It's possible that we have a bug on our end here. There are two extensions we don't fully support here: * encrypt_then_mac - we have absolutely no knowledge of this, so we should be ignoring it. * certificate_authorities - the tricky one
We do understand certificate_authorities, but we don't handle it from the client. Now, we can (and probably should) ignore it. TLS 1.3 allows the client to use it, even if it is a rare thing to see in practice. Can I suggest that you open a bug for this: https://bugzilla.mozilla.org/enter_bug.cgi?product=NSS&component=Libraries (If you are able, including a full copy of the problematic ClientHello will make this a lot easier for us to diagnose.) On Thu, Feb 2, 2023 at 4:14 AM hanumesh nk <hanumeshn...@gmail.com> wrote: > Hi Team, > Iam using nss-3.68.4-with-nspr-4.32 in my server. Client is trying to > connect to the server using STARTTLS, but after "Client Hello" message is > sent, the server sending "Unsupported Extension" to the client and the > connection getting closed. > > Could anyone help me to figure out which extension did the server not > supported? > > Below is the client hello message with extensions obtained from tcpdump: > Transport Layer Security > TLSv1.2 Record Layer: Handshake Protocol: Client Hello > Content Type: Handshake (22) > Version: TLS 1.0 (0x0301) > Length: 751 > Handshake Protocol: Client Hello > Handshake Type: Client Hello (1) > Length: 747 > Version: TLS 1.2 (0x0303) > Random: <Random> > Session ID Length: 32 > Session ID: <Session id> > Cipher Suites Length: 62 > Cipher Suites (31 suites) > Compression Methods Length: 1 > Compression Methods (1 method) > Extensions Length: 612 > Extension: ec_point_formats (len=4) > Extension: supported_groups (len=12) > Extension: encrypt_then_mac (len=0) > Extension: extended_master_secret (len=0) > Extension: signature_algorithms (len=48) > Extension: supported_versions (len=9) > Extension: psk_key_exchange_modes (len=2) > Extension: key_share (len=38) > Extension: certificate_authorities (len=463) > > Any help to resolve this problem will be really helpful. > > > Best Regards, > Hanumesh > > -- > You received this message because you are subscribed to the Google Groups " > dev-tech-crypto@mozilla.org" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to dev-tech-crypto+unsubscr...@mozilla.org. > To view this discussion on the web visit > https://groups.google.com/a/mozilla.org/d/msgid/dev-tech-crypto/CAMiJu-nkJqwp3fwY9JXPYZSLeu%3DuLU15WYbNxK3OG5ZjTxps9A%40mail.gmail.com > <https://groups.google.com/a/mozilla.org/d/msgid/dev-tech-crypto/CAMiJu-nkJqwp3fwY9JXPYZSLeu%3DuLU15WYbNxK3OG5ZjTxps9A%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "dev-tech-crypto@mozilla.org" group. To unsubscribe from this group and stop receiving emails from it, send an email to dev-tech-crypto+unsubscr...@mozilla.org. To view this discussion on the web visit https://groups.google.com/a/mozilla.org/d/msgid/dev-tech-crypto/CAPLxc%3DXrWyivFRsfUDfXgQKRGJ94FP2B0fVmXQ8LEysRcV_oRg%40mail.gmail.com.
