Merge branch 'SIGABA' of https://github.com/hettysymes/CyberChef into hettysymes-SIGABA

src/core/lib/SIGABA.mjs

@@ -0,0 +1,502 @@
+/**
+ * Emulation of the SIGABA machine
+ *
+ * @author hettysymes
+ * @copyright hettysymes 2020
+ * @license Apache-2.0
+ */
+
+/**
+ * A set of randomised example SIGABA cipher/control rotors (these rotors are interchangeable). Cipher and control rotors can be referred to as C and R rotors respectively.
+ */
+export const CR_ROTORS = [
+    {name: "Example 1", value: "SRGWANHPJZFXVIDQCEUKBYOLMT"},
+    {name: "Example 2", value: "THQEFSAZVKJYULBODCPXNIMWRG"},
+    {name: "Example 3", value: "XDTUYLEVFNQZBPOGIRCSMHWKAJ"},
+    {name: "Example 4", value: "LOHDMCWUPSTNGVXYFJREQIKBZA"},
+    {name: "Example 5", value: "ERXWNZQIJYLVOFUMSGHTCKPBDA"},
+    {name: "Example 6", value: "FQECYHJIOUMDZVPSLKRTGWXBAN"},
+    {name: "Example 7", value: "TBYIUMKZDJSOPEWXVANHLCFQGR"},
+    {name: "Example 8", value: "QZUPDTFNYIAOMLEBWJXCGHKRSV"},
+    {name: "Example 9", value: "CZWNHEMPOVXLKRSIDGJFYBTQAU"},
+    {name: "Example 10", value: "ENPXJVKYQBFZTICAGMOHWRLDUS"}
+];
+
+/**
+ * A set of randomised example SIGABA index rotors (may be referred to as I rotors).
+ */
+export const I_ROTORS = [
+    {name: "Example 1", value: "6201348957"},
+    {name: "Example 2", value: "6147253089"},
+    {name: "Example 3", value: "8239647510"},
+    {name: "Example 4", value: "7194835260"},
+    {name: "Example 5", value: "4873205916"}
+];
+
+export const NUMBERS = "0123456789".split("");
+
+/**
+ * Converts a letter to uppercase (if it already isn't)
+ *
+ * @param {char} letter - letter to convert to uppercase
+ * @returns {char}
+ */
+export function convToUpperCase(letter) {
+    const charCode = letter.charCodeAt();
+    if (97<=charCode && charCode<=122) {
+        return String.fromCharCode(charCode-32);
+    }
+    return letter;
+}
+
+/**
+ * The SIGABA machine consisting of the 3 rotor banks: cipher, control and index banks.
+ */
+export class SigabaMachine {
+
+    /**
+     * SigabaMachine constructor
+     *
+     * @param {Object[]} cipherRotors - list of CRRotors
+     * @param {Object[]} controlRotors - list of CRRotors
+     * @param {object[]} indexRotors - list of IRotors
+     */
+    constructor(cipherRotors, controlRotors, indexRotors) {
+        this.cipherBank = new CipherBank(cipherRotors);
+        this.controlBank = new ControlBank(controlRotors);
+        this.indexBank = new IndexBank(indexRotors);
+    }
+
+    /**
+     * Steps all the correct rotors in the machine.
+     */
+    step() {
+        const controlOut = this.controlBank.goThroughControl();
+        const indexOut = this.indexBank.goThroughIndex(controlOut);
+        this.cipherBank.step(indexOut);
+    }
+
+    /**
+     * Encrypts a letter. A space is converted to a "Z" before encryption, and a "Z" is converted to an "X". This allows spaces to be encrypted.
+     *
+     * @param {char} letter - letter to encrypt
+     * @returns {char}
+     */
+    encryptLetter(letter) {
+        letter = convToUpperCase(letter);
+        if (letter === " ") {
+            letter = "Z";
+        } else if (letter === "Z") {
+            letter = "X";
+        }
+        const encryptedLetter = this.cipherBank.encrypt(letter);
+        this.step();
+        return encryptedLetter;
+    }
+
+    /**
+     * Decrypts a letter. A letter decrypted as a "Z" is converted to a space before it is output, since spaces are converted to "Z"s before encryption.
