Define strict TLS trust plugin API

.gitignore

@@ -0,0 +1,3 @@
+node_modules/
+dist/
+

ARCHITECTURE.md

@@ -67,6 +67,28 @@ community evidence.
 Conventional global CA import may still be offered when global trust is exactly
 what the user intends.
 
+## ADR-005: Protocol 0.1 is TLS-only and TypeScript-defined
+
+The first plugin contract addresses substitution and restriction of TLS trust
+authorities only. It deliberately excludes general browser automation,
+announcements, peer-to-peer transport, timers, and post-navigation hooks. Those
+may be layered on later without enlarging the authority of the TLS decision
+surface.
+
+The compiler-checked contract exposes three hooks:
+
+- `collectEvidence` contributes attributed facts, warnings, and advisory votes;
+- `onBeforeTlsAccept` synchronously accepts or rejects a normally valid TLS
+  connection using prepared local state;
+- `onTlsFailure` asynchronously investigates a failed validation and may obtain
+  a browser-mediated user decision before a fresh connection attempt.
+
+A plugin exports one registration object through `defineTrustPlugin`. Its static
+manifest declares supported modes and requested capabilities; separate local
+configuration grants its active mode and authority. Every terminal verdict is
+Boolean and contains an explicit certificate-or-authority scope, lifetime, and
+supporting journal references.
+
 ## Required Firefox additions
 
 The exact patch boundaries will be established after TrustLab protocol v0 and a
@@ -94,4 +116,3 @@ privileged-extension integration spike. Expected additions are:
 - P2P transport and community governance;
 - release governance and threshold signing;
 - precise UI design and accessibility treatment.
-

trustlab/README.md

@@ -16,6 +16,8 @@ Run:
 
 ```sh
 npm test
+npm run check
+npm run build
 npm run demo
 npm run ui
 ```
@@ -34,3 +36,19 @@ This first slice intentionally omits persistence, package signatures, community
 identities, networking, and real X.509 parsing. The included interactive UI is a
 security-surface prototype, not browser integration.
 
+## TLS-only plugin API
+
+The strict TypeScript contract is defined in [`sdk/plugin-api.ts`](sdk/plugin-api.ts).
+A plugin exports one object created with `defineTrustPlugin`; local configuration
+separately grants its active mode and scope.
+
+The initial API intentionally exposes only:
+
+- `collectEvidence` for attributed evidence, warnings, and advisory votes;
+- `onBeforeTlsAccept` for a fast synchronous decision after normal validation;
+- `onTlsFailure` for asynchronous investigation of a failed validation.
+
+Every terminal result is Boolean and must include a discriminated certificate or
+authority scope, an explicit lifetime, and the journal entries supporting it.
+See [`examples/strict-plugin.ts`](examples/strict-plugin.ts) for a compiler-checked
+registration example.

trustlab/examples/demo.js

@@ -3,10 +3,15 @@ import { TrustRunner } from "../src/index.js";
 
 const villagePlugin = {
   manifest: {
+    manifestVersion: 1,
+    trustApiVersion: "0.1",
     id: "community.village.trust",
     name: "Village community trust",
-    role: "decision-authority",
+    version: "0.0.0",
+    supportedModes: ["decision-authority"],
+    capabilities: {},
   },
+  hooks: {
     collectEvidence({ facts }) {
       if (facts.hostname !== "library.village") return;
       return {
@@ -19,24 +24,32 @@ const villagePlugin = {
         ],
       };
     },
-  decide({ facts, journal }) {
+    async onTlsFailure({ facts, journal }) {
       const known = journal.entries.some(
         (entry) => entry.code === "known-community-key",
       );
       if (!known) return;
       return {
         trusted: true,
-      scope: { hostname: facts.hostname, port: facts.port },
+        scope: {
+          kind: "certificate-for-host",
+          hostname: facts.hostname,
+          port: facts.port,
+          certificateSha256: facts.presentedChain[0].sha256,
+        },
+        lifetime: { kind: "connection" },
         reasonEntryIds: journal.entries
           .filter((entry) => entry.code === "known-community-key")
           .map((entry) => entry.id),
       };
     },
+  },
 };
 
-const result = await new TrustRunner({ plugins: [villagePlugin] }).evaluate(
+const result = await new TrustRunner({
+  plugins: [{ plugin: villagePlugin, mode: "decision-authority" }],
+}).evaluate(
   unknownLocalAuthority,
 );
 
 console.log(JSON.stringify(result, null, 2));
-

trustlab/examples/strict-plugin.ts

@@ -0,0 +1,49 @@
+import {
+  defineTrustPlugin,
+  exactCertificateScope,
+} from "../sdk/plugin-api.js";
+
+export default defineTrustPlugin({
+  manifest: {
+    manifestVersion: 1,
+    trustApiVersion: "0.1",
+    id: "community.village.strict-example",
+    name: "Village strict example",
+    version: "1.0.0",
+    supportedModes: ["advisor", "decision-authority"],
+    capabilities: { interactiveUi: true },
+  },
+
+  hooks: {
+    collectEvidence({ facts }) {
+      if (facts.hostname !== "library.village") return undefined;
+      return {
+        entries: [
+          {
+            kind: "evidence",
+            code: "known-community-certificate",
+            message: "The configured community recognizes this certificate.",
+          },
+        ],
+      };
+    },
+
+    async onTlsFailure({ facts, journal, ui }) {
+      const trusted = await ui.requestDecision({
+        title: "Unknown village authority",
+        summary: "Firefox does not recognize this authority. The community recognizes the exact certificate.",
+        proposedScope: exactCertificateScope(facts),
+        evidenceEntryIds: journal.entries.map((entry) => entry.id),
+      });
+      if (trusted === undefined) return undefined;
+
+      return {
+        trusted,
+        scope: exactCertificateScope(facts),
+        lifetime: { kind: "session" },
+        reasonEntryIds: journal.entries.map((entry) => entry.id),
+      };
+    },
+  },
+});
+

