operant-mcp

Instructions

Implementation Reference

• src/tools/recon.ts:79-126 (handler)

  The "recon_dns" tool is registered and implemented in src/tools/recon.ts. It performs DNS enumeration using 'dig' for common record types and attempts zone transfers and BIND version disclosure.

  server.tool(
    "recon_dns",
    "Full DNS enumeration: A, AAAA, MX, TXT, NS, CNAME, AXFR, BIND version. Returns records object, axfr_result, and bind_version. Read-only DNS queries.",
    {
      target: z.string().describe("Target domain, e.g. example.com"),
    },
    async ({ target }) => {
      requireTool("dig");
  
      const recordTypes = ["A", "AAAA", "MX", "TXT", "NS", "CNAME", "SOA"];
      const records: Record<string, string[]> = {};
      for (const rtype of recordTypes) {
        const res = await runCmd("dig", ["+short", rtype, target]);
        records[rtype] = parseLines(res.stdout);
      }
  
      // Zone transfer attempt
      const nsServers = records["NS"] ?? [];
      let axfrResult = "";
      for (const ns of nsServers.slice(0, 3)) {
        const nsClean = ns.replace(/\.$/, "");
        const axfr = await runCmd("dig", ["AXFR", target, `@${nsClean}`], { timeout: 15 });
        if (axfr.success && axfr.stdout.length > 100) {
          axfrResult = axfr.stdout.slice(0, 3000);
          break;
        }
      }
  
      // BIND version disclosure
      let bindVersion = "";
      for (const ns of nsServers.slice(0, 2)) {
        const nsClean = ns.replace(/\.$/, "");
        const bv = await runCmd("dig", ["version.bind", "CHAOS", "TXT", `@${nsClean}`], { timeout: 10 });
        if (bv.success && bv.stdout.toLowerCase().includes("version")) {
          bindVersion = bv.stdout.slice(0, 500);
          break;
        }
      }
  
      const result = {
        records,
        axfr_result: axfrResult || "Zone transfer denied or no NS servers found.",
        bind_version: bindVersion || "Not disclosed.",
      };
  
      return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] };
    }
  );