feat: move step-ca into a plugin (C4)

plugins/step-ca/tests/backend/client.test.ts

@@ -0,0 +1,136 @@
+import crypto from "node:crypto";
+import { describe, expect, it } from "vitest";
+import {
+  buildAuthorizationUrl,
+  certificateFingerprint,
+  createPkce,
+  decodeJwtClaims,
+  fetchRootCertificate,
+  findOidcProvisioner,
+  generateSshKeyPair,
+  normalizeCaUrl,
+  normalizeFingerprint,
+  parseSshCertificate,
+} from "../../src/backend/client.js";
+import { parseHostList } from "../../src/backend/auth-session.js";
+import { CA_URL, createFakeCa, createSshCa, fakeRoot } from "./fake-ca.js";
+
+describe("step-ca client helpers", () => {
+  it("normalizes the CA url and fingerprint the way step does", () => {
+    expect(normalizeCaUrl(" https://ca.internal:9000/ ")).toBe(
+      "https://ca.internal:9000",
+    );
+    expect(() => normalizeCaUrl("http://ca.internal")).toThrow(/https/);
+    const fp = "AB:cd".repeat(16).replace(/:/g, "");
+    expect(normalizeFingerprint("AB:cd".repeat(16))).toBe(fp.toLowerCase());
+    expect(() => normalizeFingerprint("abcd")).toThrow(/SHA-256/);
+  });
+
+  it("fingerprints a PEM certificate by the sha256 of its DER", () => {
+    const root = fakeRoot();
+    expect(certificateFingerprint(root.pem)).toBe(root.fingerprint);
+  });
+
+  it("builds a PKCE authorization request", () => {
+    const { verifier, challenge } = createPkce();
+    expect(challenge).toBe(
+      crypto.createHash("sha256").update(verifier).digest("base64url"),
+    );
+    const url = new URL(
+      buildAuthorizationUrl({
+        authorizationEndpoint: "https://idp.example/auth?tenant=x",
+        clientId: "cid",
+        redirectUri: "https://termix.example/callback",
+        state: "s",
+        nonce: "n",
+        codeChallenge: challenge,
+      }),
+    );
+    expect(url.searchParams.get("tenant")).toBe("x");
+    expect(url.searchParams.get("response_type")).toBe("code");
+    expect(url.searchParams.get("code_challenge_method")).toBe("S256");
+    expect(url.searchParams.get("scope")).toContain("openid");
+  });
+
+  it("generates an ed25519 key a CA can certify, and reads the cert back", () => {
+    const { publicKeyLine, privateKeyPem } = generateSshKeyPair();
+    expect(publicKeyLine).toMatch(/^ssh-ed25519 [A-Za-z0-9+/=]+$/);
+    expect(privateKeyPem).toContain("BEGIN PRIVATE KEY");
+
+    const cert = createSshCa().sign({
+      publicKeyBlob: publicKeyLine.split(" ")[1],
+      keyId: "alice@example",
+      principals: ["alice", "ops"],
+      validAfter: 1_700_000_000,
+      validBefore: 1_700_057_600,
+    });
+    const info = parseSshCertificate(cert);
+    expect(info).toMatchObject({
+      keyType: "ssh-ed25519-cert-v01@openssh.com",
+      publicKeyLine,
+      keyId: "alice@example",
+      principals: ["alice", "ops"],
+    });
+    expect(info.validAfter.toISOString()).toBe("2023-11-14T22:13:20.000Z");
+    expect(info.validBefore.getTime() - info.validAfter.getTime()).toBe(
+      16 * 3600 * 1000,
+    );
+    expect(() => parseSshCertificate(publicKeyLine)).toThrow(/certificate/);
+    expect(() =>
+      parseSshCertificate("ssh-ed25519-cert-v01@openssh.com AAAA"),
+    ).toThrow(/certificate/);
+  });
+
+  it("reads the private endpoint list with commas or new lines", () => {
+    expect(parseHostList("ca.internal, SSO.internal\nidp.lan")).toEqual([
+      "ca.internal",
+      "sso.internal",
+      "idp.lan",
+    ]);
