With SSH, data transmissions between TinyTERM ITX for iPhone and the server are encrypted. Even
if someone manages to hack into your connection, the information won't be
readable. This helps protect your valuable information from unauthorized access.
SSH keys provide an additional layer of security for your server. With password
access disabled, brute-force attempts to login to the server will fail, as only an
authorized key pair will allow a login.
Create an SSH Key Pair
To create an SSH public/private key pair, touch the Manage SSH Keys
button. This brings up the "Private/Public Keys" dialog.
As with general connection settings,
key generation requires that you have
certain information in advance: whether the server uses the RSA or DSA
Key type, and the server's preferred Key size in bits.
For key generation, TinyTERM also requires that you enter a pass phrase
for the key, which must be entered in both the Password and Password Again fields.
This does not need to be an actual password for the server, so it can include
spaces, punctuation or any other characters you like.
If you choose to Save password, you
won't need to enter the pass phrase when connecting. Otherwise TinyTERM
will ask for that pass phrase every time you make an SSH connection.
When all the required information is entered, touch the Generate key
button. Its background will switch from white to blue briefly. The larger the
Key size, the longer this will take. When it
returns to white, your key has been generated.
Using an SSH Key
There are now two ways to move the key to another system:
- Email public key
This opens an email with the public key as both plain text and as an attachment.
- Copy public key to clipboard
This copies the public key as text to the iPhone clipboard. It can then be pasted into any
other iPhone application.
Once the public key has been copied to a server, it needs to be added to the list
of authorized keys. This command is common for an RSA key:
cat id_rsa.pub >> ~/.ssh/authorized_keys
Adjust the command as needed to match the host requirements.
The private key remains stored securely on the iPhone, available only
to TinyTERM.
Note that if you turn on the Use public key option, all SSH connections in
TinyTERM will attempt to use the key. If the host doesn't recognize the key,
TinyTERM will fall back to password or keyboard-response authentication, provided
one or the other is enabled on the host.