auth-backend: refactor identity APIs for forwards compatibility

plugins/auth-backend/migrations/20200619125845_init.js

@@ -34,10 +34,7 @@ exports.up = async function up(knex) {
       .notNullable()
       .defaultTo(knex.fn.now())
       .comment('The creation time of the key');
-    table
-      .string('key')
-      .notNullable()
-      .comment('The serialized public part of the signing key');
+    table.string('key').notNullable().comment('The serialized signing key');
   });
 };
 

plugins/auth-backend/src/identity/DatabaseKeyStore.ts

@@ -18,7 +18,7 @@ import Knex from 'knex';
 import path from 'path';
 import { utc } from 'moment';
 import { Logger } from 'winston';
-import { PublicKey } from './types';
+import { AnyJWK, KeyStore } from './types';
 
 const migrationsDir = path.resolve(
   require.resolve('@backstage/plugin-auth-backend/package.json'),
@@ -40,7 +40,7 @@ type Options = {
   keyDuration: number;
 };
 
-export class DatabaseKeyStore {
+export class DatabaseKeyStore implements KeyStore {
   static async create(options: Options): Promise<DatabaseKeyStore> {
     const { database } = options;
 
@@ -65,7 +65,7 @@ export class DatabaseKeyStore {
     this.logger = logger.child({ service: 'key-store' });
   }
 
-  async addPublicKey(key: PublicKey): Promise<void> {
+  async storeKey({ key }: { key: AnyJWK }): Promise<void> {
     this.logger.info(`Storing public key ${key.kid}`);
 
     await this.database<Row>(TABLE).insert({
@@ -74,7 +74,7 @@ export class DatabaseKeyStore {
     });
   }
 
-  async listPublicKeys(): Promise<PublicKey[]> {
+  async listKeys(): Promise<{ keys: AnyJWK[] }> {
     const rows = await this.database<Row>(TABLE).select();
 
     const [validRows, expiredRows] = this.splitExpiredRows(rows);
@@ -83,7 +83,9 @@ export class DatabaseKeyStore {
       this.removeExpiredRows(expiredRows);
     }
 
-    return validRows.map(row => JSON.parse(row.key));
+    return {
+      keys: validRows.map(row => JSON.parse(row.key)),
+    };
   }
 
   private splitExpiredRows(rows: Row[]) {

plugins/auth-backend/src/identity/TokenFactory.ts

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { TokenIssuer, TokenParams, KeyStore, PublicKey } from './types';
+import { TokenIssuer, TokenParams, KeyStore, AnyJWK } from './types';
 import { JSONWebKey, JWK, JWS } from 'jose';
 import { Logger } from 'winston';
 import { v4 as uuid } from 'uuid';
@@ -45,11 +45,11 @@ export class TokenFactory implements TokenIssuer {
     this.keyDuration = options.keyDuration;
   }
 
-  async issueToken(claims: TokenParams): Promise<string> {
+  async issueToken(params: TokenParams): Promise<string> {
     const key = await this.getKey();
 
     const iss = this.issuer;
-    const sub = claims.sub;
+    const sub = params.claims.sub;
     const aud = 'backstage';
     const iat = (Date.now() / 1000) | 0;
     const exp = iat + 3600;
@@ -79,9 +79,9 @@ export class TokenFactory implements TokenIssuer {
         alg: 'ES256',
       });
 
-      await this.keyStore.addPublicKey(
-        (key.toJWK(false) as unknown) as PublicKey,
-      );
+      await this.keyStore.storeKey({
+        key: (key.toJWK(false) as unknown) as AnyJWK,
+      });
 
       return key as JSONWebKey;
     })();

plugins/auth-backend/src/identity/router.ts

@@ -50,7 +50,7 @@ export function createOidcRouter(options: Options) {
 
   router.get('/.well-known/jwks.json', async (_req, res) => {
     logger.info('request certs');
-    const keys = await keyStore.listPublicKeys();
+    const { keys } = await keyStore.listKeys();
     res.json({ keys });
   });
 

plugins/auth-backend/src/identity/types.ts

@@ -14,23 +14,25 @@
  * limitations under the License.
  */
 
-export interface PublicKey extends Record<string, string> {
-  use: 'sig' | 'enc';
+export interface AnyJWK extends Record<string, string> {
+  use: 'sig';
   alg: string;
   kid: string;
   kty: string;
 }
 
 export type KeyStore = {
-  addPublicKey(key: PublicKey): Promise<void>;
+  storeKey(params: { key: AnyJWK }): Promise<void>;
 
-  listPublicKeys(): Promise<PublicKey[]>;
+  listKeys(): Promise<{ keys: AnyJWK[] }>;
 };
 
 export type TokenParams = {
-  sub: string;
+  claims: {
+    sub: string;
+  };
 };
 
 export type TokenIssuer = {
-  issueToken(claims: TokenParams): Promise<string>;
+  issueToken(params: TokenParams): Promise<string>;
 };

plugins/auth-backend/src/lib/OAuthProvider.ts

@@ -145,7 +145,7 @@ export class OAuthProvider implements AuthProviderRouteHandlers {
       }
 
       user.userIdToken = await this.options.tokenIssuer.issueToken({
-        sub: user.profile.email,
+        claims: { sub: user.profile.email },
       });
 
       // post message back to popup if successful
@@ -206,7 +206,7 @@ export class OAuthProvider implements AuthProviderRouteHandlers {
       );
 
       refreshInfo.userIdToken = await this.options.tokenIssuer.issueToken({
-        sub: refreshInfo.profile?.email,
+        claims: { sub: refreshInfo.profile?.email },
       });
 
       return res.send(refreshInfo);