about time , ssl and other things …
To see the certification information from linux cli (k is optional for without verification)
curl –vvIk https://<FQDN>or<IP>
To read the certificate file human readable (you can use -inform parameter to change the output format)
openssl x509 -in <your_certificate_file_name_maybe_txt_pem_whatever>
Sometimes you can have broken/corrupted pem or certificate files could be ! maybe wrong copy past , windows to linux copy , ftp copy issues that time using “curl” for only debug could not help pls try more tool to double check for example “wget”
I faced Socket error: [X509] PEM lib (_ssl.c:2751) and couldn’t find any solution and wget helped me, wget show us some of certifications files are not readable.
Another option is using openssl with s_client parameter
openssl s_client -host FQDN -port 443 -quiet
tzdata = time zone database
Sometime people are mixing UTC and GMT , GMT is time zone and UTC is time standard but both of them share same current time practice. No any country or territory use UTC as a local time.
Debian change time zone
sudo cp /usr/share/zoneinfo/xxx/xxx /etc/localtime
About how ntp work , what is stratum, what is reference clock pls check the links below. Generally reference clock is stratum-0 and its atomic time(cesium clock) some more levels there startum-1 , 2 up to 16 and looks like we are querying time from mostly startum-2 servers.
To update time with date command perfect article from nixCraft http://www.cyberciti.biz/faq/howto-set-date-time-from-linux-command-prompt/
I mostly needed this one
date +%T -s “10:13:13”
To password less sudo privileges
echo “noroot ALL=(ALL) NOPASSWD: ALL” >> /etc/sudoers
Posted on 23/08/2016, in Uncategorized and tagged How To Verify SSL Certificate From A Shell Prompt, Socket error: [X509] PEM lib (_ssl.c:2751), s_client, UTC GMT, What is UTC, [X509] PEM lib (_ssl.c:2751). Bookmark the permalink. Leave a comment.