Detailed introduction to the server handshake package of the mysql protocol and its analysis

Overview

Mysql client logging in to the mysql server requires an interactive process. Here we first look at the initial handshake packet sent by the server to the client. As shown below, after the client connects to the port specified by the server through the socket, the server will send an initial handshake packet to the client. The server will return different initialization handshake packets according to different service versions and different configurations.

client              
server   
|------connect---- >|
   |                   |
   |<----handshake-----|
   |                   |
   |                   |
   |                   |

mysql communication message structure

## stringpayloadMessage body, the length is the previously specified payload length

Type	Name	Description
int	payload length	Stored according to the least significant byte first, 3-byte payload and 1-byte sequence number Combined into a message header
int	sequence number

Initial handshake packet

HandshakeV10 protocol is as follows

1              [0a] protocol version
string[NUL]    server version
4              connection id
string[8]      auth-plugin-data-part-1
1              [00] filler
2              capability flags (lower 2 bytes)
  if more data in the packet:
1              character set
2              status flags
2              capability flags (upper 2 bytes)
  if capabilities & CLIENT_PLUGIN_AUTH {
1              length of auth-plugin-data
  } else {
1              [00]
  }
string[10]     reserved (all [00])
  if capabilities & CLIENT_SECURE_CONNECTION {
string[$len]   auth-plugin-data-part-2 ($len=MAX(13, length of auth-plugin-data - 8))
  if capabilities & CLIENT_PLUGIN_AUTH {
    if version >= (5.5.7 and < 5.5.10) or (>= 5.6.0 and < 5.6.2) {
string[EOF]    auth-plugin name
    } elseif version >= 5.5.10 or >= 5.6.2 {
string[NUL]    auth-plugin name
    }
  }

Generate initial handshake packet

1. Definition version

/**
 * 
 * @author seaboat
 * @date 2016-09-25
 * @version 1.0
 * <pre class="brush:php;toolbar:false"><b>email: </b>849586227@qq.com

 * 

<b>blog: </b>http://www.php.cn/;/pre>
 * <p>proxy's version.</p>
 */public interface Versions {

    byte PROTOCOL_VERSION = 10;    byte[] SERVER_VERSION = "5.6.0-snapshot".getBytes();
}

1. Random number tool

/**
 * 
 * @author seaboat
 * @date 2016-09-25
 * @version 1.0
 * <pre class="brush:php;toolbar:false"><b>email: </b>849586227@qq.com

 * 

<b>blog: </b>http://www.php.cn/;/pre>
 * <p>a random util .</p>
 */public class RandomUtil {
    private static final byte[] bytes = { '1', '2', '3', '4', '5', '6', '7',            
    '8', '9', '0', 'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p',            
    'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', 'z', 'x', 'c', 'v',            
    'b', 'n', 'm', 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P',            
    'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', 'Z', 'X', 'C', 'V',            
    'B', 'N', 'M' };    
    private static final long multiplier = 0x5DEECE66DL;    
    private static final long addend = 0xBL;    
    private static final long mask = (1L >> 16);        
    return b[ran % b.length];
    }    private static long next() {        
    long oldSeed = seed;        
    long nextSeed = 0L;
        do {
            nextSeed = (oldSeed * multiplier + addend) & mask;
        } 
        while (oldSeed == nextSeed);
        seed = nextSeed;        
        return nextSeed;
    }

}

1. mysql package base class

/**
 * 
 * @author seaboat
 * @date 2016-09-25
 * @version 1.0
 * <pre class="brush:php;toolbar:false"><b>email: </b>849586227@qq.com

