hkdb · Sep 10, 2026 · Sep 10, 2026 · Sep 10, 2026
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -19,11 +19,13 @@ jobs:
           go-version-file: go.mod
           cache: true
 
-      # cgo hardware backends need their C libs: hardware/chalresp uses
-      # `pkg-config: ykpers-1`, hardware/fido2 uses keys-pub/go-libfido2 (libfido2).
-      # Without these, `go build ./...` fails compiling those packages.
+      # cgo hardware backends need their C libs: hardware/chalresp uses go-hid,
+      # whose Linux hidraw backend needs libudev (libudev-dev); hardware/fido2
+      # uses keys-pub/go-libfido2 (libfido2-dev). Without these, `go build ./...`
+      # fails compiling those packages. (The optional PC/SC chalresp backend is
+      # build-tagged `pcsc` and not built here, so libpcsclite isn't needed.)
       - name: Install native deps
-        run: sudo apt-get update && sudo apt-get install -y pkg-config libykpers-1-dev libfido2-dev
+        run: sudo apt-get update && sudo apt-get install -y pkg-config libudev-dev libfido2-dev
 
       - name: Build
         run: go build ./...

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,6 +1,12 @@
 # CHANGELOG
 
 
+**v0.1.5 - 09-10-2026**
+
+- Migrated to hidapi (removed ykpers)
+- Added nitrokey 1st pass proper (needs testing)
+
+
 **v0.1.4 - 09-09-2026**
 
 - Fixed Windows identity store

diff --git a/README.md b/README.md
@@ -52,7 +52,7 @@ A Go library providing post-quantum ready encryption, signing, key management, a
 | `sharing` | Transport for encrypted file shares — uploads/downloads pre-encrypted `.icfx` ciphertext (does no cryptography itself) |
 | `cloud` | Go client SDK for Instacrypt Cloud: transport, auth, billing, encrypted blob CRUD, directory, notification sync |
 | `keystore` | Abstract key storage — OS keychain or encrypted file backend |
-| `hardware/chalresp` | Optional Yubikey/compatible HMAC-SHA1 challenge-response (libykpers) |
+| `hardware/chalresp` | Optional YubiKey/compatible HMAC-SHA1 challenge-response over HID (go-hid); optional PC/SC backend for Nitrokey 3 |
 | `hardware/fido2` | Optional FIDO2/WebAuthn security-key client (libfido2) — registration and login |
 | `config` | TOML configuration and XDG-compliant path management |
 | `profile` | Full profile backup/restore via encrypted tarballs |
@@ -72,12 +72,15 @@ A Go library providing post-quantum ready encryption, signing, key management, a
   (On macOS the OS keychain still uses the system Security.framework; use file-based key storage for a fully
   cgo-free build there.)
 - OS keychain (optional — falls back to file-based storage)
-- libykpers-1 (optional — required only if you import `hardware/chalresp` for hardware-key support)
-  - Linux (Debian/Ubuntu): `sudo apt install libykpers-1-dev`
-  - Linux (Arch): `sudo pacman -S yubikey-personalization`
-  - Linux (Fedora): `sudo dnf install ykpers-devel`
-  - macOS: `brew install ykpers`
-  - Windows: install from [Yubico's yubikey-personalization releases][ykpers-win]; link via mingw or vcpkg
+- libudev (optional — required only if you import `hardware/chalresp` for hardware-key support). `hardware/chalresp`
+  talks to the device directly over HID via [go-hid](https://github.com/sstallion/go-hid); on Linux its hidraw
+  backend links libudev. macOS and Windows use the system HID APIs — no extra library needed there.
+  - Linux (Debian/Ubuntu): `sudo apt install libudev-dev`
+  - Linux (Arch): `sudo pacman -S systemd` (provides libudev)
+  - Linux (Fedora): `sudo dnf install systemd-devel`
+  - macOS / Windows: none (system HID)
+  - Optional PC/SC backend (Nitrokey 3): build with `-tags pcsc`. On Linux this additionally needs
+    `libpcsclite-dev` + a running `pcscd`; macOS/Windows use the system PC/SC service.
   - See `hardware/chalresp/README.md` for details
 - libfido2 (optional — required only if you import `hardware/fido2` for FIDO2/WebAuthn security keys)
   - Linux (Debian/Ubuntu): `sudo apt install libfido2-dev`
@@ -92,8 +95,6 @@ A Go library providing post-quantum ready encryption, signing, key management, a
     ```
   - Windows: install libfido2; link via mingw or vcpkg
 
