Monthly Archives: January 2014

How to add an Out of Office message in Office 365 using powershell

Publicat la 22 January 2014 8 comentarii

I know it's a simply task to do from OWA, but if you want to add an Out of Office message for another user, you will have to reset it's password, login into OWA and setup the message there. But I don't want to reset the user's password. So, after connecting to office 365, use the following commands:

[codesyntax lang="powershell"]

Set-MailboxAutoReplyConfiguration -Identity user@example.com -AutoReplyState Enabled -ExternalMessage "message with whatever autoreply" -InternalMessage "internal something autoreply"

[/codesyntax]

How do I disable this?

[codesyntax lang="powershell"]

Set-MailboxAutoReplyConfiguration -Identity user@example.com -AutoReplyState Disabled

[/codesyntax]

How to deal with "RSA server certificate is a CA certificate (BasicConstraints: CA == TRUE !?)" problem

Publicat la 4 January 2014 14 comentarii

If you see [warn] RSA server certificate is a CA certificate (BasicConstraints: CA == TRUE !?) in you apache error.log file means you have created a cert that is intended to be used to sign other certs, but you're using that cert as your SSL cert. So, it depends how you create the SSL cert.

But how can we solve this problem?!

1. Generate private key and certificate signing request

[codesyntax lang="bash"]

openssl genrsa -des3 -passout pass:x -out server.pass.key 2048
openssl rsa -passin pass:x -in server.pass.key -out server.key
rm server.pass.key
openssl req -new -key server.key -out server.csr

[/codesyntax]

Note: when the openssl req command asks for a “challenge password”, just press return, leaving the password empty.

2. Generate SSL certificate

[codesyntax lang="bash"]

openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt

[/codesyntax]

Set port knocking with knockd and iptables

Publicat la 3 January 2014 No comments

This document describes a stealth method to externally open ports that, by default, are kept closed by the firewall.

Server side

1. Install knockd

[codesyntax lang="bash"]

apt-get install knockd

[/codesyntax]

2. Configure knockd

[codesyntax lang="bash"]

vim /etc/knockd.conf

[options]
        UseSyslog

[OpenClosePort]
        sequence    = 2123:udp,3543:tcp,6454:udp
        seq_timeout = 5
        Start_Command     = /sbin/iptables -I INPUT -s %IP% -p tcp --dport PORT -j ACCEPT
        tcpflags    = syn
        Cmd_timeout = 3600
        Stop_Command     = /sbin/iptables -D INPUT -s %IP% -p tcp --dport PORT -j ACCEPT

:wq

[/codesyntax]

Notes:

  • sequence - the sequence required to open desired port
  • seq_timeout - time to wait for a sequence to complete
  • Start_Command - command to be executed when a client makes the correct port-knock
  • Stop_Command - command to be executed when Cmd_Timeout seconds have passed since Start_Command has been executed
  • Cmd_Timeout - time to wait between Start_Command and Stop_Command in seconds
  • PORT - port to be opened

3. Enable knockd

 

[codesyntax lang="bash"]

vim /etc/default/knockd

:%s/START_KNOCKD=0/START_KNOCKD=1/g
:%s/#KNOCKD_OPTS="-i eth1"/KNOCKD_OPTS="-i eth0"/g
:wq

[/codesyntax]

 

4. Start knockd

[codesyntax lang="bash"]

/etc/init.d/knockd restart

[/codesyntax]

Client side

1. Knock the port

[codesyntax lang="bash"]

nmap -Pn --host_timeout 201 --max-retries 0 -sU -p 2123 host; nmap -Pn --host_timeout 201 --max-retries 0 -p 3543 host; nmap -Pn --host_timeout 201 --max-retries 0 -sU -p 6454 host

[/codesyntax]

2. Check if the port is open

[codesyntax lang="bash"]

telnet host PORT

[/codesyntax]