BUG #16829: Postgresql-12 service is not starting with SSL enabled in centos 7

The following bug has been logged on the website:

Bug reference: 16829
Logged by: Bibhu Sahoo
Email address: bibhu791(at)gmail(dot)com
PostgreSQL version: 12.5
Operating system: linux centos 7
Description:

We observed below two issues in centos 7.

1: We used 3 postgres12 rpms (postgresql12-12.5-1PGDG.rhel7.x86_64.rpm,
postgresql12-libs-12.5-1PGDG.rhel7.x86_64.rpm,
postgresql12-server-12.5-1PGDG.rhel7.x86_64.rpm).

By default ssl was 'off' in postgresql.conf. when we tried starting
postgres service getting status like 'activating (start)' and 'Starting
PostgreSQL 12'. This is not becoming to 'active and started'. But able to
connect to postgres db. Output as below.

[root(at)space-000c2932ed49 RPMS]# systemctl status postgresql-12
\u25cf postgresql-12.service - PostgreSQL 12 database server
Loaded: loaded (/usr/lib/systemd/system/postgresql-12.service; enabled;
vendor preset: disabled)
Active: activating (start) since Mon 2021-01-18 12:28:26 UTC; 25s ago
Docs: https://www.postgresql.org/docs/12/static/
Process: 11236 ExecStartPre=/usr/pgsql-12/bin/postgresql-12-check-db-dir
${PGDATA} (code=exited, status=0/SUCCESS)
Main PID: 11242 (postmaster)
Tasks: 8
CGroup: /system.slice/postgresql-12.service
\u251c\u250011242 /usr/pgsql-12/bin/postmaster -D
/var/lib/pgsql/12/data/
\u251c\u250011244 postgres: logger
\u251c\u250011246 postgres: checkpointer
\u251c\u250011247 postgres: background writer
\u251c\u250011248 postgres: walwriter
\u251c\u250011249 postgres: autovacuum launcher
\u251c\u250011250 postgres: stats collector
\u2514\u250011251 postgres: logical replication launcher

Jan 18 12:28:26 space-000c2932ed49 systemd[1]: Starting PostgreSQL 12
database server...
[root(at)space-000c2932ed49 RPMS]#

2: We changed ssl=off to ssl=on in postgresql.conf file and also added ssl
ciphers. When we tried to start the postgres service, postgres service is
not starting and showing the below error.

[root(at)space-000c2932ed49 data]# systemctl status postgresql-12
\u25cf postgresql-12.service
Loaded: not-found (Reason: No such file or directory)
Active: failed (Result: exit-code) since Mon 2021-01-18 12:53:23 UTC;
12min ago
Main PID: 15357 (code=exited, status=1/FAILURE)

Jan 18 12:53:23 space-000c2932ed49 systemd[1]: Starting PostgreSQL 12
database server...
Jan 18 12:53:23 space-000c2932ed49 systemd[1]: postgresql-12.service: main
process exited, code=exited, status=1/FAILURE
Jan 18 12:53:23 space-000c2932ed49 systemd[1]: Failed to start PostgreSQL 12
database server.
Jan 18 12:53:23 space-000c2932ed49 systemd[1]: Unit postgresql-12.service
entered failed state.
Jan 18 12:53:23 space-000c2932ed49 systemd[1]: postgresql-12.service
failed.
[root(at)space-000c2932ed49 data]#

Didn't observe any error in postgres log.