Adding FTP Users For VSFTP

1. You will need to log into your Linux server using SSH / Shell. If you are on a Windows workstation you will need to download Putty or if you are using a MacOSX based workstation you can use the built in Telnet application. If you have not used an SSH interface before you can review our support article on how to access your server using SSH by going to http://www.hosting.com/support/vps/linux/ssh.

Cài đặt FTP client CentOS

FTP (File transfer protocol) là một trong những dịch vụ quan trọng trên internet, giúp cho việc truyền tập tin đến máy chủ dễ dàng hơn. Trong bài viết này chúng tôi sẽ hướng dẫn bạn cài đặt dịch vụ FTP trên CentOS.

OpenSSL Command-Line HOWTO

Paul Heinlein <heinlein@madboa.com>

Initial publication: June 13, 2004

Most recent revision: January 3, 2013

The openssl application that ships with the OpenSSL libraries can perform a wide range of crypto operations. This HOWTO provides some cookbook-style recipes for using it.

PHP OCSP script

I have here an OCSP script in PHP. It is not needed if you use the 
apache modified distribution from FedICT:ocsp is included in apache. But
 if you use a standard distribution that is automatically updated 
against new security treats (like me!), you need this. (Probably OCSP 
will be included in apache 2.4?): 

Check and open ports in CentOS / Fedora / Redhat

If you want to open or close a port for a Linux firewall you have to edit the rules in the iptables configuration. By default iptables firewall stores its configuration at /etc/sysconfig/iptables file. You need to edit this file and add rules to open port.

Here are the steps to open the port XY using the default visual editor vi:

Open port XY

Open flle /etc/sysconfig/iptables:

# vi /etc/sysconfig/iptables

Append rule as follows:

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport XY -j ACCEPT

Save and close the file. Restart iptables:

# /etc/init.d/iptables restart

Verify that port is open

Run following command:

# netstat -tulpn | less

Make sure iptables is allowing port connections:

# iptables -L -n

For more information visit:

http://www.cyberciti.biz/faq/howto-rhel-linux-open-port-using-iptables/

Managing X.509 certificates using PHP

To generate, sign and verify certificates you need to have OpenSSL module installed and provide file with OpenSSL configuration.

Một sô lệnh hay OpenSSL

OpenSSL is a very powerful cryptography utility, perhaps a little too powerful for the average user. With all the different command line options, it can be a daunting task figuring out how to do exactly what you want to do. Here are several common tasks you may find useful. Note that some commands may require version 0.9.8a and above.