Cover and document the client KEX role check - #1223
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🟢 Approval recommended
Changes are low-risk (tests + documentation) and the new assertions better pin the intended client-side KEX role behavior.
Pull request overview
Follow-up to #1222 that tightens regression coverage for the client-side KEX role check and clarifies what IsMessageAllowed() is actually answering (receive policy) in src/internal.c.
Changes:
- Extend
TestClientOnlyKexMsgsBlockedto assert that client-expected KEX messages (e.g., 31 and 33) remain allowed in the correct handshake states, including during rekey. - Add explanatory documentation to
IsMessageAllowed()about the unusedstateparameter and the per-KEX-method meaning of message IDs 30–49.
File summaries
| File | Description |
|---|---|
| tests/regress.c | Strengthens client-side regression assertions around which KEX message IDs must be blocked vs. allowed in specific states. |
| src/internal.c | Documents IsMessageAllowed() semantics (receive-only policy / unused state) and contextualizes KEX message ID allocation. |
Review details
- Files reviewed: 2/2 changed files
- Comments generated: 1
- Review effort level: Lite
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TestClientOnlyKexMsgsBlocked now asserts that 31 and 33, the ids a client does receive, stay allowed where the handshake expects them, so widening the role check into a 30-34 range fails the suite. The IsMessageAllowed() comment records the receive-only policy and the per-KEX-method id namespace. - assert id 33 is allowed once expectMsgId is MSGID_KEXDH_GEX_REPLY - assert expectMsgId starts at MSGID_NONE, so the role check is what rejects the blocked ids - recheck all three blocked ids during a rekey on an established session
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Fenrir Automated Review — PR #1223
Scan targets checked: wolfssh-bugs, wolfssh-src
Fenrir result: Approved ✅
No new issues found in the changed files.
Advisory only — this automated result does not count as a GitHub approval.
philljj
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Sep 3, 2026
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Follow-up to #1222. Adds the client-side assertions that pin the new KEX
role check, and a comment recording what
IsMessageAllowed()actuallyanswers.
TestClientOnlyKexMsgsBlockedasserts that 31 and 33, the ids a clientdoes receive, stay allowed where the handshake expects them, so widening
the role check into a 30-34 range fails the suite
IsMessageAllowed()comment records that the side helpers implementthe receive policy only, and that ids 30 to 49 are reallocated by each
KEX method