+    expect(parseHostList(undefined)).toEqual([]);
+  });
+});
+
+describe("talking to the CA", () => {
+  it("refuses a root whose fingerprint does not match", async () => {
+    const ca = createFakeCa({ nonce: () => "" });
+    await expect(
+      fetchRootCertificate({
+        fetch: ca.fetch,
+        caUrl: CA_URL,
+        fingerprint: "b".repeat(64),
+        allowedPrivateHosts: [],
+      }),
+    ).rejects.toThrow();
+  });
+
+  it("finds the OIDC provisioner by name and passes the private hosts", async () => {
+    const ca = createFakeCa({ nonce: () => "" });
+    const target = {
+      fetch: ca.fetch,
+      caUrl: CA_URL,
+      fingerprint: ca.root.fingerprint,
+      allowedPrivateHosts: ["ca.test"],
+    };
+    const root = await fetchRootCertificate(target);
+    const provisioner = await findOidcProvisioner(target, root, "oidc");
+    expect(provisioner.clientID).toBe("termix");
+    expect(ca.calls.every((call) => call.init?.allowPrivateHosts)).toBe(true);
+    await expect(findOidcProvisioner(target, root, "jwk")).rejects.toThrow(
+      /not found/,
+    );
+  });
+});
+
+describe("decodeJwtClaims", () => {
+  it("reads the payload without verifying and tolerates junk", () => {
+    const payload = Buffer.from(
+      JSON.stringify({ email: "a@b.c", nonce: "n1" }),
+    ).toString("base64url");
+    expect(decodeJwtClaims(`x.${payload}.y`)).toEqual({
+      email: "a@b.c",
+      nonce: "n1",
+    });
+    expect(decodeJwtClaims("not-a-jwt")).toEqual({});
+  });
+});

plugins/step-ca/tests/backend/fake-ca.ts

@@ -0,0 +1,160 @@
+import crypto from "node:crypto";
+import type { PluginFetchInit } from "@termix/plugin-sdk/backend";
+
+const CERT_TYPE = "ssh-ed25519-cert-v01@openssh.com";
+
+function sshString(value: Buffer | string): Buffer {
+  const data = Buffer.isBuffer(value) ? value : Buffer.from(value, "utf8");
+  const len = Buffer.alloc(4);
+  len.writeUInt32BE(data.length, 0);
+  return Buffer.concat([len, data]);
+}
+
+function uint64(value: bigint): Buffer {
+  const out = Buffer.alloc(8);
+  out.writeBigUInt64BE(value, 0);
+  return out;
+}
+
+function uint32(value: number): Buffer {
+  const out = Buffer.alloc(4);
+  out.writeUInt32BE(value, 0);
+  return out;
+}
+
+/** An ed25519 CA that signs OpenSSH user certificates, like step-ca does. */
+export function createSshCa() {
+  const { publicKey, privateKey } = crypto.generateKeyPairSync("ed25519");
+  const raw = Buffer.from(
+    (publicKey.export({ format: "jwk" }) as { x: string }).x,
+    "base64url",
+  );
+  const caBlob = Buffer.concat([sshString("ssh-ed25519"), sshString(raw)]);
+
+  return {
+    sign(input: {
+      publicKeyBlob: string;
+      keyId: string;
+      principals: string[];
+      validAfter: number;
+      validBefore: number;
+    }): string {
+      const userBlob = Buffer.from(input.publicKeyBlob, "base64");
+      // ssh-ed25519 blob: string type, string pk
+      const pk = userBlob.subarray(4 + 11 + 4);
+      const body = Buffer.concat([
+        sshString(CERT_TYPE),
+        sshString(crypto.randomBytes(32)),
+        sshString(pk),
+        uint64(1n),
+        uint32(1),
+        sshString(input.keyId),
+        sshString(Buffer.concat(input.principals.map((p) => sshString(p)))),
+        uint64(BigInt(input.validAfter)),
+        uint64(BigInt(input.validBefore)),
+        sshString(Buffer.alloc(0)),
+        sshString(Buffer.alloc(0)),
+        sshString(Buffer.alloc(0)),
+        sshString(caBlob),
