I have an encryption function and a decryption function as part of my credit card class.
The decryption function is passed a value and a key.
If the decryption function is called from the encryption function, it works perfectly.
If the result of the encryption is converted into a string ($v[0].$v[1]) and stored as $this->encryptedNumber then later split in 2 and passed to the decryption function with the same key, it doesnt work.
I printed out both arrays that were passed in and they are both identical.
I'm absolutely baffled as to what the problem is.
PHP Code:
function encrypt()
{
$k = $this->getKey();
$v = explode("\r\n", chunk_split($this->number, ceil(strlen($this->number)/2)));
$this->xteaEncrypt($v, $k);
}
function decrypt()
{
$k = $this->getKey();
$v = explode("\r\n", chunk_split($this->encryptedNumber, ceil(strlen($this->encryptedNumber)/2)));
$this->xteaDecrypt($v, $k);
}
function getKey()
{
$k[0] = "123456789012345";
$k[1] = "678901234567890";
$k[2] = "987654321098765";
$k[3] = "432109876543210";
return $k;
}
function xteaEncrypt($v, $k) {
$sum = 0;
$delta = 0x9E3779B9;
for($i=0; $i<32; $i++) {
$v[0] += unsigned(($v[1] << 4 ^ $v[1] >> 5) + $v[1] ^ $sum + $k[$sum & 3]);
$sum += $delta;
$v[1] += unsigned(($v[0] << 4 ^ $v[0] >> 5) + $v[0] ^ $sum + $k[$sum>>11 & 3]);
}
$this->encryptedNumber = $v[0].$v[1];
$this->xteaDecrypt($v, $k);
}
function xteaDecrypt($v, $k) {
print_r($v)."<br />";
print_r($k)."<br />";
$sum = 0xC6EF3720;
$delta = 0x9E3779B9;
for($i=0; $i<32; $i++) {
$v[1] -= unsigned(($v[0] << 4 ^ $v[0] >> 5) + $v[0] ^ $sum + $k[$sum>>11 & 3]);
$sum -= $delta;
$v[0] -= unsigned(($v[1] << 4 ^ $v[1] >> 5) + $v[1] ^ $sum + $k[$sum&3]);
}
echo "<br />Funct Decrypted:".$v[0].$v[1]."<br />";
$this->number = $v[0].$v[1];
}
function unsigned($val)
{
$val = $val*$val;
$val = sqrt($val);
return $val;
}
Before you post, read our: 