+     *
+     * @param {char} letter - letter to decrypt
+     * @returns {char}
+     */
+    decryptLetter(letter) {
+        letter = convToUpperCase(letter);
+        let decryptedLetter = this.cipherBank.decrypt(letter);
+        if (decryptedLetter === "Z") {
+            decryptedLetter = " ";
+        }
+        this.step();
+        return decryptedLetter;
+    }
+
+    /**
+     * Encrypts a message of one or more letters
+     *
+     * @param {string} msg - message to encrypt
+     * @returns {string}
+     */
+    encrypt(msg) {
+        let ciphertext = "";
+        for (const letter of msg) {
+            ciphertext = ciphertext.concat(this.encryptLetter(letter));
+        }
+        return ciphertext;
+    }
+
+    /**
+     * Decrypts a message of one or more letters
+     *
+     * @param {string} msg - message to decrypt
+     * @returns {string}
+     */
+    decrypt(msg) {
+        let plaintext = "";
+        for (const letter of msg) {
+            plaintext = plaintext.concat(this.decryptLetter(letter));
+        }
+        return plaintext;
+    }
+
+}
+
+/**
+ * The cipher rotor bank consists of 5 cipher rotors in either a forward or reversed orientation.
+ */
+export class CipherBank {
+
+    /**
+     * CipherBank constructor
+     *
+     * @param {Object[]} rotors - list of CRRotors
+     */
+    constructor(rotors) {
+        this.rotors = rotors;
+    }
+
+    /**
+     * Encrypts a letter through the cipher rotors (signal goes from left-to-right)
+     *
+     * @param {char} inputPos - the input position of the signal (letter to be encrypted)
+     * @returns {char}
+     */
+    encrypt(inputPos) {
+        for (const rotor of this.rotors) {
+            inputPos = rotor.crypt(inputPos, "leftToRight");
+        }
+        return inputPos;
+    }
+
+    /**
+     * Decrypts a letter through the cipher rotors (signal goes from right-to-left)
+     *
+     * @param {char} inputPos - the input position of the signal (letter to be decrypted)
+     * @returns {char}
+     */
+    decrypt(inputPos) {
+        const revOrderedRotors = [...this.rotors].reverse();
+        for (const rotor of revOrderedRotors) {
+            inputPos = rotor.crypt(inputPos, "rightToLeft");
+        }
+        return inputPos;
+    }
+
+    /**
+     * Step the cipher rotors forward according to the inputs from the index rotors
+     *
+     * @param {number[]} indexInputs - the inputs from the index rotors
+     */
+    step(indexInputs) {
+        const logicDict = {0: [0, 9], 1: [7, 8], 2: [5, 6], 3: [3, 4], 4: [1, 2]};
+        const rotorsToMove = [];
+        for (const key in logicDict) {
+            const item = logicDict[key];
+            for (const i of indexInputs) {
+                if (item.includes(i)) {
+                    rotorsToMove.push(this.rotors[key]);
+                    break;
+                }
+            }
+        }
+        for (const rotor of rotorsToMove) {
+            rotor.step();
+        }
+    }
+
+}
+
+/**
+ * The control rotor bank consists of 5 control rotors in either a forward or reversed orientation. Signals to the control rotor bank always go from right-to-left.
+ */
+export class ControlBank {
+
+    /**
+     * ControlBank constructor. The rotors have been reversed as signals go from right-to-left through the control rotors.
+     *
+     * @param {Object[]} rotors - list of CRRotors
+     */
+    constructor(rotors) {
+        this.rotors = [...rotors].reverse();
+    }
+
+    /**
+     * Encrypts a letter.
+     *
+     * @param {char} inputPos - the input position of the signal
+     * @returns {char}
+     */
+    crypt(inputPos) {
+        for (const rotor of this.rotors) {
+            inputPos = rotor.crypt(inputPos, "rightToLeft");
+        }
+        return inputPos;
+    }
+
+    /**
+     * Gets the outputs of the control rotors. The inputs to the control rotors are always "F", "G", "H" and "I".
