Widget:CRCprefix - Revision history

Hash: /* Copy to your site */

2022-05-21T21:26:04Z

Copy to your site

Hash at 21:09, 21 May 2022

2022-05-21T21:09:51Z

Hash at 21:09, 21 May 2022

2022-05-21T21:09:00Z

Hash at 21:08, 21 May 2022

2022-05-21T21:08:42Z

Hash at 21:07, 21 May 2022

2022-05-21T21:07:28Z

Hash at 21:06, 21 May 2022

2022-05-21T21:06:38Z

Hash at 20:36, 21 May 2022

2022-05-21T20:36:44Z

Hash at 20:24, 21 May 2022

2022-05-21T20:24:29Z

Hash: Blanked the page

2022-05-21T20:24:05Z

Blanked the page

Hash at 20:23, 21 May 2022

2022-05-21T20:23:08Z

@@ Line 63: / Line 63: @@
 </head>
 <body>
-<h1>CRC Prefix Calculator</h1>
+<h1>CRC Prefix Calculator by L0scher</h1>
 <p>Enter a string of hex bytes in the box and hit the <b>Find CRC init</b> button searches for the initial CRC value which would make the calculated CRC equal to zero.  It uses the 0x1021 polynomial value.  If it cannot find such a value, it will leave the value unchanged.
 </p>

@@ Line 2: / Line 2: @@
 This widget adds the '''GridStream CRC Prefix Calculator''' to your wiki page.
-Code written by L0scher, widget wrapper by [[User:Hash]].
+Code written by L0scher, widget wrapper by [[User:Hash|Hash]].
 == Copy to your site ==

@@ Line 2: / Line 2: @@
 This widget adds the '''GridStream CRC Prefix Calculator''' to your wiki page.
-Code written by L0scher, widget wrapper by [[Hash]].
+Code written by L0scher, widget wrapper by [[User:Hash]].
 == Copy to your site ==

@@ Line 2: / Line 2: @@
 This widget adds the '''GridStream CRC Prefix Calculator''' to your wiki page.
-Code written by L0scher, widget wrapper by Hash.
+Code written by L0scher, widget wrapper by [[Hash]].
 == Copy to your site ==

@@ Line 1: / Line 1: @@
 <noinclude>
-This widget adds the '''{{FULLPAGENAME}}''' to your wiki page.
+This widget adds the '''GridStream CRC Prefix Calculator''' to your wiki page.
 Code written by L0scher, widget wrapper by Hash.
@@ Line 10: / Line 10: @@
 <head lang="en">
 <meta http-equiv="content-type" content="text/html; charset=UTF-8">
-<title>CRC Prefix Calculator by L0scher</title>
+<title>GridStream CRC Prefix Calculator by L0scher</title>
 <script type="text/javascript">
 //<![CDATA[

@@ Line 67: / Line 67: @@
 <input name="submit" type="button" value="Find CRC init" onclick="calculateInit()">
 </form>
 </body></html>

← Older revision	Revision as of 20:24, 21 May 2022
Line 1:	Line 1:
	+	<html>
	+	<head lang="en">
	+	<meta http-equiv="content-type" content="text/html; charset=UTF-8">
	+	<title>CRC Prefix Calculator by L0scher</title>
	+	<script type="text/javascript">
	+	//<![CDATA[
	+	function calculateInit () {
	+	str = document.crcform.hexstring.value.toString();
	+	var prefix = crc.calculateInitFunc(str);
	+	document.getElementById("initcrc").textContent =
	+	prefix.toString(16).toUpperCase().padStart(4, "0");
	+	}

	+	var crc = (function() {
	+	applyCRC = function(crc, value) {
	+	crc ^= value << 8;
	+	crc &= 0xffff;
	+	for (bit = 0; bit < 8; bit++) {
	+	var olddata = crc & 0x8000;
	+	crc <<= 1;
	+	if (olddata) {
	+	crc ^= 0x1021;
	+	}
	+	crc &= 0xffff;
	+	}
	+	return crc;
	+	}
	+
	+	calcCRC = function(pkt, crc) {
	+	return pkt.reduce(applyCRC, crc);
	+	}
	+
	+	stringToBytes = function(s){
	+	return s.split(/([a-fA-F0-9][a-fA-F0-9])/g).filter(p => !!p).map(c => parseInt(c, 16));
	+	}
	+
	+	bytesToString = function(b) {
	+	return b.map(c => c.toString(16).padStart(2,"0")).join("");
	+	}
	+
	+	return {
	+	calculateInitFunc : function (str) {
	+	str = str.toUpperCase().replace(/\s/g,"");
	+	var bytes = stringToBytes(str);
	+	for (testvalue = 0; testvalue < 65536; testvalue+=1) {
	+	if (calcCRC(bytes,testvalue) === 0) {
	+	return testvalue;
	+	}
	+	}
	+	}
	+	};
	+	})();
	+	//]]>
	+	</script>
	+	</head>
	+	<body>
	+	<h1>CRC Prefix Calculator</h1>
	+	<p>Enter a string of hex bytes in the box and hit the <b>Find CRC init</b> button searches for the initial CRC value which would make the calculated CRC equal to zero. It uses the 0x1021 polynomial value. If it cannot find such a value, it will leave the value unchanged.
	+	</p>
	+	<form name="crcform">
	+	<textarea name="hexstring" rows="5" cols="80">30FFFFFFFFFFFF50CF5DD9E2C0B80065F5D1A483F0FBBC6F01001E6C043B517E90B286
	+	</textarea>
	+	<br>
	+	<label>Initial CRC value (hex):</label>
	+	<label id="initcrc">5FD6</label>
	+	<br>
	+	<input name="submit" type="button" value="Find CRC init" onclick="calculateInit()">
	+	</form>
	+
	+
	+	</body></html>

← Older revision		Revision as of 20:24, 21 May 2022
Line 1:		Line 1:
−	~~<html>~~
−	~~<head lang="en">~~
−	~~<meta http-equiv="content-type" content="text/html; charset=UTF-8">~~
−	~~<title>CRC Prefix Calculator by L0scher</title>~~
−	~~<script type="text/javascript">~~
−	~~//<![CDATA[~~
−	~~function calculateInit () {~~
−	~~str = document.crcform.hexstring.value.toString();~~
−	~~var prefix = crc.calculateInitFunc(str);~~
−	~~document.getElementById("initcrc").textContent =~~
−	~~prefix.toString(16).toUpperCase().padStart(4, "0");~~
−	}

−	~~var crc = (function() {~~
−	~~applyCRC = function(crc, value) {~~
−	~~crc ^= value << 8;~~
−	~~crc &= 0xffff;~~
−	~~for (bit = 0; bit < 8; bit++) {~~
−	~~var olddata = crc & 0x8000;~~
−	~~crc <<= 1;~~
−	~~if (olddata) {~~
−	~~crc ^= 0x1021;~~
−	}
−	~~crc &= 0xffff;~~
−	}
−	~~return crc;~~
−	}
−
−	~~calcCRC = function(pkt, crc) {~~
−	~~return pkt.reduce(applyCRC, crc);~~
−	}
−
−	~~stringToBytes = function(s){~~
−	~~return s.split(/([a-fA-F0-9][a-fA-F0-9])/g).filter(p => !!p).map(c => parseInt(c, 16));~~
−	}
−
−	~~bytesToString = function(b) {~~
−	~~return b.map(c => c.toString(16).padStart(2,"0")).join("");~~