check authenticated rpc signatures in separate threads

lib/workers/check-signature.js

@@ -0,0 +1,96 @@
+/* jshint esversion: 6 */
+/* global process */
+const Nacl = require('tweetnacl/nacl-fast');
+
+const COMMANDS = {};
+
+COMMANDS.INLINE = function (data, cb) {
+    var signedMsg;
+    try {
+        signedMsg = Nacl.util.decodeBase64(data.msg);
+    } catch (e) {
+        return void cb('E_BAD_MESSAGE');
+    }
+
+    var validateKey;
+    try {
+        validateKey = Nacl.util.decodeBase64(data.key);
+    } catch (e) {
+        return void cb("E_BADKEY");
+    }
+    // validate the message
+    const validated = Nacl.sign.open(signedMsg, validateKey);
+    if (!validated) {
+        return void cb("FAILED");
+    }
+    cb();
+};
+
+const checkDetachedSignature = function (signedMsg, signature, publicKey) {
+    if (!(signedMsg && publicKey)) { return false; }
+
+    var signedBuffer;
+    var pubBuffer;
+    var signatureBuffer;
+
+    try {
+        signedBuffer = Nacl.util.decodeUTF8(signedMsg);
+    } catch (e) {
+        throw new Error("INVALID_SIGNED_BUFFER");
+    }
+
+    try {
+        pubBuffer = Nacl.util.decodeBase64(publicKey);
+    } catch (e) {
+        throw new Error("INVALID_PUBLIC_KEY");
+    }
+
+    try {
+        signatureBuffer = Nacl.util.decodeBase64(signature);
+    } catch (e) {
+        throw new Error("INVALID_SIGNATURE");
+    }
+
+    if (pubBuffer.length !== 32) {
+        throw new Error("INVALID_PUBLIC_KEY_LENGTH");
+    }
+
+    if (signatureBuffer.length !== 64) {
+        throw new Error("INVALID_SIGNATURE_LENGTH");
+    }
+
+    if (Nacl.sign.detached.verify(signedBuffer, signatureBuffer, pubBuffer) !== true) {
+        throw new Error("FAILED");
+    }
+};
+
+COMMANDS.DETACHED = function (data, cb) {
+    try {
+        checkDetachedSignature(data.msg, data.sig, data.key)
+    } catch (err) {
+        return void cb(err && err.message);
+    }
+    cb();
+};
+
+process.on('message', function (data) {
+    if (!data || !data.key || !data.msg || !data.txid) {
+        return void process.send({
+            error:'E_INVAL'
+        });
+    }
+
+    const cb = function (err) {
+        process.send({
+            txid: data.txid,
+            error: err,
+        });
+    };
+
+    const command = COMMANDS[data.command];
+    if (typeof(command) !== 'function') {
+        return void cb("E_BAD_COMMAND");
+    }
+
+    command(data, cb);
+});