PHP中Mcrypt加密字符串

php
$key = "__Joyous__";// key
$iv = "23joyous";// IV
$input = "id=123";// 加密的字符串
$bit_check=8;//检验位
$str= encrypt($input,$key,$iv,$bit_check);
echo "原字符串: $input 
 执行加密: $str 
 执行解密: ";
echo decrypt($str,$key,$iv,$bit_check);

function encrypt($text,$key,$iv,$bit_check) {
$text_num =str_split($text,$bit_check);
$text_num = $bit_check-strlen($text_num[count($text_num)-1]);
for ($i=0;$i<$text_num; $i++) {$text = $text . chr($text_num);}
$cipher = mcrypt_module_open(MCRYPT_TRIPLEDES,'','cbc','');
mcrypt_generic_init($cipher, $key, $iv);
$decrypted = mcrypt_generic($cipher,$text);
mcrypt_generic_deinit($cipher);
$return = base64_encode($decrypted);
$return = str_replace(array('=','/'),array('','') , $return);//替换部分字符串
return $return;
}

function decrypt($encrypted_text,$key,$iv,$bit_check){
$cipher = mcrypt_module_open(MCRYPT_TRIPLEDES,'','cbc','');
mcrypt_generic_init($cipher, $key, $iv);
$decrypted = mdecrypt_generic($cipher,base64_decode($encrypted_text));
mcrypt_generic_deinit($cipher);
$last_char=substr($decrypted,-1);
for($i=0;$i<$bit_check-1; $i++){
    if(chr($i)==$last_char){
       $decrypted=substr($decrypted,0,strlen($decrypted)-$i);
        break;
    }
}
return $decrypted;
}
?>