

@@ -19,15 +19,17 @@ import (
 
 // Various errors the driver might return. Can change between driver versions.
 var (
-	ErrInvalidConn = errors.New("Invalid Connection")
-	ErrMalformPkt  = errors.New("Malformed Packet")
-	ErrNoTLS       = errors.New("TLS encryption requested but server does not support TLS")
-	ErrOldPassword = errors.New("This server only supports the insecure old password authentication. If you still want to use it, please add 'allowOldPasswords=1' to your DSN. See also https://github.com/go-sql-driver/mysql/wiki/old_passwords")
-	ErrOldProtocol = errors.New("MySQL-Server does not support required Protocol 41+")
-	ErrPktSync     = errors.New("Commands out of sync. You can't run this command now")
-	ErrPktSyncMul  = errors.New("Commands out of sync. Did you run multiple statements at once?")
-	ErrPktTooLarge = errors.New("Packet for query is too large. You can change this value on the server by adjusting the 'max_allowed_packet' variable.")
-	ErrBusyBuffer  = errors.New("Busy buffer")
+	ErrInvalidConn   = errors.New("Invalid Connection")
+	ErrMalformPkt    = errors.New("Malformed Packet")
+	ErrNoTLS         = errors.New("TLS encryption requested but server does not support TLS")
+	ErrOldPassword   = errors.New("This user requires old password authentication. If you still want to use it, please add 'allowOldPasswords=1' to your DSN. See also https://github.com/go-sql-driver/mysql/wiki/old_passwords")
+	ErrClearPassword = errors.New("This user requires clear text authentication. If you still want to use it, please add 'allowClearPasswords=1' to your DSN.")
+	ErrUnknownPlugin = errors.New("The authentication plugin is not supported.")
+	ErrOldProtocol   = errors.New("MySQL-Server does not support required Protocol 41+")
+	ErrPktSync       = errors.New("Commands out of sync. You can't run this command now")
+	ErrPktSyncMul    = errors.New("Commands out of sync. Did you run multiple statements at once?")
+	ErrPktTooLarge   = errors.New("Packet for query is too large. You can change this value on the server by adjusting the 'max_allowed_packet' variable.")
+	ErrBusyBuffer    = errors.New("Busy buffer")
 )
 
 var errLog Logger = log.New(os.Stderr, "[MySQL] ", log.Ldate|log.Ltime|log.Lshortfile)

packets.go

@@ -196,7 +196,11 @@ func (mc *mysqlConn) readInitPacket() ([]byte, error) {
 		//	return
 		//}
 		//return ErrMalformPkt
-		return cipher, nil
+
+		// make a memory safe copy of the cipher slice
+		var b [20]byte
+		copy(b[:], cipher)
+		return b[:], nil
 	}
 
 	// make a memory safe copy of the cipher slice
@@ -214,6 +218,7 @@ func (mc *mysqlConn) writeAuthPacket(cipher []byte) error {
 		clientLongPassword |
 		clientTransactions |
 		clientLocalFiles |
+		clientPluginAuth |
 		mc.flags&clientLongFlag
 
 	if mc.cfg.clientFoundRows {
@@ -228,7 +233,7 @@ func (mc *mysqlConn) writeAuthPacket(cipher []byte) error {
 	// User Password
 	scrambleBuff := scramblePassword(cipher, []byte(mc.cfg.passwd))
 
-	pktLen := 4 + 4 + 1 + 23 + len(mc.cfg.user) + 1 + 1 + len(scrambleBuff)
+	pktLen := 4 + 4 + 1 + 23 + len(mc.cfg.user) + 1 + 1 + len(scrambleBuff) + 21 + 1
 
 	// To specify a db name
 	if n := len(mc.cfg.dbname); n > 0 {
@@ -294,8 +299,13 @@ func (mc *mysqlConn) writeAuthPacket(cipher []byte) error {
 	if len(mc.cfg.dbname) > 0 {
 		pos += copy(data[pos:], mc.cfg.dbname)
 		data[pos] = 0x00
+		pos++
 	}
 
+	// Assume native client during response
+	pos += copy(data[pos:], "mysql_native_password")
+	data[pos] = 0x00
+
 	// Send Auth packet
 	return mc.writePacket(data)
 }
@@ -306,7 +316,7 @@ func (mc *mysqlConn) writeOldAuthPacket(cipher []byte) error {
 	// User password
 	scrambleBuff := scrambleOldPassword(cipher, []byte(mc.cfg.passwd))
 
-	// Calculate the packet lenght and add a tailing 0
+	// Calculate the packet length and add a tailing 0
 	pktLen := len(scrambleBuff) + 1
 	data := mc.buf.takeSmallBuffer(4 + pktLen)
 	if data == nil {
@@ -322,6 +332,25 @@ func (mc *mysqlConn) writeOldAuthPacket(cipher []byte) error {
 	return mc.writePacket(data)
 }
 
