Updated upstream

.gitpod.yml

@@ -0,0 +1,11 @@
+# This configuration file was automatically generated by Gitpod.
+# Please adjust to your needs (see https://www.gitpod.io/docs/introduction/learn-gitpod/gitpod-yaml)
+# and commit this file to your remote git repository to share the goodness with others.
+
+# Learn more from ready-to-use templates: https://www.gitpod.io/docs/introduction/getting-started/quickstart
+
+tasks:
+  - init: npm install && npm run build
+    command: npm run start
+  - init: update upstream
+    command: git remote add upstream https://github.com/gchq/CyberChef.git; git fetch upstream

package.json

@@ -128,6 +128,7 @@
     "fernet": "^0.4.0",
     "file-saver": "^2.0.5",
     "flat": "^6.0.1",
+    "fzstd": "^0.1.1",
     "geodesy": "1.1.3",
     "highlight.js": "^11.9.0",
     "ieee754": "^1.2.1",

src/core/config/Categories.json

@@ -381,7 +381,8 @@
             "LZMA Compress",
             "LZ4 Decompress",
             "LZ4 Compress",
-            "LZNT1 Decompress"
+            "LZNT1 Decompress",
+            "ZStandard Decompress"
         ]
     },
     {

src/core/operations/ZStandardDecompress.mjs

@@ -0,0 +1,91 @@
+/**
+ * @author Scarjit [ferdinand@linnenberg.dev]
+ * @copyright Crown Copyright 2024
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation.mjs";
+import OperationError from "../errors/OperationError.mjs";
+import {isWorkerEnvironment} from "../Utils.mjs";
+import * as fzstd from "fzstd";
+
+/**
+ * ZStandard Decompress operation
+ */
+class ZStandardDecompress extends Operation {
+
+    /**
+     * ZStandardDecompress constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "ZStandard Decompress";
+        this.module = "Compress";
+        this.description = "ZStandard is a compression algorithm focused on fast decompression.";
+        this.infoURL = "https://wikipedia.org/wiki/Zstd"; // Usually a Wikipedia link. Remember to remove localisation (i.e. https://wikipedia.org/etc rather than https://en.wikipedia.org/etc)
+        this.inputType = "ArrayBuffer";
+        this.outputType = "ArrayBuffer";
+        this.args = [
+            {
+                "name": "Chunk Size (bytes)",
+                "type": "number",
+                "value": 65536
+            }
+        ];
+    }
+
+    /**
+     * @param {ArrayBuffer} input
+     * @param {Object[]} args
+     * @returns {ArrayBuffer}
+     */
+    run(input, args) {
+        const chunkSize = args[0];
+        if (input.byteLength <= 0) {
+            throw new OperationError("Please provide an input.");
+        }
+        // Validate input starts with ZStandard magic number
+        const ZSTD_MAGIC_NUMBER = [0x28, 0xb5, 0x2f, 0xfd];
+        const magicNumber = new Uint8Array(input, 0, 4);
+        if (!ZSTD_MAGIC_NUMBER.every((val, index) => val === magicNumber[index])) {
+            throw new OperationError("Invalid ZStandard input: does not start with magic number.");
+        }
+
+
+        if (isWorkerEnvironment()) self.sendStatusMessage("Loading ZStandard...");
+        return new Promise((resolve, reject) => {
+            const compressed = new Uint8Array(input);
+            try {
+                const outChunks = []; // Array of Uint8Array chunks
+                const stream = new fzstd.Decompress((chunk, isLast) => {
+                    // Add to the list of output chunks
+                    outChunks.push(chunk);
+                    if (isLast) {
+                        // Combine all chunks into a single Uint8Array
+                        const totalLength = outChunks.reduce((sum, chunk) => sum + chunk.length, 0);
+                        const result = new Uint8Array(totalLength);
+                        let offset = 0;
+                        for (const chunk of outChunks) {
+                            result.set(chunk, offset);
+                            offset += chunk.length;
+                        }
+                        resolve(result.buffer);
+                    }
+                });
+                const chunks = Math.ceil(compressed.length / chunkSize);
+                for (let i = 0; i < compressed.length; i += chunkSize) {
+                    if (isWorkerEnvironment()) self.sendStatusMessage(`Decompressing chunk ${i / chunkSize + 1} of ${chunks}...`);
+                    const chunk = compressed.subarray(i, i + chunkSize);
+                    stream.push(chunk);
+                }
+                stream.push(new Uint8Array(0), true); // Signal end of stream
+            } catch (error) {
+                reject(new OperationError("Decompression failed: " + error.message));
+            }
+        });
+    }
+
+}
+
+export default ZStandardDecompress;

tests/operations/tests/Compress.mjs

@@ -105,4 +105,19 @@ TestRegister.addTests([
             }
         ],
     },
+    {
+        name: "ZStandard Decompress",
+        input: "KLUv/QRYuQAAVGhlIGNhdCBzYXQgb24gdGhlIG1hdC4tJ481",
+        expectedOutput: "The cat sat on the mat.",
+        recipeConfig: [
+            {
+                "op": "From Base64",
+                "args": []
+            },
+            {
+                "op": "ZStandard Decompress",
+                "args": [65536]
+            }
+        ],
+    }
 ]);