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File: src/Core/Util.php

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File: src/Core/Util.php
Role: Class source
Content type: text/plain
Description: Class source
Class: PHP Sodium Compat
Cryptographic functions of libsodium in pure PHP
Author: By
Last change: Don't double-increment
Fix: int/char disagreement

Why did Psalm not catch this?
Add ignore to sodium_hex2bin()

This parameter was discovered to be missing in our polyfill
Fix myriad bugs with PHP 8.1 on x86

Related to #140, determined from local testing as per https://github.com/paragonie/sodium_compat/issues/140#issuecomment-1076132051
Does this shut PHP 8.1 up?
Ensure mul() is correct.
Cleanup
Prevent undefined constant
Fix typo in hash_update() phpDoc in src/Core/Util
Implement Ristretto255

This is compatible with the new ext/sodium functions landing in PHP 8.1.0 and PECL libsodium 2.0.25.

See: https://github.com/php/php-src/pull/6922
See: https://github.com/jedisct1/libsodium-php/pull/212
Date: 1 year ago
Size: 28,264 bytes
 

Contents

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<?php if (class_exists('ParagonIE_Sodium_Core_Util', false)) { return; } /** * Class ParagonIE_Sodium_Core_Util */ abstract class ParagonIE_Sodium_Core_Util { /** * @param int $integer * @param int $size (16, 32, 64) * @return int */ public static function abs($integer, $size = 0) { /** @var int $realSize */ $realSize = (PHP_INT_SIZE << 3) - 1; if ($size) { --$size; } else { /** @var int $size */ $size = $realSize; } $negative = -(($integer >> $size) & 1); return (int) ( ($integer ^ $negative) + (($negative >> $realSize) & 1) ); } /** * Convert a binary string into a hexadecimal string without cache-timing * leaks * * @internal You should not use this directly from another application * * @param string $binaryString (raw binary) * @return string * @throws TypeError */ public static function bin2hex($binaryString) { /* Type checks: */ if (!is_string($binaryString)) { throw new TypeError('Argument 1 must be a string, ' . gettype($binaryString) . ' given.'); } $hex = ''; $len = self::strlen($binaryString); for ($i = 0; $i < $len; ++$i) { /** @var array<int, int> $chunk */ $chunk = unpack('C', $binaryString[$i]); /** @var int $c */ $c = $chunk[1] & 0xf; /** @var int $b */ $b = $chunk[1] >> 4; $hex .= pack( 'CC', (87 + $b + ((($b - 10) >> 8) & ~38)), (87 + $c + ((($c - 10) >> 8) & ~38)) ); } return $hex; } /** * Convert a binary string into a hexadecimal string without cache-timing * leaks, returning uppercase letters (as per RFC 4648) * * @internal You should not use this directly from another application * * @param string $bin_string (raw binary) * @return string * @throws TypeError */ public static function bin2hexUpper($bin_string) { $hex = ''; $len = self::strlen($bin_string); for ($i = 0; $i < $len; ++$i) { /** @var array<int, int> $chunk */ $chunk = unpack('C', $bin_string[$i]); /** * Lower 16 bits * * @var int $c */ $c = $chunk[1] & 0xf; /** * Upper 16 bits * @var int $b */ $b = $chunk[1] >> 4; /** * Use pack() and binary operators to turn the two integers * into hexadecimal characters. We don't use chr() here, because * it uses a lookup table internally and we want to avoid * cache-timing side-channels. */ $hex .= pack( 'CC', (55 + $b + ((($b - 10) >> 8) & ~6)), (55 + $c + ((($c - 10) >> 8) & ~6)) ); } return $hex; } /** * Cache-timing-safe variant of ord() * * @internal You should not use this directly from another application * * @param string $chr * @return int * @throws SodiumException * @throws TypeError */ public static function chrToInt($chr) { /* Type checks: */ if (!is_string($chr)) { throw new TypeError('Argument 1 must be a string, ' . gettype($chr) . ' given.'); } if (self::strlen($chr) !== 1) { throw new SodiumException('chrToInt() expects a string that is exactly 1 character long'); } /** @var array<int, int> $chunk */ $chunk = unpack('C', $chr); return (int) ($chunk[1]); } /** * Compares two strings. * * @internal You should not use this directly from another application * * @param string $left * @param string $right * @param int $len * @return int * @throws SodiumException * @throws TypeError */ public static function compare($left, $right, $len = null) { $leftLen = self::strlen($left); $rightLen = self::strlen($right); if ($len === null) { $len = max($leftLen, $rightLen); $left = str_pad($left, $len, "\x00", STR_PAD_RIGHT); $right = str_pad($right, $len, "\x00", STR_PAD_RIGHT); } $gt = 0; $eq = 1; $i = $len; while ($i !