Updated Base85 operations for latest CyberChef version

src/core/operations/ToBase85.mjs

@@ -0,0 +1,93 @@
+/**
+ * @author PenguinGeorge [george@penguingeorge.com]
+ * @copyright Crown Copyright 2018
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import OperationError from "../errors/OperationError";
+import {alphabetName, ALPHABET_OPTIONS} from "../lib/Base85";
+
+/**
+ * To Base85 operation
+ */
+class ToBase85 extends Operation {
+
+    /**
+     * To Base85 constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "To Base85";
+        this.module = "Default";
+        this.description = "Base85 (similar to Base64) is a notation for encoding arbitrary byte data. It is usually more efficient that Base64.<br><br>This operation encodes data in an ASCII string (with an alphabet of your choosing, presets included).<br><br>e.g. <code>hello world</code> becomes <code>BOu!rD]j7BEbo7</code><br><br>Base85 is commonly used in Adobe's PostScript and PDF file formats.<br><br><strong>Options</strong><br><u>Alphabet</u><ul><li>Standard - The standard alphabet, referred to as Ascii85</li><li>Z85 (ZeroMQ) - A string-safe variant of Base85, which avoids quote marks and backslash characters</li><li>IPv6 - A variant of Base85 suitable for encoding IPv6 addresses (RFC 1924)</li></ul><u>Include delimiter</u><br>Adds a '<~' and '~>' delimiter to the start and end of the data. This is standard for Adobe's implementation of Base85.";
+        this.infoURL = "https://wikipedia.org/wiki/Ascii85";
+        this.inputType = "byteArray";
+        this.outputType = "string";
+        this.args = [
+            {
+                name: "Alphabet",
+                type: "editableOption",
+                value: ALPHABET_OPTIONS
+            },
+            {
+                name: "Include Delimeter",
+                type: "boolean",
+                value: false
+            }
+        ];
+    }
+
+    /**
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {string}
+    */
+    run(input, args) {
+        const alphabet = args[0] || ALPHABET_OPTIONS[0].value,
+            encoding = alphabetName(alphabet);
+        let result = "";
+
+        if (alphabet.length !== 85 ||
+            [].unique.call(alphabet).length !== 85) {
+            throw new OperationError("Error: alphabet must be of length 85");
+        }
+
+        if (input.length === 0) return "";
+
+        let block;
+        for (let i = 0; i < input.length; i += 4) {
+            block = (
+                ((input[i])          << 24) +
+                ((input[i + 1] || 0) << 16) +
+                ((input[i + 2] || 0) << 8)  +
+                ((input[i + 3] || 0))
+            ) >>> 0;
+
+            if (encoding !== "Standard" || block > 0) {
+                let digits = [];
+                for (let j = 0; j < 5; j++) {
+                    digits.push(block % 85);
+                    block = Math.floor(block / 85);
+                }
+
+                digits = digits.reverse();
+
+                if (input.length < i + 4) {
+                    digits.splice(input.length - (i + 4), 4);
+                }
+
+                result += digits.map(digit => alphabet[digit]).join("");
+            } else {
+                result += (encoding === "Standard") ? "z" : null;
+            }
+        }
+
+        if (args[1] === true) result = "<~" + result + "~>";
+
+        return result;
+    }
+}
+
+export default ToBase85;