Linux Kernel Security (SELinux vs AppArmor vs Grsecurity) Linux kernel is the central component of Linux operating systems. It is responsible for managing the system’s resources, the communication between hardware and software and security. Kernel play a critical role in supporting security at higher levels. Unfortunately, stock kernel is not secured out of box. There are some important Linux kernel patches to […]

How to disable a particular AppArmor profile on Ubuntu AppArmor, which is considered an alternative to SELinux, is the default application access control system of Ubuntu. Many Ubuntu packages (e.g., libvirt, MySQL) come with their corresponding AppArmor profiles which restrict the capabilities of programs to be installed. If you are suspecting that AppArmor is interfering with particular software, you can try disabling […]

Fix server certificate verification failed – manual trust CA Cert

Example do as root: echo -n | openssl s_client -connect | sed -ne ‘/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p’| tee ‘/usr/local/share/ca-certificates/git_kolab_org.crt’ echo -n | openssl s_client -connect | sed -ne ‘/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p’| tee ‘/usr/local/share/ca-certificates/’ update-ca-certificates

Enable Roundcube filters in Vesta 0.98 on CentOS 6.6 #Install Dovecot Manage Sieve yum install dovecot-pigeonhole #edit 20-managesieve.conf vi /etc/dovecot/conf.d/20-managesieve.conf #Uncomment protocols protocols = $protocols sieve #Edit 10-master.conf #add in section listed in blue vi /etc/dovecot/conf.d/10-master.conf service auth { unix_listener auth-client { group = mail mode = 0660 user = dovecot }   unix_listener auth-master { group = mail mode = 0660 user […]

Sieve Mail Filtering Setup This article covers: Email filtering e.g. showing trash can to newsletters who do not honor unsubscribe links automatically. This is like Gmail filters. Global spam filtering e.g. moving spam from inbox to junk folder (automatically) Installing packages for sieve and managesieve We are using dovecot pigeonhole project for sieve support.ap apt-get install dovecot-sieve dovecot-lmtpd dovecot-managesieved roundcube-plugins-extra libnet-sieve-script-perl libnet-sieve-perl php-net-sieve Please note […]

How to set-up server-side email filtering with Dovecot Sieve and Roundcube on a CentOS 6 VPS The following article is part 6 of the mailserver set-up with virtual users and domains using Postfix and Dovecot series. It covers the steps used to set-up server-side email filtering with Dovecot Sieve and Roundcube on a CentOS 6 VPS At the end of this article you will end up having the ability to set-up your own server-side mail filter rules and automaticallydeliver […]