If you love android as much as me for it’s customizing capabilities you will love this tutorial. I try to do much on the commandline and use as many automation as possible for this purpose. I got the Code references from the CM Wiki. So here it is, my sshd on Android Tutorial.

Why use this long tutorial when there is an app for it?

Because there is an APP for it. One more APP you have to install for things that are already on your phone.

Step 1

Install a custom ROM like Cyanogenmod or PAC-ROM. Here are many possibilities to customize your android experience. You have to unlock the developer options which will void your warranty in some countries.

Here you are.

Assuming that you are already installed and ready. (Android tools for your distribution and such), there are a few things to do on your phone. Plug your phone into your computer and follow the next steps.

Developer Options

To unlock do the following:

• go to settings -> about device and tap 7 times continously on build number.
• enable USB Debugging in settings -> developer options
• also enable root for adb

Enter the shell

fire up your favourite terminal emulator and hack this into it.

connect to your phone

adb shell su

create the directory structure

mkdir -p /data/ssh/empty chmod 700 /data/ssh chmod 700 /data/ssh/empty

create the host keys

ssh-keygen -t dsa -f /data/ssh/ssh_host_dsa_key -N "" chmod 600 /data/ssh/ssh_host_dsa_key ssh-keygen -t rsa -f /data/ssh/ssh_host_rsa_key -N "" chmod 600 /data/ssh/ssh_host_rsa_key

configure your sshd server

cat /system/etc/ssh/sshd_config |
sed ’s/#PermitRootLogin yes$/PermitRootLogin yes/’ |
sed ’s/#PubkeyAuthentication yes/PubkeyAuthentication yes/’ |
sed ’s/#PasswordAuthentication yes/PasswordAuthentication no/’ |
sed ’s/#PermitEmptyPasswords no/PermitEmptyPasswords no/’ |
sed ’s/#ChallengeResponseAuthentication yes/ChallengeResponseAuthentication no/’ |
sed ’s;/usr/libexec/sftp-server;internal-sftp;’ >
/data/ssh/sshd_config chmod 600 /data/ssh/sshd_config

create your private key

mkdir -p /data/.ssh chmod 700 /data/.ssh ssh-keygen -t rsa -f /data/.ssh/id_rsa chmod 600 /data/.ssh/id_rsa cat /data/.ssh/id_rsa.pub > /data/.ssh/authorized_keys chmod 600 /data/.ssh/authorized_keys

## Fire it up
With the following command you are able to start and stop the server. How you
inject them into your android system is up to you, but i recommend something
like Tasker to enable or disable the Server in trusted environments.

/system/bin/sshd -f /data/ssh/sshd_config

killall sshd

Both of these lines have to run as root.

And here you are with your own made ssh Server with only just yourself. Beside
that you also have learned how to enter your phone over usb cable and gain root.