Tag Archives: Linux

Check if the certificate of a domain was revoked

Just had the need to quickly check if the certificate of a domain was revoked or not, and found this tutorial:  OpenSSL: Manually verify a certificate against a CRL Well done, but two problems: If the server doesn’t send all certificates (including the root CA), the verify process will fail Too much to type… So i quickly created a bash … Continue reading

Posted in Bash, Linux, Security, SSL/TLS | Tagged , , , , , , | Leave a comment

Limit/prevent SSH brute force attempts

If you (have to) run a public available SSH server, you may have noticed already that there are a lot of brute force attacks trying to guess a user and password (have a look into /var/log/secure ). If you did it the correct way, you only allow public keys to authenticate of course. But maybe you can’t, because the client … Continue reading

Posted in CentOS, Firewalls, Linux, Security | Tagged , , , , | 1 Comment

Simple Rsync Backup Script

Over the last 10 years i’ve tested and used many different backup solutions for my Linux and Mac machines. I think the very first one i have used regularly was unison. A great tool for bidirectional syncing, but it always had problems with special characters. And, there are many commercial ones out there. The good ones often cost US$ 40-80. Simply too … Continue reading

Posted in Backup, Bash, Linux, Mac | Tagged , , , , | Leave a comment