X-Git-Url: https://git.mxchange.org/?p=core.git;a=blobdiff_plain;f=contrib%2Fchash%2Fchash.php;fp=contrib%2Fchash%2Fchash.php;h=a1e91c28c568cc741185092e906a2af57598c1fb;hp=0000000000000000000000000000000000000000;hb=d2d298a1fcc6217a93e7d67f0de7b976d5bfd5e7;hpb=421d8c20ff4014ddae23e61b6654666b039bf00d

diff --git a/contrib/chash/chash.php b/contrib/chash/chash.php
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+<?php
+error_reporting(E_ALL | E_STRICT);
+
+/**
+ * Continued-hashing
+ *
+ * @author		Roland Haeder <roland@mxchange.org>
+ * @copyright	Copyright (c) 2013 by Core Developer Team
+ * @license		See LICENSE (public-domain)
+ */
+
+/**
+ * Calculates a simple but stronger hash from given string. No salts are being
+ * added here.
+ *
+ * @param	$str	The string to be hashed
+ * @return	$hash	The hash from string $str
+ */
+function hashString ($str) {
+	// Calculate strong hash from given string
+	$hash = mhash(MHASH_RIPEMD320, $str);
+
+	// Return it hexadecimal-encoded
+	return bin2hex($hash);
+}
+
+/**
+ * Double-hashes given string. This is done by hashing the given string and
+ * then hashing the generated hash again.
+ *
+ * @param	$str	The string to be hashed 4 times
+ * @return	$hash	The generated hash
+ */
+function doubleHashString ($str) {
+	// Generate hash from given hash
+	$hash = hashString(hashString($str));
+
+	// Return it
+	return $hash;
+}
+
+/**
+ * Calculates a "modula-hash" based given two hashes.
+ *
+ * @param	$hash1	Hash 1
+ * @param	$hash2	Hash 2
+ */
+function modulaHash ($hash1, $hash2) {
+	// Both must have same length
+	assert(strlen($hash1) === strlen($hash2));
+
+	// Init new hash
+	$modulaHash = '';
+
+	// "Walk" trough first hash and get every 2 byte of both hashes
+	for ($idx = 0; $idx < strlen($hash1); $idx += 2) {
+		// Init modula value
+		$mod = 0;
+
+		// Get both hash parts and convert to ASCII number
+		$part1 = hexdec(substr($hash1, $idx, 2));
+		$part2 = hexdec(substr($hash2, $idx, 2));
+
+		/*
+		 * If part1 is larget part2, part1 is divident and vise-versa. But don't do it
+		 * if one is zero
+		 */
+		if (($part1 > $part2) && ($part2 > 0)) {
+			// 'part1' is larger than 'part2'
+			$mod = $part1 % $part2;
+		} elseif (($part1 < $part2) && ($part1 > 0)) {
+			// 'part2' is larger than 'part1'
+			$mod = $part2 % $part1;
+		}
+
+		// "Invert" the result against 255
+		$mod = 255 - $mod;
+
+		// Encode to hex, pre-pad it with zeros and add to new hash
+		$modulaHash .= padHex($mod);
+	} // END - for
+
+	// Modula hash must have same length as input hash
+	assert(strlen($modulaHash) === strlen($hash1));
+
+	// Return modula hash
+	return $modulaHash;
+}
+
+/**
+ * Calculates a "sqrt-hash" based given two hashes and single-hash it
+ *
+ * @param	$hash1	Hash 1
+ * @param	$hash2	Hash 2
+ */
+function sqrtHash ($hash1, $hash2) {
+	// Both must have same length
+	assert(strlen($hash1) === strlen($hash2));
+
+	// Init new hash
+	$sqrtHash = '';
+
+	// "Walk" trough first hash and get every 2 byte of both hashes
+	for ($idx = 0; $idx < strlen($hash1); $idx += 2) {
+		// Init modula value
+		$mod = 0;
+
+		// Get both hash parts and convert to ASCII number
+		$part1 = hexdec(substr($hash1, $idx, 2));
+		$part2 = hexdec(substr($hash2, $idx, 2));
+
+		// Calculate square root of both parts being multiplied and round up, then "invert" it against 255
+		$sqrt = intval(255 - ceil(sqrt($part1 * $part2)));
+
+		// Encode to hex, pre-pad it with zeros and add to new hash
+		$sqrtHash .= padHex($sqrt);
+	} // END - for
+
+	// "sqrt-hash" must have same length as input hash
+	assert(strlen($sqrtHash) === strlen($hash1));
+
+	// Hash reversed "sqrt-hash" again and return it
+	return hashString(strrev($sqrtHash));
+}
+
+/**
+ * Converts a number between 0 and 255 into a zero-padded hexadecimal string
+ *
+ * @param	$num	Number between 0 and 255
+ * @return	$hex	Hexadecimal string, padded with zeros
+ */
+function padHex ($num) {
+	// Must be a integer number and between 0 and 255
+	assert(is_int($num));
+	assert($num >= 0);
+	assert($num <= 255);
+
+	// Convert it
+	$hex = str_pad(dechex($num), 2, '0', STR_PAD_LEFT);
+
+	// ... and return it
+	return $hex;
+}
+
+/*
+ * Calculate "genesis" hashes, please note that these "genesis strings" are now
+ * known to the public as you can read them here in source code and therefore I
+ * will not use them for the real genesis hashes.
+ */
+$hashes = array(
+	// A famous quote from Deus Ex 2 - Invisible War
+	doublehashString('"Informations must be free." - AI Helios'),
+	// My name + URL of my first StatusNet instance
+	doubleHashString('Roland Haeder, http://status.mxchange.org'),
+	// A famous quote from Linus Torwalds
+	doubleHashString('"Software is like sex. Its better when its free." - Linus Torwalds'),
+	// Possible truth ;-)
+	doubleHashString('September 11 is a big lie.'),
+
+	// GNU is not Uni*
+	doubleHashString('GNU is Not Uni*.'),
+	// WINE is not an emulator
+	doubleHashString('WINE Is Not an Emulator.'),
+	// FlightGear - Fly free!
+	doubleHashString('FlightGear - Fly free!'),
+	// Linus Torwalds Quote
+	doubleHashString('Your code is shit.. your argument is shit.'),
+);
+
+// Calculate "modula hash" from 1st/4th and 2nd/3rd
+$modulaHashes = array(
+	// "Block" 0
+	modulaHash($hashes[0], $hashes[3]),
+	modulaHash($hashes[1], $hashes[2]),
+
+	// "Block" 1
+	modulaHash($hashes[4], $hashes[7]),
+	modulaHash($hashes[5], $hashes[6]),
+);
+
+// Calculate "sqrt hash"
+$sqrtHashes = array(
+	sqrtHash($modulaHashes[0], $modulaHashes[1]),
+	sqrtHash($modulaHashes[2], $modulaHashes[3])
+);
+
+// Calulcate modula hash
+$modulaHash = modulaHash($sqrtHashes[0], $sqrtHashes[1]);
+
+// Output results
+print ('hashes=' . print_r($hashes, TRUE));
+print ('modulaHashes=' . print_r($modulaHashes, TRUE));
+print ('sqrtHashes=' . print_r($sqrtHashes, TRUE));
+print ('modulaHash=' . $modulaHash . PHP_EOL);
+
+// [EOF]
+?>