Configure the Private Key and Public Key Authentication

Using Arcserve UDP Agent (Linux) › How to Manage the Linux Backup Server from the Command Line › Configure the Private Key and Public Key Authentication

Configure the Private Key and Public Key Authentication

The public key and the private key allow you to securely connect to the nodes when you do not provide the password. Each time the Backup Server creates an SSH connection with the nodes, the Backup Server verifies the public key and private key for the respective nodes. If the keys do not match, you get an error message.

Note:

Only the users having the root permission are supported to use the public key and private key authentication. It is not necessary to have the user name as root. The non-root users are not supported to use the public key and private key authentication. The non-root users must provide the user name and password authentication.
Public key and private key authentication takes effect when the password is not provided. The username is still required and it must match the owner of the key.

Follow these steps:

Log into the Backup Server as a root user.
Generate a public/private key using the following ssh-keygen command:
```
ssh-keygen -t rsa -f server
```
Two files are generated, namely server.pub and server.
Copy the public key file server.pub to the following location:
```
/opt/CA/d2dserver/configfiles/server_pub.key
```
Copy the private key file server to the following location:
```
/opt/CA/d2dserver/configfiles/server_pri.key
```
(Optional) Run the following command if you have provided the passphrase while generating the private and public keys:
```
echo "passphrase" | d2dutil encrypt > /opt/CA/d2dserver/configfiles/key.pass
```
Change the permission for the key.pass file using the following command:
```
chmod 600 /opt/CA/d2dserver/configfiles/key.pass
```
Log into the source node.
Copy the content from the server_pub.key file in the Backup Server to the following location in the node:
```
/root/.ssh/authorized_keys
```

The private key and the public key are successfully configured. You can connect to the source nodes using the public key and private key.