Crate redactor 

Shared #![no_std] in-process redaction and hashing utilities for network identifiers (MAC addresses, BSSIDs, and SSIDs).

This crate is #![no_std] so that platform-agnostic base crates such as net-types and ieee80211 can implement Redactable directly and share a single process-global Redactor state machine.

Responsibilities are split in two:

• A Redactor only obscures data: it maps the 6 octets of a MAC/BSSID to 6 octets safe to display, and an SSID to a fixed-size digest. It never decides how those bytes are rendered.
• A Redactable type owns its string representation. It provides its raw formatting in Redactable::fmt_unredacted and formats the bytes returned by a Redactor in Redactable::fmt_redacted; its Display/Debug impls (see impl_display_via_redactable!) call Redactable::fmt_dispatch, which picks one depending on whether a global redactor has been installed.

By default (such as on eng builds, in unit tests, and in host tools), no global redactor is installed and fmt_dispatch writes the raw value.

When initialized at component startup on user and userdebug builds:

• set_masking_redactor synchronously installs MaskingRedactor, which preserves the first 3 OUI octets of a MAC and zeroes everything else, before the per-boot salt arrives.
• set_salted_redactor transitions the global redactor to SaltedRedactor, which preserves the first 3 OUI octets of a MAC/BSSID and replaces the last 3 octets (and the SSID) with a salted SHA-256 digest keyed by a 32-byte per-boot random salt.

Macros

impl_debug_via_redactable

Implements core::fmt::Debug for a type that implements Redactable by delegating to Redactable::fmt_dispatch, so {:?} produces the same (possibly redacted) output as {}.

impl_display_via_redactable

Implements core::fmt::Display for a type that implements Redactable by delegating to Redactable::fmt_dispatch.

Structs

MaskingRedactor

A Redactor that preserves the first 3 OUI vendor octets of a MAC and zeroes the remaining 3 octets, and zeroes SSID digests. Used in the window between component startup and the per-boot salt becoming available.

SaltedRedactor

A Redactor that hashes identifiers using a 32-byte per-boot secret salt.

SetRedactorError

Error returned when attempting to install a final global Redactor after one has already been installed.

Unredacted

A Display adapter that always formats a Redactable value in its raw, unredacted form, bypassing the global redactor.

Constants

MAC_LEN

Length in bytes of an IEEE 802.3 / 802.11 MAC address or BSSID.

REDACTED_MARKER

Suffix that Redactable::fmt_redacted implementations append so a redacted identifier is distinguishable at a glance from a raw one (e.g. 00:1a:2b:9f:3e:c1*). Shared so every crate emits the same marker and cross-component correlation keeps working.

SALT_LEN

Length in bytes of the per-boot random salt.

SSID_DIGEST_LEN

Length in bytes of the digest a Redactor produces for an SSID.

Traits

Redactable

Trait implemented by identifier types (such as MAC addresses, BSSIDs, and SSIDs) whose Display and Debug representations support redaction via the global Redactor.

Redactor

Strategy for obscuring MAC addresses, BSSIDs, and SSIDs.

Functions

set_masking_redactor

Synchronously transitions the global redactor from Uninitialized to MaskingRedactor while the per-boot salt is being fetched asynchronously.

set_salted_redactor

Installs a SaltedRedactor with the given salt as the global redactor.