F18 plans M5 as 9 sub-followups (F18-F26 + F27 constant-time DH) per
design/dependencies.md:73-89. Wave-1 streams F20-F23+F24 are parallel-safe
after F19 (workspace deps). F25 (ASB client) is sequential after the
framing/encoder streams. F26 (Session over AsbTransport) is sequential
after F25.
F19 — workspace deps for the M5 crypto + framing surface: hmac, md-5,
sha1, sha2, aes, cbc, pbkdf2, flate2, rand, num-bigint, num-traits,
num-integer, quick-xml, tokio-util, zeroize. Pinned to the digest 0.10 /
cipher 0.4 generation matching mxaccess-rpc.
F23 — ports `AsbSystemAuthenticator.cs` (167 LoC) to
`mxaccess-asb-nettcp::auth`. Wire-byte parity points: .NET BigInteger
little-endian two's-complement byte order with optional 0x00 sign-byte
suffix; AES-128-CBC with PKCS7 padding; PBKDF2-SHA1 1000 iterations
over `Convert.ToBase64String(crypto_key)` with ASCII salt
"ArchestrAService"; deflate-then-AES (Baktun) vs raw-AES (Apollo)
selected by `:V2` lifetime suffix; HMAC-MD5/SHA1/SHA512 negotiated per
`AsbSolutionCryptoParameters.HashAlgorithm` (with `force_hmac=true`
fallback to HMAC-SHA1 for unrecognised algorithms).
13 unit tests cover the cryptographic primitives + DH peer agreement +
.NET byte-order round-trip + Apollo lifetime dispatch.
F27 — filed for the `num-bigint` → `crypto-bigint::BoxedUint` swap once
the latter exposes a stable heap-allocated `pow_mod`. Currently at
parity with the .NET reference (also not constant-time).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty
ed17c07c10