Add ChaCha stream cipher operation

src/core/Utils.mjs

@@ -381,6 +381,67 @@ class Utils {
         }
     }
 
+    /**
+     * Converts a byte array to an integer.
+     *
+     * @param {byteArray} byteArray
+     * @param {string} byteorder - "little" or "big"
+     * @returns {integer}
+     *
+     * @example
+     * // returns 67305985
+     * Utils.byteArrayToInt([ 1, 2, 3, 4], "little");
+     *
+     * // returns 16909060
+     * Utils.byteArrayToInt([ 1, 2, 3, 4], "big");
+     */
+    static byteArrayToInt(byteArray, byteorder) {
+        let value = 0;
+        if (byteorder === "big") {
+            for (let i = 0; i < byteArray.length; i++) {
+                value = (value * 256) + byteArray[i];
+            }
+        } else {
+            for (let i = byteArray.length - 1; i >= 0; i--) {
+                value = (value * 256) + byteArray[i];
+            }
+        }
+        return value;
+    }
+
+    /**
+     * Converts an integer to a byte array of {length} bytes.
+     *
+     * @param {integer} value
+     * @param {integer} length
+     * @param {string} byteorder - "little" or "big"
+     * @returns {byteArray}
+     *
+     * @example
+     * // returns [ 5, 255, 109, 1 ]
+     * Utils.intToByteArray(23985925, 4, "little");
+     *
+     * // returns [ 1, 109, 255, 5 ]
+     * Utils.intToByteArray(23985925, 4, "big");
+     *
+     * // returns [ 0, 0, 0, 0, 1, 109, 255, 5 ]
+     * Utils.intToByteArray(23985925, 8, "big");
+     */
+    static intToByteArray(value, length, byteorder) {
+        const arr = new Array(length);
+        if (byteorder === "little") {
+            for (let i = 0; i < length; i++) {
+                arr[i] = value & 0xFF;
+                value = value >>> 8;
+            }
+        } else {
+            for (let i = length - 1; i >= 0; i--) {
+                arr[i] = value & 0xFF;
+                value = value >>> 8;
+            }
+        }
+        return arr;
+    }
 
     /**
      * Converts a string to an ArrayBuffer.

src/core/config/Categories.json

@@ -75,6 +75,7 @@
             "AES Decrypt",
             "Blowfish Encrypt",
             "Blowfish Decrypt",
+            "ChaCha",
             "DES Encrypt",
             "DES Decrypt",
             "Triple DES Encrypt",

