bitlocker-forensic¶

A from-scratch, pure-Rust BitLocker (BDE) reader and decryptor — unlock a volume from its password and read the plaintext, plus an anomaly auditor over the key-protector metadata.

Scope

This build decrypts the password (0x2000) and recovery-password (0x0800) protectors over five of the six BitLocker ciphers, each validated by pybde: AES-128-CBC ± Elephant Diffuser (0x8000 / 0x8002), AES-256-CBC (0x8003), and XTS-AES-128/256 (0x8004 / 0x8005). Only AES-256-CBC + Elephant Diffuser (0x8001) is recognized-but-refused (no oracle yet); startup-key / TPM protectors are out of scope. The metadata parser still reports their presence. See Format Research and Validation.

What it does¶

BitLocker encrypts a whole volume behind a Full Volume Encryption Key (FVEK), itself wrapped by a Volume Master Key (VMK) that each protector (password, recovery key, TPM, …) can unwrap. bitlocker-core:

parses the -FVE-FS- / BitLocker To Go volume header and the FVE metadata block (key protectors, cipher, volume GUID),
derives the VMK from a password (double-SHA-256) or a recovery password (48 digits → eight ÷11 words → SHA-256), each fed to the 0x100000-iteration stretch → AES-CCM unwrap, then the FVEK from the VMK,
decrypts sectors with AES-CBC (± Elephant Diffuser) or AES-XTS, 128- or 256-bit, honouring BitLocker's volume-header relocation, and
exposes a plaintext Read + Seek view (read_at).

bitlocker-forensic grades the protector metadata into forensicnomicon::report findings (clear-key present, protector inventory, weak cipher, BitLocker To Go).

The two-crate split¶

Crate	Role	Depends on	Emits
`bitlocker-core`	reader / decryptor	`aes`, `cbc`, `ccm`, `sha2`, `thiserror`	plaintext view + typed metadata
`bitlocker-forensic`	anomaly analyzer	`bitlocker-core`, `forensicnomicon`	graded `Finding`s

Trust but verify¶

Every primitive is an audited RustCrypto crate; the only hand-written cryptographic routine is the Elephant Diffuser (no crate exists), validated only against the independent pybde oracle on real data — never a self-authored round-trip. Panic-free, bounds-checked parsing; unwrap/expect denied in production code; fuzzed metadata parser.