Introduce Kerberos authentication provider.

packages/kbn-es/src/cluster.js

@@ -258,6 +258,10 @@ exports.Cluster = class Cluster {
 
     this._process = execa(ES_BIN, args, {
       cwd: installPath,
+      env: {
+        ...process.env,
+        ...(options.esEnvVars || {}),
+      },
       stdio: ['ignore', 'pipe', 'pipe'],
     });
 

packages/kbn-test/src/es/es_test_cluster.js

@@ -62,7 +62,7 @@ export function createEsTestCluster(options = {}) {
       return esFrom === 'snapshot' ? 3 * minute : 6 * minute;
     }
 
-    async start(esArgs = []) {
+    async start(esArgs = [], esEnvVars) {
       let installPath;
 
       if (esFrom === 'source') {
@@ -87,6 +87,7 @@ export function createEsTestCluster(options = {}) {
           'discovery.type=single-node',
           ...esArgs,
         ],
+        esEnvVars,
       });
     }
 

packages/kbn-test/src/functional_tests/lib/run_elasticsearch.js

@@ -27,6 +27,7 @@ export async function runElasticsearch({ config, options }) {
   const { log, esFrom } = options;
   const license = config.get('esTestCluster.license');
   const esArgs = config.get('esTestCluster.serverArgs');
+  const esEnvVars = config.get('esTestCluster.serverEnvVars');
   const isSecurityEnabled = esArgs.includes('xpack.security.enabled=true');
 
   const cluster = createEsTestCluster({
@@ -41,7 +42,7 @@ export async function runElasticsearch({ config, options }) {
     dataArchive: config.get('esTestCluster.dataArchive'),
   });
 
-  await cluster.start(esArgs);
+  await cluster.start(esArgs, esEnvVars);
 
   if (isSecurityEnabled) {
     await setupUsers(log, config.get('servers.elasticsearch.port'), [

src/functional_test_runner/lib/config/schema.ts

@@ -166,6 +166,7 @@ export const schema = Joi.object()
         license: Joi.string().default('oss'),
         from: Joi.string().default('snapshot'),
         serverArgs: Joi.array(),
+        serverEnvVars: Joi.object(),
         dataArchive: Joi.string(),
       })
       .default(),

x-pack/plugins/security/server/lib/__tests__/auth_redirect.js

@@ -103,6 +103,31 @@ describe('lib/auth_redirect', function () {
     sinon.assert.notCalled(h.authenticated);
   });
 
+  it('includes `WWW-Authenticate` header if `authenticate` fails to authenticate user and provides challenges', async () => {
+    const originalEsError = Boom.unauthorized('some message');
+    originalEsError.output.headers['WWW-Authenticate'] = [
+      'Basic realm="Access to prod", charset="UTF-8"',
+      'Basic',
+      'Negotiate'
+    ];
+
+    server.plugins.security.authenticate.withArgs(request).resolves(
+      AuthenticationResult.failed(originalEsError, ['Negotiate'])
+    );
+
+    const response = await authenticate(request, h);
+
+    sinon.assert.calledWithExactly(
+      server.log,
+      ['info', 'authentication'],
+      'Authentication attempt failed: some message'
+    );
+    expect(response.message).to.eql(originalEsError.message);
+    expect(response.output.headers).to.eql({ 'WWW-Authenticate': ['Negotiate'] });
+    sinon.assert.notCalled(h.redirect);
+    sinon.assert.notCalled(h.authenticated);
+  });
+
   it('returns `unauthorized` when authentication can not be handled', async () => {
     server.plugins.security.authenticate.withArgs(request).returns(
       Promise.resolve(AuthenticationResult.notHandled())

x-pack/plugins/security/server/lib/auth_redirect.js

@@ -26,25 +26,38 @@ export function authenticateFactory(server) {
     let authenticationResult;
     try {
       authenticationResult = await server.plugins.security.authenticate(request);
-    } catch(err) {
+    } catch (err) {
       server.log(['error', 'authentication'], err);
       return wrapError(err);
     }
 
     if (authenticationResult.succeeded()) {
       return h.authenticated({ credentials: authenticationResult.user });
-    } else if (authenticationResult.redirected()) {
+    }
+
+    if (authenticationResult.redirected()) {
       // Some authentication mechanisms may require user to be redirected to another location to
       // initiate or complete authentication flow. It can be Kibana own login page for basic
       // authentication (username and password) or arbitrary external page managed by 3rd party
       // Identity Provider for SSO authentication mechanisms. Authentication provider is the one who
       // decides what location user should be redirected to.
       return h.redirect(authenticationResult.redirectURL).takeover();
-    } else if (authenticationResult.failed()) {
-      server.log(['info', 'authentication'], `Authentication attempt failed: ${authenticationResult.error.message}`);
-      return wrapError(authenticationResult.error);
-    } else {
-      return Boom.unauthorized();
     }
+
+    if (authenticationResult.failed()) {
+      server.log(
+        ['info', 'authentication'],
+        `Authentication attempt failed: ${authenticationResult.error.message}`
+      );
+
+      const error = wrapError(authenticationResult.error);
+      if (authenticationResult.challenges) {
+        error.output.headers['WWW-Authenticate'] = authenticationResult.challenges;
+      }
+
+      return error;
+    }
+
+    return Boom.unauthorized();
   };
 }

x-pack/plugins/security/server/lib/authentication/authentication_result.test.ts

@@ -4,6 +4,7 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
+import Boom from 'boom';
 import { AuthenticatedUser } from '../../../common/model';
 import { AuthenticationResult } from './authentication_result';
 
