How to SSH on alphine linux with iSH on ipad?

Question

Iam trying out linux on Ipad through the iSH app, however, i cant seem to find my username it always returns 'root' when i do whoami. So now iam confused how I can ssh into another computer or even how to ssh into my ipad, as Ive tried multiple commands to find my ip on the ipad however it just doesnt work.

e.g I try ifconfig -a but its shows /proc/net/dev: No such file or directory.

curl ifconfig.me works for the public ip, but i need the host ip for ssh which doesnt show me.

Another example :

Mathewss-iPad:~# hostname -I

hostname: unrecognized option: I
BusyBox v1.31.1 () multi-call binary.

Usage: hostname [OPTIONS] [HOSTNAME | -F FILE]

Get or set hostname or DNS domain name

        -s      Short
        -i      Addresses for the hostname
        -d      DNS domain name
        -f      Fully qualified domain name
        -F FILE Use FILE's content as hostname

issues: Can't SSH into our out to any devices because:

1. Cant find hostname just 'root'
2. Cant retrieve host ip address
3. But everything works as normal in linux apk installing packages, making folders, changing directories etc.

Answer 1

Disclaimer 1: I ran all of this from an iPhone 8 Plus with the following specs

• iOS 15.4
• Alpine 13.4
• Version 1.2.3

Disclaimer 2: ssh server will not run on iSH while the app is closed/running in the background.

Setup - iSH as ssh server on your local network

When you first install iSH, you begin as root. If you wish to create a new user: adduser -g "Your Full Name" then enter a password.

As root, you add a password by running
echo ‘yourpassword’ | chpasswd

Assuming you wish to give doas (like sudo) privileges to your new non-root user: as root... apk add doas - modify the /etc/doas.conf file with the line: permit yourusername - close and reopen the app, then login as user

• alternatively you can uncomment the line permit persist :wheel
• then add your user to the wheel group
  adduser wheel

To make your host keys, run the following as root: ssh-keygen -A

At this point, modify your /etc/ssh/sshd_config file to prevent root login. Ensure you have the lines (uncommented) PermitRootLogin no PubkeyAuthentication yes PasswordAuthentication yes

Disclaimer 3: if you fail to login as your non-root user, thenPermitRootLogin yes and troubleshoot with the following:

ssh username@localhost -vvv  

Alpine uses openrc as its init program, which will manage the startup of your sshd service for each new iSH session.

• if you need to download openrc: apk add openrc

• as root/sudo user, run rc-update add /usr/sbin/sshd default

then rc-service sshd start

check to see that your sshd daemon is running rc-status default

To find your IP, go into your iPad's Wi-Fi settings, tap the 'i' info circle next to your network name, and find your IPv4 address.

Now from your client device

ssh iSHusername@iSHipaddress

You can setup key-based authentication for more secure access ssh-keygen -t ed25519

 _enter an absolute path to your client .ssh folder and a passphrase (optional)_

- Copy the public key to your host machine.
    ssh-copy-id -i *pathtopubkey* iSHusername@iSHipaddress

- Reload sshd service
    rc-service sshd reload

Confirm the service is running rc-status default

_you should do this everytime you make changes to the config files_

iSH as ssh-client (localhost)

In your iPhone settings, make sure iSH has access to the local network, then ssh hostuser@hostipaddress

Setup - ssh from WAN (open internet)

1. _Setup port forwarding on your router

   • Something like:
     • Source Port: 22 (port of client device, unless modified)
     • Forwarding port: 443 (many routers allow ssh traffic via this port)
     • Destination port: 22 (port where ssh server is listening)

2. Configure your firewall on the server machine if necessary

   • in ufw
     • sudo ufw allow from clientipaddress to any app OpenSSH
     • sudo ufw reload

3. Connect using dynamic port forwarding ssh -D 443 username@routeripaddress

   rerun the command with -vvv option to debug in the event of failure

Sources: https://wiki.alpinelinux.org/wiki/OpenRC https://github.com/ish-app/ish/wiki/Running-an-SSH-server https://www.youtube.com/watch?v=AtuAdk4MwWw man pages for ssh-keygen, ssh, sshd, sshd_config, ssh-copy-id