-[ykpers-win]: https://developers.yubico.com/yubikey-personalization/Releases/
-
 
 ### ⚗️ Tech Stack
 ---

diff --git a/crypto/hardware.go b/crypto/hardware.go
@@ -53,6 +53,13 @@ func DeriveHardwareKEKBytes(pass, hwResponse []byte) ([]byte, error) {
 	if len(hwResponse) == 0 {
 		return nil, fmt.Errorf("empty hardware response")
 	}
+	// Reject a degenerate all-zero response: it would nullify the hardware factor
+	// (the KEK would be derivable from the passphrase alone). A genuine HMAC-SHA1
+	// is never all-zero; an all-zero salt signals a device malfunction or a
+	// non-genuine token, so fail closed rather than seal/unlock with it.
+	if allZero(hwResponse) {
+		return nil, fmt.Errorf("degenerate (all-zero) hardware response")
+	}
 	// NOTE: an empty passphrase is intentionally allowed. Keychain-origin
 	// identities (HWKEKNone) derive the KEK from the hardware response alone,
 	// with the OS keychain (Android Keystore / macOS Keychain) as the second
@@ -68,3 +75,13 @@ func DeriveHardwareKEKBytes(pass, hwResponse []byte) ([]byte, error) {
 	}
 	return kek, nil
 }
+
+// allZero reports whether every byte of b is zero.
+func allZero(b []byte) bool {
+	for _, x := range b {
+		if x != 0 {
+			return false
+		}
+	}
+	return true
+}
diff --git a/crypto/hardware_test.go b/crypto/hardware_test.go
@@ -56,6 +56,21 @@ func TestDeriveHardwareKEK_EmptyResponse(t *testing.T) {
 	}
 }
 
+// An all-zero hardware response is degenerate (it would nullify the hardware
+// factor) and must be rejected — a genuine HMAC-SHA1 is never all-zero; an
+// all-zero salt signals a malfunctioning or non-genuine device.
+func TestDeriveHardwareKEK_AllZeroResponseRejected(t *testing.T) {
+	if _, err := DeriveHardwareKEK("pass", make([]byte, 20)); err == nil {
+		t.Errorf("expected error for all-zero hardware response")
+	}
+	// A single non-zero byte makes it non-degenerate and derives normally.
+	nonzero := make([]byte, 20)
+	nonzero[19] = 0x01
+	if _, err := DeriveHardwareKEK("pass", nonzero); err != nil {
+		t.Errorf("non-degenerate response should derive: %v", err)
+	}
+}
+
 // An EMPTY passphrase must be accepted: keychain-origin identities (HWKEKNone)
 // derive the KEK from the hardware response alone, with the OS keychain as the
 // second factor. Rejecting it here breaks HW-only keychain unlock (regression

diff --git a/go.mod b/go.mod
@@ -15,6 +15,7 @@ require (
 	github.com/makiuchi-d/gozxing v0.1.1
 	github.com/pquerna/otp v1.5.0
 	github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e
+	github.com/sstallion/go-hid v0.15.0
 	github.com/zalando/go-keyring v0.2.6
 	golang.org/x/crypto v0.50.0
 )
@@ -25,6 +26,7 @@ require (
 	github.com/awnumar/memcall v0.4.0 // indirect
 	github.com/boombuler/barcode v1.0.1-0.20190219062509-6c824513bacc // indirect
 	github.com/danieljoos/wincred v1.2.2 // indirect
+	github.com/ebfe/scard v0.0.0-20241214075232-7af069cabc25 // indirect
 	github.com/godbus/dbus/v5 v5.1.0 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/x448/float16 v0.8.4 // indirect

