Added brute_force.js, added documentation to readme.

rd13 · Mar 13, 2013 · e84cf5d · e84cf5d
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diff --git a/README.md b/README.md
@@ -1,12 +1,10 @@
- ==================
-| TypeX Emulation |
- ==================
+# TypeX Emulation
 
-This is a Javascript implementation of the British Cipher Machine - TypeX. I have translated this to Javascript from a [version written in C][1].
+This is a Javascript implementation of the British Rotor Cipher Machine - [TypeX][2]. The Enigma has been used as a basis for this code as they have very similar workings, this version is a translation to Javascript from a [version written in C][1]. 
 
 Improvements that I have made to the original code include:
 
-1. It no longer uses files for input / output.
+1. No longer relies on files for input / output.
 2. I have broken down the transformation into a better (more readable) format:
 
 The transformation steps are: 
@@ -27,27 +25,33 @@ The transformation steps are:
 
 3. I wrote this with the intention of using it in a brute force attack. To do this we can iterate through all possible rotor settings / orientations. Please see brute_force.js for an example.
 
-4. Input validation has been modularised.
+4. Input validation is cleaner.
 
 5. Removed goto's, general housekeeping.
 
+6. Speed is almost double to that of the C implementation due to caching and no file read / writes (which helps when it comes to brute forcing).
+
 ##### Example 1 - Encoding
 ```javascript
 var demo1 = TypeX.init('01234', '00100', 'AOAKN', 'This is the string to be encoded');
-console.log(demo1);
 //demo1 == KLHESNYNIMQAZHIZROBHDZHKWRQFFRTY
 ```
 
 ##### Example 2 - Decoding
 ```javascript
 var demo2 = TypeX.init('01234', '00100', 'AOAKN', 'KLHESNYNIMQAZHIZROBHDZHKWRQFFRTY');
-console.log(demo2);
 //demo2 == THISXISXTHEXSTRINGXTOXBEXENCODED
 ```
 
 ##### Brute Force
 
-The code in brute_force.js loops through every possible rotor position and orientation. This assumes that we know the indicator key.
+The code in brute_force.js loops through every possible rotor position and orientation. It then inserts (in batches) the results into a Mongo collection.
+
+To run this Javascript you will need Node with the [native Mongo module][3] installed.
+
+The brute force method assumes that we know the indicator key.
+
+The indicator key is 5 letters (A-Z), that indicate the starting position of each rotor.
 
 ```javascript
 //Rotor orientations (5^2)
@@ -73,8 +77,12 @@ if((/(\d)(?=.*\1)/).test(rotorPos)) continue;
 var cipher_text = TypeX.init(rotorPos, rotorOri, 'AOAKN', 'KLHESNYNIMQAZHIZROBHDZHKWRQFFRTY');
 ```
 
-In the above example, there are 215,000 possible rotor settings, of which we can harvest them into a database. We can then crawl this database and search for cribs, or we can perform a common bigram / trigram count which is probably an easier way to reduce this number.
+In the above example, there are 215,000 possible rotor settings, we can then harvest them into a database for further processing.
+
+We can then crawl this database and search for cribs, or we can perform a common bigram / trigram count which is probably an easier way to reduce this number.
 
-See function ngram(str, n) in brute_force.js for an example of how to add these counts to your database.
+See brute_force.js for an example of how to add an ngram count to your database.
 
-[1]: http://scholarworks.sjsu.edu/cgi/viewcontent.cgi?article=1244&context=etd_projects
+[1]: http://scholarworks.sjsu.edu/cgi/viewcontent.cgi?article=1244&context=etd_projects
+[2]: http://en.wikipedia.org/wiki/Typex
+[3]: https://github.com/mongodb/node-mongodb-native
diff --git a/brute_force.js b/brute_force.js
@@ -0,0 +1,123 @@
+require("./typex.js");
+
+var mongo = require('mongodb');
+
+var Inserter = function (collection) {
+		this.collection = collection;
+		this.data = [];
+		this.maxThreads = 30;
+		this.currentThreads = 0;
+		this.batchSize = 1000;
+		this.queue = 0;
+		this.inserted = 0;
+		this.startTime = Date.now();
+};
+
+Inserter.prototype.add = function(data) {
+		this.data.push(data);
+};
+
+// Use force=true for last insert
+Inserter.prototype.insert = function(force) {
+		var that = this;
+		if (this.data.length >= this.batchSize || force) {
+				if (this.currentThreads >= this.maxThreads) {
+						this.queue++;
+						return;
+				}
+				this.currentThreads++;
+				console.log('Threads: ' + this.currentThreads);
+				this.collection.insert(this.data.splice(0, this.batchSize), {safe:true}, function() {
+						that.inserted += that.batchSize;
+						var currentTime = Date.now();
+						var workTime = Math.round((currentTime - that.startTime) / 1000)
+						console.log('Speed: ' + that.inserted / workTime + ' per sec');
+						that.currentThreads--;
+						if (that.queue > 0) {
+								that.queue--;
+								that.insert();
+						}
+				});
+		}
+};
+
+ngram = function(str,n) {
+	//http://norvig.com/mayzner.html
+	var ngrams = [[],[],
+								["th","he","in","er","an"], // 2grams
+								["the","and","ing","ion","tio"] // 3grams
+							 ];
+
+	var total = 0;
+	for (var i in ngrams[n]) {
+		var re = new RegExp(ngrams[n][i], 'gi');
+		if((didMatch = str.match(re))) {
+			total += didMatch.length;
+		}
+	}
+	return total;
+
+};
+
+var db = new mongo.Db('test', new mongo.Server('localhost', 27017, {w:1}), {native_parser:false});
+
+db.open(function(err, db) {
+		db.collection('typexResults', function(err, collection) {
+
+			var inserter = new Inserter(collection);
+			var cipher_text = 'HVPKDFNFJWYIDDCRQXSRDJHFPGOVFNMIAPXPABUZWYYNPCMPNWHJRZHNLXKGMEMKKONOIBAKEEQWAOTARBQRHDJOFMTPZEHLKXGHRGGHTJRZCQFNKTQKLDTSFQIRW';
+			var indicator = 'AOAKN';
+			x = 0;
+
+			//Rotor orientations (5^2)
+			for (r1 = 0; r1 <= 1; r1++) {
+			for (r2 = 0; r2 <= 1; r2++) {
+			for (r3 = 0; r3 <= 1; r3++) {
+			for (r4 = 0; r4 <= 1; r4++) {
+			for (r5 = 0; r5 <= 1; r5++) {
+
+			//Rotor positions (5^7)
+			for (a = 0; a <=7; a++) {
+			for (b = 0; b <=7; b++) {
+			for (c = 0; c <=7; c++) {
+			for (d = 0; d <=7; d++) {
+			for (e = 0; e <=7; e++) {
+
+				rotorPos = a.toString() + b + c + d + e;
+				rotorOri = r1.toString() + r2 + r3 + r4 + r5;
+
+				if((/(\d)(?=.*\1)/).test(rotorPos)) continue;
+
+				var ct_val = TypeX.init(rotorPos, rotorOri, indicator, cipher_text);
+
+				inserter.add({
+					c_text: ct_val,
+					two_gram: ngram(ct_val,2),
+					three_gram: ngram(ct_val,3),
+					rotor_position: rotorPos,
+					rotor_orientation: rotorOri
+				});
+
+				if(x%5000===0) {
+					inserter.insert();
+				}
+
+				x++;
+
+			}
+			}
+			}
+			}
+			}
+
+			}
+			}
+			}
+			}
+			}
+
+			//Final batch insert
+			inserter.insert(true);
+
+		});
+});