+     *
+     * @returns {number[]}
+     */
+    getOutputs() {
+        const outputs = [this.crypt("F"), this.crypt("G"), this.crypt("H"), this.crypt("I")];
+        const logicDict = {1: "B", 2: "C", 3: "DE", 4: "FGH", 5: "IJK", 6: "LMNO", 7: "PQRST", 8: "UVWXYZ", 9: "A"};
+        const numberOutputs = [];
+        for (const key in logicDict) {
+            const item = logicDict[key];
+            for (const output of outputs) {
+                if (item.includes(output)) {
+                    numberOutputs.push(key);
+                    break;
+                }
+            }
+        }
+        return numberOutputs;
+    }
+
+    /**
+     * Steps the control rotors. Only 3 of the control rotors step: one after every encryption, one after every 26, and one after every 26 squared.
+     */
+    step() {
+        const MRotor = this.rotors[1], FRotor = this.rotors[2], SRotor = this.rotors[3];
+        // 14 is the offset of "O" from "A" - the next rotor steps once the previous rotor reaches "O"
+        if (FRotor.state === 14) {
+            if (MRotor.state === 14) {
+                SRotor.step();
+            }
+            MRotor.step();
+        }
+        FRotor.step();
+    }
+
+    /**
+     * The goThroughControl function combines getting the outputs from the control rotor bank and then stepping them.
+     *
+     * @returns {number[]}
+     */
+    goThroughControl() {
+        const outputs = this.getOutputs();
+        this.step();
+        return outputs;
+    }
+
+}
+
+/**
+ * The index rotor bank consists of 5 index rotors all placed in the forwards orientation.
+ */
+export class IndexBank {
+
+    /**
+     * IndexBank constructor
+     *
+     * @param {Object[]} rotors - list of IRotors
+     */
+    constructor(rotors) {
+        this.rotors = rotors;
+    }
+
+    /**
+     * Encrypts a number.
+     *
+     * @param {number} inputPos - the input position of the signal
+     * @returns {number}
+     */
+    crypt(inputPos) {
+        for (const rotor of this.rotors) {
+            inputPos = rotor.crypt(inputPos);
+        }
+        return inputPos;
+    }
+
+    /**
+     * The goThroughIndex function takes the inputs from the control rotor bank and returns the list of outputs after encryption through the index rotors.
+     *
+     * @param {number[]} controlInputs - inputs from the control rotors
+     * @returns {number[]}
+     */
+    goThroughIndex(controlInputs) {
+        const outputs = [];
+        for (const inp of controlInputs) {
+            outputs.push(this.crypt(inp));
+        }
+        return outputs;
+    }
+
+}
+
+/**
+ * Rotor class
+ */
+export class Rotor {
+
+    /**
+     * Rotor constructor
+     *
+     * @param {number[]} wireSetting - the wirings within the rotor: mapping from left-to-right, the index of the number in the list maps onto the number at that index
+     * @param {bool} rev - true if the rotor is reversed, false if it isn't
+     * @param {number} key - the starting position or state of the rotor
+     */
+    constructor(wireSetting, key, rev) {
+        this.state = key;
+        this.numMapping = this.getNumMapping(wireSetting, rev);
+        this.posMapping = this.getPosMapping(rev);
+    }
+
+    /**
+     * Get the number mapping from the wireSetting (only different from wireSetting if rotor is reversed)
+     *
+     * @param {number[]} wireSetting - the wirings within the rotors
+     * @param {bool} rev - true if reversed, false if not
+     * @returns {number[]}
+     */
+    getNumMapping(wireSetting, rev) {
+        if (rev===false) {
+            return wireSetting;
+        } else {
+            const length = wireSetting.length;
+            const tempMapping = new Array(length);
+            for (let i=0; i<length; i++) {
+                tempMapping[wireSetting[i]] = i;
+            }
+            return tempMapping;
+        }
+    }
+
+    /**
+     * Get the position mapping (how the position numbers map onto the numbers of the rotor)
+     *
+     * @param {bool} rev - true if reversed, false if not
+     * @returns {number[]}
+     */
+    getPosMapping(rev) {
+        const length = this.numMapping.length;
+        const posMapping = [];
+        if (rev===false) {
+            for (let i = this.state; i < this.state+length; i++) {
+                let res = i%length;
+                if (res<0) {
+                    res += length;
+                }
+                posMapping.push(res);
+            }
+        } else {
+            for (let i = this.state; i > this.state-length; i--) {
+                let res = i%length;
+                if (res<0) {
+                    res += length;
+                }
+                posMapping.push(res);
+            }
+        }
+        return posMapping;
+    }
+
+    /**
+     * Encrypt/decrypt data. This process is identical to the rotors of cipher machines such as Enigma or Typex.