diff --git a/go.sum b/go.sum
@@ -23,6 +23,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/descope/virtualwebauthn v1.0.5 h1:fMXji5UMepJC51Ge6d4v5IAjiJQRKmXE9hlo/B9SczQ=
 github.com/descope/virtualwebauthn v1.0.5/go.mod h1:lLCfN+DpCM3iisM4bCILZlFEWkC1Zo7ZgsxC45CUapI=
+github.com/ebfe/scard v0.0.0-20241214075232-7af069cabc25 h1:vXmXuiy1tgifTqWAAaU+ESu1goRp4B3fdhemWMMrS4g=
+github.com/ebfe/scard v0.0.0-20241214075232-7af069cabc25/go.mod h1:BkYEeWL6FbT4Ek+TcOBnPzEKnL7kOq2g19tTQXkorHY=
 github.com/fxamacker/cbor/v2 v2.9.2 h1:X4Ksno9+x3cz0TZv69ec1hxP/+tymuR8PXQJyDwfh78=
 github.com/fxamacker/cbor/v2 v2.9.2/go.mod h1:vM4b+DJCtHn+zz7h3FFp/hDAI9WNWCsZj23V5ytsSxQ=
 github.com/godbus/dbus/v5 v5.1.0 h1:4KLkAxT3aOY8Li4FRJe/KvhoNFFxo0m6fNuFUO8QJUk=
@@ -33,8 +35,6 @@ github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/keybase/go-keychain v0.0.1 h1:way+bWYa6lDppZoZcgMbYsvC7GxljxrskdNInRtuthU=
 github.com/keybase/go-keychain v0.0.1/go.mod h1:PdEILRW3i9D8JcdM+FmY6RwkHGnhHxXwkPPMeUgOK1k=
-github.com/keys-pub/go-libfido2 v1.5.3 h1:vtgHxlSB43u6lj0TSuA3VvT6z3E7VI+L1a2hvMFdECk=
-github.com/keys-pub/go-libfido2 v1.5.3/go.mod h1:P0V19qHwJNY0htZwZDe9Ilvs/nokGhdFX7faKFyZ6+U=
 github.com/keys-pub/go-libfido2 v1.5.4-0.20251021061633-bf2d0535e75c h1:KqxSEYvMTbdiv7KvnXMl83kfGBWfkcOr7jt+cRhwzlc=
 github.com/keys-pub/go-libfido2 v1.5.4-0.20251021061633-bf2d0535e75c/go.mod h1:92J9LtSBl0UyUWljElJpTbMMNhC6VeY8dshsu40qjjo=
 github.com/makiuchi-d/gozxing v0.1.1 h1:xxqijhoedi+/lZlhINteGbywIrewVdVv2wl9r5O9S1I=
@@ -47,6 +47,8 @@ github.com/pquerna/otp v1.5.0 h1:NMMR+WrmaqXU4EzdGJEE1aUUI0AMRzsp96fFFWNPwxs=
 github.com/pquerna/otp v1.5.0/go.mod h1:dkJfzwRKNiegxyNb54X/3fLwhCynbMspSyWKnvi1AEg=
 github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e h1:MRM5ITcdelLK2j1vwZ3Je0FKVCfqOLp5zO6trqMLYs0=
 github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e/go.mod h1:XV66xRDqSt+GTGFMVlhk3ULuV0y9ZmzeVGR4mloJI3M=
+github.com/sstallion/go-hid v0.15.0 h1:WERW/VW3Us6N73V2qa7HjdqWQvwHd0CoRDOP/N707/w=
+github.com/sstallion/go-hid v0.15.0/go.mod h1:fPKp4rqx0xuoTV94gwKojsPG++KNKhxuU88goGuGM7I=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.5.2 h1:xuMeJ0Sdp5ZMRXx/aWO6RZxdr3beISkG5/G/aIRr3pY=
 github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
@@ -60,7 +62,6 @@ github.com/zalando/go-keyring v0.2.6 h1:r7Yc3+H+Ux0+M72zacZoItR3UDxeWfKTcabvkI8u
 github.com/zalando/go-keyring v0.2.6/go.mod h1:2TCrxYrbUNYfNS/Kgy/LSrkSQzZ5UPVH85RwfczwvcI=
 golang.org/x/crypto v0.50.0 h1:zO47/JPrL6vsNkINmLoo/PH1gcxpls50DNogFvB5ZGI=
 golang.org/x/crypto v0.50.0/go.mod h1:3muZ7vA7PBCE6xgPX7nkzzjiUq87kRItoJQM1Yo8S+Q=
-golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.43.0 h1:Rlag2XtaFTxp19wS8MXlJwTvoh8ArU6ezoyFsMyCTNI=
 golang.org/x/sys v0.43.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/text v0.36.0 h1:JfKh3XmcRPqZPKevfXVpI1wXPTqbkE5f7JA92a55Yxg=

diff --git a/hardware/chalresp/README.md b/hardware/chalresp/README.md
@@ -1,45 +1,55 @@
 # chalresp
 
-HMAC-SHA1 challenge-response against the OTP slot 2 of Yubikey-compatible
-hardware keys (Yubikey, NitroKey Pro/Storage, OnlyKey). CGO wrapper around
-[Yubico's libykpers][libykpers] — the same C library KeePassXC, ykman, and
-pam_yubico build on. Implements `crypto.HardwareKey` for icfx.
+HMAC-SHA1 challenge-response against OTP slot 2 of Yubico-compatible hardware
+keys, implementing `crypto.HardwareKey` for icfx.
 
