Merge branch 'PenguinGeorge-ascii85-new'

src/core/config/Categories.json

@@ -25,6 +25,8 @@
             "From Base32",
             "To Base58",
             "From Base58",
+            "To Base85",
+            "From Base85",
             "To Base",
             "From Base",
             "To BCD",

src/core/lib/Base85.mjs

@@ -0,0 +1,45 @@
+/**
+ * Base85 resources.
+ *
+ * @author PenguinGeorge [george@penguingeorge.com]
+ * @copyright Crown Copyright 2018
+ * @license Apache-2.0
+ */
+
+/**
+ * Base85 alphabet options.
+ */
+export const ALPHABET_OPTIONS = [
+    {
+        name: "Standard",
+        value: "!-u",
+    },
+    {
+        name: "Z85 (ZeroMQ)",
+        value: "0-9a-zA-Z.#\\-:+=^!/*?&<>()[]{}@%$#",
+    },
+    {
+        name: "IPv6",
+        value: "0-9A-Za-z!#$%&()*+\\-;<=>?@^_`{|~}",
+    }
+];
+
+
+/**
+ * Returns the name of the alphabet, when given the alphabet.
+ *
+ * @param {string} alphabet
+ * @returns {string}
+ */
+export function alphabetName(alphabet) {
+    alphabet = alphabet.replace("'", "&apos;");
+    alphabet = alphabet.replace("\"", "&quot;");
+    alphabet = alphabet.replace("\\", "&bsol;");
+    let name;
+
+    ALPHABET_OPTIONS.forEach(function(a) {
+        if (escape(alphabet) === escape(a.value)) name = a.name;
+    });
+
+    return name;
+}

src/core/operations/FromBase85.mjs

@@ -0,0 +1,105 @@
+/**
+ * @author PenguinGeorge [george@penguingeorge.com]
+ * @copyright Crown Copyright 2018
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import OperationError from "../errors/OperationError";
+import Utils from "../Utils";
+import {alphabetName, ALPHABET_OPTIONS} from "../lib/Base85";
+
+/**
+ * From Base85 operation
+ */
+class FromBase85 extends Operation {
+
+    /**
+     * From Base85 constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "From Base85";
+        this.module = "Default";
+        this.description = "Base85 (also called Ascii85) is a notation for encoding arbitrary byte data. It is usually more efficient that Base64.<br><br>This operation decodes data from an ASCII string (with an alphabet of your choosing, presets included).<br><br>e.g. <code>BOu!rD]j7BEbo7</code> becomes <code>hello world</code><br><br>Base85 is commonly used in Adobe's PostScript and PDF file formats.";
+        this.infoURL = "https://wikipedia.org/wiki/Ascii85";
+        this.inputType = "string";
+        this.outputType = "byteArray";
+        this.args = [
+            {
+                name: "Alphabet",
+                type: "editableOption",
+                value: ALPHABET_OPTIONS
+            },
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {byteArray}
+     */
+    run(input, args) {
+        const alphabet = Utils.expandAlphRange(args[0]).join(""),
+            encoding = alphabetName(alphabet),
+            result = [];
+
+        if (alphabet.length !== 85 ||
+            [].unique.call(alphabet).length !== 85) {
+            throw new OperationError("Alphabet must be of length 85");
+        }
+
+        if (input.length === 0) return [];
+
+        const matches = input.match(/<~(.+?)~>/);
+        if (matches !== null) input = matches[1];
+
+        let i = 0;
+        let block, blockBytes;
+        while (i < input.length) {
+            if (encoding === "Standard" && input[i] === "z") {
+                result.push(0, 0, 0, 0);
+                i++;
+            } else {
+                let digits = [];
+                digits = input
+                    .substr(i, 5)
+                    .split("")
+                    .map((chr, idx) => {
+                        const digit = alphabet.indexOf(chr);
+                        if (digit < 0 || digit > 84) {
+                            throw `Invalid character '${chr}' at index ${idx}`;
+                        }
+                        return digit;
+                    });
+
+                block =
+                    digits[0] * 52200625 +
+                    digits[1] * 614125 +
+                    (i + 2 < input.length ? digits[2] : 84) * 7225 +
+                    (i + 3 < input.length ? digits[3] : 84) * 85 +
+                    (i + 4 < input.length ? digits[4] : 84);
+
+                blockBytes = [
+                    (block >> 24) & 0xff,
+                    (block >> 16) & 0xff,
+                    (block >> 8) & 0xff,
+                    block & 0xff
+                ];
+
+                if (input.length < i + 5) {
+                    blockBytes.splice(input.length - (i + 5), 5);
+                }
+
+                result.push.apply(result, blockBytes);
+                i += 5;
+            }
+        }
+
+        return result;
+    }
+
+}
+
+export default FromBase85;

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 Utils from "../Utils";
+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 (also called Ascii85) 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 = Utils.expandAlphRange(args[0]).join(""),
+            encoding = alphabetName(alphabet),
+            includeDelim = args[1];
+        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;
+            }
+        }
+
+        return includeDelim ? `<~${result}~>` : result;
+    }
+}
+
+export default ToBase85;