fix: Azure single-tenant SSO tokens are unable to refresh (#5551)

server/utils/azure.ts

@@ -1,9 +1,36 @@
+import JWT from "jsonwebtoken";
+import env from "@server/env";
 import OAuthClient from "./oauth";
 
+type AzurePayload = {
+  /* A GUID that represents the Azure AD tenant that the user is from */
+  tid: string;
+};
+
 export default class AzureClient extends OAuthClient {
   endpoints = {
     authorize: "https://login.microsoftonline.com/common/oauth2/v2.0/authorize",
     token: "https://login.microsoftonline.com/common/oauth2/v2.0/token",
     userinfo: "https://graph.microsoft.com/v1.0/me",
   };
+
+  async rotateToken(
+    accessToken: string,
+    refreshToken: string
+  ): Promise<{
+    accessToken: string;
+    refreshToken?: string;
+    expiresAt: Date;
+  }> {
+    if (env.isCloudHosted()) {
+      return super.rotateToken(accessToken, refreshToken);
+    }
+
+    const payload = JWT.decode(accessToken) as AzurePayload;
+    return super.rotateToken(
+      accessToken,
+      refreshToken,
+      `https://login.microsoftonline.com/${payload.tid}/oauth2/v2.0/token`
+    );
+  }
 }

server/utils/oauth.ts

@@ -1,4 +1,5 @@
 import fetch from "fetch-with-proxy";
+import Logger from "@server/logging/Logger";
 import { AuthenticationError, InvalidRequestError } from "../errors";
 
 export default abstract class OAuthClient {
@@ -41,18 +42,22 @@ export default abstract class OAuthClient {
     return data;
   };
 
-  rotateToken = async (
-    refreshToken: string
+  async rotateToken(
+    _accessToken: string,
+    refreshToken: string,
+    endpoint = this.endpoints.token
   ): Promise<{
     accessToken: string;
     refreshToken?: string;
     expiresAt: Date;
-  }> => {
+  }> {
     let data;
     let response;
 
     try {
-      response = await fetch(this.endpoints.token, {
+      Logger.debug("utils", "Rotating token", { endpoint });
+
+      response = await fetch(endpoint, {
         method: "POST",
         headers: {
           "Content-Type": "application/x-www-form-urlencoded",
@@ -79,5 +84,5 @@ export default abstract class OAuthClient {
       accessToken: data.access_token,
       expiresAt: new Date(Date.now() + data.expires_in * 1000),
     };
-  };
+  }
 }