-icfx does NOT program slots. Slot 2 must be pre-programmed for HMAC-SHA1
-challenge-response by the user's preferred tool (`ykman otp chalresp
---generate 2`, KeePassXC's setup flow, `ykpersonalize`, etc.) before icfx
-can use it.
-
-## Build dependency
-
-| Platform | Install |
-|---|---|
-| Linux (Arch / CachyOS) | `sudo pacman -S yubikey-personalization` |
-| Linux (Debian / Ubuntu) | `sudo apt install libykpers-1-dev` |
-| Linux (Fedora / RHEL) | `sudo dnf install ykpers-devel` |
-| macOS | `brew install ykpers` |
-| Windows | install the [yubikey-personalization Windows build][ykpers-win] (bundles the DLL); link via mingw or vcpkg |
-
-`pkg-config --modversion ykpers-1` should report a version after install.
-The `#cgo pkg-config: ykpers-1` directive in `chalresp.go` resolves the
-include path and link flags from there.
+It speaks the wire protocols directly — **no libykpers, no libusb** — via
+[hidapi][gohid] (and optionally [PC/SC][scard]). This is what `ykman` and
+KeePassXC do, and it works on macOS/Windows/Linux/BSD without claiming the USB
+interface or any code-signing/entitlement.
 
-**Don't need hardware keys?** Build the whole module with `-tags nohw` (see the top-level README) to compile the
-pure-Go stub instead — then libykpers-1 is not required and cgo can be disabled entirely.
-
-## Single-device today
-
-`chalresp.List()` opens via libykpers' `yk_open_first_key`, which picks the
-first detected device. Multi-device support (plug in two keys, choose one
-by serial) is post-MVP — the existing `DeviceDescriptor.Serial` field is
-populated for forward compatibility.
+icfx does NOT program slots. Slot 2 must be pre-programmed for HMAC-SHA1
+challenge-response by the user's tool (`ykman otp chalresp --generate 2`,
+Yubico Authenticator, KeePassXC's setup, the OnlyKey app, `nitropy nk3 secrets
+add-challenge-response 2 …`) before icfx can use it.
+
+## Supported devices
+
+| Device | Transport | Build | Notes |
+|---|---|---|---|
+| **YubiKey** (OTP-capable models) | HID (keyboard interface) | default | reference implementation; hardware-validated |
+| **OnlyKey** (firmware ≥2.1.0) | HID (keyboard interface) | default | firmware mirrors the YubiKey protocol byte-for-byte |
+| **Nitrokey 3** | CCID / PC-SC (Yubico OATH applet) | `-tags pcsc` | implemented to spec, **untested pending hardware** |
+| YubiKey over CCID | CCID / PC-SC | `-tags pcsc` | bonus of the PC/SC path |
+
+**Not supported:** Nitrokey Pro / Storage (they have no YubiKey-style HMAC-SHA1
+challenge-response — the earlier "NitroKey Pro/Storage" claim was never real).
+
+## Build dependencies
+
+- **Default (HID: YubiKey + OnlyKey)** — cgo via `sstallion/go-hid`, which
+  bundles hidapi. Linux uses the hidraw backend (a `libudev` dev package may be
+  needed to build; a `/dev/hidraw*` udev rule for VID `1050`/`1d50` for runtime
+  access). macOS/Windows need no extra packages.
+- **`-tags pcsc` (adds Nitrokey 3 + YubiKey-CCID)** — cgo via `ebfe/scard`.
+  macOS (`PCSC.framework`) and Windows (`WinSCard`) ship PC/SC in the system;
+  **Linux needs `libpcsclite`-dev to build and `pcscd` running at runtime.**
+  Keep `github.com/ebfe/scard` in `go.mod` — a bare `go mod tidy` (without the
+  `pcsc` tag) will prune it and break the tagged build.
+- **No hardware keys?** Build the module with `-tags nohw` for the pure-Go stub
+  — cgo can be disabled entirely and neither dependency is required.
+
+## Multi-transport enumeration
+
+`chalresp.List()` merges HID and (when built with `-tags pcsc`) PC/SC results;
+`Open`/`Challenge`/`IsSlot2Programmed` route to the transport the device was
+found on. PC/SC enumeration is best-effort — a missing `pcscd` never breaks HID.
 
 ## Mobile (Android / iOS) is out of scope
 
-Mobile USB / NFC access does not flow through libykpers — Android requires
-the Yubico Android SDK (Java/Kotlin via JNI) and iOS requires the Yubico
-iOS SDK (Swift, with NFC for non-MFi access). Each is a separate flugo
-bridge effort. Desktop only here.
+The desktop files are `//go:build !android && !ios && !nohw`; mobile uses the
+`chalresp_mobile.go` stub. Actual mobile HW-key support lives in flugo
+(`flugo/pkg/hardware/nfckey`) via the Yubico Android/iOS SDKs.
 
-[libykpers]: https://github.com/Yubico/yubikey-personalization
-[ykpers-win]: https://developers.yubico.com/yubikey-personalization/Releases/
+[gohid]: https://github.com/sstallion/go-hid
+[scard]: https://github.com/ebfe/scard