A Windows 11 credential provider DLL that accepts unlock commands over a named pipe. Any application that can write to a pipe can unlock the lock screen or approve a credential prompt -- no Windows Hello enrollment, no built-in biometric hardware required.
Your App ──UNLOCK:.\user:pass──> \\.\pipe\CredentialProviderPipe ──> UnlockProvider.dll ──> Windows LSA ──> Unlock
The DLL runs inside LogonUI.exe on the lock screen. When your app sends a command, the DLL packages the credentials and hands them to Windows for validation. If valid, the workstation unlocks.
Requires VS2022 with C++ desktop workload.
build.batProduces UnlockProvider.dll and test_unlock.exe.
register.bat &:: Run as Administratortest_unlock.exe myuser mypassword
test_unlock.exe myuser mypassword MYDOMAINLocks the screen, waits 5 seconds, sends the unlock command.
unregister.bat &:: Run as AdministratorA camera service runs in the background. When the lock screen appears, it captures a frame, runs face detection, and if the face matches the enrolled user, sends the unlock command. The user walks up to the PC and it unlocks.
Camera -> Face Detection Model -> Match? -> UNLOCK:.\user:pass -> Pipe -> Unlocked
Works with any face recognition stack: OpenCV + dlib, MediaPipe, Azure Face API, AWS Rekognition, a custom ONNX model -- anything that can produce a match/no-match result.
A microphone listener runs in the user session. It performs speech-to-text (locally with Vosk/Whisper or via a cloud API). When a trigger phrase is recognized ("unlock my computer", a custom passphrase, or a voice biometric match), it sends the unlock command.
Microphone -> Speech-to-Text -> Trigger Phrase? -> UNLOCK:.\user:pass -> Pipe -> Unlocked
Can also be combined with speaker verification: only unlock when the right voice says the right phrase.
A USB fingerprint reader, palm scanner, or iris camera has its own SDK that fires an event when a known print/pattern is matched. The event handler sends the unlock command.
Fingerprint Reader SDK -> Match Event -> UNLOCK:.\user:pass -> Pipe -> Unlocked
This lets you use biometric hardware that Windows Hello does not natively support.
A companion app on the user's phone advertises a BLE beacon. A background service on the PC monitors RSSI. When the phone is within range and the screen is locked, it unlocks. When the phone leaves range, it locks.
Phone BLE Beacon -> PC BLE Scanner -> In Range? -> UNLOCK:.\user:pass -> Pipe -> Unlocked
Phone out of range -> LockWorkStation()
An NFC reader detects a known badge or smart card. The reader's SDK fires a card-read event containing a card UID. The handler maps the UID to stored credentials and sends the unlock command.
NFC Reader -> Card UID -> Lookup Credentials -> UNLOCK:.\user:pass -> Pipe -> Unlocked
A kiosk application manages user sessions. When a customer authenticates through the kiosk UI (PIN, QR code scan, membership card), the kiosk app unlocks the workstation to their profile and locks it again when the session ends.
Kiosk UI -> Customer Authenticated -> UNLOCK:.\kiosk_user:pass -> Pipe -> Unlocked
Session End -> LockWorkStation()
A management tool on the network needs to unlock a workstation for remote maintenance. An agent running on the target machine receives the command over a secure channel and relays it to the local pipe.
Admin Console -> TLS/SSH to Agent -> Agent -> UNLOCK:.\admin:pass -> Pipe -> Unlocked
Combine any of the above. A service requires both face match AND voice passphrase before sending the unlock command.
Face Match = true AND Voice Match = true -> UNLOCK:.\user:pass -> Pipe -> Unlocked
| Item | Value |
|---|---|
| Pipe path | \\.\pipe\CredentialProviderPipe |
| Command | UNLOCK:domain\username:password |
| Domain | . for local, NetBIOS name for domain |
| Response | OK or ERR:INVALID_CMD / ERR:NO_PROVIDER / ERR:PROVIDER_FAILED |
OK = credentials handed to Windows. Logon result (success/wrong password/locked account) appears on the lock screen.
| Language | Source | Docs |
|---|---|---|
| Python | sdk/python/credential_provider.py | docs/SDK_Python.md |
| Node.js | sdk/nodejs/credential-provider.js | docs/SDK_NodeJS.md |
| Delphi | sdk/delphi/CredentialPipe.pas | docs/SDK_Delphi.md |
All SDKs have zero third-party dependencies. Any language that can open a named pipe works -- the protocol is 1 write + 1 read of a UTF-8 string.
Run Sysinternals DebugView as Administrator with "Capture Global Win32" enabled. The DLL logs every step with [UnlockProvider], [Credential], and [PipeListener] prefixes.
- Pipe DACL: SYSTEM and Administrators get full access, Authenticated Users get read/write, Anonymous and Network are denied.
- Remote pipe connections are blocked (
PIPE_REJECT_REMOTE_CLIENTS). - Pipe squatting is prevented (
FILE_FLAG_FIRST_PIPE_INSTANCE). - Passwords are wiped with
SecureZeroMemoryafter use. - DLL installs to
C:\Windows\System32(admin-writable only).