Smart Card Reader Driver Debugging (Windows)

Core Concept: Synchronous vs Asynchronous Cards

Key insight: Microsoft CCID driver (wudfusbcciddriver.inf) only implements ISO 7816 T=0/T=1. It returns empty GET_FEATURE_REQUEST (no SET_CARD_TYPE), and SCardConnect with T=0/T=1 fails with 0x00000005 (SCARD_E_PROTO_MISMATCH).

The Working Path: Vendor CT-API

Alcor Micro readers (AU9540, AK9543, AU9520) ship with CTAlc001.dll — a proprietary CT-API (ISO 7816-4 CT-BCS) that bypasses PC/SC entirely.

DLL Exports (CTAlc001.dll)

CT_init(ctn: uint16, pn: uint16) -> int16
CT_data(ctn, dad, sad, lenc, command, lenr, response) -> int16
CT_close(ctn) -> int16

Python 32-bit Interop (Required — DLL is 32-bit)

# Download 32-bit Python embed package
Invoke-WebRequest -Uri "https://www.python.org/ftp/python/3.11.9/python-3.11.9-embed-win32.zip" -OutFile "python32.zip"
Expand-Archive python32.zip -DestinationPath C:\Temp\py32

import ctypes
dll = ctypes.windll.LoadLibrary(r"C:\path\to\CTAlc001.dll")

dll.CT_init.argtypes = [ctypes.c_uint16, ctypes.c_uint16]
dll.CT_init.restype = ctypes.c_int16

dll.CT_data.argtypes = [
    ctypes.c_uint16,
    ctypes.POINTER(ctypes.c_ubyte),  # dad
    ctypes.POINTER(ctypes.c_ubyte),  # sad
    ctypes.c_uint16,                  # lenc
    ctypes.POINTER(ctypes.c_ubyte),   # command
    ctypes.POINTER(ctypes.c_uint16),  # lenr
    ctypes.POINTER(ctypes.c_ubyte),   # response
]
dll.CT_data.restype = ctypes.c_int16

dll.CT_close.argtypes = [ctypes.c_uint16]
dll.CT_close.restype = ctypes.c_int16

# Initialize (port 100 = USB for Alcor)
handle = dll.CT_init(0, 100)  # returns 0 on success

SLE4442 Commands via CT-API

# Verify PSC (default FFFFFF)
cmd = bytes([0xFF, 0x20, 0x00, 0x00, 0x03, 0xFF, 0xFF, 0xFF])

# Read 4 bytes at offset 0
cmd = bytes([0xFF, 0xB0, 0x00, 0x00, 0x04])

# Read error counter (address 0x1F)
cmd = bytes([0xFF, 0xB0, 0x00, 0x1F, 0x01])

# Write byte
cmd = bytes([0xFF, 0xD0, 0x00, offset, 0x01, value])

# Change PSC (after verify)
cmd = bytes([0xFF, 0xD2, 0x00, 0x00, 0x03, new_p1, new_p2, new_p3])

Driver Binding Strategies (Critical Blocker)

Problem

Windows binds Alcor readers (VID_058F) to Microsoft CCID. Rebranded readers (e.g., Pincop ICU02 = VID_2CE3 PID_9563) have no matching INF.

Strategy 1: Modify Original INF + Test Signing (Most Reliable)

1. Copy original driver folder (contains .sys, .dll, .inf, .cat)
2. Edit SZCCID.INF → add your VID/PID to [DeviceList.NTamd64]
3. Enable test signing: bcdedit /set testsigning on (reboot)
4. Re-sign .cat with self-cert or use pnputil /add-driver with modified INF
5. Force bind: pnputil /remove-device <instance> → pnputil /scan-devices

Strategy 2: Registry Force-Bind (No Reboot, Fragile)

# Find device instance
$inst = "USB\VID_2CE3&PID_9563\5&3639e268&0&4"

# Set driver to SZCCID (oem58.inf = AlcorMicro)
pnputil /remove-device $inst
# Edit registry:
# HKLM\SYSTEM\CurrentControlSet\Enum\USB\VID_2CE3&PID_9563\...\Driver = "{50dd5230-ba8a-11d1-bf5d-0000f805f530}\0001"
# HKLM\...\Service = "szccid"
pnputil /scan-devices

Strategy 3: DevCon (If Available)

devcon update "SZCCID.INF" "USB\VID_2CE3&PID_9563"

Alcor Driver Package Structure

AU9540_V1.7.2.0\program_files\AlcorMicro\x64\
├── CTAlc001.dll       ← CT-API (32-bit & 64-bit versions exist)
├── SZCCID.sys         ← Kernel driver (binds to device)
├── SzCcidV1900.dll    ← Co-installer / user-mode CCID
├── SCPwrSetSvr.exe    ← Power management
├── SZCCID.INF         ← Installation INF
├── szccid.cat         ← WHQL signature (must re-sign if INF modified)
└── AlcGener.sys       ← Generic helper

Common Error Codes

Critical Blockers (Lessons from Pincop ICU02 = VID_2CE3 PID_9563)

Secure Boot Blocks Test Signing

bcdedit /set testsigning on
→ "The value is protected by Secure Boot policy and cannot be modified or deleted."

