在有些时候我们需要存贮到数据库中的内容是加密信息,比如 password,money 等敏感信息,以提高安全等级,
这里是一个带公钥的加密解密程序 ,测试是不错性能的,
<?php
/*
字符串加密解密函数,用于mysql存贮加密解密信息
*/
class MyClass_Crypt{
//公钥
protected $key = “123456”;
private function keyED($txt,$encrypt_key)
{
$encrypt_key = md5($encrypt_key);
$ctr=0;
$tmp = “”;
for ($i=0;$i<strlen($txt);$i++)
{
if ($ctr==strlen($encrypt_key)) $ctr=0;
$tmp.= substr($txt,$i,1) ^ substr($encrypt_key,$ctr,1);
$ctr++;
}
return $tmp;
}
//$txt 是需要加密的字符串
public function encrypt($txt,$key=”)
{
if(empty($key))
$key=$this->key;
srand((double)microtime()*1000000);
$encrypt_key = md5(rand(0,32000));
$ctr=0;
$tmp = “”;
for ($i=0;$i<strlen($txt);$i++)
{
if ($ctr==strlen($encrypt_key)) $ctr=0;
$tmp.= substr($encrypt_key,$ctr,1) .
(substr($txt,$i,1) ^ substr($encrypt_key,$ctr,1));
$ctr++;
}
return $this->keyED($tmp,$key);
}
//$txt 是需要解密的字符串
public function decrypt($txt,$key=”)
{
if(empty($key))
$key=$this->key;
$txt = $this->keyED($txt,$key);
$tmp = “”;
for ($i=0;$i<strlen($txt);$i++)
{
$md5 = substr($txt,$i,1);
$i++;
$tmp.= (substr($txt,$i,1) ^ $md5);
}
return $tmp;
}
public function setKey($key)
{
if(empty($key))
return Null;
$this->key=$key;
}
public function getKey()
{
return $this->key;
}
}
/*
$string = “123456”;
$crypt= new Crypt;
echo $crypt->getKey().'<br>’;
$crypt->setKey(‘sdfsd’);
echo $crypt->getKey().'<br>’;
// encrypt $string, and store it in $enc_text
$enc_text = $crypt->encrypt($string);
// decrypt the encrypted text $enc_text, and store it in $dec_text
$dec_text = $crypt->decrypt($enc_text);
print “Original text : $string<br>\n”;
print “Encrypted text : $enc_text<br>\n”;
print “Decrypted text : $dec_text\n”;
*/
?>