F-5606: don't enforce DTLS 1.3 2^48-1 epoch cap on the receive side#2
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F-5606: don't enforce DTLS 1.3 2^48-1 epoch cap on the receive side#2julek-wolfssl wants to merge 1 commit into
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RFC 9147 Section 8's 2^48-1 epoch ceiling is a sender-only rule; the same paragraph says receiving implementations MUST NOT enforce it. The KeyUpdate receive path was rejecting a peer epoch that crossed 2^48-1, violating that. Guard only the genuine wrap-to-zero (Section 4.2.1) and let the receiving epoch advance past 2^48-1. The sender-side gates are unchanged.
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Superseded by wolfSSL#10627 (opened against wolfSSL master). |
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Summary
Follow-up to F-5606 (wolfSSL#10575). RFC 9147 Section 8's
2^48-1epoch ceiling is a sender-only rule; the same paragraph states that receiving implementations MUST NOT enforce it ("In order to allow this value to be changed later").The KeyUpdate receive path in
DoTls13KeyUpdatewas rejecting a peer epoch that crossed2^48-1, which violates that requirement. This changes the receive-side guard to catch only the genuine wrap-to-zero (RFC 9147 Section 4.2.1) — which would alias epoch 0 and reuse keys — and otherwise lets the receiving (peer) epoch advance past2^48-1.The sender-side gates that keep our own epoch at or below
2^48-1(SendTls13KeyUpdate,Dtls13KeyUpdateAckReceived) are unchanged.Testing
./configure --enable-dtls13 --enable-dtlsand rebuild — compiles cleanly under-Wall -Wextra.