+      ]);
+      const signature = Buffer.concat([
+        sshString("ssh-ed25519"),
+        sshString(crypto.sign(null, body, privateKey)),
+      ]);
+      return `${CERT_TYPE} ${Buffer.concat([body, sshString(signature)]).toString("base64")}`;
+    },
+  };
+}
+
+/** A root "certificate" the client fingerprints by the sha256 of its DER. */
+export function fakeRoot() {
+  const der = crypto.randomBytes(128);
+  return {
+    pem: `-----BEGIN CERTIFICATE-----\n${der.toString("base64")}\n-----END CERTIFICATE-----\n`,
+    fingerprint: crypto.createHash("sha256").update(der).digest("hex"),
+  };
+}
+
+export function jwt(claims: Record<string, unknown>): string {
+  const part = (value: object) =>
+    Buffer.from(JSON.stringify(value)).toString("base64url");
+  return `${part({ alg: "none" })}.${part(claims)}.sig`;
+}
+
+export const CA_URL = "https://ca.test";
+export const DISCOVERY_URL =
+  "https://idp.test/.well-known/openid-configuration";
+
+export interface FakeCaOptions {
+  /** Principals the CA puts on the certificate; defaults to what was asked. */
+  principals?: string[];
+  /** Nonce the identity provider puts in the id token. */
+  nonce: () => string;
+  /** Status for /1.0/ssh/sign. */
+  signStatus?: number;
+}
+
+/**
+ * Answers ctx.fetch as a step-ca server plus its identity provider would.
+ * Records every call so a test can check the TLS options.
+ */
+export function createFakeCa(options: FakeCaOptions) {
+  const root = fakeRoot();
+  const ca = createSshCa();
+  const calls: Array<{ url: string; init?: PluginFetchInit }> = [];
+  const json = (body: unknown, status = 200) =>
+    new Response(JSON.stringify(body), {
+      status,
+      headers: { "content-type": "application/json" },
+    });
+
+  const fetch = async (url: string, init?: PluginFetchInit) => {
+    calls.push({ url, init });
+    if (url === `${CA_URL}/root/${root.fingerprint}`) {
+      return json({ ca: root.pem });
+    }
+    if (url.startsWith(`${CA_URL}/provisioners`)) {
+      return json({
+        provisioners: [
+          { name: "jwk", type: "JWK" },
+          {
+            name: "oidc",
+            type: "OIDC",
+            clientID: "termix",
+            configurationEndpoint: DISCOVERY_URL,
+          },
+        ],
+      });
+    }
+    if (url === DISCOVERY_URL) {
+      return json({
+        authorization_endpoint: "https://idp.test/authorize",
+        token_endpoint: "https://idp.test/token",
+      });
+    }
+    if (url === "https://idp.test/token") {
+      return json({
+        id_token: jwt({ email: "alice@example.com", nonce: options.nonce() }),
+      });
+    }
+    if (url === `${CA_URL}/1.0/ssh/sign`) {
+      if (options.signStatus && options.signStatus !== 200) {
+        return json({ message: "not allowed" }, options.signStatus);
+      }
+      const body = JSON.parse(init?.body ?? "{}");
+      const now = Math.floor(Date.now() / 1000);
+      return json({
+        crt: ca.sign({
+          publicKeyBlob: body.publicKey,
+          keyId: body.keyID,
+          principals: options.principals ?? body.principals,
+          validAfter: now - 60,
+          validBefore: now + 16 * 3600,
+        }),
+      });
+    }
+    return new Response("not found", { status: 404 });
+  };
+
+  return { fetch, calls, root, ca };
+}

plugins/step-ca/tests/backend/helpers.ts

@@ -0,0 +1,105 @@
+import http from "node:http";
+import type { AddressInfo } from "node:net";
