usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed - if you are prompted now it is to install the new password: usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed The best way to copy the public key is with ssh-copy-id so you don't have to worry about permission, path etc ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub" Now copy the public key to the remote node to which you wish to connect via SSH. SHA256:m9TcEC+9H53ObDbnC/Tp5OnNd9ztwv+x3LskMMf1wZI key's randomart image is: Your public key has been saved in /root/.ssh/id_rsa.pub. Your identification has been saved in /root/.ssh/id_rsa. Use ssh-keygen to generate a key pair with -P "" to provide an empty password ~]# ssh-keygen -t rsa -P ""Įnter file in which to save the key (/root/.ssh/id_rsa): In this example we create a password less key pair so that the SSH won't prompt for any password. Scenario-1: Create a password less passphrase to perform SSH Since I have already explained about how public private key combination works, I will be very brief here with the commands. There are 6 different types of authentication methods with SSH but we will for now concentrate on public key based authentication for this tutorial. I have already written a well detailed article on how SSH public key based authentication works. This is definitely the most recommended method to use ssh if you want to automate the SSH process. Method 3: Using Private Public passphrase instead of password You can get all these information from the man page of sshpass. There are many other methods to use sshpass such as use a text file which contains the password, define a variable SSHPASS and use it instead of plain text password. You can put this in a script and use it to securely login to a server without getting a password prompt. This part of code snippet is taken from stackoverflow # Create a pipe This is the most recommended method to use sshpass wherein we provide the password as a file descriptor instead of plain text. Scenario-3: Use file descriptor with sshpass In this example we copy a file /tmp/src_file to our remote server with scp and sshpass ~]# sshpass -p 'redhat' scp /tmp/src_file ' redhat' is my password. You can also transfer files without getting a password prompt by combining scp with sshpass. If we wish to check the hostname of remote server, then the command would be: ~]# sshpass -p redhat ssh hostname In this example we provide a plain text password to sshpass which is highly insecure because any user with access to your server and history can see the password. Scenario-1: Provide clear text password with sshpass Let's quickly install this rpm for the demonstration: ~]# dnf install sshpass -y Sshpass.x86_64 : Non-interactive SSH authentication utility Last metadata expiration check: 0:00:27 ago on Thu 01:25:51 PM IST. You can search for this package in the repository ~]# dnf search sshpass If it is not installed, then you can install the same using: ~]# dnf -y install epel-release Make sure EPEL repository is installed on your server: ~]# rpm -q epel-release This rpm is provided as part of EPEL repository and does not requires a key for performing SSH. Sshpass is a utility designed for running ssh using the mode referred to as "keyboard-interactive" password authentication, but in non-interactive mode. Method 2: Use sshpass to provide password with SSH Here since we only intend to copy the files and hence there is a single expect block and in the end we use interact to return to our terminal ~]# dnf install expectīelow is a sample expect script which can use used to perform SSH and execute a command, the password is provided internally in the script: 1 #!/usr/bin/expectġ2 send_log " Connecting to $HOST using $USER user \n"ġ3 eval spawn ssh -o UserKnownHostsFile=/dev/null -o StrictHostKe圜hecking=no -o Connect timeout = 30 " $HOST"ġ5 timeout Install expect if it is not installed already on your server. If you are on Ubuntu/Debian then you can use apt to install/update the rpm I will be using RHEL distribution for all the example output in this tutorial which uses dnf/yum as package manager.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |