Implement a generic OpenIdConnect auth-provider

2020-11-16 14:04:24 -08:00
parent 17f4d7deb2
commit 8d948b243b
15 changed files with 727 additions and 3 deletions
@@ -25,12 +25,15 @@
    "@backstage/catalog-model": "^0.2.0",
    "@backstage/config": "^0.1.1",
    "@types/express": "^4.17.6",
+    "@types/express-session": "^1.17.2",
+    "@types/openid-client": "^3.7.0",
    "compression": "^1.7.4",
    "cookie-parser": "^1.4.5",
    "cors": "^2.8.5",
    "cross-fetch": "^3.0.6",
    "express": "^4.17.1",
    "express-promise-router": "^3.0.3",
+    "express-session": "^1.17.1",
    "fs-extra": "^9.0.0",
    "got": "^11.5.2",
    "helmet": "^4.0.0",
@@ -39,6 +42,7 @@
    "knex": "^0.21.6",
    "moment": "^2.26.0",
    "morgan": "^1.10.0",
+    "openid-client": "^4.2.1",
    "passport": "^0.4.1",
    "passport-github2": "^0.1.12",
    "passport-gitlab2": "^5.0.0",
@@ -18,6 +18,7 @@ import { createGithubProvider } from './github';
 import { createGitlabProvider } from './gitlab';
 import { createGoogleProvider } from './google';
 import { createOAuth2Provider } from './oauth2';
+import { createOidcProvider } from './oidc';
 import { createOktaProvider } from './okta';
 import { createSamlProvider } from './saml';
 import { createAuth0Provider } from './auth0';
@@ -34,6 +35,7 @@ const factories: { [providerId: string]: AuthProviderFactory } = {
  auth0: createAuth0Provider,
  microsoft: createMicrosoftProvider,
  oauth2: createOAuth2Provider,
+  oidc: createOidcProvider,
  onelogin: createOneLoginProvider,
 };