+import { fileURLToPath } from "node:url";
+import express, { type Router } from "express";
+import {
+  createMockCtx,
+  createTestDb,
+  type MockPluginContext,
+  type TestDb,
+} from "@termix/plugin-sdk/testing";
+import type {
+  PluginFetchInit,
+  PluginSshAuthProvider,
+} from "@termix/plugin-sdk/backend";
+import type { PluginManifest } from "@termix/plugin-sdk/manifest";
+import manifestJson from "../../manifest.json";
+
+export const pluginDir = fileURLToPath(new URL("../..", import.meta.url));
+export const manifest = manifestJson as unknown as PluginManifest;
+
+/** A fake terminal socket that records what it was sent. */
+export function fakeSocket() {
+  const sent: Array<Record<string, unknown>> = [];
+  const closers: Array<() => void> = [];
+  return {
+    sent,
+    socket: {
+      send: (data: string) => sent.push(JSON.parse(data)),
+      on: (_event: "close", listener: () => void) => closers.push(listener),
+    },
+    close: () => closers.forEach((listener) => listener()),
+  };
+}
+
+export interface TestServer {
+  db: TestDb;
+  mock: MockPluginContext;
+  provider: () => PluginSshAuthProvider;
+  get: (path: string) => Promise<{ status: number; body: string }>;
+  close: () => Promise<void>;
+}
+
+export async function startServer(
+  options: {
+    settings?: Record<string, unknown>;
+    fetch?: (url: string, init?: PluginFetchInit) => Promise<Response>;
+  } = {},
+): Promise<TestServer> {
+  const db = await createTestDb(pluginDir);
+  db.sqlite
+    .prepare("INSERT OR IGNORE INTO users (id) VALUES (?)")
+    .run("user-1");
+  db.sqlite.prepare("INSERT OR IGNORE INTO ssh_data (id) VALUES (?)").run(7);
+
+  let router: Router | null = null;
+  const mock = createMockCtx({
+    pluginId: manifest.id,
+    manifest,
+    capabilities: manifest.capabilities,
+    db: db.database,
+    router: () => (router = express.Router()),
+    settings: options.settings,
+    fetch: options.fetch,
+    baseUrl: "https://termix.test",
+  });
+
+  const { activate } = await import("../../src/backend/index.js");
+  await activate(mock.ctx);
+
+  const app = express();
+  app.use((req, res, next) => router!(req, res, next));
+  const server = http.createServer(app);
+  await new Promise<void>((resolve) => server.listen(0, resolve));
+  const { port } = server.address() as AddressInfo;
+
+  return {
+    db,
+    mock,
+    provider: () =>
+      mock.auth.sshAuthProviders.find(
+        (provider) => provider.type === "stepca",
+      )!,
+    async get(path) {
+      const response = await fetch(`http://127.0.0.1:${port}${path}`, {
+        redirect: "manual",
+      });
+      return { status: response.status, body: await response.text() };
+    },
+    async close() {
+      await new Promise<void>((resolve) => server.close(() => resolve()));
+      db.close();
+    },
+  };
+}
+
+export const env = (hostId = 7) => ({
+  client: {},
+  userId: "user-1",
+  hostId,
+  purpose: "terminal",
+  interactive: true,
+  log: () => {},
+});
+
+export const HOST = { id: 7, ip: "10.0.0.7", port: 22, username: "root" };

plugins/step-ca/tests/backend/step-ca.test.ts

@@ -0,0 +1,295 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { PluginCapabilityError } from "@termix/plugin-sdk/backend";
+import { createMockCtx, createTestDb } from "@termix/plugin-sdk/testing";
+import { CA_URL, createFakeCa } from "./fake-ca.js";
+import {
+  HOST,
+  env,
+  fakeSocket,
+  manifest,
+  pluginDir,
+  startServer,