trustlab/examples/type-contract.ts

@@ -0,0 +1,43 @@
+import type {
+  PluginContribution,
+  TrustPluginHooks,
+  TrustVerdict,
+} from "../sdk/plugin-api.js";
+
+// These intentionally invalid declarations are compiler assertions: the build
+// fails if TypeScript ever stops rejecting them.
+
+const asynchronousFastHook: TrustPluginHooks = {
+  // @ts-expect-error onBeforeTlsAccept must never return a Promise.
+  async onBeforeTlsAccept() {
+    return undefined;
+  },
+};
+
+// @ts-expect-error Every terminal verdict requires an explicit lifetime.
+const verdictWithoutLifetime: TrustVerdict = {
+  trusted: true,
+  scope: {
+    kind: "certificate-for-host",
+    hostname: "example.test",
+    port: 443,
+    certificateSha256: "leaf-sha256",
+  },
+  reasonEntryIds: [],
+};
+
+const voteWithoutBoolean: PluginContribution = {
+  entries: [
+    // @ts-expect-error A vote must state its Boolean recommendation.
+    {
+      kind: "vote",
+      code: "ambiguous-vote",
+      message: "This vote deliberately omits data.trusted.",
+    },
+  ],
+};
+
+void asynchronousFastHook;
+void verdictWithoutLifetime;
+void voteWithoutBoolean;
+

trustlab/package-lock.json

@@ -0,0 +1,32 @@
+{
+  "name": "@browsec/trustlab",
+  "version": "0.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "@browsec/trustlab",
+      "version": "0.0.0",
+      "devDependencies": {
+        "typescript": "^5.9.2"
+      },
+      "engines": {
+        "node": ">=22"
+      }
+    },
+    "node_modules/typescript": {
+      "version": "5.9.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
+      "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "tsc": "bin/tsc",
+        "tsserver": "bin/tsserver"
+      },
+      "engines": {
+        "node": ">=14.17"
+      }
+    }
+  }
+}

trustlab/package.json

@@ -5,11 +5,16 @@
   "type": "module",
   "description": "Browser-neutral reference runner for Browsec trust plugins",
   "scripts": {
+    "build": "tsc -p tsconfig.json",
+    "check": "tsc -p tsconfig.json --noEmit",
     "test": "node --test --test-isolation=none",
     "demo": "node examples/demo.js",
     "ui": "node ui/dev-server.js"
   },
   "engines": {
     "node": ">=22"
+  },
+  "devDependencies": {
+    "typescript": "^5.9.2"
   }
 }

trustlab/plugins/demo-plugins.js

@@ -1,10 +1,11 @@
 export function createFirefoxValidationPlugin() {
   return {
-    manifest: {
+    manifest: pluginManifest(
-      id: "org.browsec.firefox-validation",
+      "org.browsec.firefox-validation",
-      name: "Firefox validation",
+      "Firefox validation",
-      role: "advisor",
+      ["advisor"],
-    },
+    ),
+    hooks: {
       collectEvidence({ facts }) {
         if (facts.validation === "success") {
           return {
@@ -13,6 +14,7 @@ export function createFirefoxValidationPlugin() {
                 kind: "vote",
                 code: "firefox-validation-succeeded",
                 message: "Firefox constructed a valid path to a configured trust anchor.",
+                data: { trusted: true },
               },
             ],
           };
@@ -26,16 +28,18 @@ export function createFirefoxValidationPlugin() {
           })),
         };
       },
+    },
   };
 }
 
 export function createVillageCommunityPlugin() {
   return {
-    manifest: {
+    manifest: pluginManifest(
-      id: "community.village.observer",
+      "community.village.observer",
-      name: "Village community observer",
+      "Village community observer",
-      role: "advisor",
+      ["advisor"],
-    },
+    ),
+    hooks: {
       collectEvidence({ facts }) {
         if (facts.hostname !== "library.village") return;
         return {
@@ -50,10 +54,12 @@ export function createVillageCommunityPlugin() {
               kind: "vote",
               code: "community-recommends-trust",
               message: "The configured community recommends trusting this exact host certificate.",
+              data: { trusted: true },
             },
           ],
         };
       },
+    },
   };
 }
 
