First piece of Hitag support. Adds the Hitag2 48-bit stream cipher and a
software-sim transponder/reader over SoftwareMedium (parity with the
other LF tags).
- hitag2_crypto.py: pure-Python port of the Proxmark reference cipher
(firmware tools/hitag2crack/hitag2_gen_nRaR.py). Validated bit-for-bit
against the classic MIKRON golden vector (keystream 0xD7237FCE, full
16-byte sequence). Hitag2Cipher wraps a running session (bits() for the
authenticator, transcrypt() for link encryption).
- hitag2.py: Hitag2Tag (8 x 32-bit pages, UID/key/config/password) and
Hitag2Reader. Faithful UID request (5-bit START_AUTH), password-mode
auth (page-1 RWD password), and crypto-mode auth (64-bit nR||aR + aR
verify + transcrypt). Wrong key is rejected; UID page is read-only.
Software-sim command framing between our own tag/reader; the crypto and
auth handshake are bit-faithful to real tags. 12 tests.
Hitag S / Hitag u, the reader client commands, and sniff/trace decode
follow in subsequent commits.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
