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 [email protected]
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 [email protected] <implicit> none
debug1: kex: client->server [email protected] <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

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

Answer 2

Step 1: Generate KEY

- cd   ~/.ssh

- ssh-keygen -t rsa -b 4096 -C "[email protected]"

NOTE - Keys need to be only readable by you:

chmod 400 ~/.ssh/id_rsa

If Keys need to be read-writable by you:

chmod 600 ~/.ssh/id_rsa

Step 2: Check the Contents and copy

cat ~/.ssh/nameOfFile.pub | pbcopy

Step 3: Configure your SSH key into Bitbucket (similar applies to Github)

GOTO settings => SSHKEY

- Add what you copied in Step 2 and give it a name

Step 4: Clone your repository using SSH protocol

git clone [email protected]:{username}/repo.git

git clone [email protected]:{username}/repo.git

This should work BUT

If you keep getting this error

[
Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
]

Follow this steps.

i. ssh -T [email protected] OR ssh -T [email protected] depending on which you are using { This will test your connection to Bitbucket OR Github).

ii. If you do not see a message similar  to (logged in as username.). Go to the next step

iii. ssh-add ~/.ssh/identity (identity is whatever name you saved the file when generating a key)

iv. You will get this message (Identity added: /path to ssh file/.ssh/mywork ([email protected])
v. You can now clone your repository.