+     *
+     * @param {number} inputPos - the input position of the signal (the data to encrypt/decrypt)
+     * @param {string} direction - one of "leftToRight" and "rightToLeft", states the direction in which the signal passes through the rotor
+     * @returns {number}
+     */
+    cryptNum(inputPos, direction) {
+        const inpNum = this.posMapping[inputPos];
+        let outNum;
+        if (direction === "leftToRight") {
+            outNum = this.numMapping[inpNum];
+        } else if (direction === "rightToLeft") {
+            outNum = this.numMapping.indexOf(inpNum);
+        }
+        const outPos = this.posMapping.indexOf(outNum);
+        return outPos;
+    }
+
+    /**
+     * Steps the rotor. The number at position 0 will be moved to position 1 etc.
+     */
+    step() {
+        const lastNum = this.posMapping.pop();
+        this.posMapping.splice(0, 0, lastNum);
+        this.state = this.posMapping[0];
+    }
+
+}
+
+/**
+ * A CRRotor is a cipher (C) or control (R) rotor. These rotors are identical and interchangeable. A C or R rotor consists of 26 contacts, one for each letter, and may be put into either a forwards of reversed orientation.
+ */
+export class CRRotor extends Rotor {
+
+    /**
+     * CRRotor constructor
+     *
+     * @param {string} wireSetting - the rotor wirings (string of letters)
+     * @param {char} key - initial state of rotor
+     * @param {bool} rev - true if reversed, false if not
+     */
+    constructor(wireSetting, key, rev=false) {
+        wireSetting = wireSetting.split("").map(CRRotor.letterToNum);
+        super(wireSetting, CRRotor.letterToNum(key), rev);
+    }
+
+    /**
+     * Static function which converts a letter into its number i.e. its offset from the letter "A"
+     *
+     * @param {char} letter - letter to convert to number
+     * @returns {number}
+     */
+    static letterToNum(letter) {
+        return letter.charCodeAt()-65;
+    }
+
+    /**
+     * Static function which converts a number (a letter's offset from "A") into its letter
+     *
+     * @param {number} num - number to convert to letter
+     * @returns {char}
+     */
+    static numToLetter(num) {
+        return String.fromCharCode(num+65);
+    }
+
+    /**
+     * Encrypts/decrypts a letter.
+     *
+     * @param {char} inputPos - the input position of the signal ("A" refers to position 0 etc.)
+     * @param {string} direction - one of "leftToRight" and "rightToLeft"
+     * @returns {char}
+     */
+    crypt(inputPos, direction) {
+        inputPos = CRRotor.letterToNum(inputPos);
+        const outPos = this.cryptNum(inputPos, direction);
+        return CRRotor.numToLetter(outPos);
+    }
+
+}
+
+/**
+ * An IRotor is an index rotor, which consists of 10 contacts each numbered from 0 to 9. Unlike C and R rotors, they cannot be put in the reversed orientation. The index rotors do not step at any point during encryption or decryption.
+ */
+export class IRotor extends Rotor {
+
+    /**
+     * IRotor constructor
+     *
+     * @param {string} wireSetting - the rotor wirings (string of numbers)
+     * @param {char} key - initial state of rotor
+     */
+    constructor(wireSetting, key) {
+        wireSetting = wireSetting.split("").map(Number);
+        super(wireSetting, Number(key), false);
+    }
+
+    /**
+     * Encrypts a number
+     *
+     * @param {number} inputPos - the input position of the signal
+     * @returns {number}
+     */
+    crypt(inputPos) {
+        return this.cryptNum(inputPos, "leftToRight");
+    }
+
+}