From aa771335ae9310afc24f13575b6eb129b4e9a3a1 Mon Sep 17 00:00:00 2001
From: Richard Bao <richardbao2004@gmail.com>
Date: Thu, 13 Apr 2023 19:50:26 +1000
Subject: [PATCH] updated it with new changes from other people

---
 backend/src/auth.ts                  | 47 +++++++++++++++++++++++++++-
 backend/src/index.ts                 | 10 ++++++
 backend/src/interfaces/interfaces.ts |  8 +++++
 backend/src/middleware.ts            |  6 ++++
 4 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/backend/src/auth.ts b/backend/src/auth.ts
index 9f1a0c04c..5b69fc7e5 100644
--- a/backend/src/auth.ts
+++ b/backend/src/auth.ts
@@ -8,7 +8,8 @@ import Helpers, { IResponseWithStatus } from './helpers';
 import JWT from './jwt';
 import { Logger, LogModule } from './logging';
 import Secrets from './secrets';
-import { AuthRequest } from './interfaces/interfaces';
+import { AuthRequest, VerifyTokenRequest } from './interfaces/interfaces';
+import Middleware from './middleware';
 import ev from './environment';
 
 const LM = new LogModule('AUTH');
@@ -244,4 +245,48 @@ export default class Auth {
     }
     return true;
   }
+
+  // check if token is valid
+  public static AuthenticateToken(
+    this: void,
+    req: VerifyTokenRequest,
+    res: Response,
+    next: NextFunction,
+  ) {
+    // const encodedJwt = req.body.jwt;
+    const { accountType } = req.body;
+    let response: IResponseWithStatus;
+
+    // currently this line does not work as jwt decryption algorithm doesn't work
+    // const jwt: IToken = JWT.get(encodedJwt);
+
+    // hard coded example
+    const jwt: IToken = {
+      id: 'test',
+      type: AccountType.Student,
+      lastRequestTimestamp: Date.now(),
+      ipAddress: '::1',
+    };
+
+    // checks it token is valid or not
+    try {
+      Middleware.verifyToken(req, jwt, accountType);
+
+      response = {
+        status: StatusCodes.OK,
+        msg: jwt,
+      };
+    } catch (error) {
+      // Error thrown meaning that token is invalid.
+      response = { status: StatusCodes.UNAUTHORIZED, msg: 'Token is invalid' };
+    }
+
+    if (response.msg === undefined) {
+      res.sendStatus(response.status);
+    }
+    else {
+      res.status(response.status).send(response.msg);
+    }
+    next();
+  }
 }
diff --git a/backend/src/index.ts b/backend/src/index.ts
index de289f50b..32be6ca3a 100644
--- a/backend/src/index.ts
+++ b/backend/src/index.ts
@@ -43,6 +43,7 @@ import {
   UpdateCompanyDetailsRequest,
   VerifyCompanyAccountRequest,
   SearchJobRequest,
+  VerifyTokenRequest,
 } from './interfaces/interfaces';
 
 const LM = new LogModule('INDEX');
@@ -470,6 +471,15 @@ app.get(
   Middleware.genericLoggingMiddleware,
 );
 
+app.get(
+  '/check-token-valid',
+  cors(corsOptions),
+  (req: VerifyTokenRequest, res, next) => {
+    Auth.AuthenticateToken(req, res, next);
+  },
+  Middleware.genericLoggingMiddleware,
+);
+
 if (ev.data().NODE_ENV === 'development') {
   app.post('/email', (req, res) => {
     (async () => {
diff --git a/backend/src/interfaces/interfaces.ts b/backend/src/interfaces/interfaces.ts
index 02f7c9551..e77419c9f 100644
--- a/backend/src/interfaces/interfaces.ts
+++ b/backend/src/interfaces/interfaces.ts
@@ -1,5 +1,6 @@
 import { Request } from 'express';
 import { ParamsDictionary } from 'express-serve-static-core';
+import { AccountType } from '../auth';
 
 import {
   JobMode,
@@ -86,6 +87,11 @@ interface Year {
   year: string;
 }
 
+interface VerifyBody {
+  jwt: string;
+  accountType: AccountType;
+}
+
 interface JobIDParams extends ParamsDictionary, JobID {}
 interface CompanyIdParams extends ParamsDictionary, CompanyID {}
 interface CompanyAccountIdParams extends ParamsDictionary, CompanyAccountID {}
@@ -101,6 +107,8 @@ export interface PasswordResetRequest extends Request, CompanyAccountID {}
 // * Auth Functions
 export type AuthRequest = Request<Record<string, never>, never, AuthBody>;
 
+export type VerifyTokenRequest = Request<Record<string, never>, never, VerifyBody>;
+
 // * Admin Functions
 type AdminRequestBase = AdminID & JbToken;
 
diff --git a/backend/src/middleware.ts b/backend/src/middleware.ts
index abb2348a0..dd0ebc039 100644
--- a/backend/src/middleware.ts
+++ b/backend/src/middleware.ts
@@ -11,6 +11,7 @@ import {
   AuthoriseCompanyRequest,
   AuthoriseAdminRequest,
   PasswordResetRequest,
+  VerifyTokenRequest,
 } from './interfaces/interfaces';
 import ev from './environment';
 
@@ -205,4 +206,9 @@ export default class Middleware {
       next();
     }
   }
+
+  public static verifyToken(req: VerifyTokenRequest, jwt: IToken, expectedType: AccountType) {
+    Middleware.verifyAccountType(jwt.type, expectedType);
+    Middleware.verifyTokenProperties(req, jwt);
+  }
 }