phpseclib: BigInteger Examples and Notes

<?php
include('Math/BigInteger.php');

$a = new Math_BigInteger(5);
$b = new Math_BigInteger(3);
$c = new Math_BigInteger(4);

$a = new Math_BigInteger(50);
$b = new Math_BigInteger(30);

$a = new Math_BigInteger(30);
$b = new Math_BigInteger(50);

$a = new Math_BigInteger('1100', 2);
$b = new Math_BigInteger('1010', 2);

$a = new Math_BigInteger(pack('H*', 'FA'), 256);

echo $a->add($b); // outputs 5
echo $a->subtract($b); // outputs 2
echo $a->multiply($b); // outputs 15
list($quotient, $residue) = $a->divide($b);
echo $quotient . "\r\n<br />\r\n"; // outputs 1
echo $residue;                     // outputs 2
echo $a->powMod($b, $c); // outputs 1 (eg. 125 % (4 * 31))
echo $a->modInverse($b); // outputs 2
echo $a->gcd($b); // outputs 10
extract($a->extendedGCD($b));

echo $gcd. "\r\n<br />\r\n"; // outputs  10
echo $x  . "\r\n<br />\r\n"; // outputs  29
echo $y;                     // outputs -48
$a = new Math_BigInteger(-5);

echo $a->abs(); // outputs 5
echo $a->compare($b) . "\r\n<br />\r\n"; // outputs  1
echo $b->compare($a) . "\r\n<br />\r\n"; // outputs -1
echo $a->compare($a);                    // outputs  0
var_dump($a->equals($b)); // outputs bool(false)
$rand = new Math_BigInteger();
echo $rand->random($a, $b); // outputs random number between 30 and 50, inclusive
$rand = new Math_BigInteger();
echo $rand->randomPrime($a, $b); // outputs random prime between 30 and 50, inclusive
$a = new Math_BigInteger(47);
var_dump($a->isPrime()); // outputs bool(true)
$a = new Math_BigInteger(347);
$a->setPrecision(8);

echo $a->toBits() . "\r\n<br />\r\n"; // outputs 01011011
$a = $a->bitwise_leftRotate(2);
echo $a->toBits();                    // outputs 01101101
echo $a->bitwise_and($b)->toBits(); // outputs 1000
echo $a->bitwise_or($b)->toBits(); // outputs 1110
echo $a->bitwise_xor($b)->toBits(); // outputs 110
$a = new Math_BigInteger('010', 2);
$a->setPrecision(3);

echo $a->bitwise_not()->toBits(); // outputs 101
$a = new Math_BigInteger('11', 2);

echo $a->bitwise_leftShift(2)->toBits(); // outputs 1100
$a = new Math_BigInteger('1001', 2);
$a->setPrecision(4);

echo $a->bitwise_leftRotate(2)->toBits(); // outputs 0110
$a = new Math_BigInteger('11', 2);

echo $a->bitwise_leftShift(1)->toBits(); // outputs 1
$a = new Math_BigInteger('1001', 2);
$a->setPrecision(4);

echo $a->bitwise_leftRotate(2)->toBits(); // outputs 0110
// all of these are equal to 250
new Math_BigInteger(pack('H*', 'FA'),   256);
new Math_BigInteger(pack('H*', '00FA'),-256);
new Math_BigInteger('FA',   16);
new Math_BigInteger('00FA',-16);
new Math_BigInteger('250',  10);
new Math_BigInteger('250',-10);
new Math_BigInteger('11111010',  2);
new Math_BigInteger('011111010',-2);

// all of these are equal to -6
new Math_BigInteger(pack('H*', 'FA'), -256);
new Math_BigInteger('FA', -16);
new Math_BigInteger('-6', -10);
new Math_BigInteger('11111010', -2);
echo $a->toString(); // outputs 250
echo bin2hex($a->toBytes()) . "\r\n<br />\r\n"; // outputs fa
echo bin2hex($a->toBytes(true));                // outputs 00fa
echo $a->toHex() . "\r\n<br />\r\n"; // outputs fa
echo $a->toHex(true);                // outputs 00fa
echo $a->toBits() . "\r\n<br />\r\n"; // outputs  11111010
echo $a->toBits(true);                // outputs 011111010
?>

Notes

$x  > $y: $x->compare($y)  > 0
$x  < $y: $x->compare($y)  < 0
$x == $y: $x->compare($y) == 0
$x >= $y: $x->compare($y) >= 0
$x <= $y: $x->compare($y) <= 0

Math_BigInteger randomPrime(Math_BigInteger $min, Math_BigInteger $max, int $timeout = false)