Using SSL Communication with Linux-Based Agent

You can secure communication between the Uptime monitoring station and the Uptime Linux agent by enabling SSL encryption. Enabling SSL is a two-step process:

Enabling SSL on the Linux Agent System

To enable SSL encryption, complete the following steps on each agent system:

1. Ensure Stunnel is installed on the agent server. If you do not have access to a distribution, you can download it from Stunnel.org.

2. Edit the /etc/xinetd.d/uptmagnt file so that it includes the following configuration information:

   service uptmagnt 
   { 
   disable = no 
   flags = REUSE 
   socket_type = stream 
   wait = no 
   user = nobody 
   server = /usr/sbin/stunnel 
   server_args = /etc/stunnel/uptmagnt.conf 
   }

3. Create the certificate that will be used by Stunnel. For example:

   openssl req -new -x509 -days 365 -nodes -config stunnel.cnf -out stunnel.pem -keyout stunnel.pem

   The following is a sample stunnel.cnf for the openssl program:

   # create RSA certs - Server
   RANDFILE = stunnel.rnd
   [ req ]
   default_bits = 1024
   encrypt_key = yes
   distinguished_name = req_dn
   x509_extensions = cert_type
   [ req_dn ]
   countryName = Country Name (2 letter code)
   countryName_default = PL
   countryName_min = 2
   countryName_max = 2
   stateOrProvinceName = State or Province Name (full name)
   stateOrProvinceName_default = Some-State
   localityName = Locality Name (eg, city)
   0.organizationName = Organization Name (eg, company)
   0.organizationName_default = Stunnel Developers Ltd
   organizationalUnitName = Organizational Unit Name (eg, section)
   #organizationalUnitName_default =
   0.commonName = Common Name (FQDN of your server)
   0.commonName_default = localhost
   # To create a certificate for more than one name uncomment:
   # 1.commonName = DNS alias of your server
   # 2.commonName = DNS alias of your server
   # ...
   # See http://home.netscape.com/eng/security/ssl_2.0_certificate.html
   # to see how Netscape understands commonName.
   [ cert_type ]
   nsCertType = server

4. Copy stunnel.pem to /etc/stunnel/uptmagnt.pem.
   Create the /etc/stunnel/uptmagnt.conf file and add the following lines:

   cert=/etc/stunnel/uptmagnt.pem 
   exec=/opt/uptime-agent/bin/uptmagnt

   Restart the xinetd service. After doing this, your agent should now be in SSL mode.

   You can verify that your agent is communicating securely by running the following command on your monitoring station:

   agentcmd +s -p 9998 <hostname> df-k

Enabling SSL in the Uptime UI

If the Linux agent has already been added to Uptime, complete the following steps in the Uptime Web interface for each agent system that you want to configure to use SSL.

1. Click My Infrastructure.
2. Click the name of the agent system for which you want to enable SSL.
3. On the system information page, click the Edit Performance Monitor link in the System Profile section.
4. In the new Edit Service Monitor window that appears, select the Use SSL (HTTPS) option.
5. Click Save.
   Once saved, your Monitoring Station and agent system will be communicating via SSL.

If you have not yet added the agent system to Uptime, follow the steps that are detailed in the Uptime User Guide. When adding the agent system, ensure that the Agent Port Number option is set to 9998, and that the Use SSL (HTTPS) option is enabled.