Bug 1686579
| Summary: | GnuTLS server sends downgrade sentinel when negotiating TLS 1.3 | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 8 | Reporter: | Hubert Kario <hkario> |
| Component: | gnutls | Assignee: | Anderson Sasaki <ansasaki> |
| Status: | CLOSED ERRATA | QA Contact: | Tomas Mraz <tmraz> |
| Severity: | high | Docs Contact: | |
| Priority: | high | ||
| Version: | 8.0 | CC: | dueno, pasik, tmraz |
| Target Milestone: | rc | Keywords: | TestBlocker, Triaged |
| Target Release: | 8.0 | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | gnutls-3.6.8-1.el8 | Doc Type: | If docs needed, set a value |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2019-11-05 22:26:14 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 1682477, 1689967 | ||
| Bug Blocks: | |||
Upstream fix: https://gitlab.com/gnutls/gnutls/merge_requests/918 One more problem: the server is not setting the downgrade sentinel when the TLS 1.3 support is disabled and TLS 1.1 or TLS 1.0 is negotiated. see also: bug 1716563 Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2019:3600 |
Description of problem: ServerHello message sent by gnutls server includes the sentinel value in server_random that should be used when the server has TLS 1.3 enabled but negotiated TLS 1.2, despite the connection using TLS 1.3. Version-Release number of selected component (if applicable): gnutls-3.6.5-2.el8.x86_64 How reproducible: always Steps to Reproduce: 1. run any tlsfuzzer test that negotiates TLS 1.3, e.g. test-tls13-keyupdate.py Actual results: sanity ... Error encountered while processing node <tlsfuzzer.expect.ExpectServerHello object at 0x7f6103b1eef0> (child: <tlsfuzzer.expect.ExpectChangeCipherSpec object at 0x7f6103b1ef28>) with last message being: <tlslite.messages.Message object at 0x7f6103b62668> Error while processing Traceback (most recent call last): File "tlsfuzzer/scripts/test-tls13-keyupdate.py", line 585, in main runner.run() File "/tmp/tmp.bVoGaKAI5j/tlsfuzzer/tlsfuzzer/runner.py", line 227, in run node.process(self.state, msg) File "/tmp/tmp.bVoGaKAI5j/tlsfuzzer/tlsfuzzer/expect.py", line 586, in process self._check_downgrade_protection(srv_hello) File "/tmp/tmp.bVoGaKAI5j/tlsfuzzer/tlsfuzzer/expect.py", line 666, in _check_downgrade_protection "Server set downgrade protection sentinel but shouldn't " AssertionError: Server set downgrade protection sentinel but shouldn't have done that Expected results: connection established, error not printed, random not including the sentinel value Additional info: