peripheral_core/
lib.rs

1//! `peripheral-core` — external-device (peripheral) connection forensic reader.
2//!
3//! Parses Windows `setupapi.dev.log` device-installation logs into a uniform
4//! [`DeviceConnection`] stream: bus-classified, with each timestamp tagged
5//! authoritative-vs-inferred and the USB iSerial kept distinct from any volume
6//! serial. The input is attacker-controllable evidence — parsing is lenient
7//! (lossy UTF-8), bounds-checked, and never panics. No `unsafe`.
8//!
9//! Findings (DMA-capable device, mass-storage, HID/BadUSB, OS-generated serial)
10//! live in the sibling `peripheral-forensic` crate; this crate only decodes.
11//!
12//! ## v0.2 enrichment (not in this release)
13//!
14//! The richest source — the Windows registry `SYSTEM\CurrentControlSet\Enum\`
15//! keys (USBSTOR/USB), `MountedDevices`, and the device-property `0066`/`0067`
16//! Last-Arrival/Last-Removal `FILETIME`s — plus EVTX device events require the
17//! (unpublished) `winreg-core` and `winevt-forensic` crates. They are deferred
18//! to v0.2; v0.1 is scoped to the self-contained `setupapi.dev.log` source.
19
20#![forbid(unsafe_code)]
21
22pub mod linux_syslog;
23pub mod registry;
24pub mod setupapi;
25
26/// The physical/logical bus a peripheral attached through.
27///
28/// The variant drives the DMA-capability and storage-class threat lenses
29/// downstream (see [`DeviceConnection::dma_capable`]).
30#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
31pub enum Bus {
32    /// USB (host-controller mediated; not directly DMA-capable as mass storage).
33    Usb,
34    /// Media Transfer Protocol (phones/cameras) — surfaced via `WpdBusEnumRoot`.
35    Mtp,
36    /// IEEE 1394 FireWire — bus-mastering DMA.
37    FireWire,
38    /// Thunderbolt — PCIe tunnelled, bus-mastering DMA.
39    Thunderbolt,
40    /// PCI Express — bus-mastering DMA.
41    Pcie,
42    /// External SATA — SATA/storage transport, explicitly NOT DMA.
43    Esata,
44    /// SD/MMC card.
45    SdMmc,
46    /// Bluetooth (typically HID/wireless).
47    Bluetooth,
48    /// ExpressCard — PCIe-backed, bus-mastering DMA.
49    ExpressCard,
50    /// SCSI / SAS storage transport.
51    ScsiSas,
52    /// NVMe storage.
53    Nvme,
54    /// Bus could not be determined from the enumerator.
55    Unknown,
56}
57
58impl Bus {
59    /// Classify a bus from a setupapi/instance-id **enumerator** prefix — the
60    /// leading token of a device instance id (`USBSTOR`, `USB`, `1394`, `PCI`,
61    /// `SCSI`, `SD`, `WpdBusEnumRoot`, …), matched case-insensitively.
62    ///
63    /// Returns [`Bus::Unknown`] for an unrecognized or empty enumerator; the
64    /// caller never gets a panic.
65    #[must_use]
66    pub fn from_enumerator(enumerator: &str) -> Self {
67        let e = enumerator.trim().to_ascii_uppercase();
68        match e.as_str() {
69            "USBSTOR" | "USB" => Self::Usb,
70            "1394" => Self::FireWire,
71            "THUNDERBOLT" => Self::Thunderbolt,
72            "PCI" | "PCIE" => Self::Pcie,
73            "SCSI" | "SAS" => Self::ScsiSas,
74            "NVME" => Self::Nvme,
75            "SD" | "MMC" | "SDBUS" => Self::SdMmc,
76            "ESATA" => Self::Esata,
77            "BTHENUM" | "BTHLE" | "BLUETOOTH" => Self::Bluetooth,
78            "EXPRESSCARD" => Self::ExpressCard,
79            "WPDBUSENUMROOT" | "MTP" => Self::Mtp,
80            _ => Self::Unknown,
81        }
82    }
83
84    /// Whether this bus can perform **bus-mastering DMA**, the property that
85    /// makes a device a direct-memory-access attack surface (MITRE T1200).
86    ///
87    /// DMA-capable: FireWire, Thunderbolt, PCIe, ExpressCard. Storage-class
88    /// transports (USB mass storage, eSATA, SD/MMC, SCSI/SAS, NVMe) and
89    /// HID/wireless transports (USB-HID, Bluetooth) are NOT DMA in this model.
90    ///
91    /// Caveat: SD-Express tunnels PCIe and *can* be DMA-capable; this v0.1
92    /// classifier treats bare `SD` as the legacy non-DMA SD/MMC bus, the common
93    /// case. Distinguishing SD-Express needs the device-capability bits that the
94    /// registry/EVTX v0.2 source carries.
