Cyberchef cli

cli.js

@@ -0,0 +1,180 @@
+#!/usr/bin/env node
+/**
+ * @author Boolean263 [[email protected]]
+ * @copyright Crown Copyright 2020
+ * @license Apache-2.0
+ */
+'use strict';
+
+const fs = require("fs");
+
+///////// Helper Functions /////////
+
+let slurpStream = (istream) => { // {{{1
+    // Slurp the contents of a stream up into a Buffer to pass to CyberChef
+    var ret = [];
+    var len = 0;
+    return new Promise(resolve => {
+        istream.on('readable', () => {
+            var chunk;
+            while ((chunk = istream.read()) !== null) {
+                ret.push(chunk);
+                len += chunk.length;
+            }
+            resolve(Buffer.concat(ret, len));
+        });
+    });
+}; // }}}1
+
+let slurp = (fname) => { // {{{1
+    // Slurp the contents of a file (or stdin) into a Buffer
+    let istream;
+
+    if (fname === undefined || fname == '-') {
+        istream = process.stdin;
+        if (istream.isTTY) {
+            return Promise.reject(new Error("TTY input not supported"));
+        }
+    }
+    else {
+        istream = fs.createReadStream(fname, { flags: 'r' });
+    }
+    return slurpStream(istream);
+}; // }}}1
+
+let getPort = (value, dummyPrevious) => { // {{{1
+    // Get a valid port number from the command line
+    let ret = parseInt(value, 10);
+    if (ret < 1 || ret > 65535) {
+        throw new Error("invalid port number");
+    }
+    return ret;
+};
+// }}}1
+
+///////// MAIN ///////// {{{1
+
+const chef = require("cyberchef");
+const program = require("commander");
+
+program
+    .version(require('./package.json').version)
+    .description('Bake data from files and/or TCP clients '
+        + 'using a CyberChef recipe.')
+    .usage('[options] [file [file ...]]')
+    .requiredOption('-r, --recipe-file <file>',
+        'recipe JSON file')
+    .option('-l, --listen [port]',
+        'listen on TCP port for data (random if not given)', getPort, false)
+    .option('-o, --output <file-or-dir>',
+        'where to write result (file input only; default:stdout)');
+
+try {
+    program.exitOverride().parse(process.argv);
+}
+catch (e) {
+    if (e.code != 'commander.helpDisplayed') {
+        console.error("Run with '--help' for usage");
+    }
+    process.exit(1);
+}
+
+// If we get no inputs and we aren't running a server,
+// make stdin our single input
+let inputs = program.args;
+if (inputs.length == 0 && !program.listen) {
+    inputs = [ '-' ];
+}
+
+// Likewise stdout for our output
+let ostream;
+let path;
+let outputIsDir = false;
+if (program.output === undefined && !program.listen) {
+    ostream = process.stdout;
+}
+else if (inputs.length > 0) {
+    // See if our output is a directory
+    let st;
+    try {
+        st = fs.statSync(program.output);
+        outputIsDir = st.isDirectory();
+    }
+    catch(err) {
+        // We're fine if the output doesn't exist yet
+        if (err.code != 'ENOENT') throw err;
+    }
+    if (!outputIsDir) {
+        ostream = fs.createWriteStream(program.output);
+    }
+}
+if (outputIsDir) path = require("path");
+
+let recipe;
+slurp(program.recipeFile).then((data) => {
+    recipe = JSON.parse(data);
+})
+.catch((err) => {
+    console.error(`Error parsing recipe: ${err.message}`);
+    process.exit(2);
+})
+.then(() => {
+    // First, deal with any files we want to read
+    for(let i of inputs) {
+        slurp(i).then((data) => {
+            let output = chef.bake(data, recipe);
+            if (outputIsDir) {
+                let outFileName = path.basename(i);
+                if (outFileName == '-') outFileName = 'from-stdin';
+                ostream = fs.createWriteStream(
+                    path.join(program.output, outFileName));
+            }
+            ostream.write(output.presentAs("string", true));
+            if (outputIsDir) ostream.end();
+        },
+        (err) => {
+            console.error(err.message);
+            process.exitCode = 2;
+        })
+        .catch((err) => {
+            console.error(err.message);
+            process.exitCode = 2;
+        });
+    }
+
+    // Next, listen for TCP requests.
+    // This is intentionally hardcoded to localhost to discourage
+    // the use of this script as a production system.
+    if (program.listen) {
+        const net = require('net');
+        const server = net.createServer((socket) => {
+            slurpStream(socket).then((data) => {
+                let output = chef.bake(data, recipe);
+                socket.write(output.presentAs("string", true));
+                socket.end();
+            })
+            .catch((err) => {
+                console.error(err);
+            });
+        });
+
+        // If no port given by user, let the OS choose one
+        if (program.listen === true) program.listen = 0;
+        server.listen(program.listen, '127.0.0.1')
+            .on('listening', () => {
+                console.log('Now listening on '
+                    + server.address().address
+                    + ":" + server.address().port);
+            });
+
+        // Exit gracefully
+        process.on('SIGINT', () => {
+            console.log("Exiting");
+            server.close();
+        });
+    }
+})
+.catch((err) => {
+    console.error(err);
+    process.exit(3);
+})

package.json

@@ -35,6 +35,9 @@
     "Firefox >= 38",
     "node >= 10"
   ],
+  "bin": {
+    "cyberchef": "./cli.js"
+  },
   "devDependencies": {
     "@babel/core": "^7.8.7",
     "@babel/plugin-transform-runtime": "^7.8.3",
@@ -98,6 +101,7 @@
     "bson": "^4.0.3",
     "chi-squared": "^1.1.0",
     "codepage": "^1.14.0",
+    "commander": "^2.14.1",
     "core-js": "^3.6.4",
     "crypto-api": "^0.8.5",
     "crypto-js": "^4.0.0",