Linux Passwordless Authentication Or Trust Relationship

PASSWORDLESS Authentication /TRUST RELATIONSHIP..
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Server1 ==} server2



1. ssh-keygen
it will create .ssh folder (700)
and id_rsa(600), id_rsa.pub(644) files in .ssh folder
2. you need to copy/share the "id_rsa.pub" to the remote systems...
either you can do it manually or you can run "ssh-copy-id" command

ssh-copy-id -i id_rsa.pub user@IP
OR
create folder .ssh (700)
and create file named "authorized_keys" file with 600 permissions
and copy id_rsa.pub data into this file..


id_rsa (Private Key):

--It's a private key
--it should be kept strictly confidential and secure.
--Used for authentication and should never be shared or exposed to others.

Public Key (id_rsa.pub):

--The public key is part of a key pair
--it is intended to be shared with other systems.

Authentication Flow:

1. When the user tries to log in to the remote server, the client presents its private key as part of the authentication process.

2. The server looks for the corresponding public key in its authorized_keys file.

3. If a matching public key is found, the server allows the user to log in without asking password.