microsoft / microsoft/demikernel

[inetstack] Initial Sequence Number Selection is not RFC 6528 Compliant

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enhancement
Dominant language
Rust
Stars
1.2k
Forks
151
PR merge metrics
No merged PRs in 30d

Description

Context

RFC 6528 recommends using a cryptographic hash function, along with a (temporally constant) secret key, in the generation of a TCP connection's initial sequence number (ISN). Our current implementation (isn_generator.rs) doesn't appear to do either (the nonce it uses changes with each new ISN calculation, while the secret key shouldn't, see the RFC for the full explanation).

Proposed Solution

Fix our implementation to (a) use an actual cryptographic hash function, along with (b) an appropriate secret key.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with isn_generator.rs and compare its current nonce and secret-key behavior with the requirements in RFC 6528. Trace how TCP initial sequence numbers are generated, then verify that the implementation uses a cryptographic hash and an appropriate temporally constant secret key. Done means the generator follows the RFC’s stated requirements.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
networking, security
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

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