+  type TestServer,
+} from "./helpers.js";
+
+const certs = vi.hoisted(() => ({ applyCertificateAuth: vi.fn() }));
+vi.mock("@termix/plugin-sdk/ssh-certs", () => certs);
+
+let server: TestServer | null = null;
+let nonce = "";
+
+beforeEach(() => {
+  certs.applyCertificateAuth.mockReset();
+  nonce = "";
+});
+
+afterEach(async () => {
+  await server?.close();
+  server = null;
+});
+
+async function startWithCa(
+  options: {
+    principals?: string[];
+    signStatus?: number;
+    wrongNonce?: boolean;
+    settings?: Record<string, unknown>;
+  } = {},
+) {
+  const ca = createFakeCa({
+    principals: options.principals,
+    signStatus: options.signStatus,
+    nonce: () => (options.wrongNonce ? "other" : nonce),
+  });
+  server = await startServer({
+    fetch: ca.fetch,
+    settings: {
+      caUrl: CA_URL,
+      fingerprint: ca.root.fingerprint,
+      provisioner: "oidc",
+      ...options.settings,
+    },
+  });
+  return ca;
+}
+
+/** Starts a sign-in and returns the socket and the authorization URL. */
+async function startSignIn() {
+  const socket = fakeSocket();
+  await server!.provider().startInteraction!({
+    userId: "user-1",
+    hostId: 7,
+    host: { name: "box", ip: "10.0.0.7", username: "root" },
+    socket: socket.socket,
+    requestOrigin: "https://termix.test",
+    payload: {},
+  });
+  const chooser = socket.sent.find((m) => m.stage === "chooser");
+  const url = chooser ? new URL(String(chooser.url)) : null;
+  nonce = url?.searchParams.get("nonce") ?? "";
+  return { socket, url, state: url?.searchParams.get("state") ?? "" };
+}
+
+describe("the certs table", () => {
+  it("is created on a fresh install", async () => {
+    const db = await createTestDb(pluginDir);
+    expect(
+      db.sqlite
+        .prepare(
+          "SELECT name FROM sqlite_master WHERE name = 'p_step_ca_certs'",
+        )
+        .get(),
+    ).toBeTruthy();
+    db.close();
+  });
+});
+
+describe("activate", () => {
+  it("registers the stepca auth type and its callback route", async () => {
+    server = await startServer();
+    expect(server.provider()).toMatchObject({
+      type: "stepca",
+      interaction: "stepca",
+      supportsBackground: false,
+    });
+    expect(server.mock.httpRouters).toHaveLength(1);
+  });
+
+  it.each(["db:own", "auth:provide", "network:serve"])(
+    "fails closed without %s",
+    async (capability) => {
+      const mock = createMockCtx({
+        pluginId: manifest.id,
+        manifest,
+        capabilities: manifest.capabilities.filter((c) => c !== capability),
+        db: (await createTestDb(pluginDir)).database,
+      });
+      const { activate } = await import("../../src/backend/index.js");
+      await expect(activate(mock.ctx)).rejects.toThrow(PluginCapabilityError);
+    },
+  );
+});
+
+describe("issuing a certificate", () => {
+  it("runs the OIDC flow against the CA and stores the certificate sealed", async () => {
+    const ca = await startWithCa();
+    const { socket, url, state } = await startSignIn();
+
+    expect(url?.origin + url?.pathname).toBe("https://idp.test/authorize");
+    expect(url?.searchParams.get("client_id")).toBe("termix");
+    expect(url?.searchParams.get("redirect_uri")).toBe(
+      "https://termix.test/plugin-api/step-ca/callback",
+    );
+    expect(url?.searchParams.get("code_challenge_method")).toBe("S256");
+
+    // The root is fetched unverified and checked by fingerprint, then pinned.