@@ -45,6 +46,28 @@ describe('AuthenticationResult', () => {
       expect(authenticationResult.state).toBeUndefined();
       expect(authenticationResult.redirectURL).toBeUndefined();
     });
+
+    it('can provide `challenges` for `401` errors', () => {
+      const failureReason = Boom.unauthorized();
+      const authenticationResult = AuthenticationResult.failed(failureReason, ['Negotiate']);
+
+      expect(authenticationResult.failed()).toBe(true);
+      expect(authenticationResult.notHandled()).toBe(false);
+      expect(authenticationResult.succeeded()).toBe(false);
+      expect(authenticationResult.redirected()).toBe(false);
+
+      expect(authenticationResult.challenges).toEqual(['Negotiate']);
+      expect(authenticationResult.error).toBe(failureReason);
+      expect(authenticationResult.user).toBeUndefined();
+      expect(authenticationResult.state).toBeUndefined();
+      expect(authenticationResult.redirectURL).toBeUndefined();
+    });
+
+    it('can not provide `challenges` for non-`401` errors', () => {
+      expect(() => AuthenticationResult.failed(Boom.badRequest(), ['Negotiate'])).toThrowError(
+        'Challenges can only be provided with `401 Unauthorized` errors.'
+      );
+    });
   });
 
   describe('succeeded', () => {

x-pack/plugins/security/server/lib/authentication/authentication_result.ts

@@ -8,6 +8,7 @@
  * Represents status that `AuthenticationResult` can be in.
  */
 import { AuthenticatedUser } from '../../../common/model';
+import { getErrorStatusCode } from '../errors';
 
 enum AuthenticationResultStatus {
   /**
@@ -40,6 +41,7 @@ enum AuthenticationResultStatus {
  */
 interface AuthenticationOptions {
   error?: Error;
+  challenges?: string[];
   redirectURL?: string;
   state?: unknown;
   user?: AuthenticatedUser;
@@ -73,13 +75,21 @@ export class AuthenticationResult {
   /**
    * Produces `AuthenticationResult` for the case when authentication fails.
    * @param error Error that occurred during authentication attempt.
+   * @param [challenges] Optional list of the challenges that will be returned to the user within
+   * `WWW-Authenticate` HTTP header. Multiple challenges will result in multiple headers (one per
+   * challenge) as it's better supported by the browsers than comma separated list within a single
+   * header. Challenges can only be set for errors with `401` error status.
    */
-  public static failed(error: Error) {
+  public static failed(error: Error, challenges?: string[]) {
     if (!error) {
       throw new Error('Error should be specified.');
     }
 
-    return new AuthenticationResult(AuthenticationResultStatus.Failed, { error });
+    if (challenges != null && getErrorStatusCode(error) !== 401) {
+      throw new Error('Challenges can only be provided with `401 Unauthorized` errors.');
+    }
+
+    return new AuthenticationResult(AuthenticationResultStatus.Failed, { error, challenges });
   }
 
   /**
@@ -117,6 +127,13 @@ export class AuthenticationResult {
     return this.options.error;
   }
 
+  /**
+   * Challenges that need to be sent to the user within `WWW-Authenticate` HTTP header.
+   */
+  public get challenges() {
+    return this.options.challenges;
+  }
+
   /**
    * URL that should be used to redirect user to complete authentication only available
    * for `redirected` result).

x-pack/plugins/security/server/lib/authentication/authenticator.ts

@@ -12,6 +12,8 @@ import {
   AuthenticationProviderOptions,
   BaseAuthenticationProvider,
   BasicAuthenticationProvider,
+  KerberosAuthenticationProvider,
+  RequestWithLoginAttempt,
   SAMLAuthenticationProvider,
   TokenAuthenticationProvider,
   OIDCAuthenticationProvider,
@@ -37,6 +39,7 @@ const providerMap = new Map<
   ) => BaseAuthenticationProvider
 >([
   ['basic', BasicAuthenticationProvider],
+  ['kerberos', KerberosAuthenticationProvider],
   ['saml', SAMLAuthenticationProvider],
   ['token', TokenAuthenticationProvider],
   ['oidc', OIDCAuthenticationProvider],
@@ -163,7 +166,7 @@ class Authenticator {
    * Performs request authentication using configured chain of authentication providers.
    * @param request Request instance.
    */
-  async authenticate(request: Legacy.Request) {
+  async authenticate(request: RequestWithLoginAttempt) {
     assertRequest(request);
 
     const isSystemApiRequest = this.server.plugins.kibana.systemApi.isSystemApiRequest(request);
@@ -227,7 +230,7 @@ class Authenticator {
    * Deauthenticates current request.
    * @param request Request instance.
    */
-  async deauthenticate(request: Legacy.Request) {
+  async deauthenticate(request: RequestWithLoginAttempt) {
     assertRequest(request);
 
     const sessionValue = await this.getSessionValue(request);
@@ -307,8 +310,10 @@ export async function initAuthenticator(server: Legacy.Server) {
     return loginAttempts.get(request);
   });
 
