ssh or similar applications use Public and Private Key mechanism in order to authenticate and authorize given users. We have all ready examined Key based authentication and authorization in previous tutorials. Permission denied(public key) error is generally occurs for can not reading Public and Private key properly to authenticate to remove server. In this tutorial we will learn general causes and solutions. Troubleshooting We will start with a simple troubleshooting. When...
Tagged: private key
ssh provides secure access to the remote systems console or command line. All linux boxes uses ssh securely. There are a lot of steps to make things secure and easy while connecting and using ssh. ssh provides passwordless authentication with certificates. We can use ssh-copy-id to send our certificate to the remote system but what can we do if we get following error
/usr/bin/ssh-copy-id: ERROR: failed to open ID file '/home/ismail/.pub': No such file
(to install the contents of '/home/ismail/.pub' anyway, look at the -f option)
Try ssh-copy-id Now we want to copy our ssh public...
Security is important part of the today’s IT operations. There are a lot of tools which provides some part of the secure operations. GNU Privacy Guard or simply GPG is a one of them. It provides encryption, decryption, digital signatures and signing. Install GPG To Ubuntu, Debian, Mint and Kali For deb or apt based distributions we can install GPG with the following command for gnupg package.
$ sudo apt install gnupg
Install GPG To...
SSH protocol provides different ways for authentication. Key based authentication is the most secure one. In order to use key based authentication we should store the key in a command place. SSH agents reads keys and uses for authentication with remote system. We can use ssh-add to store keys in a common path. Key Files Public and private keys are store in files according to their algorithm. ~/.ssh/identity holds RSA version...
OpenSSL provides different features about security and certificates. Public and Private Key cryptography also supported by OpenSSL. Websites, Firewalls and other applications uses Certificates in order to encrypt their network traffic or authenticate each other. In this tutorial we will look how to create Certificate Signing Request. Generate RSA Key Now we assume we do not have any Public and Private Key pair. If we have Public and Private key...
OpenSSL is free security protocols and implementation library provided by Free Software community. OpenSSL libraries are used by a lot of enterprises in their systems and products. OpenSSL libraries and algorithms can be used with openssl command. In this tutorial we will look different use cases for openssl command. Private Key Private keys should kept secret. Private keys generally used to decrypt data. Public Key Public keys are provided every one and...
Ssh is a secure and popular protocol for managing different type of IT devices like Linux systems, Network devices etc. What makes ssh secure is the encryption of the network traffic. Network traffic is encrypted with different type of encryption algorithms. There is also user authentication done with encryption algorithms. These algorithms needs keys to operate. Keys are generally produced with auxiliary tools. ssh-keygen is defacto tool used by ssh...
GnuPG or GPG is Gnu version of Open PG standard implementation. It is very popular especially at personal use for mails etc. Here I will look basic usage of gpg2 in Linux command line interface. gpg2 is the second major version of gpg. Create/Generate Private GPG Keys Here we will create public and private keys for key-ring. Required information asked while certificate generation process. Real name and Email address is...
I work on Ubuntu and want to use multiple ssh keys to connect different serves. I have tried some different method but unluckily they have failed. How can I use multiple ssh keys? Multiple Hosts Multiple Keys Ssh config resides in .ssh/config file in user home directory. The magic is here.
Host cen1 cen1.example.com
Host ubu1 ubu1.example.org
Hostname cen1.example.com is the hostname of the remote system. While connecting to this system with IdentityFile ~/.ssh/cen1_rsa configuration makes to use cen1_rsa as...
Ssh is a protocol designed to make network connections between hosts secure. Ssh is a defacto standard for Linux and related operating system. Ssh encrypts the connection between sides. Ssh gives terminal access between host and server. To get a terminal there need to be an authentication process. The authentication process is generally password-based but there are some caveats for password-based authentication. Brute force attacks can guess the password and...