CODEWITHSUNDEEP
sshamazon-ec2
alex
alex

Reputation: 1917

How do I setup passwordless ssh on AWS

How do I setup passwordless ssh between nodes on AWS cluster

Upvotes: 8

Views: 20946

Answers (5)

Mohammed Aman
Mohammed Aman

Reputation: 1

How Did I Setup Password-Less Authentication between two Instances is the following:

  1. Launch two EC2 Instances from AWS Console(also create new access key for each instance. Assume instances as server_instance and target instance).
  2. Now your goal is to setup Password-Less Authentication so, you can Log in to target_instance from server_instance without entering the password.
  3. Now Log in to the server_instance(through any teminal).
  4. Now go to the location cd ~/.ssh and create a file vim target_instance_key.pem and paste the contents of target_instance access key (which is created during launch of target_instance in AWS console) inside target_instance_key.pem and save the file.
  5. Now don't forget to change the permission of target_instance_key.pem i.e chmod 600 target_instance_key.pem
  6. Now create rsa keys by ssh-keygen -t rsa
  7. Now execute the command ssh-copy-id -f "-o IdentityFile ~/.ssh/target_instance_key.pem" ubuntu@<TARGET_INSTANCE-PUBLIC-IP> and for fingerprint type yes and enter.
  8. So Password-Less Authentication is done.
  9. Execute the command ssh ubuntu@<TARGET_INSTANCE_PUBLIC-IP-ADDRESS> and you have Logged in to the target_instance from server_instance through Password-Less Authentication.

NOTE : server_instance can be any machine(i.e, EC2 instance (or) your local machine).

Upvotes: 0

Rakesh Vaddi
Rakesh Vaddi

Reputation: 11

how I made Paswordless shh work between two instances is the following:

  • create ec2 instances – they should be in the same subnet and have the same security group

  • Open ports between them – make sure instances can communicate to each other. Use the default security group which has one rule relevant for this case:

    • Type: All Traffic
    • Source: Custom – id of the security group

  • Log in to the instance you want to connect from to the other instance

  • Run: 1 ssh-keygen -t rsa -N "" -f /home/ubuntu/.ssh/id_rsa to generate a new rsa key.

  • Copy your private AWS key as ~/.ssh/my.key (or whatever name you want to use)

  • Make sure you change the permission to 600 1 chmod 600 .ssh/my.key

  • Copy the public key to the instance you wish to connect to passwordless 1 cat ~/.ssh/id_rsa.pub | ssh -i ~/.ssh/my.key [email protected] "cat >> ~/.ssh/authorized_keys"

  • If you test the passwordless ssh to the other machine, it should work. 1 ssh 10.0.0.X

Upvotes: 1

Mayank Jaiswal
Mayank Jaiswal

Reputation: 13076

Following steps to setup password less authentication are tested thoroughly for Centos and Ubuntu.

Assumptions:

  1. You already have access to your EC2 machine. May be using the pem key or you have credentials for a unix user which has root permissions.
  2. You have already setup RSA keys on you local machine. Private key and public key are available at "~/.ssh/id_rsa" and "~/.ssh/id_rsa.pub" respectively.

Steps:

  1. Login to you EC2 machine as a root user.

  2. Create a new user 

    useradd -m <yourname> 
sudo su <yourname>
cd 
mkdir -p ~/.ssh
touch ~/.ssh/authorized_keys

    Append contents of file ~/.ssh/id_rsa.pub on you local machine to ~/.ssh/authorized_keys on EC2 machine.

    chmod -R 700 ~/.ssh
chmod 600 ~/.ssh/*

  3. Make sure sshing is permitted by the machine. In file /etc/ssh/sshd_config, make sure that line containing "PasswordAuthentication yes" is uncommented. Restart sshd service if you make any change in this file:

    service sshd restart # On Centos
service ssh restart # On Ubuntu

  4. Your passwordless login should work now. Try following on your local machine:

    ssh -A <yourname>@ec2-xx-xx-xxx-xxx.ap-southeast-1.compute.amazonaws.com

  5. Making yourself a super user. Open /etc/sudoers. Make sure following two lines are uncommented:

    ## Allows people in group wheel to run all commands
%wheel ALL=(ALL)       ALL

## Same thing without a password
%wheel ALL=(ALL)       NOPASSWD: ALL

    Add yourself to wheel group.

    usermod -aG wheel <yourname>

Upvotes: 9

Vikas Hardia
Vikas Hardia

Reputation: 2695

This may help someone

Copy the pem file on the machine then copy the content of pem file to the .ssh/id_rsa file you can use bellow command or your own 

cat my.pem > ~/.ssh/id_rsa

try ssh localhost it should work and same with the other machines in the cluster

Upvotes: 4

Paul Ma
Paul Ma

Reputation: 615

you can use ssh keys like described here: http://pkeck.myweb.uga.edu/ssh/

Upvotes: -5

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