mysqlnd cannot connect to MySQL 4.1+ using the old insecure authentication

Warning: mysql_connect() [function.mysql-connect]: Premature end of data (mysqlnd_wireprotocol.c:554) in path/to/the/file/where/connection/script/is/written/

Warning: mysql_connect() [function.mysql-connect]: OK packet 1 bytes shorter than expected in path/to/the/file/where/connection/script/is/written/

Warning: mysql_connect() [function.mysql-connect]: mysqlnd cannot connect to MySQL 4.1+ using the old insecure authentication. Please use an administration tool to reset your password with the command SET PASSWORD = PASSWORD('your_existing_password'). This will store a new, and more secure, hash value in mysql.user. If this user is used in other scripts executed by PHP 5.2 or earlier you might need to remove the old-passwords flag from your my.cnf file in path/to/the/file/where/connection/script/is/written/

1. Change MySQL to NOT to use old_passwords
It seems that even MySQL 5.x versions still default to the old password hashes. You need to change this in “my.cnf” (e.g. /etc/my.cnf): remove or comment out the line that says
old_passwords = 1
 //
old_passwords = 1為16位
//所以這裡要先
/
/SET old_passwords = 0;
//這樣使新密碼的長度也變成41位
Restart MySQL. If you don’t, MySQL will keep using the old password format, which will mean that you cannot upgrade the passwords using the builtin PASSWORD() hashing function. You can test this by running:

具體原因我還不是很清楚，跟old密碼長度有關？先記錄下來，日後研究。解決方案如下：

代碼如下	複製代碼
SET old_passwords = 0; UPDATE mysql.user SET PASSWORD = PASSWORD( 'www.chajian8.com' ) WHERE User = 'chajian8' LIMIT 1 ; SELECT LENGTH( PASSWORD ) FROM mysql.user WHERE User = 'chajian8'; FLUSH PRIVILEGES ;

附 PHP串連MySQL測試代碼：

代碼如下	複製代碼
<?php $con = mysql_connect("192.168.3.240:3306","chajian8",www.111cn.net); if (!$con) {  die('Could not connect: ' . mysql_error()); } ?>