From 38faa475bae024e3ef2f376888ff09fb1665b4af Mon Sep 17 00:00:00 2001
From: Shubham Kumar <shubham.24bcs10320@sst.scaler.com>
Date: Mon, 10 Nov 2025 21:22:16 +0530
Subject: [PATCH] fix(oauth2): replace localStorage with sessionStorage in
 callback component (#2790)

---
 src/app/zitadel/auth.service.ts               | 85 +++++++++----------
 .../zitadel/callback/callback.component.ts    | 26 ++++--
 src/index.html                                |  2 +-
 3 files changed, 60 insertions(+), 53 deletions(-)

diff --git a/src/app/zitadel/auth.service.ts b/src/app/zitadel/auth.service.ts
index c94f9fc23..75af2d531 100644
--- a/src/app/zitadel/auth.service.ts
+++ b/src/app/zitadel/auth.service.ts
@@ -33,7 +33,7 @@ export class AuthService {
   async login() {
     const codeVerifier = this.generateRandomString();
     const codeChallenge = await this.generateCodeChallenge(codeVerifier);
-    localStorage.setItem('code_verifier', codeVerifier);
+    sessionStorage.setItem('code_verifier', codeVerifier);
     const url =
       `${this.authUrl}` +
       `?client_id=${encodeURIComponent(this.clientId)}` +
@@ -105,56 +105,51 @@ export class AuthService {
     return base64;
   }
 
-  exchangeCodeForTokens(code: string, codeVerifier: string | null) {
+  async exchangeCodeForTokens(code: string, codeVerifier: string | null): Promise<void> {
     const payload = {
       code: code,
       code_verifier: codeVerifier || ''
     };
 
-    fetch(this.api + 'authentication/token', {
-      method: 'POST',
-      headers: {
-        'Content-Type': 'application/json'
-      },
-      body: JSON.stringify(payload)
-    })
-      .then((res) => {
-        if (!res.ok) {
-          throw new Error(`Error exchanging code: ${res.status} ${res.statusText}`);
-        }
-        return res.json();
-      })
-      .then(
-        (tokens: {
-          access_token: string;
-          id_token: string;
-          refresh_token: string;
-          expires_in: number;
-          token_type: string;
-        }) => {
-          const token: OAuth2Token = {
-            access_token: tokens.access_token,
-            token_type: tokens.token_type,
-            refresh_token: tokens.refresh_token,
-            expires_in: tokens.expires_in,
-            scope: 'Bearer'
-          };
-
-          localStorage.setItem('id_token', tokens.id_token);
-          localStorage.setItem('mifosXZitadel', 'true');
-          sessionStorage.setItem('mifosXZitadelTokenDetails', JSON.stringify(token));
-          localStorage.setItem('refresh_token', tokens.refresh_token);
-          this.scheduleRefresh(tokens.expires_in);
-          localStorage.removeItem('auth_code');
-          localStorage.removeItem('code_verifier');
-          this.userdetails();
-        }
-      )
-      .catch((error) => {
-        localStorage.removeItem('auth_code');
-        localStorage.removeItem('code_verifier');
-        window.location.href = '/#/login';
+    try {
+      const response = await fetch(this.api + 'authentication/token', {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json'
+        },
+        body: JSON.stringify(payload)
       });
+
+      if (!response.ok) {
+        throw new Error(`Error exchanging code: ${response.status} ${response.statusText}`);
+      }
+
+      const tokens: {
+        access_token: string;
+        id_token: string;
+        refresh_token: string;
+        expires_in: number;
+        token_type: string;
+      } = await response.json();
+
+      const token: OAuth2Token = {
+        access_token: tokens.access_token,
+        token_type: tokens.token_type,
+        refresh_token: tokens.refresh_token,
+        expires_in: tokens.expires_in,
+        scope: 'Bearer'
+      };
+
+      sessionStorage.setItem('mifosXZitadelTokenDetails', JSON.stringify(token));
+      localStorage.setItem('id_token', tokens.id_token);
+      localStorage.setItem('refresh_token', tokens.refresh_token);
+      localStorage.setItem('mifosXZitadel', 'true');
+      this.scheduleRefresh(tokens.expires_in);
+      await this.userdetails();
+    } catch (error) {
+      window.location.href = '/#/login';
+      throw error;
+    }
   }
 
   userdetails() {
diff --git a/src/app/zitadel/callback/callback.component.ts b/src/app/zitadel/callback/callback.component.ts
index 97697e11a..e94feb7ca 100644
--- a/src/app/zitadel/callback/callback.component.ts
+++ b/src/app/zitadel/callback/callback.component.ts
@@ -1,5 +1,5 @@
 import { Component, OnInit } from '@angular/core';
-import { ActivatedRoute } from '@angular/router';
+import { ActivatedRoute, Router } from '@angular/router';
 import { AuthService } from '../auth.service';
 
 @Component({
@@ -9,15 +9,27 @@ import { AuthService } from '../auth.service';
 export class CallbackComponent implements OnInit {
   constructor(
     private route: ActivatedRoute,
+    private router: Router,
     private authService: AuthService
   ) {}
 
-  ngOnInit(): void {
-    let code = localStorage.getItem('auth_code');
-
-    if (code) {
-      const codeVerifier = localStorage.getItem('code_verifier');
-      this.authService.exchangeCodeForTokens(code, codeVerifier);
+  async ngOnInit(): Promise<void> {
+    try {
+      const code = sessionStorage.getItem('auth_code');
+      if (code) {
+        const codeVerifier = sessionStorage.getItem('code_verifier');
+        try {
+          await this.authService.exchangeCodeForTokens(code, codeVerifier);
+        } finally {
+          // Clean up sensitive data immediately after use
+          sessionStorage.removeItem('auth_code');
+          sessionStorage.removeItem('code_verifier');
+        }
+      }
+    } catch (error) {
+      console.error('Authentication failed:', error);
+      // Navigate to login page
+      this.router.navigate(['/login']);
     }
   }
 }
diff --git a/src/index.html b/src/index.html
index a168e7b28..870489224 100644
--- a/src/index.html
+++ b/src/index.html
@@ -25,7 +25,7 @@
       }
       const code = getQueryParam('code');
       if (code) {
-        localStorage.setItem('auth_code', code);
+        sessionStorage.setItem('auth_code', code);
         window.location.href = '/#/callback';
       }
     </script>