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pma/vendor/fgrosse/phpasn1/lib/Utility/BigInteger.php

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+<?php
+/*
+ * This file is part of the PHPASN1 library.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace FG\Utility;
+
+/**
+ * Class BigInteger
+ * Utility class to remove dependence on a single large number library. Not intended for external use, this class only
+ * implements the functionality needed throughout this project.
+ *
+ * Instances are immutable, all operations return a new instance with the result.
+ *
+ * @package FG\Utility
+ * @internal
+ */
+abstract class BigInteger
+{
+    /**
+     * Force a preference on the underlying big number implementation, useful for testing.
+     * @var string|null
+     */
+    private static $_prefer;
+
+    public static function setPrefer($prefer = null)
+    {
+        self::$_prefer = $prefer;
+    }
+
+    /**
+     * Create a BigInteger instance based off the base 10 string or an integer.
+     * @param string|int $val
+     * @return BigInteger
+     * @throws \InvalidArgumentException
+     */
+    public static function create($val)
+    {
+        if (self::$_prefer) {
+            switch (self::$_prefer) {
+                case 'gmp':
+                    $ret = new BigIntegerGmp();
+                    break;
+                case 'bcmath':
+                    $ret = new BigIntegerBcmath();
+                    break;
+                default:
+                    throw new \UnexpectedValueException('Unknown number implementation: ' . self::$_prefer);
+            }
+        }
+        else {
+            // autodetect
+            if (function_exists('gmp_add')) {
+                $ret = new BigIntegerGmp();
+            }
+            elseif (function_exists('bcadd')) {
+                $ret = new BigIntegerBcmath();
+            } else {
+                throw new \RuntimeException('Requires GMP or bcmath extension.');
+            }
+        }
+
+        if (is_int($val)) {
+            $ret->_fromInteger($val);
+        }
+        else {
+            // convert to string, if not already one
+            $val = (string)$val;
+
+            // validate string
+            if (!preg_match('/^-?[0-9]+$/', $val)) {
+                throw new \InvalidArgumentException('Expects a string representation of an integer.');
+            }
+            $ret->_fromString($val);
+        }
+
+        return $ret;
+    }
+
+    /**
+     * BigInteger constructor.
+     * Prevent directly instantiating object, use BigInteger::create instead.
+     */
+    protected function __construct()
+    {
+
+    }
+
+    /**
+     * Subclasses must provide clone functionality.
+     * @return BigInteger
+     */
+    abstract public function __clone();
+
+    /**
+     * Assign the instance value from base 10 string.
+     * @param string $str
+     */
+    abstract protected function _fromString($str);
+
+    /**
+     * Assign the instance value from an integer type.
+     * @param int $integer
+     */
+    abstract protected function _fromInteger($integer);
+
+    /**
+     * Must provide string implementation that returns base 10 number.
+     * @return string
+     */
+    abstract public function __toString();
+
+    /* INFORMATIONAL FUNCTIONS */
+
+    /**
+     * Return integer, if possible. Throws an exception if the number can not be represented as a native integer.
+     * @return int
+     * @throws \OverflowException
+     */
+    abstract public function toInteger();
+
+    /**
+     * Is represented integer negative?
+     * @return bool
+     */
+    abstract public function isNegative();
+
+    /**
+     * Compare the integer with $number, returns a negative integer if $this is less than number, returns 0 if $this is
+     * equal to number and returns a positive integer if $this is greater than number.
+     * @param BigInteger|string|int $number
+     * @return int
+     */
+    abstract public function compare($number);
+
+    /* MODIFY */
+
+    /**
+     * Add another integer $b and returns the result.
+     * @param BigInteger|string|int $b
+     * @return BigInteger
+     */
+    abstract public function add($b);
+
+    /**
+     * Subtract $b from $this and returns the result.
+     * @param BigInteger|string|int $b
+     * @return BigInteger
+     */
+    abstract public function subtract($b);
+
+    /**
+     * Multiply value.
+     * @param BigInteger|string|int $b
+     * @return BigInteger
+     */
+    abstract public function multiply($b);
+
+    /**
+     * The value $this modulus $b.
+     * @param BigInteger|string|int $b
+     * @return BigInteger
+     */
+    abstract public function modulus($b);
+
+    /**
+     * Raise $this to the power of $b and returns the result.
+     * @param BigInteger|string|int $b
+     * @return BigInteger
+     */
+    abstract public function toPower($b);
+
+    /**
+     * Shift the value to the right by a set number of bits and returns the result.
+     * @param int $bits
+     * @return BigInteger
+     */
+    abstract public function shiftRight($bits = 8);
+
+    /**
+     * Shift the value to the left by a set number of bits and returns the result.
+     * @param int $bits
+     * @return BigInteger
+     */
+    abstract public function shiftLeft($bits = 8);
+
+    /**
+     * Returns the absolute value.
+     * @return BigInteger
+     */
+    abstract public function absoluteValue();
+}