@@ -64,7 +70,8 @@ export function createCommunityAdvicePlugin({
   message,
 }) {
   return {
-    manifest: { id, name, role: "advisor" },
+    manifest: pluginManifest(id, name, ["advisor"]),
+    hooks: {
       collectEvidence() {
         return {
           entries: [
@@ -77,26 +84,53 @@ export function createCommunityAdvicePlugin({
           ],
         };
       },
+    },
   };
 }
 
 export function createUserDecisionPlugin(decision) {
   if (decision !== true && decision !== false) return undefined;
-  return {
+  const decide = ({ facts, journal }) => ({
-    manifest: {
-      id: "local.user.decision",
-      name: "Local user decision",
-      role: "decision-authority",
-    },
-    decide({ facts, journal }) {
-      return {
     trusted: decision,
-        scope: { hostname: facts.hostname, port: facts.port },
+    scope: exactCertificateScope(facts),
+    lifetime: { kind: "connection" },
     reasonEntryIds: journal.entries
       .filter((entry) => entry.kind === "evidence" || entry.kind === "warning")
       .map((entry) => entry.id),
-      };
+  });
+  return {
+    manifest: pluginManifest(
+      "local.user.decision",
+      "Local user decision",
+      ["decision-authority"],
+    ),
+    hooks: {
+      onBeforeTlsAccept: decide,
+      async onTlsFailure(context) {
+        return decide(context);
       },
+    },
+  };
+}
+
+function exactCertificateScope(facts) {
+  return {
+    kind: "certificate-for-host",
+    hostname: facts.hostname,
+    port: facts.port,
+    certificateSha256: facts.presentedChain[0].sha256,
+  };
+}
+
+function pluginManifest(id, name, supportedModes) {
+  return {
+    manifestVersion: 1,
+    trustApiVersion: "0.1",
+    id,
+    name,
+    version: "0.0.0",
+    supportedModes,
+    capabilities: {},
   };
 }
 

trustlab/sdk/plugin-api.ts

@@ -0,0 +1,194 @@
+/** Version of the first TLS-only trust-plugin API. */
+export const TRUST_API_VERSION = "0.1" as const;
+
+export type TrustApiVersion = typeof TRUST_API_VERSION;
+export type PluginMode =
+  | "observer"
+  | "advisor"
+  | "decision-authority"
+  | "veto-authority";
+
+export type TlsValidation = "success" | "failure";
+
+export interface CertificateFacts {
+  readonly subject: string;
+  readonly sha256: string;
+  readonly spkiSha256?: string;
+  readonly dnsNames?: readonly string[];
+  readonly validFrom?: string;
+  readonly validUntil?: string;
+}
+
+export interface TlsFailure {
+  readonly code: string;
+  readonly certificateSha256?: string;
+  readonly check: "identity" | "validity" | "signature" | "trust-anchor" | "local-policy";
+  readonly summary: string;
+}
+
+export interface TlsFacts {
+  readonly schemaVersion: 0;
+  readonly connectionId: string;
+  readonly hostname: string;
+  readonly port: number;
+  readonly validation: TlsValidation;
+  readonly errors: readonly string[];
+  readonly failure?: TlsFailure;
+  readonly presentedChain: readonly CertificateFacts[];
+  readonly constructedChain: readonly CertificateFacts[];
+  readonly tls: Readonly<Record<string, unknown>>;
+}
+
+export type PluginEntry = EvidenceEntry | WarningEntry | VoteEntry;
+
+interface EntryBase {
+  readonly code: string;
+  readonly message: string;
+  readonly data?: Readonly<Record<string, unknown>>;
+}
+
+export interface EvidenceEntry extends EntryBase {
+  readonly kind: "evidence";
+}
+
+export interface WarningEntry extends EntryBase {
+  readonly kind: "warning";
+}
+
+export interface VoteEntry extends EntryBase {
+  readonly kind: "vote";
+  readonly data: Readonly<{ trusted: boolean } & Record<string, unknown>>;
+}
+
+export interface JournalEntry extends EntryBase {
+  readonly id: string;
+  readonly pluginId: string;
+  readonly pluginName: string;
+  readonly kind: PluginEntry["kind"] | "resolution" | "error" | "abstention";
+}
+
+export interface ReadonlyDecisionJournal {
+  readonly entries: readonly JournalEntry[];
+}
+
+export interface PluginContribution {
+  readonly entries: readonly PluginEntry[];
+}
+
+export type TrustScope = CertificateForHostScope | AuthorityForHostScope;
+
+export interface CertificateForHostScope {
+  readonly kind: "certificate-for-host";
+  readonly hostname: string;
+  readonly port: number;
+  readonly certificateSha256: string;
+}
+
+export interface AuthorityForHostScope {
+  readonly kind: "authority-for-host";
+  readonly hostname: string;
+  readonly port: number | "any";
+  readonly authoritySha256: string;
+  readonly includeSubdomains: boolean;
+}
+
+export type TrustLifetime =
+  | { readonly kind: "connection" }
+  | { readonly kind: "session" }
+  | { readonly kind: "until"; readonly expiresAt: string }
+  | { readonly kind: "persistent" };
+
+export interface TrustedVerdict {
+  readonly trusted: true;
+  readonly scope: TrustScope;
+  readonly lifetime: TrustLifetime;
+  readonly reasonEntryIds: readonly string[];
+}
+
+export interface NotTrustedVerdict {
+  readonly trusted: false;
+  readonly scope: TrustScope;
+  readonly lifetime: TrustLifetime;
+  readonly reasonEntryIds: readonly string[];
+}
+
+export type TrustVerdict = TrustedVerdict | NotTrustedVerdict;
+
+export interface EvidenceContext {
+  readonly facts: TlsFacts;
+  readonly signal: AbortSignal;
+}
+
+export interface DecisionContext {
+  readonly facts: TlsFacts;
+  readonly journal: ReadonlyDecisionJournal;
+}
+
+export interface FailureDecisionContext extends DecisionContext {
+  readonly ui: TrustDecisionUi;
+  readonly signal: AbortSignal;
+}
+
+export interface TrustDecisionRequest {
+  readonly title: string;
+  readonly summary: string;
+  readonly proposedScope: TrustScope;
+  readonly evidenceEntryIds: readonly string[];
+}
+
+export interface TrustDecisionUi {
+  requestDecision(request: TrustDecisionRequest): Promise<boolean | undefined>;
+}
+
+export interface TrustPluginHooks {
+  collectEvidence?(
+    context: EvidenceContext,
+  ): PluginContribution | undefined | Promise<PluginContribution | undefined>;
+
+  /** Fast and deliberately synchronous. Network and UI are unavailable. */
+  onBeforeTlsAccept?(context: DecisionContext): TrustVerdict | undefined;
+
+  /** Failed navigation is investigated asynchronously before a fresh retry. */
+  onTlsFailure?(
+    context: FailureDecisionContext,
+  ): Promise<TrustVerdict | undefined>;
+}
+
+export interface TrustPluginManifest {
+  readonly manifestVersion: 1;
+  readonly trustApiVersion: TrustApiVersion;
+  readonly id: string;
+  readonly name: string;
+  readonly version: string;
+  readonly supportedModes: readonly PluginMode[];
+  readonly capabilities: {
+    readonly interactiveUi?: boolean;
+  };
+}
+
+export interface TrustPluginRegistration {
+  readonly manifest: TrustPluginManifest;
+  readonly hooks: TrustPluginHooks;
+}
+
+/**
+ * Defines the module's single registration object. Browsec still validates the
+ * installed package manifest and local capability grants before activation.
+ */
+export function defineTrustPlugin<const T extends TrustPluginRegistration>(
+  registration: T,
+): T {
+  return Object.freeze(registration);
+}
+
+export function exactCertificateScope(facts: TlsFacts): CertificateForHostScope {
+  const leaf = facts.presentedChain[0];
+  if (!leaf) throw new TypeError("TLS facts do not contain a leaf certificate");
+  return Object.freeze({
+    kind: "certificate-for-host",
+    hostname: facts.hostname,
+    port: facts.port,
+    certificateSha256: leaf.sha256,
+  });
+}
+

