Encryption and decryption functions in PHP and DES encryption and decryption examples, phpdes encryption and decryption examples_PHP tutorial

/*
*Function: Encrypt string
*Parameter 1: Content that needs to be encrypted
*Parameter 2: Key
*/
function passport_encrypt($str,$key){ //Encryption function
srand((double)microtime() * 1000000);
$encrypt_key=md5(rand(0, 32000));
$ctr=0;
$tmp='';
for($i=0;$i $ctr=$ctr==strlen($encrypt_key)?0:$ctr;
$tmp.=$encrypt_key[$ctr].($str[$i] ^ $encrypt_key[$ctr++]);
}
return base64_encode(passport_key($tmp,$key));
}

/*
*Function: Decrypt string
*Parameter 1: Ciphertext to be decrypted
*Parameter 2: Key
*/
function passport_decrypt($str,$key){ //Decryption function
$str=passport_key(base64_decode($str),$key);
$tmp='';
for($i=0;$i $md5=$str[$i];
$tmp.=$str[++$i] ^ $md5;
}
return $tmp;
}

/*
*Auxiliary function
*/
function passport_key($str,$encrypt_key){
$encrypt_key=md5($encrypt_key);
$ctr=0;
$tmp='';
for($i=0;$i $ctr=$ctr==strlen($encrypt_key)?0:$ctr;
$tmp.=$str[$i] ^ $encrypt_key[$ctr++];
}
return $tmp;
}

$str='Author: www.jb51.net';
$key='123456';
$encrypt=passport_encrypt($str,$key);
$decrypt=passport_decrypt($encrypt,$key);
echo 'Original text:',$str."

---

";
echo 'Cryptotext:',$encrypt."

---

";
echo 'Translation:',$decrypt."

---

";

class DES
{
var $key;
var $iv; //Offset

function DES( $key, $iv=0 ) {
//Key length 8, for example: 1234abcd
$this->key = $key;
if( $iv == 0 ) {
$this->iv = $key;
} else {
$this->iv = $iv; //mcrypt_create_iv (mcrypt_get_block_size (MCRYPT_DES, MCRYPT_MODE_CBC), MCRYPT_DEV_RANDOM);
}
}

function encrypt($str) {
//Encrypt, return uppercase hexadecimal string
$size = mcrypt_get_block_size ( MCRYPT_DES, MCRYPT_MODE_CBC );
$str = $this->pkcs5Pad ( $str, $size );
Return strtoupper( bin2hex( mcrypt_cbc(MCRYPT_DES, $this->key, $str, MCRYPT_ENCRYPT, $this->iv ) ) );
}

function decrypt($str) {
//Decrypt
$strBin = $this->hex2bin( strtolower( $str ) );
$str = mcrypt_cbc( MCRYPT_DES, $this->key, $strBin, MCRYPT_DECRYPT, $this->iv );
$str = $this->pkcs5Unpad( $str );
Return $str;
}

function hex2bin($hexData) {
$binData = "";
for($i = 0; $i < strlen ( $hexData ); $i += 2) {
$binData .= chr ( hexdec ( substr ( $hexData, $i, 2 ) ) );
}
Return $binData;
}

function pkcs5Pad($text, $blocksize) {
$pad = $blocksize - (strlen ( $text ) % $blocksize);
return $text . str_repeat ( chr ( $pad ), $pad );
}

function pkcs5Unpad($text) {
$pad = ord ( $text {strlen ( $text ) - 1} );
if ($pad > strlen ( $text ))
Return false;
if (strspn ( $text, chr ( $pad ), strlen ( $text ) - $pad ) != $pad)
Return false;
Return substr ( $text, 0, - 1 * $pad );
}
}
?>

$str = '12345678';
$key = '1234abcd';
$crypt = new DES($key);
$mstr = $crypt->encrypt($str);
$str = $crypt->decrypt($mstr);
echo $str.' <=> '.$mstr;

/**
*Encrypt parameters that need to be passed in the url through get method
*/
function args_encode($data) {
if(is_array($data)) {
$string = http_build_query($data);
return base64_encode($string);
} else {
return false;
}
}

/**
*Get the parameters passed in the get method in the url
*/
function getargs() {
$string = base64_decode($_GET['args']);
parse_str($string,$g);
return $g;
}