Add custom authority lookup

lib/msal-core/src/authority/Authority.ts

@@ -146,7 +146,7 @@ export class Authority {
         if (this.IsValidationEnabled) {
             const host = this.canonicalAuthorityUrlComponents.HostNameAndPort;
             if (TrustedAuthority.getTrustedHostList().length === 0) {
-                await TrustedAuthority.setTrustedAuthoritiesFromNetwork(telemetryManager, correlationId);
+                await TrustedAuthority.setTrustedAuthoritiesFromNetwork(this.canonicalAuthority, telemetryManager, correlationId);
             }
 
             if (!TrustedAuthority.IsInTrustedHostList(host)) {

lib/msal-core/src/authority/TrustedAuthority.ts

@@ -2,6 +2,7 @@ import TelemetryManager from "../telemetry/TelemetryManager";
 import { XhrClient, XhrResponse } from "../XHRClient";
 import HttpEvent from "../telemetry/HttpEvent";
 import { AAD_INSTANCE_DISCOVERY_ENDPOINT, NetworkRequestType } from "../utils/Constants";
+import { UrlUtils } from '../utils/UrlUtils';
 
 export class TrustedAuthority {
     private static TrustedHostList: Array<string> = [];
@@ -24,12 +25,13 @@ export class TrustedAuthority {
      * @param telemetryManager 
      * @param correlationId 
      */
-    private static async getAliases(telemetryManager: TelemetryManager, correlationId?: string): Promise<Array<any>> {
+    private static async getAliases(authorityToVerify: string, telemetryManager: TelemetryManager, correlationId?: string): Promise<Array<any>> {
         const client: XhrClient = new XhrClient();
 
         const httpMethod = NetworkRequestType.GET;
-        const httpEvent: HttpEvent = telemetryManager.createAndStartHttpEvent(correlationId, httpMethod, AAD_INSTANCE_DISCOVERY_ENDPOINT, "getAliases");
-        return client.sendRequestAsync(AAD_INSTANCE_DISCOVERY_ENDPOINT, httpMethod, true)
+        const instanceDiscoveryEndpoint = `${AAD_INSTANCE_DISCOVERY_ENDPOINT}${authorityToVerify}oauth2/v2.0/authorize`;
+        const httpEvent: HttpEvent = telemetryManager.createAndStartHttpEvent(correlationId, httpMethod, instanceDiscoveryEndpoint, "getAliases");
+        return client.sendRequestAsync(instanceDiscoveryEndpoint, httpMethod, true)
             .then((response: XhrResponse) => {
                 httpEvent.httpResponseStatus = response.statusCode;
                 telemetryManager.stopEvent(httpEvent);
@@ -47,14 +49,20 @@ export class TrustedAuthority {
      * @param telemetryManager 
      * @param correlationId 
      */
-    public static async setTrustedAuthoritiesFromNetwork(telemetryManager: TelemetryManager, correlationId?: string): Promise<void> {
-        const metadata = await this.getAliases(telemetryManager, correlationId);
+    public static async setTrustedAuthoritiesFromNetwork(authorityToVerify: string, telemetryManager: TelemetryManager, correlationId?: string): Promise<void> {
+        const metadata = await this.getAliases(authorityToVerify, telemetryManager, correlationId);
         metadata.forEach(function(entry: any){
             const authorities: Array<string> = entry.aliases;
             authorities.forEach(function(authority: string) {
                 TrustedAuthority.TrustedHostList.push(authority.toLowerCase());
             });
         });
+
+        const host = UrlUtils.GetUrlComponents(authorityToVerify).HostNameAndPort;
+        if (TrustedAuthority.getTrustedHostList().length && !TrustedAuthority.IsInTrustedHostList(host)){
+            // Custom Domain scenario, host is trusted because Instance Discovery call succeeded
+            TrustedAuthority.TrustedHostList.push(host.toLowerCase());
+        }
     } 
 
     public static getTrustedHostList(): Array<string> {

lib/msal-core/src/utils/Constants.ts

@@ -102,8 +102,8 @@ export enum ErrorCacheKeys {
     ERROR_DESC = "error.description"
 }
 
-export const DEFAULT_AUTHORITY: string = "https://login.microsoftonline.com/common";
-export const AAD_INSTANCE_DISCOVERY_ENDPOINT: string = `${DEFAULT_AUTHORITY}/discovery/instance?api-version=1.1&authorization_endpoint=${DEFAULT_AUTHORITY}/oauth2/v2.0/authorize`;
+export const DEFAULT_AUTHORITY: string = "https://login.microsoftonline.com/common/";
+export const AAD_INSTANCE_DISCOVERY_ENDPOINT: string = `${DEFAULT_AUTHORITY}/discovery/instance?api-version=1.1&authorization_endpoint=`;
 
 /**
  * @hidden

lib/msal-core/test/authority/TrustedAuthority.spec.ts

@@ -42,9 +42,14 @@ describe("TrustedAuthority.ts Class", function () {
     describe("setTrustedAuthoritiesFromNetwork", () => {
         it("Sets TrustedHostList with Authorities known to Microsoft via Instance Discovery Network Call", async () => {
             const countBefore = TrustedAuthority.getTrustedHostList().length;
-            await TrustedAuthority.setTrustedAuthoritiesFromNetwork(stubbedTelemetryManager);
+            await TrustedAuthority.setTrustedAuthoritiesFromNetwork(TEST_CONFIG.validAuthority + "/", stubbedTelemetryManager);
             const countAfter = TrustedAuthority.getTrustedHostList().length;
             expect(countBefore).to.be.lessThan(countAfter);
         });
+
+        it("Sets TrustedHostList with Custom Domain known to Microsoft via Instance Discovery Network Call", async () => {
+            await TrustedAuthority.setTrustedAuthoritiesFromNetwork("https://login.windows-ppe.net/common/", stubbedTelemetryManager);
+            expect(TrustedAuthority.IsInTrustedHostList("login.windows-ppe.net")).to.be.true;
+        });
     });
 });