 * 

<b>blog: </b>http://www.php.cn/;/pre>
 * <p>MySQLPacket is mysql's basic packet.</p>
 */public abstract class MySQLPacket {
    /**
     * none, this is an internal thread state
     */
    public static final byte COM_SLEEP = 0;    /**
     * mysql_close
     */
    public static final byte COM_QUIT = 1;    /**
     * mysql_select_db
     */
    public static final byte COM_INIT_DB = 2;    /**
     * mysql_real_query
     */
    public static final byte COM_QUERY = 3;    /**
     * mysql_list_fields
     */
    public static final byte COM_FIELD_LIST = 4;    /**
     * mysql_create_db (deprecated)
     */
    public static final byte COM_CREATE_DB = 5;    /**
     * mysql_drop_db (deprecated)
     */
    public static final byte COM_DROP_DB = 6;    /**
     * mysql_refresh
     */
    public static final byte COM_REFRESH = 7;    /**
     * mysql_shutdown
     */
    public static final byte COM_SHUTDOWN = 8;    /**
     * mysql_stat
     */
    public static final byte COM_STATISTICS = 9;    /**
     * mysql_list_processes
     */
    public static final byte COM_PROCESS_INFO = 10;    /**
     * none, this is an internal thread state
     */
    public static final byte COM_CONNECT = 11;    /**
     * mysql_kill
     */
    public static final byte COM_PROCESS_KILL = 12;    /**
     * mysql_dump_debug_info
     */
    public static final byte COM_DEBUG = 13;    /**
     * mysql_ping
     */
    public static final byte COM_PING = 14;    /**
     * none, this is an internal thread state
     */
    public static final byte COM_TIME = 15;    /**
     * none, this is an internal thread state
     */
    public static final byte COM_DELAYED_INSERT = 16;    /**
     * mysql_change_user
     */
    public static final byte COM_CHANGE_USER = 17;    /**
     * used by slave server mysqlbinlog
     */
    public static final byte COM_BINLOG_DUMP = 18;    /**
     * used by slave server to get master table
     */
    public static final byte COM_TABLE_DUMP = 19;    /**
     * used by slave to log connection to master
     */
    public static final byte COM_CONNECT_OUT = 20;    /**
     * used by slave to register to master
     */
    public static final byte COM_REGISTER_SLAVE = 21;    /**
     * mysql_stmt_prepare
     */
    public static final byte COM_STMT_PREPARE = 22;    /**
     * mysql_stmt_execute
     */
    public static final byte COM_STMT_EXECUTE = 23;    /**
     * mysql_stmt_send_long_data
     */
    public static final byte COM_STMT_SEND_LONG_DATA = 24;    /**
     * mysql_stmt_close
     */
    public static final byte COM_STMT_CLOSE = 25;    /**
     * mysql_stmt_reset
     */
    public static final byte COM_STMT_RESET = 26;    /**
     * mysql_set_server_option
     */
    public static final byte COM_SET_OPTION = 27;    /**
     * mysql_stmt_fetch
     */
    public static final byte COM_STMT_FETCH = 28;    /**
     * mysql packet length
     */
    public int packetLength;    /**
     * mysql packet id
     */
    public byte packetId;    /**
     * calculate mysql packet length
     */
    public abstract int calcPacketSize();    /**
     * mysql packet info
     */
    protected abstract String getPacketInfo();    @Override
    public String toString() {        return new StringBuilder().append(getPacketInfo()).append("{length=")
                .append(packetLength).append(",id=").append(packetId)
                .append('}').toString();
    }

}

1. Handshake package class

/**
 * 
 * @author seaboat
 * @date 2016-09-25
 * @version 1.0
 * <pre class="brush:php;toolbar:false"><b>email: </b>849586227@qq.com

 * 

<b>blog: </b>http://www.php.cn/;/pre>
 * <p>AuthPacket means mysql initial handshake packet .</p>
 */public class HandshakePacket extends MySQLPacket {
    private static final byte[] FILLER_13 = new byte[] { 0, 0, 0, 0, 0, 0, 0,            
    0, 0, 0, 0, 0, 0 };    
    public byte protocolVersion;    
    public byte[] serverVersion;    
    public long threadId;    
    public byte[] seed;    
    public int serverCapabilities;    
    public byte serverCharsetIndex;    
    public int serverStatus;    
    public byte[] restOfScrambleBuff;    
    public void read(byte[] data) {
        MySQLMessage mm = new MySQLMessage(data);
        packetLength = mm.readUB3();
        packetId = mm.read();
        protocolVersion = mm.read();
        serverVersion = mm.readBytesWithNull();
        threadId = mm.readUB4();
        seed = mm.readBytesWithNull();
        serverCapabilities = mm.readUB2();
        serverCharsetIndex = mm.read();
        serverStatus = mm.readUB2();
        mm.move(13);
        restOfScrambleBuff = mm.readBytesWithNull();
    }    @Override
    public int calcPacketSize() {        int size = 1;
        size += serverVersion.length;// n
        size += 5;// 1+4
        size += seed.length;// 8
        size += 19;// 1+2+1+2+13
        size += restOfScrambleBuff.length;// 12
        size += 1;// 1
        return size;
    }    public void write(ByteBuffer buffer) {
        BufferUtil.writeUB3(buffer, calcPacketSize());
        buffer.put(packetId);
        buffer.put(protocolVersion);
        BufferUtil.writeWithNull(buffer, serverVersion);
        BufferUtil.writeUB4(buffer, threadId);
        BufferUtil.writeWithNull(buffer, seed);
        BufferUtil.writeUB2(buffer, serverCapabilities);
        buffer.put(serverCharsetIndex);
        BufferUtil.writeUB2(buffer, serverStatus);
        buffer.put(FILLER_13);
        BufferUtil.writeWithNull(buffer, restOfScrambleBuff);
    }    @Override
    protected String getPacketInfo() {        
    return "MySQL Handshake Packet";
    }

}

1. Server capability class

/**
 * 
 * @author seaboat
 * @date 2016-09-25
 * @version 1.0
 * <pre class="brush:php;toolbar:false"><b>email: </b>849586227@qq.com