+    expect(ca.calls[0].init?.tls).toEqual({ rejectUnauthorized: false });
+    expect(ca.calls[1].init?.tls).toEqual({ ca: ca.root.pem });
+
+    const response = await server!.get(`/callback?state=${state}&code=abc`);
+    expect(response.status).toBe(200);
+    expect(response.body).toContain("Signed in");
+    expect(socket.sent.at(-1)).toMatchObject({
+      type: "stepca_completed",
+      requestId: state,
+    });
+
+    const sign = ca.calls.find((call) => call.url.endsWith("/1.0/ssh/sign"));
+    expect(JSON.parse(sign!.init!.body!)).toMatchObject({
+      certType: "user",
+      principals: ["root"],
+      keyID: "alice@example.com",
+    });
+    expect(sign!.init!.tls).toEqual({ ca: ca.root.pem });
+
+    const row = server!.db.sqlite
+      .prepare("SELECT * FROM p_step_ca_certs")
+      .get() as Record<string, string>;
+    expect(row.user_id).toBe("user-1");
+    expect(row.email).toBe("alice@example.com");
+    expect(row.ssh_cert).toMatch(/^sealed:/);
+    expect(row.private_key).toMatch(/^sealed:/);
+  });
+
+  it("answers a second use of the same callback with an error", async () => {
+    await startWithCa();
+    const { state } = await startSignIn();
+    await server!.get(`/callback?state=${state}&code=abc`);
+    const again = await server!.get(`/callback?state=${state}&code=abc`);
+    expect(again.status).toBe(400);
+    expect(again.body).toContain("no longer active");
+  });
+
+  it("refuses an id token issued for another sign-in", async () => {
+    await startWithCa({ wrongNonce: true });
+    const { socket, state } = await startSignIn();
+    const response = await server!.get(`/callback?state=${state}&code=abc`);
+    expect(response.status).toBe(400);
+    expect(socket.sent.at(-1)).toMatchObject({
+      type: "stepca_error",
+      error: expect.stringContaining("does not match"),
+    });
+    expect(
+      server!.db.sqlite.prepare("SELECT * FROM p_step_ca_certs").all(),
+    ).toHaveLength(0);
+  });
+
+  it("reports the CA refusing to sign", async () => {
+    await startWithCa({ signStatus: 403 });
+    const { socket, state } = await startSignIn();
+    await server!.get(`/callback?state=${state}&code=abc`);
+    expect(socket.sent.at(-1)).toMatchObject({
+      type: "stepca_error",
+      error: expect.stringContaining("HTTP 403"),
+    });
+  });
+
+  it("rejects a certificate without the host username", async () => {
+    await startWithCa({ principals: ["someone-else"] });
+    const { socket, state } = await startSignIn();
+    await server!.get(`/callback?state=${state}&code=abc`);
+    expect(socket.sent.at(-1)).toMatchObject({
+      type: "stepca_error",
+      error: expect.stringContaining("host username"),
+    });
+  });
+
+  it("passes an identity provider error through", async () => {
+    await startWithCa();
+    const { socket, state } = await startSignIn();
+    const response = await server!.get(
+      `/callback?state=${state}&error=access_denied&error_description=Denied`,
+    );
+    expect(response.status).toBe(400);
+    expect(socket.sent.at(-1)).toMatchObject({
+      type: "stepca_error",
+      error: "Step CA: Denied",
+    });
+  });
+
+  it("sends the 2.8 redirect URI while legacyCallback is on", async () => {
+    await startWithCa({ settings: { legacyCallback: true } });
+    const { url } = await startSignIn();
+    expect(url?.searchParams.get("redirect_uri")).toBe(
+      "https://termix.test/host/step-ca-callback",
+    );
+  });
+
+  it("tells the terminal when Step CA is not configured", async () => {
+    server = await startServer();
+    const { socket } = await startSignIn();
+    expect(socket.sent).toEqual([
+      expect.objectContaining({ type: "stepca_config_error" }),