src/core/operations/ChaCha.mjs

@@ -0,0 +1,236 @@
+/**
+ * @author joostrijneveld [joost@joostrijneveld.nl]
+ * @copyright Crown Copyright 2022
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation.mjs";
+import OperationError from "../errors/OperationError.mjs";
+import Utils from "../Utils.mjs";
+import { toHex } from "../lib/Hex.mjs";
+
+/**
+ * Computes the ChaCha block function
+ *
+ * @param {byteArray} key
+ * @param {byteArray} nonce
+ * @param {byteArray} counter
+ * @param {integer} rounds
+ * @returns {byteArray}
+ */
+function chacha(key, nonce, counter, rounds) {
+    const tau = "expand 16-byte k";
+    const sigma = "expand 32-byte k";
+
+    let state, c;
+    if (key.length === 16) {
+        c = Utils.strToByteArray(tau);
+        state = c.concat(key).concat(key);
+    } else {
+        c = Utils.strToByteArray(sigma);
+        state = c.concat(key);
+    }
+    state = state.concat(counter).concat(nonce);
+
+    const x = Array();
+    for (let i = 0; i < 64; i += 4) {
+        x.push(Utils.byteArrayToInt(state.slice(i, i + 4), "little"));
+    }
+    const a = [...x];
+
+    /**
+     * Macro to compute a 32-bit rotate-left operation
+     *
+     * @param {integer} x
+     * @param {integer} n
+     * @returns {integer}
+     */
+    function ROL32(x, n) {
+        return ((x << n) & 0xFFFFFFFF) | (x >>> (32 - n));
+    }
+
+    /**
+     * Macro to compute a single ChaCha quarterround operation
+     *
+     * @param {integer} x
+     * @param {integer} a
+     * @param {integer} b
+     * @param {integer} c
+     * @param {integer} d
+     * @returns {integer}
+     */
+    function quarterround(x, a, b, c, d) {
+        x[a] = ((x[a] + x[b]) & 0xFFFFFFFF); x[d] = ROL32(x[d] ^ x[a], 16);
+        x[c] = ((x[c] + x[d]) & 0xFFFFFFFF); x[b] = ROL32(x[b] ^ x[c], 12);
+        x[a] = ((x[a] + x[b]) & 0xFFFFFFFF); x[d] = ROL32(x[d] ^ x[a], 8);
+        x[c] = ((x[c] + x[d]) & 0xFFFFFFFF); x[b] = ROL32(x[b] ^ x[c], 7);
+    }
+
+    for (let i = 0; i < rounds / 2; i++)  {
+        quarterround(x, 0, 4,  8, 12);
+        quarterround(x, 1, 5,  9, 13);
+        quarterround(x, 2, 6, 10, 14);
+        quarterround(x, 3, 7, 11, 15);
+        quarterround(x, 0, 5, 10, 15);
+        quarterround(x, 1, 6, 11, 12);
+        quarterround(x, 2, 7,  8, 13);
+        quarterround(x, 3, 4,  9, 14);
+    }
+
+    for (let i = 0; i < 16; i++) {
+        x[i] = (x[i] + a[i]) & 0xFFFFFFFF;
+    }
+
+    let output = Array();
+    for (let i = 0; i < 16; i++) {
+        output = output.concat(Utils.intToByteArray(x[i], 4, "little"));
+    }
+    return output;
+}
+
+/**
+ * ChaCha operation
+ */
+class ChaCha extends Operation {
+
+    /**
+     * ChaCha constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "ChaCha";
+        this.module = "Default";
+        this.description = "ChaCha is a stream cipher designed by Daniel J. Bernstein. It is a variant of the Salsa stream cipher. Several parameterizations exist; 'ChaCha' may refer to the original construction, or to the variant as described in RFC-8439. ChaCha is often used with Poly1305, in the ChaCha20-Poly1305 AEAD construction.<br><br><b>Key:</b> ChaCha uses a key of 16 or 32 bytes (128 or 256 bits).<br><br><b>Nonce:</b> ChaCha uses a nonce of 8 or 12 bytes (64 or 96 bits).<br><br><b>Counter:</b> ChaCha uses a counter of 4 or 8 bytes (32 or 64 bits); together, the nonce and counter must add up to 16 bytes. The counter starts at zero at the start of the keystream, and is incremented at every 64 bytes.";
+        this.infoURL = "https://wikipedia.org/wiki/Salsa20#ChaCha_variant";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [
+            {
+                "name": "Key",
+                "type": "toggleString",
+                "value": "",
+                "toggleValues": ["Hex", "UTF8", "Latin1", "Base64"]
+            },
+            {
+                "name": "Nonce",
+                "type": "toggleString",
+                "value": "",
+                "toggleValues": ["Hex", "UTF8", "Latin1", "Base64", "Integer"]
+            },
+            {
+                "name": "Counter",
+                "type": "number",
+                "value": 0,
+                "min": 0
+            },
+            {
+                "name": "Rounds",
+                "type": "option",
+                "value": ["20", "12", "8"]
+            },
+            {
+                "name": "Input",
+                "type": "option",
+                "value": ["Hex", "Raw"]
+            },
+            {
+                "name": "Output",
+                "type": "option",
+                "value": ["Raw", "Hex"]
+            }
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        const key = Utils.convertToByteArray(args[0].string, args[0].option),
+            nonceType = args[1].option,
+            rounds = parseInt(args[3], 10),
+            inputType = args[4],
+            outputType = args[5];
+
+        if (key.length !== 16 && key.length !== 32) {
+            throw new OperationError(`Invalid key length: ${key.length} bytes.
+
+ChaCha uses a key of 16 or 32 bytes (128 or 256 bits).`);
+        }
+        let counter, nonce;
+        let counterLength;
+        if (nonceType !== "Integer") {
+            nonce = Utils.convertToByteArray(args[1].string, args[1].option);
+            if (!(nonce.length === 12 || nonce.length === 8)) {
+                throw new OperationError(`Invalid nonce length: ${nonce.length} bytes.
+
+ChaCha uses a nonce of 8 or 12 bytes (64 or 96 bits).`);
+            }
+            counterLength = 16 - nonce.length;
+            counter = Utils.intToByteArray(args[2], counterLength, "little");
+        }
+        if (nonceType === "Integer") {
+            nonce = Utils.intToByteArray(parseInt(args[1].string, 10), 12, "little");
+            counterLength = 4;
+            counter = Utils.intToByteArray(args[2], counterLength, "little");
+        }
+
+        const output = new Array();
+        input = Utils.convertToByteArray(input, inputType);
+
+        let counterAsInt = Utils.byteArrayToInt(counter, "little");
+        for (let i = 0; i < input.length; i += 64) {
+            counter = Utils.intToByteArray(counterAsInt, counterLength, "little");
+            const stream = chacha(key, nonce, counter, rounds);
+            for (let j = 0; j < 64 && i + j < input.length; j++) {
+                output.push(input[i + j] ^ stream[j]);
+            }
+            counterAsInt++;
+        }
+
+        if (outputType === "Hex") {
+            return toHex(output);
+        } else {
+            return Utils.arrayBufferToStr(output);
+        }
+    }
+
+    /**
+     * Highlight ChaCha
+     *
+     * @param {Object[]} pos
+     * @param {number} pos[].start
+     * @param {number} pos[].end
+     * @param {Object[]} args
+     * @returns {Object[]} pos
+     */
+    highlight(pos, args) {
+        const inputType = args[4],
+            outputType = args[5];
+        if (inputType === "Raw" && outputType === "Raw") {
+            return pos;
+        }
+    }
+
+    /**
+     * Highlight ChaCha in reverse
+     *
+     * @param {Object[]} pos
+     * @param {number} pos[].start
+     * @param {number} pos[].end
+     * @param {Object[]} args
+     * @returns {Object[]} pos
+     */
+    highlightReverse(pos, args) {
+        const inputType = args[4],
+            outputType = args[5];
+        if (inputType === "Raw" && outputType === "Raw") {
+            return pos;
+        }
+    }
+
+}
+
+export default ChaCha;

tests/operations/index.mjs

@@ -30,6 +30,7 @@ import "./tests/ByteRepr.mjs";
 import "./tests/CartesianProduct.mjs";
 import "./tests/CetaceanCipherEncode.mjs";
 import "./tests/CetaceanCipherDecode.mjs";
+import "./tests/ChaCha.mjs";
 import "./tests/CharEnc.mjs";
 import "./tests/ChangeIPFormat.mjs";
 import "./tests/Charts.mjs";