<?php
/**************************************************
 * RSA Algorithm Private and Public Key Generator *
 *              Coded by Moonbat                  *
 *              October 22, 2008                  *
 **************************************************/
set_time_limit(0);

class RSA {
	
	var $p; 	  /* Prime number #1 */
	var $q; 	  /* Prime number #2 */
	var $n; 	  /* Modulus to be used */
	var $totient; /* Totient of $n, used to find public key $e */
	var $e; 	  /* The public key */
	var $d; 	  /* The private key */
	
	public function __construct() {
		$this->p = $this->GeneratePrime();
		$this->q = $this->GeneratePrime();
		$this->n = $this->p * $this->q;
		$this->totient = ($this->p - 1) * ($this->q - 1);
	}

	public function IsPrime($number) {
		if ($number < 2) { /* We don't want zero or one showing up as prime */
			return FALSE;
		}
		for ($i=2; $i<=($number / 2); $i++) {
			if($number % $i == 0) { /* Modulus operator, very useful */
				return FALSE;
			}
		}
		return TRUE;
	}
	
	public function GeneratePrime() {
		$number = 0;
		while (!$this->IsPrime($number)) { /* Keep going till we get a prime number */
			$number = rand();
		}
		return $number;
	}
	
	/* FindGCF Function - Credit goes to [url="http://us2.php.net/manual/en/function.gmp-gcd.php#69189"]http://us2.php.net/manual/en/function.gmp-gcd.php#69189[/url] */
	public  function FindGCF($z, $totient) {
    	return ($z % $totient) ? $this->FindGCF($totient, $z % $totient) : $totient;
	}
	
	public function GeneratePublicKey() {
		$this->e = rand(2, $this->totient);
		while ($this->FindGCF($this->e, $this->totient) != 1) { // Keep going till $e is coprime with $totient
			$this->e = rand(2, $this->totient);
		}
	}
	
	public function GeneratePrivateKey() {
		$this->d = rand();
		while (($this->d % $this->totient) != ($this->e % $this->totient)) {
			$this->d = rand();
		}
	}
		
}

$encrypt = new RSA();
$encrypt->GeneratePublicKey();
$encrypt->GeneratePrivateKey();

echo "p = $encrypt->p <br>";
echo "q = $encrypt->q <br>";
echo "n = $encrypt->n <br>";
echo "Totient of n = $encrypt->totient";
echo "<br><br>";
echo "The public key is <font color='green'><b>(n = $encrypt->n, e = $encrypt->e)</b></font><br>";
echo "The private key is <font color='red'><b>(n = $encrypt->n, d = $encrypt->d)</b></font>";

?>

$encrypt->GeneratePrivateKey();

					@=====@
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		 \\_______________________________________________\
		  \  ___________________________________________  |
		  || |										 || |
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