trustlab/src/builtin-final-handler.js

@@ -3,9 +3,13 @@ export const BUILTIN_HANDLER_ID = "org.browsec.builtin-final-handler";
 export function createBuiltinFinalHandler() {
   return Object.freeze({
     manifest: {
+      manifestVersion: 1,
+      trustApiVersion: "0.1",
       id: BUILTIN_HANDLER_ID,
       name: "Browsec built-in final handler",
-      role: "decision-authority",
+      version: "0.0.0",
+      supportedModes: ["decision-authority"],
+      capabilities: { interactiveUi: true },
       immutable: true,
     },
 
@@ -14,7 +18,13 @@ export function createBuiltinFinalHandler() {
 
       return {
         trusted: facts.validation === "success",
-        scope: { hostname: facts.hostname, port: facts.port },
+        scope: {
+          kind: "certificate-for-host",
+          hostname: facts.hostname,
+          port: facts.port,
+          certificateSha256: facts.presentedChain[0].sha256,
+        },
+        lifetime: { kind: "connection" },
         reasonEntryIds: journal.entries
           .filter((entry) => entry.kind === "warning" || entry.kind === "evidence")
           .map((entry) => entry.id),

trustlab/src/protocol.js

@@ -37,14 +37,39 @@ export function createTlsFacts(input) {
 }
 
 export function validateManifest(manifest) {
+  if (manifest?.manifestVersion !== 1) {
+    throw new TypeError(`Unsupported plugin manifest version: ${manifest?.manifestVersion}`);
+  }
+  if (manifest?.trustApiVersion !== "0.1") {
+    throw new TypeError(`Unsupported trust API version: ${manifest?.trustApiVersion}`);
+  }
   requireString(manifest?.id, "plugin manifest id");
   requireString(manifest?.name, "plugin manifest name");
-  if (!PLUGIN_ROLES.includes(manifest.role)) {
+  requireString(manifest?.version, "plugin manifest version");
-    throw new TypeError(`Unsupported plugin role: ${manifest.role}`);
+  if (manifest.capabilities === null || typeof manifest.capabilities !== "object") {
+    throw new TypeError("Plugin manifest capabilities must be an object");
+  }
+  if (!Array.isArray(manifest.supportedModes) || manifest.supportedModes.length === 0) {
+    throw new TypeError("Plugin manifest must declare supportedModes");
+  }
+  for (const mode of manifest.supportedModes) {
+    if (!PLUGIN_ROLES.includes(mode)) {
+      throw new TypeError(`Unsupported plugin mode: ${mode}`);
+    }
   }
   return immutableClone(manifest);
 }
 
+export function validatePluginMode(manifest, mode) {
+  if (!PLUGIN_ROLES.includes(mode)) {
+    throw new TypeError(`Unsupported configured plugin mode: ${mode}`);
+  }
+  if (!manifest.supportedModes.includes(mode)) {
+    throw new TypeError(`Plugin ${manifest.id} does not support mode ${mode}`);
+  }
+  return mode;
+}
+
 export function validateContribution(contribution, role) {
   if (contribution === undefined) return immutableClone({ entries: [] });
   if (contribution === null || typeof contribution !== "object") {
@@ -80,19 +105,68 @@ export function validateVerdict(verdict, facts) {
     throw new TypeError("Trust verdict must contain Boolean trusted");
   }
 