+    ]);
+  });
+
+  it("lets a pending sign-in be cancelled", async () => {
+    await startWithCa();
+    const { state } = await startSignIn();
+    await server!.provider().cancelInteraction!({
+      userId: "user-1",
+      requestId: state,
+    });
+    const response = await server!.get(`/callback?state=${state}&code=abc`);
+    expect(response.status).toBe(400);
+  });
+});
+
+describe("the stepca provider", () => {
+  it("asks for a sign-in without a certificate", async () => {
+    server = await startServer();
+    const outcome = await server.provider().prepare({}, HOST, env());
+    expect(outcome).toMatchObject({
+      status: "interaction-required",
+      interaction: "stepca",
+    });
+    expect(certs.applyCertificateAuth).not.toHaveBeenCalled();
+  });
+
+  it("connects with the issued certificate", async () => {
+    await startWithCa();
+    const { state } = await startSignIn();
+    await server!.get(`/callback?state=${state}&code=abc`);
+
+    const config: Record<string, unknown> = {};
+    const outcome = await server!.provider().prepare(config, HOST, env());
+    expect(outcome).toEqual({ status: "ready" });
+    const [passedConfig, , credentials, username] =
+      certs.applyCertificateAuth.mock.calls[0];
+    expect(passedConfig).toBe(config);
+    expect(username).toBe("root");
+    expect(credentials.certificate).toMatch(
+      /^ssh-ed25519-cert-v01@openssh\.com /,
+    );
+    expect(credentials.privateKey).toContain("BEGIN PRIVATE KEY");
+  });
+
+  it("forgets an expired certificate", async () => {
+    await startWithCa();
+    const { state } = await startSignIn();
+    await server!.get(`/callback?state=${state}&code=abc`);
+    server!.db.sqlite
+      .prepare("UPDATE p_step_ca_certs SET expires_at = ?")
+      .run("2000-01-01T00:00:00.000Z");
+    const outcome = await server!.provider().prepare({}, HOST, env());
+    expect(outcome.status).toBe("interaction-required");
+    expect(
+      server!.db.sqlite.prepare("SELECT * FROM p_step_ca_certs").all(),
+    ).toHaveLength(0);
+  });
+
+  it("drops the certificate when the host rejects it", async () => {
+    await startWithCa();
+    const { state } = await startSignIn();
+    await server!.get(`/callback?state=${state}&code=abc`);
+    const decision = server!.provider().onAuthFailed!(HOST, env(), {
+      error: new Error("All configured authentication methods failed"),
+    } as never);
+    expect(decision).toMatchObject({ status: "interaction-required" });
+    await vi.waitFor(() =>
+      expect(
+        server!.db.sqlite.prepare("SELECT * FROM p_step_ca_certs").all(),
+      ).toHaveLength(0),
+    );
+  });
+});

plugins/step-ca/tests/frontend/activate.test.tsx

@@ -0,0 +1,137 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { act, fireEvent, render, screen } from "@testing-library/react";
+import {
+  renderWithApp,
+  type RenderedPluginApp,
+} from "@termix/plugin-sdk/testing";
+import type { PluginManifest } from "@termix/plugin-sdk/manifest";
+import * as plugin from "../../src/frontend/index";
+import { StepCaOverlay } from "../../src/frontend/StepCaOverlay";
+import { redirectUri } from "../../src/frontend/RedirectUriSetting";
+import manifestJson from "../../manifest.json";
+import locales from "../../locales/en.json";
+
+vi.mock("@termix/plugin-sdk/frontend", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("@termix/plugin-sdk/frontend")>()),
+  useTranslation: () => ({ t: (key: string) => key }),
+}));
+
+const manifest = manifestJson as unknown as PluginManifest;
+
+let rendered: RenderedPluginApp | null = null;
+
+afterEach(async () => {
+  await rendered?.deactivate();
+  rendered = null;
+});
