I know I know, there are plenty of openssl cheat sheets out there already (1 or 2). But as I keep using googling it again and again to find the most useful openssl commands I decided to do my own – the first version of the blog entries is already 3 years old actually. Another reason for creating the list is that I remember things better when I am writing the down.

If you come across the situation, that your java programs are not able to connect to ssl encrypted services, it might be most likely that the java cacerts keystore is empty or not uptodate. This might also be due to a bug in the java (or ca-certificate-java) package ((https://bugs.launchpad.net/ubuntu/+source/ca-certificates-java/+bug/1396760)). In order to fix the issue, you can run: sudo /var/lib/dpkg/info/ca-certificates-java.postinst configure

If you are using Cisco ASA, you most likely will also have certificate(s) installed. This is what you need to pay attention to (Version 9.1, higher versions might behave differently):