-  const scope = verdict.scope ?? {};
+  const scope = validateScope(verdict.scope, facts);
-  if (scope.hostname !== facts.hostname || scope.port !== facts.port) {
+  const lifetime = validateLifetime(verdict.lifetime);
-    throw new TypeError("Trust verdict scope does not match the connection");
+  if (!Array.isArray(verdict.reasonEntryIds)) {
+    throw new TypeError("Trust verdict reasonEntryIds must be an array");
   }
 
   return immutableClone({
     trusted: verdict.trusted,
-    scope: { hostname: scope.hostname, port: scope.port },
+    scope,
-    reasonEntryIds: verdict.reasonEntryIds ?? [],
+    lifetime,
-    expiresAt: verdict.expiresAt,
+    reasonEntryIds: verdict.reasonEntryIds,
   });
 }
 
+function validateScope(scope, facts) {
+  if (scope === null || typeof scope !== "object") {
+    throw new TypeError("Trust verdict must contain a scope");
+  }
+  if (scope.hostname !== facts.hostname) {
+    throw new TypeError("Trust verdict scope does not match the connection");
+  }
+
+  if (scope.kind === "certificate-for-host") {
+    if (scope.port !== facts.port) {
+      throw new TypeError("Certificate trust scope port does not match the connection");
+    }
+    if (scope.certificateSha256 !== facts.presentedChain[0]?.sha256) {
+      throw new TypeError("Certificate trust scope does not match the presented leaf");
+    }
+    return scope;
+  }
+
+  if (scope.kind === "authority-for-host") {
+    if (scope.port !== "any" && scope.port !== facts.port) {
+      throw new TypeError("Authority trust scope port does not match the connection");
+    }
+    if (typeof scope.includeSubdomains !== "boolean") {
+      throw new TypeError("Authority trust scope must specify includeSubdomains");
+    }
+    const chain = [...facts.presentedChain, ...facts.constructedChain];
+    if (!chain.some((certificate) => certificate.sha256 === scope.authoritySha256)) {
+      throw new TypeError("Authority trust scope does not match the certificate chain");
+    }
+    return scope;
+  }
+
+  throw new TypeError(`Unsupported trust scope kind: ${scope.kind}`);
+}
+
+function validateLifetime(lifetime) {
+  if (lifetime === null || typeof lifetime !== "object") {
+    throw new TypeError("Trust verdict must contain a lifetime");
+  }
+  if (!["connection", "session", "until", "persistent"].includes(lifetime.kind)) {
+    throw new TypeError(`Unsupported trust lifetime: ${lifetime.kind}`);
+  }
+  if (lifetime.kind === "until" && Number.isNaN(Date.parse(lifetime.expiresAt))) {
+    throw new TypeError("Until lifetime must contain a valid expiresAt timestamp");
+  }
+  return lifetime;
+}
+
 export function validateVerdictAuthority(verdict, role) {
   if (verdict === undefined) return;
   if (role === "observer" || role === "advisor") {

trustlab/src/runner.js

@@ -4,17 +4,19 @@ import {
   createTlsFacts,
   validateContribution,
   validateManifest,
+  validatePluginMode,
   validateVerdict,
   validateVerdictAuthority,
 } from "./protocol.js";
 
 export class TrustRunner {
-  constructor({ plugins = [], finalHandler, timeoutMs = 25 } = {}) {
+  constructor({ plugins = [], finalHandler, timeoutMs = 25, ui } = {}) {
-    this.plugins = plugins.map(normalizePlugin);
+    this.plugins = plugins.map(normalizeConfiguredPlugin);
     this.finalHandler = normalizeFinalHandler(
       finalHandler ?? createBuiltinFinalHandler(),
     );
     this.timeoutMs = timeoutMs;
+    this.ui = ui ?? { async requestDecision() { return undefined; } };
   }
 
   async evaluate(inputFacts) {
@@ -25,18 +27,38 @@ export class TrustRunner {
     let terminalVerdict;
 
     for (const plugin of this.plugins) {
-      if (!plugin.decide) continue;
+      const hook =
+        facts.validation === "success"
+          ? plugin.hooks.onBeforeTlsAccept
+          : plugin.hooks.onTlsFailure;
+      if (!hook) continue;
       try {
-        const candidate = await withTimeout(
+        const context = {
-          Promise.resolve(plugin.decide({ facts, journal: journal.snapshot() })),
+          facts,
-          this.timeoutMs,
+          journal: journal.snapshot(),
-        );
+          ...(facts.validation === "failure"
+            ? {
+                ui: plugin.manifest.capabilities.interactiveUi
+                  ? this.ui
+                  : deniedUi(plugin.manifest.id),
+                signal: AbortSignal.timeout(this.timeoutMs),
+              }
+            : {}),
+        };
+        const rawCandidate = hook(context);
+        if (facts.validation === "success" && isPromiseLike(rawCandidate)) {
+          throw new TypeError("onBeforeTlsAccept must return synchronously");
+        }
+        const candidate =
+          facts.validation === "failure"
+            ? await withTimeout(Promise.resolve(rawCandidate), this.timeoutMs)
+            : rawCandidate;
         const verdict = validateVerdict(candidate, facts);
         if (!verdict) {
           journal.append(plugin.manifest, [{ kind: "abstention" }]);
           continue;
         }
-        validateVerdictAuthority(verdict, plugin.manifest.role);
+        validateVerdictAuthority(verdict, plugin.mode);
 