+//  Client clear text authentication packet
+// http://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::AuthSwitchResponse
+func (mc *mysqlConn) writeClearAuthPacket() error {
+	// Calculate the packet length and add a tailing 0
+	pktLen := len(mc.cfg.passwd) + 1
+        data := mc.buf.takeSmallBuffer(4 + pktLen)
+        if data == nil {
+                // can not take the buffer. Something must be wrong with the connection
+                errLog.Print(ErrBusyBuffer)
+                return driver.ErrBadConn
+        }
+
+	// Add the clear password [null terminated string]
+	copy(data[4:], mc.cfg.passwd)
+	data[4+pktLen-1] = 0x00
+
+	return mc.writePacket(data)
+}
+
 /******************************************************************************
 *                             Command Packets                                 *
 ******************************************************************************/
@@ -405,8 +434,20 @@ func (mc *mysqlConn) readResultOK() error {
 			return mc.handleOkPacket(data)
 
 		case iEOF:
-			// someone is using old_passwords
-			return ErrOldPassword
+			if len(data) > 1 {
+				plugin := string(data[1:bytes.IndexByte(data, 0x00)])
+				if plugin == "mysql_old_password" {
+					// using old_passwords
+					return ErrOldPassword
+				} else if plugin == "mysql_clear_password" {
+					// using clear text password
+					return ErrClearPassword
+				} else {
+					return ErrUnknownPlugin
+				}
+			} else {
+				return ErrOldPassword
+			}
 
 		default: // Error otherwise
 			return mc.handleErrorPacket(data)

utils.go

@@ -201,6 +201,14 @@ func parseDSNParams(cfg *config, params string) (err error) {
 				return fmt.Errorf("Invalid Bool value: %s", value)
 			}
 
+		// Use cleartext authentication mode (MySQL 5.5.10+)
+		case "allowClearPasswords":
+			var isBool bool
+			cfg.allowClearPasswords, isBool = readBool(value)
+			if !isBool {
+				return fmt.Errorf("Invalid Bool value: %s", value)
+			}
+
 		// Use old authentication mode (pre MySQL 4.1)
 		case "allowOldPasswords":
 			var isBool bool

utils_test.go

@@ -22,19 +22,19 @@ var testDSNs = []struct {
 	out string
 	loc *time.Location
 }{
-	{"username:password@protocol(address)/dbname?param=value", "&{user:username passwd:password net:protocol addr:address dbname:dbname params:map[param:value] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"username:password@protocol(address)/dbname?param=value&columnsWithAlias=true", "&{user:username passwd:password net:protocol addr:address dbname:dbname params:map[param:value] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:true interpolateParams:false}", time.UTC},
-	{"user@unix(/path/to/socket)/dbname?charset=utf8", "&{user:user passwd: net:unix addr:/path/to/socket dbname:dbname params:map[charset:utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"user:password@tcp(localhost:5555)/dbname?charset=utf8&tls=true", "&{user:user passwd:password net:tcp addr:localhost:5555 dbname:dbname params:map[charset:utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"user:password@tcp(localhost:5555)/dbname?charset=utf8mb4,utf8&tls=skip-verify", "&{user:user passwd:password net:tcp addr:localhost:5555 dbname:dbname params:map[charset:utf8mb4,utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"user:password@/dbname?loc=UTC&timeout=30s&allowAllFiles=1&clientFoundRows=true&allowOldPasswords=TRUE&collation=utf8mb4_unicode_ci", "&{user:user passwd:password net:tcp addr:127.0.0.1:3306 dbname:dbname params:map[] loc:%p tls:<nil> timeout:30000000000 collation:224 allowAllFiles:true allowOldPasswords:true clientFoundRows:true columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"user:p@ss(word)@tcp([de:ad:be:ef::ca:fe]:80)/dbname?loc=Local", "&{user:user passwd:p@ss(word) net:tcp addr:[de:ad:be:ef::ca:fe]:80 dbname:dbname params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.Local},
-	{"/dbname", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname:dbname params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"@/", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"/", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"user:p@/ssword@/", "&{user:user passwd:p@/ssword net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"unix/?arg=%2Fsome%2Fpath.ext", "&{user: passwd: net:unix addr:/tmp/mysql.sock dbname: params:map[arg:/some/path.ext] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"username:password@protocol(address)/dbname?param=value", "&{user:username passwd:password net:protocol addr:address dbname:dbname params:map[param:value] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"username:password@protocol(address)/dbname?param=value&columnsWithAlias=true", "&{user:username passwd:password net:protocol addr:address dbname:dbname params:map[param:value] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:true interpolateParams:false}", time.UTC},
+	{"user@unix(/path/to/socket)/dbname?charset=utf8", "&{user:user passwd: net:unix addr:/path/to/socket dbname:dbname params:map[charset:utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"user:password@tcp(localhost:5555)/dbname?charset=utf8&tls=true", "&{user:user passwd:password net:tcp addr:localhost:5555 dbname:dbname params:map[charset:utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"user:password@tcp(localhost:5555)/dbname?charset=utf8mb4,utf8&tls=skip-verify", "&{user:user passwd:password net:tcp addr:localhost:5555 dbname:dbname params:map[charset:utf8mb4,utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"user:password@/dbname?loc=UTC&timeout=30s&allowAllFiles=1&clientFoundRows=true&allowOldPasswords=TRUE&collation=utf8mb4_unicode_ci", "&{user:user passwd:password net:tcp addr:127.0.0.1:3306 dbname:dbname params:map[] loc:%p tls:<nil> timeout:30000000000 collation:224 allowAllFiles:true allowOldPasswords:true allowClearPasswords:false clientFoundRows:true columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"user:p@ss(word)@tcp([de:ad:be:ef::ca:fe]:80)/dbname?loc=Local", "&{user:user passwd:p@ss(word) net:tcp addr:[de:ad:be:ef::ca:fe]:80 dbname:dbname params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.Local},
+	{"/dbname", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname:dbname params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"@/", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"/", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"user:p@/ssword@/", "&{user:user passwd:p@/ssword net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"unix/?arg=%2Fsome%2Fpath.ext", "&{user: passwd: net:unix addr:/tmp/mysql.sock dbname: params:map[arg:/some/path.ext] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false allowClearPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
 }
 
 func TestDSNParser(t *testing.T) {