Putty + Remote tunnel + RDP

Installing Putty and Configuring SSH Tunnel and Remote Desktop

On the CLIENT computer we are connecting from, we will need to install Putty and configure it to connect RDP over SSH (ie create the tunnel).

1. To install putty, just extract the Zip for to your C:\Putty folder.  The Putty folder should contain several .exe programs.

2. To run putty, we will just run the Putty.exe in the C:\Putty folder.  To make it easier to launch, you can create a shortcut to Putty.exe and put it on your desktop or in your Start Menu.

3. Under the Session section (on left pane), type in the host name of the pc we are connecting to (in our example on our local network). 10.0.1.5 and leave the port at 22.  Also you can go under the Saved Session box and enter a name to save the profile as for easy connection (more later on this).

Under the Connection > SSH > Tunnels tab, under Source Port, enter in a local port to connect to as our tunnel (i use a very high port in the 40000 range, we’ll use 40000), in the Destination box, we can put in the ip address of the remote computer we have running Copssh/SSH, 10.0.1.5 in my example.

Go back to the Sessions section and click the Save button under the Saved Sessions box and then hit the Open button.

4. You should get a prompt to accept a key the first time we connect, click Yes.

5.  We now should get a command window like interface asking for a user.  Enter your remote computers login username and password.  Once you connect, the command window will change to a local window.

Connecting via Remote Desktop over the SSH Tunnel

1. On the laptop/client computer, open Remote Desktop Connection (Start Menu > All Programs > Accessories > Remote Desktop Connection)

2. Enter in 127.0.0.1:40000 for the computer to connect to.

127.0.0.1 = the local tcp/ip stack loopback address and 40000 = port to connect over.  This in turn forces our remote desktop client to use the SSH tunnel we created at 40000 to connect to our remote pc at the 22 port.

Mail Server-Postfix+Centos+Dovecot

Setup mail server in centos 6

» Installing and configuring postfix

» Installing and configuring dovecot

» Creating users and testing

» Installing and configuring squirrelmail

» Installing and configuring postfix

 

Step 1 »Before installation assign a static ip and add a host entry for your domain to that IP in the /etc/hosts file like below.
echo "23.236.147.74 keralainindia.asia" >> /etc/hosts
Step 2 » install postfix

[root@kerala ~]# yum -y install postfix

Step 3 » install SMTP AUTH packages .

[root@kerala ~]# yum -y install cyrus-sasl cyrus-sasl-devel cyrus-sasl-gssapi cyrus-sasl-md5 cyrus-sasl-plain

Postfix package installation is completed .

Step 4 »creating SSL Cert.

[root@kerala ~]# mkdir /etc/postfix/ssl
[root@kerala ~]# cd /etc/postfix/ssl/
[root@kerala ssl]# openssl genrsa -des3 -rand /etc/hosts -out smtpd.key 1024
[root@kerala ssl]# chmod 600 smtpd.key
[root@kerala ssl]# openssl req -new -key smtpd.key -out smtpd.csr
[root@kerala ssl]# openssl x509 -req -days 365 -in smtpd.csr -signkey smtpd.key -out smtpd.crt
[root@kerala ssl]# openssl rsa -in smtpd.key -out smtpd.key.unencrypted
[root@kerala ssl]# mv -f smtpd.key.unencrypted smtpd.key
[root@kerala ssl]# openssl req -new -x509 -extensions v3_ca -keyout cakey.pem -out cacert.pem -days 365

Step 4 » Now open /etc/postfix/main.cf file .

Find and comment the below lines .
#inet_interfaces = localhost #---> line no 116
#mydestination = $myhostname, localhost.$mydomain, localhost #--> line no 164

and add these lines at the bottom of the file.

myhostname = mail.keralainindia.asia
mydomain = keralainindia.asia
myorigin = $mydomain
home_mailbox = mail/
mynetworks = 127.0.0.0/8
inet_interfaces = all
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
smtpd_sasl_auth_enable = yes
smtpd_sasl_type = cyrus
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtpd_sasl_authenticated_header = yes
smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination
smtpd_tls_auth_only = no
smtp_use_tls = yes
smtpd_use_tls = yes
smtp_tls_note_starttls_offer = yes
smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key
smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt
smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom

 

Step 5 » Now open /etc/postfix/master.cf file and add the below line after smtp

smtps inet n - n - - smtpd
-o smtpd_sasl_auth_enable=yes
-o smtpd_reject_unlisted_sender=yes
-o smtpd_recipient_restrictions=permit_sasl_authenticated,reject
-o broken_sasl_auth_clients=yes

Step 6 » Now start postfix and saslauthd service

[root@kerala ~]# service postfix start

[root@kerala ~]# service saslauthd start

» Issue the below commands to start the postfix and saslauthd at startup
[root@kerala ~]# chkconfig --level 235 postfix on

[root@kerala ~]# chkconfig --level 235 saslauthd on

Step 7 » Now check your smtp connectivity . just telnet localhost on port 25 and type this command ehlo localhost

[root@kerala ~]# telnet localhost 25
Trying ::1...
Connected to localhost.
Escape character is '^]'.
220 mail.keralainindia.asia ESMTP Postfix
ehlo localhost <---- type this command
250-mail.keralainindia.asia
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
quit
221 2.0.0 Bye
Connection closed by foreign host.