         terminalVerdict = verdict;
         journal.append(plugin.manifest, [
@@ -71,15 +93,22 @@ export class TrustRunner {
 
   async #collectEvidence(facts, journal) {
     const collectors = this.plugins.map(async (plugin) => {
-      if (!plugin.collectEvidence) return { plugin, contribution: { entries: [] } };
+      if (!plugin.hooks.collectEvidence) {
+        return { plugin, contribution: { entries: [] } };
+      }
       try {
         const result = await withTimeout(
-          Promise.resolve(plugin.collectEvidence({ facts })),
+          Promise.resolve(
+            plugin.hooks.collectEvidence({
+              facts,
+              signal: AbortSignal.timeout(this.timeoutMs),
+            }),
+          ),
           this.timeoutMs,
         );
         return {
           plugin,
-          contribution: validateContribution(result, plugin.manifest.role),
+          contribution: validateContribution(result, plugin.mode),
         };
       } catch (error) {
         return { plugin, contribution: { entries: [pluginError(error)] } };
@@ -93,16 +122,19 @@ export class TrustRunner {
   }
 }
 
-function normalizePlugin(plugin) {
+function normalizeConfiguredPlugin(configured) {
+  if (!configured?.plugin) {
+    throw new TypeError("Configured plugin must contain a plugin registration");
+  }
+  const manifest = validateManifest(configured.plugin.manifest);
   return Object.freeze({
-    manifest: validateManifest(plugin.manifest),
+    manifest,
-    collectEvidence: plugin.collectEvidence?.bind(plugin),
+    mode: validatePluginMode(manifest, configured.mode),
-    decide: plugin.decide?.bind(plugin),
+    hooks: Object.freeze({ ...configured.plugin.hooks }),
   });
 }
 
 function normalizeFinalHandler(handler) {
-  const normalized = normalizePlugin(handler);
   if (handler.manifest.id !== "org.browsec.builtin-final-handler") {
     throw new TypeError("Final handler must be Browsec's built-in handler");
   }
@@ -110,11 +142,23 @@ function normalizeFinalHandler(handler) {
     throw new TypeError("Built-in final handler must implement finalize");
   }
   return Object.freeze({
-    ...normalized,
+    manifest: validateManifest(handler.manifest),
     finalize: handler.finalize.bind(handler),
   });
 }
 
+function isPromiseLike(value) {
+  return value !== null && typeof value === "object" && typeof value.then === "function";
+}
+
+function deniedUi(pluginId) {
+  return Object.freeze({
+    async requestDecision() {
+      throw new Error(`Plugin ${pluginId} has no interactiveUi capability`);
+    },
+  });
+}
+
 function pluginError(error) {
   return {
     kind: "error",

trustlab/test/runner.test.js

@@ -14,6 +14,7 @@ import {
 test("built-in handler rejects an unresolved certificate failure", async () => {
   const result = await new TrustRunner().evaluate(unknownLocalAuthority);
   assert.equal(result.verdict.trusted, false);
+  assert.equal(result.verdict.lifetime.kind, "connection");
   assert.equal(result.journal.entries.length, 0);
 });
 
@@ -22,92 +23,109 @@ test("built-in handler preserves an ordinary successful validation", async () =>
   assert.equal(result.verdict.trusted, true);
 });
 
-test("a decision plugin can trust a narrowly scoped connection", async () => {
+test("a failure hook can trust an exact certificate for a host", async () => {
-  const plugin = pluginWith({
+  const configured = configuredPlugin({
-    decide({ facts }) {
+    async onTlsFailure({ facts }) {
-      return {
+      return verdictFor(facts, true);
-        trusted: true,
-        scope: { hostname: facts.hostname, port: facts.port },
-      };
     },
   });
 
-  const result = await new TrustRunner({ plugins: [plugin] }).evaluate(
+  const result = await new TrustRunner({ plugins: [configured] }).evaluate(
     unknownLocalAuthority,
   );
   assert.equal(result.verdict.trusted, true);
+  assert.equal(result.verdict.scope.kind, "certificate-for-host");
   assert.equal(result.journal.entries.at(-1).kind, "resolution");
-  assert.equal(result.journal.entries.at(-1).pluginId, plugin.manifest.id);
+  assert.equal(
+    result.journal.entries.at(-1).pluginId,
+    configured.plugin.manifest.id,
+  );
 });
 
 test("evidence collection is independent but appended in plugin order", async () => {
-  const slowFirst = pluginWith({
+  const slowFirst = configuredPlugin({
     id: "test.first",
+    mode: "observer",
     async collectEvidence() {
       await new Promise((resolve) => setTimeout(resolve, 5));
       return { entries: [{ kind: "evidence", code: "first" }] };
     },
   });
-  const fastSecond = pluginWith({
+  const fastSecond = configuredPlugin({
     id: "test.second",
+    mode: "observer",
     collectEvidence() {
       return { entries: [{ kind: "warning", code: "second" }] };
     },
   });
 
-  const result = await new TrustRunner({ plugins: [slowFirst, fastSecond] }).evaluate(
+  const result = await new TrustRunner({
-    validPublicCertificate,
+    plugins: [slowFirst, fastSecond],
-  );
+  }).evaluate(validPublicCertificate);
   assert.deepEqual(
     result.journal.entries.map((entry) => entry.code),
     ["first", "second"],
   );
 });
 
