can't connect to github via ssh

Question

I tried to clone one of my repositories on github from my newly installed linux machine running manjaro with fluxbox. i set up the user.name and user.email and uploaded the correct ssh key. but i always get

The authenticity of host 'github.com (192.30.252.129)' can't be established.
RSA key fingerprint is SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8.
Are you sure you want to continue connecting (yes/no)? 
Host key verification failed.
fatal: Could not read from remote repository.

Please make sure you have the correct access rights and the repository exists.

I googled it and found that i should do ssh-keygen -R github.com which should delete github from my known_hosts file but the known_hosts file doesn't even exist yet, because i just finished setting up a new linux install.

so i tried ssh -vT git@github which gave me

ssh -vT [e-mail]
OpenSSH_7.1p1, OpenSSL 1.0.2d 9 Jul 2015
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to github.com [192.30.252.128] port 22.
debug1: Connection established.
debug1: identity file /home/masterkraft0r/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /home/masterkraft0r/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/masterkraft0r/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/masterkraft0r/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/masterkraft0r/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/masterkraft0r/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/masterkraft0r/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/masterkraft0r/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.1
debug1: Remote protocol version 2.0, remote software version libssh-0.7.0
debug1: no match: libssh-0.7.0
debug1: Authenticating to github.com:22 as 'git'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client [e-mail] <implicit> none
debug1: kex: client->server [e-mail] <implicit> none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ssh-rsa SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8
The authenticity of host 'github.com (192.30.252.128)' can't be established.
RSA key fingerprint is SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8.
Are you sure you want to continue connecting (yes/no)? 
Host key verification failed.

which is way over my head. can somebody tell me what went wrong and maybe how to fix this mess?

Answer 1

This problem also happens to me when set the origin with newly generated ssh key due to re-installation of windows.

When I Update the ssh key path (new generated) it solved my problem using the following code

 eval $(ssh-agent -s)
 ssh-add /d/key    **(path of new key d:/key)**

Answer 2

If you just want to clone the repository, but you also use bitbucket or any other git tools, try to use https instead of ssh.

Answer 3

I'm no expert on git, but looking at this it seems like something was wrong with the connection between the server and your PC. It says:

    Host key verification failed.
    fatal: Could not read from remote repository.

That sounds like something went wrong when you received the data. Have you tried it multiple times and gotten the same response?

Try checking your internet connection, or if github was temporarily offline.

Answer 4

Did you try to add github as known host?

If you have an existing known_hosts file and do not want to overwrite (as @Puce suggested in the comment), use this.

ssh-keyscan -t rsa github.com >> ~/.ssh/known_hosts

This will add the rsa key to the end of the known_hosts.

If you have no idea what known_hosts is/means, or you never engaged with it for sure, you can simply write a new one, but note that this will remove the existing one if you had any.

ssh-keyscan -t rsa github.com > ~/.ssh/known_hosts