95    #[must_use]
96    pub fn is_dma_capable(self) -> bool {
97        matches!(
98            self,
99            Self::FireWire | Self::Thunderbolt | Self::Pcie | Self::ExpressCard
100        )
101    }
102
103    /// Whether this bus is a removable mass-storage transport (the
104    /// data-exfiltration / autorun lens, MITRE T1052.001 / T1091).
105    #[must_use]
106    pub fn is_mass_storage(self) -> bool {
107        matches!(
108            self,
109            Self::Usb | Self::Esata | Self::SdMmc | Self::ScsiSas | Self::Nvme
110        )
111    }
112}
113
114/// How much trust a timestamp carries.
115#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
116pub enum Confidence {
117    /// Directly recorded by the source as the stated event
118    /// (e.g. the setupapi section-header install time → first-seen).
119    Authoritative,
120    /// Derived/undocumented — the value's meaning is inferred, not stated by the
121    /// source (e.g. the registry `0066`/`0067` Last-Arrival/Last-Removal
122    /// device-property `FILETIME`s, which are undocumented).
123    Inferred,
124}
125
126/// A timestamp tagged with its evidentiary confidence.
127///
128/// Pairing the value with its [`Confidence`] in the type makes the
129/// authoritative-vs-inferred distinction impossible to drop on the floor: a
130/// consumer cannot read `value` without also seeing how trustworthy it is.
131#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
132pub struct Stamp {
133    /// Unix epoch seconds.
134    pub value: i64,
135    /// How the value should be trusted.
136    pub confidence: Confidence,
137}
138
139impl Stamp {
140    /// An authoritative (source-stated) timestamp.
141    #[must_use]
142    pub fn authoritative(value: i64) -> Self {
143        Self {
144            value,
145            confidence: Confidence::Authoritative,
146        }
147    }
148
149    /// An inferred (derived/undocumented) timestamp.
150    #[must_use]
151    pub fn inferred(value: i64) -> Self {
152        Self {
153            value,
154            confidence: Confidence::Inferred,
155        }
156    }
157}
158
159/// A MITRE ATT&CK technique a connection is *consistent with* — never a verdict.
160#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
161pub struct MitreRef(pub &'static str);
162
163/// One external-device connection, normalized across sources.
164///
165/// The forensic cautions are baked into the type, not just the docs:
166/// - [`device_serial`](Self::device_serial) is the **USB iSerial** and is a
167///   distinct field from [`volume_serial`](Self::volume_serial) (a filesystem
168///   volume serial), so the two can never be conflated.
169/// - [`serial_is_os_generated`](Self::serial_is_os_generated) records that the
170///   device had no real iSerial (Windows synthesized one), weakening attribution.
171/// - Each timestamp is a [`Stamp`] carrying its authoritative-vs-inferred
172///   [`Confidence`].
173#[derive(Debug, Clone, PartialEq, Eq)]
174pub struct DeviceConnection {
175    // ── Identity ────────────────────────────────────────────────────────────
176    /// The classified bus.
177    pub bus: Bus,
178    /// Device setup-class GUID, when known.
179    pub device_class_guid: Option<String>,
180    /// USB vendor id (`VID_xxxx`).
181    pub vid: Option<u16>,
182    /// USB product id (`PID_xxxx`).
183    pub pid: Option<u16>,
184    /// The **USB iSerial** — the device-unique serial reported by the device.
185    /// DISTINCT from any [`volume_serial`](Self::volume_serial).
186    pub device_serial: Option<String>,
187    /// `true` when the instance-id serial was synthesized by Windows (the
188    /// serial's 2nd character is `&`) — the device exposed no real iSerial, so
189    /// attribution is weaker.
190    pub serial_is_os_generated: bool,
191    /// Human-readable friendly name, when present.
192    pub friendly_name: Option<String>,
193    /// The full device instance id (e.g.
194    /// `USB\VID_0781&PID_5583\1234567890AB`) — the primary key.
195    pub device_instance_id: String,
196
197    // ── Timestamps (each tagged authoritative-vs-inferred) ───────────────────
198    /// First-seen / first-install — authoritative when from the setupapi
199    /// section header.
200    pub first_install: Option<Stamp>,
201    /// Last install/driver event.
202    pub last_install: Option<Stamp>,
203    /// Last arrival (connect). INFERRED — derived from the undocumented registry
204    /// `0066` device property (v0.2).
205    pub last_arrival: Option<Stamp>,
206    /// Last removal (disconnect). INFERRED — derived from the undocumented
207    /// registry `0067` device property (v0.2).
208    pub last_removal: Option<Stamp>,
209
210    // ── Correlation join keys (volume_serial kept DISTINCT from device_serial) ─
211    /// `ParentIdPrefix` — joins the storage device to its volume.
212    pub parent_id_prefix: Option<String>,
213    /// Volume GUID (`\\?\Volume{...}`).
214    pub volume_guid: Option<String>,
215    /// Mounted drive letter.
216    pub drive_letter: Option<char>,
217    /// Filesystem **volume** serial (NTFS/FAT) — DISTINCT from the device's
218    /// USB [`device_serial`](Self::device_serial).
