<?php
/**
 * @author    Andreas Fischer <bantu@phpbb.com>
 * @copyright MMXII Andreas Fischer
 * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
 */

require_once 'Math/BigInteger.php';

abstract class Math_BigInteger_TestCase extends PhpseclibTestCase
{
    static public function setUpBeforeClass()
    {
        parent::setUpBeforeClass();

        self::reRequireFile('Math/BigInteger.php');
    }

    public function getInstance($x = 0, $base = 10)
    {
        return new Math_BigInteger($x, $base);
    }

    public function testConstructorBase2()
    {
        // 2**65 = 36893488147419103232
        $this->assertSame('36893488147419103232', (string) $this->getInstance('1' . str_repeat('0', 65), 2));
    }

    public function testConstructorBase10()
    {
        $this->assertSame('18446744073709551616', (string) $this->getInstance('18446744073709551616'));
    }

    public function testConstructorBase16()
    {
        $this->assertSame('50',                        (string) $this->getInstance('0x32', 16));
        $this->assertSame('12345678910',            (string) $this->getInstance('0x2DFDC1C3E', 16));
        $this->assertSame('18446744073709551615',    (string) $this->getInstance('0xFFFFFFFFFFFFFFFF', 16));
        $this->assertSame('18446744073709551616',    (string) $this->getInstance('0x10000000000000000', 16));
    }

    public function testToBytes()
    {
        $this->assertSame(chr(65), $this->getInstance('65')->toBytes());
    }

    public function testToBytesTwosCompliment()
    {
        $this->assertSame(chr(126), $this->getInstance('01111110', 2)->toBytes(true));
    }

    public function testToHex()
    {
         $this->assertSame('41', $this->getInstance('65')->toHex());
    }

    public function testToBits()
    {
        $this->assertSame('1000001', $this->getInstance('65')->toBits());
    }

    public function testAdd()
    {
        $x = $this->getInstance('18446744073709551615');
        $y = $this->getInstance(        '100000000000');

        $a = $x->add($y);
        $b = $y->add($x);

        $this->assertTrue($a->equals($b));
        $this->assertTrue($b->equals($a));

        $this->assertSame('18446744173709551615', (string) $a);
        $this->assertSame('18446744173709551615', (string) $b);
    }

    public function testSubtract()
    {
        $x = $this->getInstance('18446744073709551618');
        $y = $this->getInstance(       '4000000000000');
        $this->assertSame('18446740073709551618', (string) $x->subtract($y));
    }

    public function testMultiply()
    {
        $x = $this->getInstance('8589934592');                // 2**33
        $y = $this->getInstance('36893488147419103232');    // 2**65

        $a = $x->multiply($y); // 2**98
        $b = $y->multiply($x); // 2**98

        $this->assertTrue($a->equals($b));
        $this->assertTrue($b->equals($a));

        $this->assertSame('316912650057057350374175801344', (string) $a);
        $this->assertSame('316912650057057350374175801344', (string) $b);
    }

    public function testDivide()
    {
        $x = $this->getInstance('1180591620717411303425');    // 2**70 + 1
        $y = $this->getInstance('12345678910');

        list($q, $r) = $x->divide($y);

        $this->assertSame('95627922070', (string) $q);
        $this->assertSame('10688759725', (string) $r);
    }

    public function testModPow()
    {
        $a = $this->getInstance('10');
        $b = $this->getInstance('20');
        $c = $this->getInstance('30');
        $d = $a->modPow($b, $c);

        $this->assertSame('10', (string) $d);
    }

    public function testModInverse()
    {
        $a = $this->getInstance(30);
        $b = $this->getInstance(17);

        $c = $a->modInverse($b);
        $this->assertSame('4', (string) $c);

        $d = $a->multiply($c);
        list($q, $r) = $d->divide($b);
        $this->assertSame('1', (string) $r);
    }

    public function testExtendedGCD()
    {
        $a = $this->getInstance(693);
        $b = $this->getInstance(609);

        $arr = $a->extendedGCD($b);

        $this->assertSame('21', (string) $arr['gcd']);
        $this->assertSame(21, $a->toString() * $arr['x']->toString() + $b->toString() * $arr['y']->toString());
    }

    public function testGCD()
    {
        $x = $this->getInstance(693);
        $y = $this->getInstance(609);
        $this->assertSame('21', (string) $x->gcd($y));
    }

    public function testAbs()
    {
        $x = $this->getInstance('-18446744073709551617');
        $y = $x->abs();

        $this->assertSame('-18446744073709551617', (string) $x);
        $this->assertSame('18446744073709551617', (string) $y);
    }

    public function testEquals()
    {
        $x = $this->getInstance('18446744073709551616');
        $y = $this->getInstance('18446744073709551616');

        $this->assertTrue($x->equals($y));
        $this->assertTrue($y->equals($x));
    }

    public function testCompare()
    {
        $a = $this->getInstance('-18446744073709551616');
        $b = $this->getInstance('36893488147419103232');
        $c = $this->getInstance('36893488147419103232');
        $d = $this->getInstance('316912650057057350374175801344');

