diff options
Diffstat (limited to 'vendor/paragonie/random_compat/lib/random_int.php')
| -rw-r--r-- | vendor/paragonie/random_compat/lib/random_int.php | 319 |
1 files changed, 159 insertions, 160 deletions
diff --git a/vendor/paragonie/random_compat/lib/random_int.php b/vendor/paragonie/random_compat/lib/random_int.php index fd3ef87a..5b2143a1 100644 --- a/vendor/paragonie/random_compat/lib/random_int.php +++ b/vendor/paragonie/random_compat/lib/random_int.php @@ -1,191 +1,190 @@ <?php -/** - * Random_* Compatibility Library - * for using the new PHP 7 random_* API in PHP 5 projects - * - * The MIT License (MIT) - * - * Copyright (c) 2015 Paragon Initiative Enterprises - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE - * SOFTWARE. - */ - -/** - * Fetch a random integer between $min and $max inclusive - * - * @param int $min - * @param int $max - * - * @throws Exception - * - * @return int - */ -function random_int($min, $max) -{ - /** - * Type and input logic checks - * - * If you pass it a float in the range (~PHP_INT_MAX, PHP_INT_MAX) - * (non-inclusive), it will sanely cast it to an int. If you it's equal to - * ~PHP_INT_MAX or PHP_INT_MAX, we let it fail as not an integer. Floats - * lose precision, so the <= and => operators might accidentally let a float - * through. - */ - - try { - $min = RandomCompat_intval($min); - } catch (TypeError $ex) { - throw new TypeError( - 'random_int(): $min must be an integer' - ); - } - try { - $max = RandomCompat_intval($max); - } catch (TypeError $ex) { - throw new TypeError( - 'random_int(): $max must be an integer' - ); - } - +if (!is_callable('random_int')) { /** - * Now that we've verified our weak typing system has given us an integer, - * let's validate the logic then we can move forward with generating random - * integers along a given range. + * Random_* Compatibility Library + * for using the new PHP 7 random_* API in PHP 5 projects + * + * The MIT License (MIT) + * + * Copyright (c) 2015 - 2017 Paragon Initiative Enterprises + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. */ - if ($min > $max) { - throw new Error( - 'Minimum value must be less than or equal to the maximum value' - ); - } - - if ($max === $min) { - return $min; - } /** - * Initialize variables to 0 - * - * We want to store: - * $bytes => the number of random bytes we need - * $mask => an integer bitmask (for use with the &) operator - * so we can minimize the number of discards + * Fetch a random integer between $min and $max inclusive + * + * @param int $min + * @param int $max + * + * @throws Exception + * + * @return int */ - $attempts = $bits = $bytes = $mask = $valueShift = 0; - - /** - * At this point, $range is a positive number greater than 0. It might - * overflow, however, if $max - $min > PHP_INT_MAX. PHP will cast it to - * a float and we will lose some precision. - */ - $range = $max - $min; - - /** - * Test for integer overflow: - */ - if (!is_int($range)) { - + function random_int($min, $max) + { /** - * Still safely calculate wider ranges. - * Provided by @CodesInChaos, @oittaa - * - * @ref https://gist.github.com/CodesInChaos/03f9ea0b58e8b2b8d435 - * - * We use ~0 as a mask in this case because it generates all 1s - * - * @ref https://eval.in/400356 (32-bit) - * @ref http://3v4l.org/XX9r5 (64-bit) + * Type and input logic checks + * + * If you pass it a float in the range (~PHP_INT_MAX, PHP_INT_MAX) + * (non-inclusive), it will sanely cast it to an int. If you it's equal to + * ~PHP_INT_MAX or PHP_INT_MAX, we let it fail as not an integer. Floats + * lose precision, so the <= and => operators might accidentally let a float + * through. */ - $bytes = PHP_INT_SIZE; - $mask = ~0; - } else { + try { + $min = RandomCompat_intval($min); + } catch (TypeError $ex) { + throw new TypeError( + 'random_int(): $min must be an integer' + ); + } - /** - * $bits is effectively ceil(log($range, 2)) without dealing with - * type juggling - */ - while ($range > 0) { - if ($bits % 8 === 0) { - ++$bytes; - } - ++$bits; - $range >>= 1; - $mask = $mask << 1 | 1; + try { + $max = RandomCompat_intval($max); + } catch (TypeError $ex) { + throw new TypeError( + 'random_int(): $max must be an integer' + ); } - $valueShift = $min; - } - /** - * Now that we have our parameters set up, let's begin generating - * random integers until one falls between $min and $max - */ - do { /** - * The rejection probability is at most 0.5, so this corresponds - * to a failure probability of 2^-128 for a working RNG + * Now that we've verified our weak typing system has given us an integer, + * let's validate the logic then we can move forward with generating random + * integers along a given range. */ - if ($attempts > 128) { - throw new Exception( - 'random_int: RNG is broken - too many rejections' + if ($min > $max) { + throw new Error( + 'Minimum value must be less than or equal to the maximum value' ); } + if ($max === $min) { + return (int) $min; + } + /** - * Let's grab the necessary number of random bytes + * Initialize variables to 0 + * + * We want to store: + * $bytes => the number of random bytes we need + * $mask => an integer bitmask (for use with the &) operator + * so we can minimize the number of discards */ - $randomByteString = random_bytes($bytes); - if ($randomByteString === false) { - throw new Exception( - 'Random number generator failure' - ); - } + $attempts = $bits = $bytes = $mask = $valueShift = 0; /** - * Let's turn $randomByteString into an integer - * - * This uses bitwise operators (<< and |) to build an integer - * out of the values extracted from ord() - * - * Example: [9F] | [6D] | [32] | [0C] => - * 159 + 27904 + 3276800 + 201326592 => - * 204631455 + * At this point, $range is a positive number greater than 0. It might + * overflow, however, if $max - $min > PHP_INT_MAX. PHP will cast it to + * a float and we will lose some precision. */ - $val = 0; - for ($i = 0; $i < $bytes; ++$i) { - $val |= ord($randomByteString[$i]) << ($i * 8); - } + $range = $max - $min; /** - * Apply mask + * Test for integer overflow: */ - $val &= $mask; - $val += $valueShift; + if (!is_int($range)) { + + /** + * Still safely calculate wider ranges. + * Provided by @CodesInChaos, @oittaa + * + * @ref https://gist.github.com/CodesInChaos/03f9ea0b58e8b2b8d435 + * + * We use ~0 as a mask in this case because it generates all 1s + * + * @ref https://eval.in/400356 (32-bit) + * @ref http://3v4l.org/XX9r5 (64-bit) + */ + $bytes = PHP_INT_SIZE; + $mask = ~0; - ++$attempts; + } else { + + /** + * $bits is effectively ceil(log($range, 2)) without dealing with + * type juggling + */ + while ($range > 0) { + if ($bits % 8 === 0) { + ++$bytes; + } + ++$bits; + $range >>= 1; + $mask = $mask << 1 | 1; + } + $valueShift = $min; + } + + $val = 0; /** - * If $val overflows to a floating point number, - * ... or is larger than $max, - * ... or smaller than $min, - * then try again. + * Now that we have our parameters set up, let's begin generating + * random integers until one falls between $min and $max */ - } while (!is_int($val) || $val > $max || $val < $min); + do { + /** + * The rejection probability is at most 0.5, so this corresponds + * to a failure probability of 2^-128 for a working RNG + */ + if ($attempts > 128) { + throw new Exception( + 'random_int: RNG is broken - too many rejections' + ); + } + + /** + * Let's grab the necessary number of random bytes + */ + $randomByteString = random_bytes($bytes); - return (int) $val; + /** + * Let's turn $randomByteString into an integer + * + * This uses bitwise operators (<< and |) to build an integer + * out of the values extracted from ord() + * + * Example: [9F] | [6D] | [32] | [0C] => + * 159 + 27904 + 3276800 + 201326592 => + * 204631455 + */ + $val &= 0; + for ($i = 0; $i < $bytes; ++$i) { + $val |= ord($randomByteString[$i]) << ($i * 8); + } + + /** + * Apply mask + */ + $val &= $mask; + $val += $valueShift; + + ++$attempts; + /** + * If $val overflows to a floating point number, + * ... or is larger than $max, + * ... or smaller than $min, + * then try again. + */ + } while (!is_int($val) || $val > $max || $val < $min); + + return (int) $val; + } } |