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export { createOidcProvider } from './provider';
@@ -0,0 +1,216 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import express from 'express';
+import {
+  Issuer,
+  Client,
+  Strategy as OidcStrategy,
+  TokenSet,
+  UserinfoResponse,
+} from 'openid-client';
+import {
+  OAuthAdapter,
+  OAuthProviderOptions,
+  OAuthHandlers,
+  OAuthResponse,
+  OAuthEnvironmentHandler,
+  OAuthStartRequest,
+  encodeState,
+  OAuthRefreshRequest,
+} from '../../lib/oauth';
+import {
+  executeFetchUserProfileStrategy,
+  executeFrameHandlerStrategy,
+  executeRedirectStrategy,
+  executeRefreshTokenStrategy,
+  PassportDoneCallback,
+} from '../../lib/passport';
+import { RedirectInfo, AuthProviderFactory, ProfileInfo } from '../types';
+
+type PrivateInfo = {
+  refreshToken: string;
+};
+
+export type OidcAuthProviderOptions = OAuthProviderOptions & {
+  authorizationUrl: string;
+  tokenUrl: string;
+  adUrl: string;
+  tokenSignedResponseAlg?: string;
+};
+
+export class OidcAuthProvider implements OAuthHandlers {
+  private readonly _strategy: Promise<OidcStrategy<UserinfoResponse, Client>>;
+
+  constructor(options: OidcAuthProviderOptions) {
+    this._strategy = this.setupStrategy(options);
+  }
+
+  async start(req: OAuthStartRequest): Promise<RedirectInfo> {
+    const strategy = await this._strategy;
+    return await executeRedirectStrategy(req, strategy, {
+      accessType: 'offline',
+      prompt: 'consent',
+      scope: `${req.scope} default`,
+      state: encodeState(req.state),
+    });
+  }
+
+  async handler(
+    req: express.Request,
+  ): Promise<{ response: OAuthResponse; refreshToken: string }> {
+    const strategy = await this._strategy;
+    const { response, privateInfo } = await executeFrameHandlerStrategy<
+      OAuthResponse,
+      PrivateInfo
+    >(req, strategy);
+
+    return {
+      response: await this.populateIdentity(response),
+      refreshToken: privateInfo.refreshToken,
+    };
+  }
+
+  async refresh(req: OAuthRefreshRequest): Promise<OAuthResponse> {
+    const strategy = await this._strategy;
+    const refreshTokenResponse = await executeRefreshTokenStrategy(
+      strategy,
+      req.refreshToken,
+      req.scope,
+    );
+    const {
+      accessToken,
+      params,
+      refreshToken: updatedRefreshToken,
+    } = refreshTokenResponse;
+
+    const profile = await executeFetchUserProfileStrategy(
+      strategy,
+      accessToken,
+      params.id_token,
+    );
+
+    return this.populateIdentity({
+      providerInfo: {
+        accessToken,
+        refreshToken: updatedRefreshToken,
+        idToken: params.id_token,
+        expiresInSeconds: params.expires_in,
+        scope: params.scope,
+      },
+      profile,
+    });
+  }
+
+  private async setupStrategy(
+    options: OidcAuthProviderOptions,
+  ): Promise<OidcStrategy<UserinfoResponse, Client>> {
+    const issuer = await Issuer.discover(options.adUrl);
+    // console.log('Discovered issuer %s %O', issuer.issuer, issuer.metadata);
+    const client = new issuer.Client({
+      client_id: options.clientId,
+      client_secret: options.clientSecret,
+      redirect_uris: [options.callbackUrl],
+      response_types: ['code'],
+      id_token_signed_response_alg: options.tokenSignedResponseAlg || 'RS256',
+    });
+
+    const strategy = new OidcStrategy(
+      {
+        client,
+        passReqToCallback: false as true,
+      },
+      (
+        tokenset: TokenSet,
+        userinfo: UserinfoResponse,
+        done: PassportDoneCallback<OAuthResponse, PrivateInfo>,
+      ) => {
+        const profile: ProfileInfo = {
+          displayName: userinfo.name,
+          email: userinfo.email,
+          picture: userinfo.picture,
+        };
+
+        done(
+          undefined,
+          {
+            providerInfo: {
+              idToken: tokenset.id_token || '',
+              accessToken: tokenset.access_token || '',
+              scope: tokenset.scope || '',
+              expiresInSeconds: tokenset.expires_in,
+            },
+            profile,
+          },
+          {
+            refreshToken: tokenset.refresh_token || '',
+          },
+        );
+      },
+    );
+    strategy.error = console.error;
+    return strategy;
+  }
+
+  // Use this function to grab the user profile info from the token
+  // Then populate the profile with it
+  private async populateIdentity(
+    response: OAuthResponse,
+  ): Promise<OAuthResponse> {
+    const { profile } = response;
+
+    if (!profile.email) {
+      throw new Error('Profile does not contain an email');
+    }
+    const id = profile.email.split('@')[0];
+
+    return { ...response, backstageIdentity: { id } };
+  }
+}
+
+export const createOidcProvider: AuthProviderFactory = ({
+  globalConfig,
+  config,
+  tokenIssuer,
+}) =>
+  OAuthEnvironmentHandler.mapConfig(config, envConfig => {
+    const providerId = 'oidc';
+    const clientId = envConfig.getString('clientId');
+    const clientSecret = envConfig.getString('clientSecret');
+    const callbackUrl = `${globalConfig.baseUrl}/${providerId}/handler/frame`;
+    const authorizationUrl = envConfig.getString('authorizationUrl');
+    const adUrl = envConfig.getString('adUrl');
+    const tokenUrl = envConfig.getString('tokenUrl');
+    const tokenSignedResponseAlg = envConfig.getString(
+      'tokenSignedResponseAlg',
+    );
+
+    const provider = new OidcAuthProvider({
+      clientId,
+      clientSecret,
+      callbackUrl,
+      authorizationUrl,
+      tokenUrl,
+      tokenSignedResponseAlg,
+      adUrl,
+    });
+
+    return OAuthAdapter.fromConfig(globalConfig, provider, {
+      disableRefresh: false,
+      providerId,
+      tokenIssuer,
+    });
+  });
@@ -27,6 +27,7 @@ import Router from 'express-promise-router';
 import { Logger } from 'winston';
 import { createOidcRouter, DatabaseKeyStore, TokenFactory } from '../identity';
 import { createAuthProvider } from '../providers';
+import session from 'express-session';

 export interface RouterOptions {
  logger: Logger;
@@ -59,7 +60,9 @@ export async function createRouter({
  });
  const catalogApi = new CatalogClient({ discoveryApi: discovery });

-  router.use(cookieParser());
+  const secret = 'backstage secret'; // TODO: Allow an override here
+  router.use(cookieParser(secret));
+  router.use(session({ secret }));
  router.use(express.urlencoded({ extended: false }));
  router.use(express.json());