219    pub volume_serial: Option<u32>,
220    /// MBR disk signature.
221    pub disk_signature: Option<u32>,
222
223    // ── Threat lens ──────────────────────────────────────────────────────────
224    /// Whether the bus is bus-mastering DMA-capable (see [`Bus::is_dma_capable`]).
225    pub dma_capable: bool,
226    /// MITRE ATT&CK techniques this connection is *consistent with*.
227    pub mitre: Vec<MitreRef>,
228
229    // ── Provenance ───────────────────────────────────────────────────────────
230    /// Where this record came from (source file + 1-based line).
231    pub source: Provenance,
232}
233
234/// Where a [`DeviceConnection`] was decoded from.
235#[derive(Debug, Clone, PartialEq, Eq)]
236pub struct Provenance {
237    /// The source file (e.g. `setupapi.dev.log`, or the hive name `SYSTEM`).
238    pub file: String,
239    /// 1-based line number of the section header the record came from, for
240    /// line-oriented sources (`setupapi.dev.log`). `0` when the source is not
241    /// line-oriented (e.g. a registry hive — see [`key_path`](Self::key_path)).
242    pub line: usize,
243    /// The full registry key path the record was decoded from, for hive sources
244    /// (e.g. `ControlSet001\Enum\SCSI\Disk&Ven_…\5&22be343f&0&000000`). `None` for
245    /// line-oriented sources.
246    pub key_path: Option<String>,
247}
248
249#[cfg(test)]
250mod tests {
251    use super::*;
252
253    #[test]
254    fn usb_enumerators_classify_as_usb() {
255        assert_eq!(Bus::from_enumerator("USBSTOR"), Bus::Usb);
256        assert_eq!(Bus::from_enumerator("USB"), Bus::Usb);
257        assert_eq!(Bus::from_enumerator("usbstor"), Bus::Usb); // case-insensitive
258    }
259
260    #[test]
261    fn bus_specific_enumerators_classify() {
262        assert_eq!(Bus::from_enumerator("1394"), Bus::FireWire);
263        assert_eq!(Bus::from_enumerator("SCSI"), Bus::ScsiSas);
264        assert_eq!(Bus::from_enumerator("PCI"), Bus::Pcie);
265        assert_eq!(Bus::from_enumerator("SD"), Bus::SdMmc);
266        assert_eq!(Bus::from_enumerator("WpdBusEnumRoot"), Bus::Mtp);
267        assert_eq!(Bus::from_enumerator("THUNDERBOLT"), Bus::Thunderbolt);
268        assert_eq!(Bus::from_enumerator("ESATA"), Bus::Esata);
269        assert_eq!(Bus::from_enumerator("EXPRESSCARD"), Bus::ExpressCard);
270        assert_eq!(Bus::from_enumerator("BTHENUM"), Bus::Bluetooth);
271        assert_eq!(Bus::from_enumerator("NVME"), Bus::Nvme);
272    }
273
274    #[test]
275    fn unknown_enumerator_is_unknown_never_panics() {
276        assert_eq!(Bus::from_enumerator("HID"), Bus::Unknown);
277        assert_eq!(Bus::from_enumerator(""), Bus::Unknown);
278        assert_eq!(Bus::from_enumerator("   "), Bus::Unknown);
279    }
280
281    #[test]
282    fn dma_capable_is_exactly_firewire_thunderbolt_pcie_expresscard() {
283        for b in [Bus::FireWire, Bus::Thunderbolt, Bus::Pcie, Bus::ExpressCard] {
284            assert!(b.is_dma_capable(), "{b:?} must be DMA-capable");
285        }
286        // Storage-only transports are explicitly NOT DMA (eSATA is SATA/storage).
287        for b in [Bus::Usb, Bus::Esata, Bus::SdMmc, Bus::ScsiSas, Bus::Nvme] {
288            assert!(!b.is_dma_capable(), "{b:?} must NOT be DMA-capable");
289        }
290        // HID/wireless transports are not DMA either.
291        for b in [Bus::Bluetooth, Bus::Mtp, Bus::Unknown] {
292            assert!(!b.is_dma_capable(), "{b:?} must NOT be DMA-capable");
293        }
294    }
295
296    #[test]
297    fn mass_storage_classes() {
298        for b in [Bus::Usb, Bus::Esata, Bus::SdMmc, Bus::ScsiSas, Bus::Nvme] {
299            assert!(b.is_mass_storage(), "{b:?} should be mass storage");
300        }
301        for b in [Bus::FireWire, Bus::Thunderbolt, Bus::Bluetooth, Bus::Mtp] {
302            assert!(!b.is_mass_storage(), "{b:?} should not be mass storage");
303        }
304    }
305
306    #[test]
307    fn stamp_carries_confidence() {
308        assert_eq!(
309            Stamp::authoritative(10).confidence,
310            Confidence::Authoritative
311        );
312        assert_eq!(Stamp::inferred(10).confidence, Confidence::Inferred);
313    }
314}
peripheral_core/lib.rs

peripheral_core/
lib.rs