If Secure Boot is enabled, you CANNOT enable test signing. Options:

1. Enter UEFI/BIOS → disable Secure Boot → reboot → enable test signing → reboot → install driver
2. Buy a reader whose VID/PID is in the vendor's WHQL-signed INF (e.g., ACS ACR38U)
3. Buy the same chip with original VID (Alcor AU9540 = VID_058F PID_9540)

Registry Force-Bind Doesn't Survive pnputil /enable-device

Setting Service=SzCCID in the Enum key works temporarily, but pnputil /enable-device triggers PnP re-enumeration which overrides Service back to WUDFRd based on USB\Class_0B CompatibleID. The registry value remains SzCCID but the actual driver stack reverts to WUDF CCID.

Workaround attempted: Disable device → change registry → enable device. Result: PnP still re-binds to wudfusbcciddriver.inf because it's the highest-ranked signed driver for USB\Class_0B&SubClass_00&Prot_00.

MS CCID Direct IOCTL Access (Dead End)

Opening \\?\USB#VID_2CE3&PID_9563#...#{a5dcbf10-...} via CreateFileW succeeds, but DeviceIoControl only responds to 2 IOCTLs:

• IOCTL+0x028 → returns empty (ack-only)
• IOCTL+0x038 → returns 02000000 (version/capabilities DWORD)

ALL standard smartcard IOCTLs return ERROR_INVALID_FUNCTION (err=1):

• GET_FEATURE_REQUEST, SET_CARD_TYPE, POWER, TRANSMIT, SET_PROTOCOL, IS_PRESENT → all fail
• CCID_ESCAPE (0x004) with raw CCID messages → fails
• WriteFile/ReadFile → written=0 (WUDF doesn't support raw I/O)

Conclusion: WUDF CCID driver is a sealed box. Cannot send CCID escape commands or SET_CARD_TYPE. The only path out is replacing the driver entirely.

CTAlc001.dll Bitness

• CTAlc001.dll from Alcor x64 package is PE32 (i386, 32-bit)
• SZCCID.sys is AMD64 (64-bit)
• Must use 32-bit Python to load the DLL: python-3.11.9-embed-win32.zip
• 64-bit Python → WinError 193: not a valid Win32 application
• DLL communicates with kernel driver via DeviceIoControl (works across 32→64 bitness)
• BUT: CT_init still returns -8 if the kernel driver isn't bound to the device

32-bit Python Setup (Embed Package)

# Download 32-bit embeddable Python (no installer needed)
Invoke-WebRequest -Uri "https://www.python.org/ftp/python/3.11.9/python-3.11.9-embed-win32.zip" -OutFile "C:\Temp\py311-32.zip"
Expand-Archive -Path C:\Temp\py311-32.zip -DestinationPath C:\Python311-32 -Force

# Verify it's 32-bit
C:\Python311-32\python.exe -c "import struct; print(struct.calcsize('P')*8)"
# → 32

⚠️ SLE4442 Safety Rules (MANDATORY)

PSC has a 3-strike lockout — PERMANENT if exhausted.

1. Always read Security Memory first → check Error Counter (EC) byte
2. Never blind-guess PSC — common defaults: FF FF FF, B2 B2 B2
3. Stop when EC ≤ 1 attempt remaining — preserve at least 1 try
4. Successful Verify resets EC — no attempt consumed when PSC is correct

Full attack surface analysis: see smart-card-reader-sle4442 → references/sle4442-security-attacks.md

Debugging Checklist

1. Verify hardware: pnputil /enum-devices → confirm VID/PID
2. Check current driver: Look for wudfusbcciddriver.inf (Microsoft) vs szccid.inf (Alcor)
3. Install Alcor driver: pnputil /add-driver SZCCID.INF /install
4. Force re-enumeration: Remove device → scan
5. Test CT-API: 32-bit Python + CT_init(0, 100) → must return 0
6. If CT_init returns -8: Device still bound to Microsoft CCID → fix binding

Reader Replacement Recommendations

When driver binding cannot be resolved (Secure Boot enabled, unsigned INF rejected, PnP overrides registry), replacing the reader is the most practical solution.

Recommended Readers for SLE4442 (Taiwan availability)

Shopee (蝦皮) Search Keywords

ACR38U, SLE4442 讀卡機, 冷氣卡 讀卡機, AU9540 讀卡機, IC卡讀卡器 4442

Before Buying — Verify

• ✅ Description mentions SLE4442 / 4428 / 同步卡 / 記憶卡
• ❌ Only mentions CPU卡 / ISO 7816 → cannot read synchronous cards
• ❌ Rebranded readers with non-standard VIDs (unless vendor provides signed driver)

References

• references/alcor-au9540-driver-notes.md — Detailed Alcor AU9540/AK9543 driver internals
• references/sle4442-ctapi-commands.md — Complete SLE4442 command set for CT-API
• references/windows-driver-binding-tactics.md — Registry/INF/test-signing tactics
• references/sle4442-security-attacks.md — Complete SLE4442 attack surface analysis

Scripts

• scripts/test_ctapi_sle4442.py — Ready-to-run CT-API test (requires 32-bit Python)
• scripts/force_bind_szccid.ps1 — PowerShell script to force device bind to SZCCID