如何在JavaScript中获取Windows登录用户名及密码？跨服务器场景可行吗？

Short Answer #

• Username: Indirectly possible only if your server uses Windows Integrated Authentication (NTLM/Kerberos) and explicitly passes the authenticated username to your client-side app. Client-side JavaScript cannot directly access the OS-level username.
• Password: Impossible. Windows does not expose plaintext passwords to any application (including web browsers), and browser security sandboxes prevent scripts from accessing sensitive OS credentials.

Detailed Breakdown #

Windows Username #

Client-side JavaScript runs in a browser sandbox, which isolates it from the underlying operating system for security. This means you can't directly pull the logged-in Windows username using JS alone. However, here's a valid workaround:

• If your remote server is configured to use Windows Integrated Authentication (common in enterprise environments with IIS, for example), the browser will automatically authenticate the user using their Windows credentials when accessing the app (assuming the server is in a trusted domain/zone).
• The server can then retrieve the authenticated username (e.g., via Request.LogonUserIdentity.Name in ASP.NET, or equivalent in other server-side frameworks) and pass it to your client-side app—either by embedding it in the page HTML, returning it via an API endpoint, or storing it in a secure cookie.
• Once the server sends the username to the client, your JavaScript can use that value as needed.

Windows Password #

This is a hard no for multiple critical reasons:

• Windows stores passwords as salted hashes (not plaintext), so even the OS itself doesn't have access to the original password.
• Browser security policies strictly prohibit client-side scripts from accessing any sensitive authentication credentials stored by the OS.
• Attempting to retrieve or transmit a user's password would violate basic security best practices and could expose you to legal or compliance risks (like GDPR, HIPAA, etc.).

Key Security Notes #

• Never attempt to capture or transmit user passwords in plaintext—this is a severe security vulnerability.
• If you need user authentication, rely on established protocols like Windows Integrated Authentication, OAuth, or SSO instead of trying to pull credentials directly via JS.

内容的提问来源于stack exchange，提问作者Abirlal Mukherjee