function encryptDecrypt($key, $string, $decrypt){ 
	if($decrypt){ 
		$decrypted = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($key), base64_decode($string), MCRYPT_MODE_CBC, md5(md5($key))), "12"); 
		return $decrypted; 
	}else{ 
		$encrypted = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5($key), $string, MCRYPT_MODE_CBC, md5(md5($key)))); 
		return $encrypted; 
	} 
} 

使用方法：

echo "加密：".encryptDecrypt('password', '尚锦科技www.nmgsj.shop',0); 
echo "<br />解密：".encryptDecrypt('password', 'AvWc0amI3DImdpm3cwjgvWRkZpdzId973ZJCb6uucf4=',1);