On Sun, Nov 01, 2026 at 08:03:04PM +0000, Christopher Staite wrote:
> Subject: [PATCH] BUG/MEDIUM: ssl: skip TLS 1.3 suites in the FIPS TLS 1.2
> cipher check
> Hi,
>
> I’ve been working on my PKCS#11 patch some more
Great to read that :-)
> and I came across a bug that was introduced into 3.5.
>
> With AWS-LC in FIPS mode, ssl_fips_check_ciphers() walks the list returned
> by SSL_CTX_get_ciphers() and rejects any entry whose key exchange is not
> ECDHE (or DHE). But AWS-LC documents that this list includes the TLS 1.3
> cipher suites as well, and for these SSL_CIPHER_get_kx_nid() returns
> NID_kx_any since TLS 1.3 suites do not specify the key exchange. Every
> TLS 1.3 suite is thus reported as a non-FIPS cipher, including the
> FIPS-approved ones that are set by default:
>
> FIPS mode active but non-FIPS cipher(s) configured:
> 'TLS_AES_128_GCM_SHA256', 'TLS_AES_256_GCM_SHA384'.
>
> Since the internal httpclient server is checked as well, HAProxy refuses
> to start in FIPS mode with any configuration, even one without a single
> SSL setting. This was observed with AWS-LC FIPS 4.0.0.
>
> TLS 1.3 suites are already validated against their own list by
> ssl_fips_check_ciphersuites(), so ssl_fips_check_ciphers() must only
> consider TLS 1.2 ciphers. Skip the ciphers whose minimum protocol version
> is TLS 1.3 or above. SSL_CIPHER_get_min_version() was preferred over
> testing for NID_kx_any because it expresses the intent directly rather
> than relying on a side effect of how TLS 1.3 suites are described. Non-FIPS
> TLS 1.2 ciphers (e.g. AES128-SHA or ECDHE-RSA-CHACHA20-POLY1305) and
> non-FIPS TLS 1.3 suites (e.g. TLS_CHACHA20_POLY1305_SHA256) are still
> rejected.
>
> This bug was introduced in 3.5-dev3 by commit 9e2809508 ("MEDIUM: ssl: add
> FIPS TLS 1.2 cipher check for AWS-LC"), no backport is needed.
>
> Thanks, Chris.
Thanks Christopher, I had the same patch in my backlog, in fact that changed
with AWS-LC 4.0.0 because previous versions didn't returned TLS1.3 suites in
SSL_CTX_get_ciphers().
I'm merging it.
--
William Lallemand