-  server.expose('authenticate', (request: Legacy.Request) => authenticator.authenticate(request));
-  server.expose('deauthenticate', (request: Legacy.Request) =>
+  server.expose('authenticate', (request: RequestWithLoginAttempt) =>
+    authenticator.authenticate(request)
+  );
+  server.expose('deauthenticate', (request: RequestWithLoginAttempt) =>
     authenticator.deauthenticate(request)
   );
   server.expose('registerAuthScopeGetter', (scopeExtender: ScopesGetter) =>

x-pack/plugins/security/server/lib/authentication/providers/base.ts

@@ -7,6 +7,14 @@
 import { Legacy } from 'kibana';
 import { AuthenticationResult } from '../authentication_result';
 import { DeauthenticationResult } from '../deauthentication_result';
+import { LoginAttempt } from '../login_attempt';
+
+/**
+ * Describes a request complemented with `loginAttempt` method.
+ */
+export interface RequestWithLoginAttempt extends Legacy.Request {
+  loginAttempt: () => LoginAttempt;
+}
 
 /**
  * Represents available provider options.
@@ -40,7 +48,10 @@ export abstract class BaseAuthenticationProvider {
    * @param request Request instance.
    * @param [state] Optional state object associated with the provider.
    */
-  abstract authenticate(request: Legacy.Request, state?: unknown): Promise<AuthenticationResult>;
+  abstract authenticate(
+    request: RequestWithLoginAttempt,
+    state?: unknown
+  ): Promise<AuthenticationResult>;
 
   /**
    * Invalidates user session associated with the request.

x-pack/plugins/security/server/lib/authentication/providers/basic.ts

@@ -10,8 +10,7 @@ import { Legacy } from 'kibana';
 import { canRedirectRequest } from '../../can_redirect_request';
 import { AuthenticationResult } from '../authentication_result';
 import { DeauthenticationResult } from '../deauthentication_result';
-import { LoginAttempt } from '../login_attempt';
-import { BaseAuthenticationProvider } from './base';
+import { BaseAuthenticationProvider, RequestWithLoginAttempt } from './base';
 
 /**
  * Utility class that knows how to decorate request with proper Basic authentication headers.
@@ -24,7 +23,7 @@ export class BasicCredentials {
    * @param username User name.
    * @param password User password.
    */
-  public static decorateRequest<T extends Legacy.Request>(
+  public static decorateRequest<T extends RequestWithLoginAttempt>(
     request: T,
     username: string,
     password: string
@@ -48,10 +47,6 @@ export class BasicCredentials {
   }
 }
 
-type RequestWithLoginAttempt = Legacy.Request & {
-  loginAttempt: () => LoginAttempt;
-};
-
 /**
  * The state supported by the provider.
  */
@@ -153,7 +148,7 @@ export class BasicAuthenticationProvider extends BaseAuthenticationProvider {
    * forward to Elasticsearch backend.
    * @param request Request instance.
    */
-  private async authenticateViaHeader(request: Legacy.Request) {
+  private async authenticateViaHeader(request: RequestWithLoginAttempt) {
     this.debug('Trying to authenticate via header.');
 
     const authorization = request.headers.authorization;
@@ -189,7 +184,10 @@ export class BasicAuthenticationProvider extends BaseAuthenticationProvider {
    * @param request Request instance.
    * @param state State value previously stored by the provider.
    */
-  private async authenticateViaState(request: Legacy.Request, { authorization }: ProviderState) {
+  private async authenticateViaState(
+    request: RequestWithLoginAttempt,
+    { authorization }: ProviderState
+  ) {
     this.debug('Trying to authenticate via state.');
 
     if (!authorization) {

x-pack/plugins/security/server/lib/authentication/providers/index.ts

@@ -4,8 +4,13 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-export { BaseAuthenticationProvider, AuthenticationProviderOptions } from './base';
+export {
+  BaseAuthenticationProvider,
+  AuthenticationProviderOptions,
+  RequestWithLoginAttempt,
+} from './base';
 export { BasicAuthenticationProvider, BasicCredentials } from './basic';
+export { KerberosAuthenticationProvider } from './kerberos';
 export { SAMLAuthenticationProvider } from './saml';
 export { TokenAuthenticationProvider } from './token';
 export { OIDCAuthenticationProvider } from './oidc';