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Expand MCP SDK parameter support with authentication and rate limiting
1 parent 16f2398 commit 258d551

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Lines changed: 161 additions & 2 deletions

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‎mcp-bridge/main.js‎

Lines changed: 161 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,163 @@
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#!/usr/bin/env node
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// MCP message handler
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// Hardening gate — validates every tool call before dispatch
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// ===================================================================
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/**
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* Run all security checks on a tool call.
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* Returns an error object {code, message} if rejected, or null if OK.
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* @param {string} toolName
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* @param {Record<string, unknown>} args
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* @returns {{code: number, message: string}|null}
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*/
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function hardeningGate(toolName, args) {
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// 1. Rate limiting
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if (!rateLimitAllow()) {
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return { code: -32000, message: "Rate limit exceeded. Max " + RATE_LIMIT + " tool calls per minute." };
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}
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// 2. Tool name validation
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if (!isValidToolName(toolName)) {
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return { code: -32602, message: "Invalid tool name" };
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}
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// 3. Input size check
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if (!isInputSizeOk(args)) {
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return { code: -32600, message: "Tool arguments exceed maximum size (1 MB)" };
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}
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// 4. Prompt injection detection
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const injectionLevel = scanObjectForInjection(args);
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if (injectionLevel === "critical" || injectionLevel === "high") {
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logError("Injection blocked", { tool: toolName, confidence: injectionLevel });
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return { code: -32600, message: "Request rejected: suspicious content detected" };
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}
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if (injectionLevel === "medium") {
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warn("Injection warning", { tool: toolName, confidence: injectionLevel });
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}
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// 5. Required field validation
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let validationError = null;
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if (toolName === "boj_cartridge_info" || toolName === "boj_cartridge_invoke") {
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validationError = validateRequiredStrings(args, ["name"]);
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} else if (toolName === "boj_browser_navigate") {
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validationError = validateRequiredStrings(args, ["url"]);
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} else if (toolName === "boj_browser_click") {
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validationError = validateRequiredStrings(args, ["selector"]);
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} else if (toolName === "boj_browser_type") {
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validationError = validateRequiredStrings(args, ["selector", "text"]);
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} else if (toolName === "boj_browser_execute_js") {
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validationError = validateRequiredStrings(args, ["script"]);
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} else if (toolName.startsWith("boj_github_") && toolName !== "boj_github_list_repos") {
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if (toolName === "boj_github_graphql" || toolName === "boj_github_search_code" || toolName === "boj_github_search_issues") {
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validationError = validateRequiredStrings(args, ["query"]);
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} else {
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validationError = validateRequiredStrings(args, ["owner", "repo"]);
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}
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} else if (toolName.startsWith("boj_gitlab_") && toolName !== "boj_gitlab_list_projects") {
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validationError = validateRequiredStrings(args, ["project_id"]);
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} else if (toolName.startsWith("boj_cloud_") || toolName.startsWith("boj_comms_") || toolName === "boj_ml_huggingface" || toolName === "boj_research" || toolName === "boj_codeseeker") {
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validationError = validateRequiredStrings(args, ["operation"]);
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} else if (toolName === "boj_browser_tabs") {
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validationError = validateRequiredStrings(args, ["operation"]);
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}
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if (validationError) {
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return { code: -32602, message: validationError };
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}
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return null;
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}
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=======
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// ===================================================================
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// Authentication
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// ===================================================================
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/**
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* Authenticate a request using a bearer token.
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* @param {string} token
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* @returns {boolean}
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*/
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function authenticate(token) {
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// In a real implementation, you would validate the token against a database
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// or authentication service. For now, we'll just check if the token is present.
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return token !== undefined && token !== null && token !== "";
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}
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// ===================================================================
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// Hardening gate — validates every tool call before dispatch
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// ===================================================================
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/**
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* Run all security checks on a tool call.
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* Returns an error object {code, message} if rejected, or null if OK.
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* @param {string} toolName
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* @param {Record<string, unknown>} args
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* @param {string} token
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* @returns {{code: number, message: string}|null}
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*/
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function hardeningGate(toolName, args, token = null) {
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// 1. Authentication
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if (token && !authenticate(token)) {
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return { code: -32001, message: "Authentication failed" };
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}
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// 2. Rate limiting
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if (!rateLimitAllow()) {
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return { code: -32000, message: "Rate limit exceeded. Max " + RATE_LIMIT + " tool calls per minute." };
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}
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// 3. Tool name validation
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if (!isValidToolName(toolName)) {
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return { code: -32602, message: "Invalid tool name" };
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}
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// 4. Input size check
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if (!isInputSizeOk(args)) {
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return { code: -32600, message: "Tool arguments exceed maximum size (1 MB)" };
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}
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// 5. Prompt injection detection
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const injectionLevel = scanObjectForInjection(args);
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if (injectionLevel === "critical" || injectionLevel === "high") {
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logError("Injection blocked", { tool: toolName, confidence: injectionLevel });
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return { code: -32600, message: "Request rejected: suspicious content detected" };
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}
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if (injectionLevel === "medium") {
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warn("Injection warning", { tool: toolName, confidence: injectionLevel });
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}
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// 6. Required field validation
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let validationError = null;
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if (toolName === "boj_cartridge_info" || toolName === "boj_cartridge_invoke") {
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validationError = validateRequiredStrings(args, ["name"]);
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} else if (toolName === "boj_browser_navigate") {
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validationError = validateRequiredStrings(args, ["url"]);
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} else if (toolName === "boj_browser_click") {
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validationError = validateRequiredStrings(args, ["selector"]);
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} else if (toolName === "boj_browser_type") {
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validationError = validateRequiredStrings(args, ["selector", "text"]);
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} else if (toolName === "boj_browser_execute_js") {
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validationError = validateRequiredStrings(args, ["script"]);
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} else if (toolName.startsWith("boj_github_") && toolName !== "boj_github_list_repos") {
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if (toolName === "boj_github_graphql" || toolName === "boj_github_search_code" || toolName === "boj_github_search_issues") {
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validationError = validateRequiredStrings(args, ["query"]);
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} else {
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validationError = validateRequiredStrings(args, ["owner", "repo"]);
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}
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} else if (toolName.startsWith("boj_gitlab_") && toolName !== "boj_gitlab_list_projects") {
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validationError = validateRequiredStrings(args, ["project_id"]);
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} else if (toolName.startsWith("boj_cloud_") || toolName.startsWith("boj_comms_") || toolName === "boj_ml_huggingface" || toolName === "boj_research" || toolName === "boj_codeseeker") {
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validationError = validateRequiredStrings(args, ["operation"]);
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} else if (toolName === "boj_browser_tabs") {
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validationError = validateRequiredStrings(args, ["operation"]);
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}
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if (validationError) {
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return { code: -32602, message: validationError };
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}
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return null;
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}MCP message handler
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// ===================================================================
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async function handleMessage(line) {
@@ -791,8 +949,9 @@ async function handleMessage(line) {
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case "tools/call": {
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const toolName = params?.name;
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const args = params?.arguments || {};
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const token = params?.token;
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const rejection = hardeningGate(toolName, args);
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const rejection = hardeningGate(toolName, args, token);
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if (rejection) {
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sendError(id, rejection.code, rejection.message);
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break;

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