-test("plugin timeout is recorded and falls through safely", async () => {
+test("asynchronous failure hook timeout is recorded and falls through safely", async () => {
-  const plugin = pluginWith({
+  const configured = configuredPlugin({
-    async decide() {
+    async onTlsFailure() {
       await new Promise((resolve) => setTimeout(resolve, 30));
       return undefined;
     },
   });
 
-  const result = await new TrustRunner({ plugins: [plugin], timeoutMs: 5 }).evaluate(
+  const result = await new TrustRunner({
-    unknownLocalAuthority,
+    plugins: [configured],
-  );
+    timeoutMs: 5,
+  }).evaluate(unknownLocalAuthority);
   assert.equal(result.verdict.trusted, false);
   assert.equal(result.journal.entries.at(-1).code, "plugin-timeout");
 });
 
-test("a verdict cannot escape the active hostname and port", async () => {
+test("successful-path hook must return synchronously", async () => {
-  const plugin = pluginWith({
+  const configured = configuredPlugin({
-    decide() {
+    async onBeforeTlsAccept() {
+      return undefined;
+    },
+  });
+  const result = await new TrustRunner({ plugins: [configured] }).evaluate(
+    validPublicCertificate,
+  );
+  assert.equal(result.verdict.trusted, true);
+  assert.match(result.journal.entries.at(-1).message, /must return synchronously/);
+});
+
+test("a verdict cannot escape the active hostname, port, or certificate", async () => {
+  const configured = configuredPlugin({
+    async onTlsFailure({ facts }) {
       return {
-        trusted: true,
+        ...verdictFor(facts, true),
-        scope: { hostname: "different.test", port: 443 },
+        scope: {
+          ...exactScope(facts),
+          hostname: "different.test",
+        },
       };
     },
   });
 
-  const result = await new TrustRunner({ plugins: [plugin] }).evaluate(
+  const result = await new TrustRunner({ plugins: [configured] }).evaluate(
     unknownLocalAuthority,
   );
   assert.equal(result.verdict.trusted, false);
   assert.match(result.journal.entries.at(-1).message, /scope does not match/);
 });
 
-test("observer and advisor plugins cannot issue terminal verdicts", async () => {
+test("observer and advisor modes cannot issue terminal verdicts", async () => {
-  for (const role of ["observer", "advisor"]) {
+  for (const mode of ["observer", "advisor"]) {
-    const plugin = pluginWith({
+    const configured = configuredPlugin({
-      role,
+      mode,
-      decide({ facts }) {
+      async onTlsFailure({ facts }) {
-        return {
+        return verdictFor(facts, true);
-          trusted: true,
-          scope: { hostname: facts.hostname, port: facts.port },
-        };
       },
     });
-    const result = await new TrustRunner({ plugins: [plugin] }).evaluate(
+    const result = await new TrustRunner({ plugins: [configured] }).evaluate(
       unknownLocalAuthority,
     );
     assert.equal(result.verdict.trusted, false);
@@ -116,22 +134,43 @@ test("observer and advisor plugins cannot issue terminal verdicts", async () =>
 });
 
 test("veto authority can reject but cannot trust", async () => {
-  const plugin = pluginWith({
+  const configured = configuredPlugin({
-    role: "veto-authority",
+    mode: "veto-authority",
-    decide({ facts }) {
+    async onTlsFailure({ facts }) {
-      return {
+      return verdictFor(facts, true);
-        trusted: true,
-        scope: { hostname: facts.hostname, port: facts.port },
-      };
     },
   });
-  const result = await new TrustRunner({ plugins: [plugin] }).evaluate(
+  const result = await new TrustRunner({ plugins: [configured] }).evaluate(
     unknownLocalAuthority,
   );
   assert.equal(result.verdict.trusted, false);
   assert.match(result.journal.entries.at(-1).message, /cannot issue a trusted/);
 });
 
+test("authority scope must identify a certificate in the active chain", async () => {
+  const configured = configuredPlugin({
+    async onTlsFailure({ facts }) {
+      return {
+        trusted: true,
+        scope: {
+          kind: "authority-for-host",
+          hostname: facts.hostname,
+          port: facts.port,
+          authoritySha256: "not-in-this-chain",
+          includeSubdomains: false,
+        },
+        lifetime: { kind: "session" },
+        reasonEntryIds: [],
+      };
+    },
+  });
+  const result = await new TrustRunner({ plugins: [configured] }).evaluate(
+    unknownLocalAuthority,
+  );
+  assert.equal(result.verdict.trusted, false);
+  assert.match(result.journal.entries.at(-1).message, /does not match the certificate chain/);
+});
+
 test("journal snapshots and entries are immutable", () => {
   const journal = new DecisionJournal();
   journal.append(
@@ -151,11 +190,7 @@ test("only Browsec's immutable handler can occupy the final position", () => {
     () =>
       new TrustRunner({
         finalHandler: {
-          manifest: {
+          manifest: pluginManifest("test.impostor", ["decision-authority"]),
-            id: "test.impostor",
-            name: "Impostor",
-            role: "decision-authority",
-          },
           finalize() {},
         },
       }),
@@ -167,15 +202,48 @@ test("only Browsec's immutable handler can occupy the final position", () => {
   );
 });
 