If you get this output .. Great .. everything is fine till now.

» Installing and configuring dovecot

Step 8 » Issue this command to install dovecot

[root@kerala ~]# yum -y install dovecot

 

Step 9 » After installation open /etc/dovecot/dovecot.conf file and add the below line at the end of the file. please make sure mail_location and home_mailbox in postfix configuration are using the same name.

protocols = imap pop3
mail_location = maildir:~/mail
pop3_uidl_format = %08Xu%08Xv

 

Step 10 » Now start dovecot service
[root@kerala ~]# service dovecot start

» Issue the below command to start the dovecot at startup
[root@kerala ~]# chkconfig --level 235 dovecot on

 

Step 11 » Now test your pop3 connectivity .
[root@kerala ~]# telnet localhost 110
Trying ::1...
Connected to localhost.
Escape character is '^]'.
+OK Dovecot ready.
quit
+OK Logging out
Connection closed by foreign host.

Yes .. your server is ready to receive mails .

» Creating users and testing
Step 11 » Now create users to test your configuration.
[root@kerala ~]# useradd -m ramraj -s /sbin/nologin
and create passwords for the users created
[root@kerala ~]# passwd ramraj
Step 12 » Now you can send and receive mails using this server. In case of any issues please check the log file /var/log/maillog )

your mail server is ready …

» Installing and configuring squirrelmail

Step 13 » you need to add EPEL repository to install squirrelmail package. you can find latest EPEL repository rpm here ( http://ftp.jaist.ac.jp/pub/Linux/Fedora/epel/6/i386/repoview/epel-release.html )
[root@kerala ~]# rpm -ivh http://ftp.jaist.ac.jp/pub/Linux/Fedora/epel/6/i386/epel-release-6-8.noarch.rpm

Step 14» Issue the below command to install squirrelmail.
[root@kerala ~]# yum install squirrelmail

This command will install squirrelmail along with apache and php.

Step 15 » Now run the below command to configure squirrelmail .
[root@kerala ~]# perl /usr/share/squirrelmail/config/conf.pl

»»» 1 »»» 1 »»» krizna (type Organization name ) »»» R ( return )
»»» 2 »»» 1 »»» ( hit space for empty Domain name ) and choose 3 »»» SMTP ( choose SMTP ) »»» R ( return )
»»» D »»» dovecot ( type ) »»» press enter with default
»»» s ( save and quit)
Step 16 » Open /etc/httpd/conf.d/squirrelmail.conf file and uncomment below lines if you are using ssl. If you are not using ssl Don't Do it.
# RewriteCond %{HTTPS} !=on
# RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}

Step 17» start apache service
[root@kerala ~]# service httpd start

» Issue the below commands to start the httpd at startup
[root@kerala ~]# chkconfig --level 235 httpd on

Step 18» Now open http://serverip/webmail path in your browser .

Git Part 2

http://superuser.com/questions/261060/git-how-can-i-config-git-to-ignore-file-permissions-changes
turn off the filemode so that permissions of files are not considered.

For Mac Machines
http://stackoverflow.com/questions/8402281/github-push-error-permission-denied
cd ~
ssh-keygen
cat .ssh/id_rsa.pub > .ssh/authorized_keys

Internalize a project in server
cd /opt/git/
mkdir <Project-name>
cd <Project-name>
git inti --bare

In client
git clone xxxx@xxx.xxx.xxx.xxx:/opt/git/<Project-name>
cd <Project-name>
git add *
git commit -m "Test Files"
>>git remote add <remote-name> <git-repo-URL>
git remote add orgin xxxx@xxx.xxx.xxx.xxx:/opt/git/<Project-name>
git push orgin master

Branching
git checkout -b <Branch-name>
git push <remote-name> <branch-name>
git push <remote-name> <local-branch-name>:<remote-branch-name>

List ALL Branching
git branch -a
List Remote Branching
git branch -r

Merge two branch
git checkout a (you will switch to branch a)
git merge b (this will merge all changes from branch b into branch a)
git commit -a (this will commit your changes)

List Merged Branches
git branch --merged lists the branches that have been merged into the current branch
git branch --no-merged lists the branches that have not been merged into the current branch