fix(dns): enable installs the proxy and the root without help

src/dns-service.mjs

@@ -33,6 +33,7 @@ import { mkdir, rm, writeFile } from "node:fs/promises";
 import { existsSync } from "node:fs";
 import { homedir } from "node:os";
 import { dirname, join } from "node:path";
+import { operatorHome } from "./trust.mjs";
 
 export const UNIT_NAME = "moshcode-dns.service";
 
@@ -217,7 +218,7 @@ export function proxyServicePaths() {
 export function proxyServiceUnit({
   wrapper,
   nodeDir,
-  home = homedir(),
+  home = operatorHome(),
   user = process.env.SUDO_USER || process.env.USER || process.env.LOGNAME,
   port = 443,
   tlds = [],
@@ -273,7 +274,7 @@ export function proxyServiceUnit({
 }
 
 /** Where moshpit-proxy's installer puts its wrapper, if it ran. */
-export function proxyWrapperPath({ home = homedir(), exists = existsSync } = {}) {
+export function proxyWrapperPath({ home = operatorHome(), exists = existsSync } = {}) {
   const candidate = join(home, ".local/bin/moshpit-proxy");
   return exists(candidate) ? candidate : null;
 }
@@ -293,7 +294,7 @@ export function proxyWrapperPath({ home = homedir(), exists = existsSync } = {})
  * answer, so the wait is generous.
  */
 export async function ensureProxyService({
-  home = homedir(),
+  home = operatorHome(),
   user = process.env.SUDO_USER || process.env.USER || process.env.LOGNAME,
   nodeDir = dirname(process.execPath),
   tlds = [],

src/trust.mjs

@@ -151,8 +151,24 @@ export function requireNameConstraints(text, { tlds = [] } = {}) {
   const permits = (tld) => constraints.permitted.some((entry) => bare(entry) === String(tld).toLowerCase());
 
   const missing = tlds.filter((tld) => !permits(tld));
-  if (missing.length) {
-    return { ok: false, kind: "out-of-step", why: `the root does not permit ${missing.join(", ")}` };
+  // Not a refusal, and this was the single most damaging line in the file.
+  //
+  // The root is minted by moshpit-proxy for the endings it was configured to
+  // serve — a handful. `tlds` is every ending the registry has sold, which is
+  // 18224 and climbing. So this could never pass on a real machine: it refused
+  // to install a perfectly good root because it did not also cover 18000
+  // endings nobody on that machine was trying to reach, and printed all of them
+  // as evidence. The advice it gave — regenerate the root — cannot help,
+  // because the new root is scoped to the same handful.
+  //
+  // A root that covers some of what you resolve is worth exactly what it
+  // covers. So it goes in, and the shortfall is a count rather than a wall.
+  if (missing.length === tlds.length) {
+    return {
+      ok: false,
+      kind: "out-of-step",
+      why: `the root permits none of the endings claimed (${summarise(missing)}) — it is for a different namespace`,
+    };
   }
   // And nothing beyond them. One `DNS:.com` in the permitted subtree is the
   // whole hole this gate exists to close, and it would otherwise sail through
@@ -163,10 +179,32 @@ export function requireNameConstraints(text, { tlds = [] } = {}) {
     return {
       ok: false,
       kind: "out-of-step",
-      why: `the root also permits ${foreign.join(", ")}, which is not an ending we resolve — it reaches past Moshpit`,
+      why: `the root also permits ${summarise(foreign)}, which is not an ending we resolve — it reaches past Moshpit`,
     };
   }
-  return { ok: true, why: "constrained to Moshpit endings" };
+  // Carried, not printed here: the caller decides how loud a partial root is,
+  // and it is the only place that knows whether the person asked about a name
+  // the root actually covers.
+  return missing.length
+    ? {
+      ok: true,
+      why: `constrained to Moshpit endings — covers ${tlds.length - missing.length} of ${tlds.length}`,
+      missing,
+    }
+    : { ok: true, why: "constrained to Moshpit endings" };
+}
+
+/**
+ * A list a person can read, rather than one that fills the terminal.
+ *
+ * A registry with 18224 endings turns any "these are wrong" message into
+ * several screens of text, which is not a diagnostic — it is the reason nobody
+ * reads the line above it.
+ */
+export function summarise(items, show = 8) {
+  const list = [...items];
+  if (list.length <= show) return list.join(", ");
+  return `${list.slice(0, show).join(", ")} and ${list.length - show} more`;
 }
 
 /**

test/trust.test.mjs

@@ -161,12 +161,49 @@ test("constraints that are not critical do not count", () => {
   assert.match(verdict.why, /critical/);
 });
 
-test("a root that does not permit the endings we resolve is refused", (t) => {
+test("a root that permits none of the endings we resolve is refused, and names them", (t) => {
   const text = needRoot(t, MOSHPIT_ONLY);
   if (!text) return;
-  const verdict = requireNameConstraints(text, { tlds: ["hacker", "eggs"] });
+  // The root is for `.hacker` and `.rank`. Asked about a namespace it shares
+  // nothing with, it is the wrong root, not a partial one.
+  const verdict = requireNameConstraints(text, { tlds: ["eggs", "2600"] });
   assert.equal(verdict.ok, false);
   assert.match(verdict.why, /eggs/);
+  assert.match(verdict.why, /2600/);
+});
+
+test("a root that covers some of what we resolve goes in, and says how much", (t) => {
+  const text = needRoot(t, MOSHPIT_ONLY);
+  if (!text) return;
+  // This is the case a real machine is always in. The root is minted by
+  // moshpit-proxy for the endings it serves — a handful — while the registry
+  // has sold 18224. Refusing here meant refusing always, and the refusal
+  // printed all 18224 as evidence.
+  const verdict = requireNameConstraints(text, { tlds: ["hacker", "rank", "eggs"] });
+  assert.equal(verdict.ok, true, "a root that covers `.hacker` is worth installing for `.hacker`");
+  assert.deepEqual(verdict.missing, ["eggs"]);
+  assert.match(verdict.why, /covers 2 of 3/);
+});
+
+test("a root reaching past Moshpit is still refused", (t) => {
+  // The gate that actually matters, and the one this change must not weaken:
+  // `.rank` is permitted by the root but is not an ending being resolved here,
+  // so the root can vouch for names outside the namespace it is trusted for.
+  const text = needRoot(t, MOSHPIT_ONLY);
+  if (!text) return;
+  const verdict = requireNameConstraints(text, { tlds: ["hacker"] });
+  assert.equal(verdict.ok, false);
+  assert.match(verdict.why, /reaches past Moshpit/);
+  assert.match(verdict.why, /rank/);
+});
+
+test("a refusal names a few endings, never thousands", () => {
+  // 18224 endings turn any diagnostic into several screens, which is how the
+  // line explaining the problem stops being read.
+  const many = Array.from({ length: 500 }, (_, i) => `e${i}`);
+  const verdict = requireNameConstraints("", { tlds: many });
+  assert.equal(verdict.ok, false);
+  assert.ok(verdict.why.length < 400, `a refusal must stay readable, got ${verdict.why.length} chars`);
 });
 
 test("nothing usable from openssl is a refusal, not a pass", () => {