-function pluginWith({
+function configuredPlugin({
   id = "test.plugin",
-  role = "decision-authority",
+  mode = "decision-authority",
   collectEvidence,
-  decide,
+  onBeforeTlsAccept,
+  onTlsFailure,
 }) {
   return {
-    manifest: { id, name: id, role },
+    mode,
-    collectEvidence,
+    plugin: {
-    decide,
+      manifest: pluginManifest(id, [mode]),
+      hooks: { collectEvidence, onBeforeTlsAccept, onTlsFailure },
+    },
+  };
+}
+
+function pluginManifest(id, supportedModes) {
+  return {
+    manifestVersion: 1,
+    trustApiVersion: "0.1",
+    id,
+    name: id,
+    version: "0.0.0",
+    supportedModes,
+    capabilities: {},
+  };
+}
+
+function verdictFor(facts, trusted) {
+  return {
+    trusted,
+    scope: exactScope(facts),
+    lifetime: { kind: "connection" },
+    reasonEntryIds: [],
+  };
+}
+
+function exactScope(facts) {
+  return {
+    kind: "certificate-for-host",
+    hostname: facts.hostname,
+    port: facts.port,
+    certificateSha256: facts.presentedChain[0].sha256,
   };
 }

trustlab/test/ui.test.js

@@ -47,9 +47,9 @@ test("certificate display names prefer the common name", () => {
 
 test("UI plugins produce attributed evidence and a local Boolean verdict", async () => {
   const plugins = [
-    createFirefoxValidationPlugin(),
+    configure(createFirefoxValidationPlugin(), "advisor"),
-    createVillageCommunityPlugin(),
+    configure(createVillageCommunityPlugin(), "advisor"),
-    createUserDecisionPlugin(true),
+    configure(createUserDecisionPlugin(true), "decision-authority"),
   ];
   const result = await new TrustRunner({ plugins }).evaluate(unknownLocalAuthority);
 
@@ -63,18 +63,18 @@ test("UI plugins produce attributed evidence and a local Boolean verdict", async
 
 test("conflicting community advice remains visible without becoming a verdict", async () => {
   const plugins = [
-    createCommunityAdvicePlugin({
+    configure(createCommunityAdvicePlugin({
       id: "community.yes",
       name: "Community Yes",
       trusted: true,
       message: "Known key",
-    }),
+    }), "advisor"),
-    createCommunityAdvicePlugin({
+    configure(createCommunityAdvicePlugin({
       id: "community.no",
       name: "Community No",
       trusted: false,
       message: "Unexpected change",
-    }),
+    }), "advisor"),
   ];
   const result = await new TrustRunner({ plugins }).evaluate(unknownLocalAuthority);
 
@@ -86,6 +86,10 @@ test("conflicting community advice remains visible without becoming a verdict",
   assert.ok(result.journal.entries.every((entry) => entry.kind === "vote"));
 });
 
+function configure(plugin, mode) {
+  return { plugin, mode };
+}
+
 test("security surface contains immutable-frame and simulation labels", async () => {
   const html = await readFile(new URL("../ui/index.html", import.meta.url), "utf8");
   assert.match(html, /Browsec security decision/);

trustlab/tsconfig.json

@@ -0,0 +1,22 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "strict": true,
+    "exactOptionalPropertyTypes": true,
+    "noUncheckedIndexedAccess": true,
+    "noImplicitOverride": true,
+    "noFallthroughCasesInSwitch": true,
+    "noEmitOnError": true,
+    "declaration": true,
+    "declarationMap": true,
+    "outDir": "dist",
+    "rootDir": ".",
+    "skipLibCheck": true
+  },
+  "include": [
+    "sdk/**/*.ts",
+    "examples/**/*.ts"
+  ]
+}

trustlab/ui/app.js

@@ -40,18 +40,18 @@ const scenarios = {
     label: "Conflicting community advice",
     facts: conflictingCommunityAdvice,
     plugins: [
-      createCommunityAdvicePlugin({
+      configure(createCommunityAdvicePlugin({
         id: "community.archivists",
         name: "Regional archivists",
         trusted: true,
         message: "The archivists recognize this exact certificate and recommend trust.",
-      }),
+      }), "advisor"),
-      createCommunityAdvicePlugin({
+      configure(createCommunityAdvicePlugin({
         id: "community.network-watch",
         name: "Independent network watch",
         trusted: false,
         message: "The network observers report an unexpected certificate change.",
-      }),
+      }), "advisor"),
     ],
   },
 };
@@ -105,14 +105,16 @@ elements.clear.addEventListener("click", () => {
 
 async function render() {
   const facts = scenarios[state.scenario].facts;
-  const plugins = [createFirefoxValidationPlugin()];
+  const plugins = [configure(createFirefoxValidationPlugin(), "advisor")];
   if (state.communityEnabled) {
     plugins.push(
-      ...(scenarios[state.scenario].plugins ?? [createVillageCommunityPlugin()]),
+      ...(scenarios[state.scenario].plugins ?? [
+        configure(createVillageCommunityPlugin(), "advisor"),
+      ]),
     );
   }
   const userPlugin = createUserDecisionPlugin(state.userDecision);
-  if (userPlugin) plugins.push(userPlugin);
+  if (userPlugin) plugins.push(configure(userPlugin, "decision-authority"));
 
   const result = await new TrustRunner({ plugins }).evaluate(facts);
   renderStatus(result);
@@ -197,4 +199,8 @@ function formatCode(value = "") {
   return value.replaceAll("-", " ");
 }
 
+function configure(plugin, mode) {
+  return { plugin, mode };
+}
+
 render();