        // a < b
        $this->assertLessThan(0, $a->compare($b));
        $this->assertGreaterThan(0, $b->compare($a));

        // b = c
        $this->assertSame(0, $b->compare($c));
        $this->assertSame(0, $c->compare($b));

        // c < d
        $this->assertLessThan(0, $c->compare($d));
        $this->assertGreaterThan(0, $d->compare($c));
    }

    public function testBitwiseAND()
    {
        $x = $this->getInstance('66666666666666666666666', 16);
        $y = $this->getInstance('33333333333333333333333', 16);
        $z = $this->getInstance('22222222222222222222222', 16);

        $this->assertSame($z->toHex(), $x->bitwise_AND($y)->toHex());
    }

    public function testBitwiseOR()
    {
        $x = $this->getInstance('11111111111111111111111', 16);
        $y = $this->getInstance('EEEEEEEEEEEEEEEEEEEEEEE', 16);
        $z = $this->getInstance('FFFFFFFFFFFFFFFFFFFFFFF', 16);

        $this->assertSame($z->toHex(), $x->bitwise_OR($y)->toHex());
    }

    public function testBitwiseXOR()
    {
        $x = $this->getInstance('AFAFAFAFAFAFAFAFAFAFAFAF', 16);
        $y = $this->getInstance('133713371337133713371337', 16);
        $z = $this->getInstance('BC98BC98BC98BC98BC98BC98', 16);

        $this->assertSame($z->toHex(), $x->bitwise_XOR($y)->toHex());
    }

    public function testBitwiseNOT()
    {
        $x = $this->getInstance('EEEEEEEEEEEEEEEEEEEEEEE', 16);
        $z = $this->getInstance('11111111111111111111111', 16);

        $this->assertSame($z->toHex(), $x->bitwise_NOT()->toHex());
    }

    public function testBitwiseLeftShift()
    {
        $x = $this->getInstance('0x0000000FF0000000', 16);
        $y = $this->getInstance('0x000FF00000000000', 16);

        $this->assertSame($y->toHex(), $x->bitwise_LeftShift(16)->toHex());
    }

    public function testBitwiseRightShift()
    {
        $x = $this->getInstance('0x0000000FF0000000', 16);
        $y = $this->getInstance('0x00000000000FF000', 16);
        $z = $this->getInstance('0x000000000000000F', 16);
        $n = $this->getInstance(0);

        $this->assertSame($y->toHex(), $x->bitwise_RightShift(16)->toHex());
        $this->assertSame($z->toHex(), $x->bitwise_RightShift(32)->toHex());
        $this->assertSame($n->toHex(), $x->bitwise_RightShift(36)->toHex());
    }

    public function testSerializable()
    {
        $x = $this->getInstance('18446744073709551616');
        $y = unserialize(serialize($x));

        $this->assertTrue($x->equals($y));
        $this->assertTrue($y->equals($x));

        $this->assertSame('18446744073709551616', (string) $x);
        $this->assertSame('18446744073709551616', (string) $y);
    }

    public function testClone()
    {
        $x = $this->getInstance('18446744073709551616');
        $y = clone $x;

        $this->assertTrue($x->equals($y));
        $this->assertTrue($y->equals($x));

        $this->assertSame('18446744073709551616', (string) $x);
        $this->assertSame('18446744073709551616', (string) $y);
    }

    /**
    * @group github279
    */
    public function testDiffieHellmanKeyAgreement()
    {
        // "Oakley Group 14" 2048-bit modular exponentiation group as used in
        // SSH2 diffie-hellman-group14-sha1
        $prime = $this->getInstance(
            'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1' .
            '29024E088A67CC74020BBEA63B139B22514A08798E3404DD' .
            'EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245' .
            'E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' .
            'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D' .
            'C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F' .
            '83655D23DCA3AD961C62F356208552BB9ED529077096966D' .
            '670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B' .
            'E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9' .
            'DE2BCBF6955817183995497CEA956AE515D2261898FA0510' .
            '15728E5A8AACAA68FFFFFFFFFFFFFFFF',
            16
        );
        $generator = $this->getInstance(2);

        $one = $this->getInstance(1);
        $max = $one->bitwise_leftShift(512)->subtract($one);

        $alicePrivate = $one->random($one, $max);
        $alicePublic = $generator->modPow($alicePrivate, $prime);

        $bobPrivate = $one->random($one, $max);
        $bobPublic =  $generator->modPow($bobPrivate, $prime);

        $aliceShared = $bobPublic->modPow($alicePrivate, $prime);
        $bobShared = $alicePublic->modPow($bobPrivate, $prime);

        $this->assertTrue(
            $aliceShared->equals($bobShared),
            'Failed asserting that Alice and Bob share the same BigInteger.'
        );
    }
}