 * 

<b>blog: </b>http://www.php.cn/;/pre>
 * <p>server capabilities .</p>
 */public interface Capabilities {

    // new more secure passwords
    int CLIENT_LONG_PASSWORD = 1;    // Found instead of affected rows
    int CLIENT_FOUND_ROWS = 2;    // Get all column flags
    int CLIENT_LONG_FLAG = 4;    // One can specify db on connect
    int CLIENT_CONNECT_WITH_DB = 8;    // Don't allow database.table.column
    int CLIENT_NO_SCHEMA = 16;    // Can use compression protocol
    int CLIENT_COMPRESS = 32;    // Odbc client
    int CLIENT_ODBC = 64;    // Can use LOAD DATA LOCAL
    int CLIENT_LOCAL_FILES = 128;    // Ignore spaces before '('
    int CLIENT_IGNORE_SPACE = 256;    // New 4.1 protocol This is an interactive client
    int CLIENT_PROTOCOL_41 = 512;    // This is an interactive client
    int CLIENT_INTERACTIVE = 1024;    // Switch to SSL after handshake
    int CLIENT_SSL = 2048;    // IGNORE sigpipes
    int CLIENT_IGNORE_SIGPIPE = 4096;    // Client knows about transactions
    int CLIENT_TRANSACTIONS = 8192;    // Old flag for 4.1 protocol
    int CLIENT_RESERVED = 16384;    // New 4.1 authentication
    int CLIENT_SECURE_CONNECTION = 32768;    // Enable/disable multi-stmt support
    int CLIENT_MULTI_STATEMENTS = 65536;    // Enable/disable multi-results
    int CLIENT_MULTI_RESULTS = 131072;

}

1. Test class

/**
 * 
 * @author seaboat
 * @date 2016-09-25
 * @version 1.0
 * <pre class="brush:php;toolbar:false"><b>email: </b>849586227@qq.com

 * 

<b>blog: </b>http://www.php.cn/;/pre>
 * <p>test handshake packet.</p>
 */public class HandshakePacketTest {
    private final static byte[] hex = "0123456789ABCDEF".getBytes();    @Test
    public void produce() {        
    byte[] rand1 = RandomUtil.randomBytes(8);        
    byte[] rand2 = RandomUtil.randomBytes(12);        
    byte[] seed = new byte[rand1.length + rand2.length];
        System.arraycopy(rand1, 0, seed, 0, rand1.length);
        System.arraycopy(rand2, 0, seed, rand1.length, rand2.length);
        HandshakePacket hs = new HandshakePacket();
        hs.packetId = 0;
        hs.protocolVersion = Versions.PROTOCOL_VERSION;
        hs.serverVersion = Versions.SERVER_VERSION;
        hs.threadId = 1000;
        hs.seed = rand1;
        hs.serverCapabilities = getServerCapabilities();
        hs.serverCharsetIndex = (byte) (CharsetUtil.getIndex("utf8") & 0xff);
        hs.serverStatus = 2;
        hs.restOfScrambleBuff = rand2;

        ByteBuffer buffer = ByteBuffer.allocate(256);
        hs.write(buffer);
        buffer.flip();        
        byte[] bytes = new byte[buffer.remaining()];
        buffer.get(bytes, 0, bytes.length);
        String result = Bytes2HexString(bytes);
        assertTrue(Integer.valueOf(result.substring(0,2),16)==result.length()/2-4);
    }    public static String Bytes2HexString(byte[] b) {        
    byte[] buff = new byte[2 * b.length];        
    for (int i = 0; i > 4) & 0x0f];
            buff[2 * i + 1] = hex[b[i] & 0x0f];
        }        return new String(buff);
    }    public static String str2HexStr(String str) {        
    char[] chars = "0123456789ABCDEF".toCharArray();
        StringBuilder sb = new StringBuilder("");        
        byte[] bs = str.getBytes();        
        int bit;        
        for (int i = 0; i > 4;
            sb.append(chars[bit]);
            bit = bs[i] & 0x0f;
            sb.append(chars[bit]);
        }        return sb.toString();
    }    protected int getServerCapabilities() {        
    int flag = 0;
        flag |= Capabilities.CLIENT_LONG_PASSWORD;
        flag |= Capabilities.CLIENT_FOUND_ROWS;
        flag |= Capabilities.CLIENT_LONG_FLAG;
        flag |= Capabilities.CLIENT_CONNECT_WITH_DB;
        flag |= Capabilities.CLIENT_ODBC;
        flag |= Capabilities.CLIENT_IGNORE_SPACE;
        flag |= Capabilities.CLIENT_PROTOCOL_41;
        flag |= Capabilities.CLIENT_INTERACTIVE;
        flag |= Capabilities.CLIENT_IGNORE_SIGPIPE;
        flag |= Capabilities.CLIENT_TRANSACTIONS;
        flag |= Capabilities.CLIENT_SECURE_CONNECTION;        
        return flag;
    }

}

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