== 0) { --$i; $gt |= ((self::chrToInt($right[$i]) - self::chrToInt($left[$i])) >> 8) & $eq; $eq &= ((self::chrToInt($right[$i]) ^ self::chrToInt($left[$i])) - 1) >> 8; } return ($gt + $gt + $eq) - 1; } /** * If a variable does not match a given type, throw a TypeError. * * @param mixed $mixedVar * @param string $type * @param int $argumentIndex * @throws TypeError * @throws SodiumException * @return void */ public static function declareScalarType(&$mixedVar = null, $type = 'void', $argumentIndex = 0) { if (func_num_args() === 0) { /* Tautology, by default */ return; } if (func_num_args() === 1) { throw new TypeError('Declared void, but passed a variable'); } $realType = strtolower(gettype($mixedVar)); $type = strtolower($type); switch ($type) { case 'null': if ($mixedVar !== null) { throw new TypeError('Argument ' . $argumentIndex . ' must be null, ' . $realType . ' given.'); } break; case 'integer': case 'int': $allow = array('int', 'integer'); if (!in_array($type, $allow)) { throw new TypeError('Argument ' . $argumentIndex . ' must be an integer, ' . $realType . ' given.'); } $mixedVar = (int) $mixedVar; break; case 'boolean': case 'bool': $allow = array('bool', 'boolean'); if (!in_array($type, $allow)) { throw new TypeError('Argument ' . $argumentIndex . ' must be a boolean, ' . $realType . ' given.'); } $mixedVar = (bool) $mixedVar; break; case 'string': if (!is_string($mixedVar)) { throw new TypeError('Argument ' . $argumentIndex . ' must be a string, ' . $realType . ' given.'); } $mixedVar = (string) $mixedVar; break; case 'decimal': case 'double': case 'float': $allow = array('decimal', 'double', 'float'); if (!in_array($type, $allow)) { throw new TypeError('Argument ' . $argumentIndex . ' must be a float, ' . $realType . ' given.'); } $mixedVar = (float) $mixedVar; break; case 'object': if (!is_object($mixedVar)) { throw new TypeError('Argument ' . $argumentIndex . ' must be an object, ' . $realType . ' given.'); } break; case 'array': if (!is_array($mixedVar)) { if (is_object($mixedVar)) { if ($mixedVar instanceof ArrayAccess) { return; } } throw new TypeError('Argument ' . $argumentIndex . ' must be an array, ' . $realType . ' given.'); } break; default: throw new SodiumException('Unknown type (' . $realType .') does not match expect type (' . $type . ')'); } } /** * Evaluate whether or not two strings are equal (in constant-time) * * @param string $left * @param string $right * @return bool * @throws SodiumException * @throws TypeError */ public static function hashEquals($left, $right) { /* Type checks: */ if (!is_string($left)) { throw new TypeError('Argument 1 must be a string, ' . gettype($left) . ' given.'); } if (!is_string($right)) { throw new TypeError('Argument 2 must be a string, ' . gettype($right) . ' given.'); } if (is_callable('hash_equals')) { return hash_equals($left, $right); } $d = 0; /** @var int $len */ $len = self::strlen($left); if ($len !== self::strlen($right)) { return false; } for ($i = 0; $i < $len; ++$i) { $d |= self::chrToInt($left[$i]) ^ self::chrToInt($right[$i]); } if ($d !== 0) { return false; } return $left === $right; } /** * Catch hash_update() failures and throw instead of silently proceeding * * @param HashContext|resource &$hs * @param string $data * @return void * @throws SodiumException * @psalm-suppress PossiblyInvalidArgument */ protected static function hash_update(&$hs, $data) { if (!hash_update($hs, $data)) { throw new SodiumException('hash_update() failed'); } } /** * Convert a hexadecimal string into a binary string without cache-timing * leaks * * @internal You should not use this directly from another application * * @param string $hexString * @param string $ignore * @param bool $strictPadding * @return string (raw binary) * @throws RangeException * @throws TypeError */ public static function hex2bin($hexString, $ignore = '', $strictPadding = false) { /* Type checks: */ if (!is_string($hexString)) { throw new TypeError('Argument 1 must be a string, ' . gettype($hexString) . ' given.'); } if (!is_string($ignore)) { throw new TypeError('Argument 2 must be a string, ' . gettype($hexString) . ' given.'); } $hex_pos = 0; $bin = ''; $c_acc = 0; $hex_len = self::strlen($hexString); $state = 0; if (($hex_len & 1) !