+
+describe("step-ca activate", () => {
+  it("registers the auth editor, the terminal overlay and the settings field", async () => {
+    rendered = await renderWithApp(plugin, { manifest, locales });
+    expect(rendered.registered.settingsComponents()).toEqual(["redirectUri"]);
+    expect(rendered.registered.slot("terminal.overlay")).toEqual([
+      "step-ca.signIn",
+    ]);
+    await rendered.deactivate();
+    expect(rendered.registered.settingsComponents()).toEqual([]);
+    expect(rendered.registered.slot("terminal.overlay")).toEqual([]);
+    rendered = null;
+  });
+});
+
+describe("redirectUri", () => {
+  it("names the plugin callback, or the 2.8 one", () => {
+    expect(redirectUri(false, "https://t.example/app/")).toBe(
+      "https://t.example/app/plugin-api/step-ca/callback",
+    );
+    expect(redirectUri(true, "https://t.example/")).toBe(
+      "https://t.example/host/step-ca-callback",
+    );
+  });
+});
+
+describe("StepCaOverlay", () => {
+  function setup() {
+    let listener: (message: {
+      type: string;
+      [key: string]: unknown;
+    }) => void = () => {};
+    const props = {
+      host: { id: 7 },
+      subscribe: vi.fn((next: typeof listener) => {
+        listener = next;
+        return () => {};
+      }),
+      holdConnectTimeout: vi.fn(),
+      fail: vi.fn(),
+      disconnect: vi.fn(),
+      send: vi.fn(),
+      connectPayload: vi.fn(() => ({ hostId: 7, cols: 80, rows: 24 })),
+    };
+    render(<StepCaOverlay {...props} />);
+    const emit = (message: { type: string; [key: string]: unknown }) =>
+      act(() => listener(message));
+    return { props, emit };
+  }
+
+  it("starts the sign-in once, then reports a second request as a failure", () => {
+    const { props, emit } = setup();
+    emit({ type: "stepca_auth_required", hostId: 7 });
+    expect(props.send).toHaveBeenCalledWith("stepca_start_auth", { hostId: 7 });
+    expect(props.holdConnectTimeout).toHaveBeenCalledWith(true);
+
+    emit({ type: "stepca_auth_required", hostId: 7 });
+    expect(props.fail).toHaveBeenCalledWith("errors.authFailed");
+  });
+
+  it("opens the identity provider, waits, and reconnects once signed in", () => {
+    const open = vi.spyOn(window, "open").mockReturnValue(null);
+    const { props, emit } = setup();
+    emit({ type: "stepca_auth_required", hostId: 7 });
+    emit({
+      type: "stepca_status",
+      stage: "chooser",
+      requestId: "req-1",
+      url: "https://idp.test/authorize?state=req-1",
+    });
+    fireEvent.click(screen.getByText("dialog.openBrowser"));
+    expect(open).toHaveBeenCalledWith(
+      "https://idp.test/authorize?state=req-1",
+      "_blank",
+    );
+    expect(screen.getByText("dialog.waiting")).toBeTruthy();
+
+    emit({ type: "stepca_completed", requestId: "req-1" });
+    expect(props.send).toHaveBeenCalledWith("stepca_auth_completed", {
+      hostId: 7,
+      cols: 80,
+      rows: 24,
+    });
+    expect(screen.queryByText("dialog.title")).toBeNull();
+    open.mockRestore();
+  });
+
+  it("cancels a pending sign-in", () => {
+    const { props, emit } = setup();
+    emit({
+      type: "stepca_status",
+      stage: "chooser",
+      requestId: "req-2",
+      url: "https://idp.test/authorize",
+    });
+    fireEvent.click(screen.getByText("common.cancel"));
+    expect(props.send).toHaveBeenCalledWith("stepca_cancel", {
+      requestId: "req-2",
+    });
+  });
+
+  it("shows a config error", () => {
+    const { emit } = setup();
+    emit({
+      type: "stepca_config_error",
+      requestId: "",
+      error: "Step CA is not configured.",
+    });
+    expect(screen.getByText("Step CA is not configured.")).toBeTruthy();
+  });
+});