#1004086 apache2-bin: mod_ssl ignores SSLOpenSSLConfCmd DHParameters

Package:
apache2-bin
Source:
apache2
Description:
Apache HTTP Server (modules and other binary files)
Submitter:
"craft-haiku-1955@t-online.de"
Date:
2022-01-20 16:12:04 UTC
Severity:
normal
#1004086#5
Date:
2022-01-20 16:01:44 UTC
From:
To:
Dear Maintainer,

I use a 4096-bit RSA certificate and corresponding 4096-bit DH parameters generated with

openssl dhparam -outform pem -out /etc/apache2/ssl/dhparam4k.pem 4096

I configured these parameters in Apache with

SSLOpenSSLConfCmd DHParameters /etc/apache2/ssl/dhparam4k.pem

Since the upgrade to Bullseye, these parameters seem to be ignored:
sslscan and ssllabs show that my DHE parameters are only 3072 bits.

When I test the same configuration on a Buster machine the correct 4096 bits are shown.