The sys admin's daily grind: SSLScan
Keychain for Life
If, like our author Charly, you manage SSL-secured servers, read on to discover a tool that you will definitely appreciate. It checks whether the complete security setup is up to date.
SSL-secured services are the rule today, rather than the exception. But, how can I quickly and easily check a large number of servers to see whether the encryption methods in use are still up to date? With the SSLScan tool [1].
In the simplest case, I can just call SSLScan with the URL of the website that I want to test: sslscan example.com
. Listing 1 shows that SSLScan simply tried a long list of ciphers and returned a status of Accepted, Rejected, or Failed for each one.
Listing 1
sslscan example.com
However, I am primarily interested in what ciphers the server accepts, not what it rejects. The following command:
sslscan --no-failed www.example.com
helps me significantly thin out the output, reducing it to a third of the original length. Things become even clearer if I add more restrictions. For example, if I want to know whether the server still supports SSLv2, I can check the target like this:
sslscan --no-failed --ssl2 www.example.com
The --ssl3
and --tls1
parameters work in the same way; however, SSLScan also lets you test mail servers, not just web servers. You need the --starttls
parameter to do this. Figure 1 shows the output from
sslscan --no-failed --starttls --tlsv1kuehnast.com:25
The last column of the figure shows which ciphers the server prefers.
Redirection
I can use --xml=<file name>
to redirect the output to an XML file. This method is useful for a script with which I periodically check and/or document the encryption capabilities of the server. A combination with --targets=<file name>
is useful here. I can use this to write a list of host names to the file – along with the port numbers, if there happen to be any ports other than 443. SSLScan then automatically checks the machines one after another.
Another addition to my toolbox! The SSLScan security checker is fast, lean, and easy to automate.
Infos
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
TUXEDO Computers Unveils Linux Laptop Featuring AMD Ryzen CPU
This latest release is the first laptop to include the new CPU from Ryzen and Linux preinstalled.
-
XZ Gets the All-Clear
The back door xz vulnerability has been officially reverted for Fedora 40 and versions 38 and 39 were never affected.
-
Canonical Collaborates with Qualcomm on New Venture
This new joint effort is geared toward bringing Ubuntu and Ubuntu Core to Qualcomm-powered devices.
-
Kodi 21.0 Open-Source Entertainment Hub Released
After a year of development, the award-winning Kodi cross-platform, media center software is now available with many new additions and improvements.
-
Linux Usage Increases in Two Key Areas
If market share is your thing, you'll be happy to know that Linux is on the rise in two areas that, if they keep climbing, could have serious meaning for Linux's future.
-
Vulnerability Discovered in xz Libraries
An urgent alert for Fedora 40 has been posted and users should pay attention.
-
Canonical Bumps LTS Support to 12 years
If you're worried that your Ubuntu LTS release won't be supported long enough to last, Canonical has a surprise for you in the form of 12 years of security coverage.
-
Fedora 40 Beta Released Soon
With the official release of Fedora 40 coming in April, it's almost time to download the beta and see what's new.
-
New Pentesting Distribution to Compete with Kali Linux
SnoopGod is now available for your testing needs
-
Juno Computers Launches Another Linux Laptop
If you're looking for a powerhouse laptop that runs Ubuntu, the Juno Computers Neptune 17 v6 should be on your radar.