== 0) { if ($strictPadding) { throw new RangeException( 'Expected an even number of hexadecimal characters' ); } else { $hexString = '0' . $hexString; ++$hex_len; } } $chunk = unpack('C*', $hexString); while ($hex_pos < $hex_len) { ++$hex_pos; /** @var int $c */ $c = $chunk[$hex_pos]; $c_num = $c ^ 48; $c_num0 = ($c_num - 10) >> 8; $c_alpha = ($c & ~32) - 55; $c_alpha0 = (($c_alpha - 10) ^ ($c_alpha - 16)) >> 8; if (($c_num0 | $c_alpha0) === 0) { if ($ignore && $state === 0 && strpos($ignore, self::intToChr($c)) !== false) { continue; } throw new RangeException( 'hex2bin() only expects hexadecimal characters' ); } $c_val = ($c_num0 & $c_num) | ($c_alpha & $c_alpha0); if ($state === 0) { $c_acc = $c_val * 16; } else { $bin .= pack('C', $c_acc | $c_val); } $state ^= 1; } return $bin; } /** * Turn an array of integers into a string * * @internal You should not use this directly from another application * * @param array<int, int> $ints * @return string */ public static function intArrayToString(array $ints) { $args = $ints; foreach ($args as $i => $v) { $args[$i] = (int) ($v & 0xff); } array_unshift($args, str_repeat('C', count($ints))); return (string) (call_user_func_array('pack', $args)); } /** * Cache-timing-safe variant of ord() * * @internal You should not use this directly from another application * * @param int $int * @return string * @throws TypeError */ public static function intToChr($int) { return pack('C', $int); } /** * Load a 3 character substring into an integer * * @internal You should not use this directly from another application * * @param string $string * @return int * @throws RangeException * @throws TypeError */ public static function load_3($string) { /* Type checks: */ if (!is_string($string)) { throw new TypeError('Argument 1 must be a string, ' . gettype($string) . ' given.'); } /* Input validation: */ if (self::strlen($string) < 3) { throw new RangeException( 'String must be 3 bytes or more; ' . self::strlen($string) . ' given.' ); } /** @var array<int, int> $unpacked */ $unpacked = unpack('V', $string . "\0"); return (int) ($unpacked[1] & 0xffffff); } /** * Load a 4 character substring into an integer * * @internal You should not use this directly from another application * * @param string $string * @return int * @throws RangeException * @throws TypeError */ public static function load_4($string) { /* Type checks: */ if (!is_string($string)) { throw new TypeError('Argument 1 must be a string, ' . gettype($string) . ' given.'); } /* Input validation: */ if (self::strlen($string) < 4) { throw new RangeException( 'String must be 4 bytes or more; ' . self::strlen($string) . ' given.' ); } /** @var array<int, int> $unpacked */ $unpacked = unpack('V', $string); return (int) $unpacked[1]; } /** * Load a 8 character substring into an integer * * @internal You should not use this directly from another application * * @param string $string * @return int * @throws RangeException * @throws SodiumException * @throws TypeError */ public static function load64_le($string) { /* Type checks: */ if (!is_string($string)) { throw new TypeError('Argument 1 must be a string, ' . gettype($string) . ' given.'); } /* Input validation: */ if (self::strlen($string) < 4) { throw new RangeException( 'String must be 4 bytes or more; ' . self::strlen($string) . ' given.' ); } if (PHP_VERSION_ID >= 50603 && PHP_INT_SIZE === 8) { /** @var array<int, int> $unpacked */ $unpacked = unpack('P', $string); return (int) $unpacked[1]; } /** @var int $result */ $result = (self::chrToInt($string[0]) & 0xff); $result |= (self::chrToInt($string[1]) & 0xff) << 8; $result |= (self::chrToInt($string[2]) & 0xff) << 16; $result |= (self::chrToInt($string[3]) & 0xff) << 24; $result |= (self::chrToInt($string[4]) & 0xff) << 32; $result |= (self::chrToInt($string[5]) & 0xff) << 40; $result |= (self::chrToInt($string[6]) & 0xff) << 48; $result |= (self::chrToInt($string[7]) & 0xff) << 56; return (int) $result; } /** * @internal You should not use this directly from another application * * @param string $left * @param string $right * @return int * @throws SodiumException * @throws TypeError */ public static function memcmp($left, $right) { if (self::hashEquals($left, $right)) { return 0; } return -1; } /** * Multiply two integers in constant-time * * Micro-architecture timing side-channels caused by how your CPU * implements multiplication are best prevented by never using the * multiplication operators and ensuring that our code always takes * the same number of operations to complete, regardless of the values * of $a and $b. * * @internal You should not use this directly from another application * * @param int $a * @param int $b * @param int $size Limits the number of operations (useful for small, * constant operands) * @return int */ public static function mul($a, $b, $size = 0) { if (ParagonIE_Sodium_Compat::$fastMult) { return (int) ($a * $b); } static $defaultSize = null; /** @var int $defaultSize */ if (!$defaultSize) { /** @var int $defaultSize */ $defaultSize = (PHP_INT_SIZE << 3) - 1; } if ($size < 1) { /** @var int $size */ $size = $defaultSize; } /** @var int $size */ $c = 0; /** * Mask is either -1 or 0. * * -1 in binary looks like 0x1111 ... 1111 * 0 in binary looks like 0x0000 ... 0000 * * @var int */ $mask = -(($b >> ((int) $defaultSize)) & 1); /** * Ensure $b is a positive integer, without creating * a branching side-channel * * @var int $b */ $b = ($b & ~$mask) | ($mask & -$b); /** * Unless $size is provided: * * This loop always runs 32 times when PHP_INT_SIZE is 4. * This loop always runs 64 times when PHP_INT_SIZE is 8. */ for ($i = $size; $i >= 0; --$i) { $c += (int) ($a & -($b & 1)); $a <<= 1; $b >>= 1; } $c = (int) @($c & -1); /** * If $b was negative, we then apply the same value to $c here. * It doesn't matter much if $a was negative; the $c += above would * have produced a negative integer to begin with. But a negative $b * makes $b >>= 1 never return 0, so we would end up with incorrect * results. * * The end result is what we'd expect from integer multiplication. */ return (int) (($c & ~$mask) | ($mask & -$c)); } /** * Convert any arbitrary numbers into two 32-bit integers that represent * a 64-bit integer. * * @internal You should not use this directly from another application * * @param int|float $num * @return array<int, int> */ public static function numericTo64BitInteger($num) { $high = 0; /** @var int $low */ if (PHP_INT_SIZE === 4) { $low = (int) $num; } else { $low = $num & 0xffffffff; } if ((+(abs($num))) >= 1) { if ($num > 0) { /** @var int $high */ $high = min((+(floor($num/4294967296))), 4294967295); } else { /** @var int $high */ $high = ~~((+(ceil(($num - (+((~~($num)))))/4294967296)))); } } return array((int) $high, (int) $low); } /** * Store a 24-bit integer into a string, treating it as big-endian. * * @internal You should not use this directly from another application * * @param int $int * @return string * @throws TypeError */ public static function store_3($int) { /* Type checks: */ if (!is_int($int)) { if (is_numeric($int)) { $int = (int) $int; } else { throw new TypeError('Argument 1 must be an integer, ' . gettype($int) . ' given.'); } } /** @var string $packed */ $packed = pack('N', $int); return self::substr($packed, 1, 3); } /** * Store a 32-bit integer into a string, treating it as little-endian. * * @internal You should not use this directly from another application * * @param int $int * @return string * @throws TypeError */ public static function store32_le($int) { /* Type checks: */ if (!is_int($int)) { if (is_numeric($int)) { $int = (int) $int; } else { throw new TypeError('Argument 1 must be an integer, ' . gettype($int) . ' given.'); } } /** @var string $packed */ $packed = pack('V', $int); return $packed; } /** * Store a 32-bit integer into a string, treating it as big-endian. * * @internal You should not use this directly from another application * * @param int $int * @return string * @throws TypeError */ public static function store_4($int) { /* Type checks: */ if (!is_int($int)) { if (is_numeric($int)) { $int = (int) $int; } else { throw new TypeError('Argument 1 must be an integer, ' . gettype($int) . ' given.'); } } /** @var string $packed */ $packed = pack('N', $int); return $packed; } /** * Stores a 64-bit integer as an string, treating it as little-endian. * * @internal You should not use this directly from another application * * @param int $int * @return string * @throws TypeError */ public static function store64_le($int) { /* Type checks: */ if (!is_int($int)) { if (is_numeric($int)) { $int = (int) $int; } else { throw new TypeError('Argument 1 must be an integer, ' . gettype($int) . ' given.'); } } if (PHP_INT_SIZE === 8) { if (PHP_VERSION_ID >= 50603) { /** @var string $packed */ $packed = pack('P', $int); return $packed; } return self::intToChr($int & 0xff) . self::intToChr(($int >> 8) & 0xff) . self::intToChr(($int >> 16) & 0xff) . self::intToChr(($int >> 24) & 0xff) . self::intToChr(($int >> 32) & 0xff) . self::intToChr(($int >> 40) & 0xff) . self::intToChr(($int >> 48) & 0xff) . self::intToChr(($int >> 56) & 0xff); } if ($int > PHP_INT_MAX) { list($hiB, $int) = self::numericTo64BitInteger($int); } else { $hiB = 0; } return self::intToChr(($int ) & 0xff) . self::intToChr(($int >> 8) & 0xff) . self::intToChr(($int >> 16) & 0xff) . self::intToChr(($int >> 24) & 0xff) . self::intToChr($hiB & 0xff) . self::intToChr(($hiB >> 8) & 0xff) . self::intToChr(($hiB >> 16) & 0xff) . self::intToChr(($hiB >> 24) & 0xff); } /** * Safe string length * * @internal You should not use this directly from another application * * @ref mbstring.func_overload * * @param string $str * @return int * @throws TypeError */ public static function strlen($str) { /* Type checks: */ if (!is_string($str)) { throw new TypeError('String expected'); } return (int) ( self::isMbStringOverride() ? mb_strlen($str, '8bit') : strlen($str) ); } /** * Turn a string into an array of integers * * @internal You should not use this directly from another application * * @param string $string * @return array<int, int> * @throws TypeError */ public static function stringToIntArray($string) { if (!is_string($string)) { throw new TypeError('String expected'); } /** * @var array<int, int> */ $values = array_values( unpack('C*', $string) ); return $values; } /** * Safe substring * * @internal You should not use this directly from another application * * @ref mbstring.func_overload * * @param string $str * @param int $start * @param int $length * @return string * @throws TypeError */ public static function substr($str, $start = 0, $length = null) { /* Type checks: */ if (!is_string($str)) { throw new TypeError('String expected'); } if ($length === 0) { return ''; } if (self::isMbStringOverride()) { if (PHP_VERSION_ID < 50400 && $length === null) { $length = self::strlen($str); } $sub = (string) mb_substr($str, $start, $length, '8bit'); } elseif ($length === null) { $sub = (string) substr($str, $start); } else { $sub = (string) substr($str, $start, $length); } if ($sub !== '') { return $sub; } return ''; } /** * Compare a 16-character byte string in constant time. * * @internal You should not use this directly from another application * * @param string $a * @param string $b * @return bool * @throws SodiumException * @throws TypeError */ public static function verify_16($a, $b) { /* Type checks: */ if (!is_string($a)) { throw new TypeError('String expected'); } if (!is_string($b)) { throw new TypeError('String expected'); } return self::hashEquals( self::substr($a, 0, 16), self::substr($b, 0, 16) ); } /** * Compare a 32-character byte string in constant time. * * @internal You should not use this directly from another application * * @param string $a * @param string $b * @return bool * @throws SodiumException * @throws TypeError */ public static function verify_32($a, $b) { /* Type checks: */ if (!is_string($a)) { throw new TypeError('String expected'); } if (!is_string($b)) { throw new TypeError('String expected'); } return self::hashEquals( self::substr($a, 0, 32), self::substr($b, 0, 32) ); } /** * Calculate $a ^ $b for two strings. * * @internal You should not use this directly from another application * * @param string $a * @param string $b * @return string * @throws TypeError */ public static function xorStrings($a, $b) { /* Type checks: */ if (!is_string($a)) { throw new TypeError('Argument 1 must be a string'); } if (!is_string($b)) { throw new TypeError('Argument 2 must be a string'); } return (string) ($a ^ $b); } /** * Returns whether or not mbstring.func_overload is in effect. * * @internal You should not use this directly from another application * * Note: MB_OVERLOAD_STRING === 2, but we don't reference the constant * (for nuisance-free PHP 8 support) * * @return bool */ protected static function isMbStringOverride() { static $mbstring = null; if ($mbstring === null) { if (!defined('MB_OVERLOAD_STRING')) { $mbstring = false; return $mbstring; } $mbstring = extension_loaded('mbstring') && defined('MB_OVERLOAD_STRING') && ((int) (ini_get('mbstring.func_overload')) & 2); // MB_OVERLOAD_STRING === 2 } /** @var bool $mbstring */ return $mbstring; } }