github access denied access for push

Question

Hi I'm following a beginner tutorial for an rails app. But I'm having an issue with pushing the repository. Each time I'm doing and git push -u to origin master I'm having this error.

guinslym@ubuntu:~/Documents/rails_tuto/first_app$ git remote add origin https://github.com/guinslym/first_app.git
fatal: remote origin already exists.
guinslym@ubuntu:~/Documents/rails_tuto/first_app$ git push -u origin master
Warning: Permanently added the RSA host key for IP address '192.30.252.130' to the list of known hosts.
Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
guinslym@ubuntu:~/Documents/rails_tuto/first_app$ 

guinslym@ubuntu:~/Documents/rails_tuto/first_app$ ssh -vT git@github.com
OpenSSH_5.9p1 Debian-5ubuntu1.1, OpenSSL 1.0.1 14 Mar 2012
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to github.com [192.30.252.130] port 22.
debug1: Connection established.
debug1: identity file /home/guinslym/.ssh/id_rsa type 1
debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
debug1: identity file /home/guinslym/.ssh/id_rsa-cert type -1
debug1: identity file /home/guinslym/.ssh/id_dsa type -1
debug1: identity file /home/guinslym/.ssh/id_dsa-cert type -1
debug1: identity file /home/guinslym/.ssh/id_ecdsa type -1
debug1: identity file /home/guinslym/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9p1 Debian-5ubuntu1+github5
debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1+github5 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.1
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: RSA 16:27[Private information I will not post it to stackoverflow]
debug1: Host 'github.com' is known and matches the RSA host key.
debug1: Found key in /home/guinslym/.ssh/known_hosts:1
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/guinslym/.ssh/id_rsa
debug1: Server accepts key: pkalg ssh-rsa blen 279
debug1: Authentication succeeded (publickey).
Authenticated to github.com ([192.30.252.130]:22).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: Remote: Forced command.
debug1: Remote: Port forwarding disabled.
debug1: Remote: X11 forwarding disabled.
debug1: Remote: Agent forwarding disabled.
debug1: Remote: Pty allocation disabled.
debug1: Remote: Forced command.
debug1: Remote: Port forwarding disabled.
debug1: Remote: X11 forwarding disabled.
debug1: Remote: Agent forwarding disabled.
debug1: Remote: Pty allocation disabled.
debug1: Sending environment.
debug1: Sending env LANG = en_US.UTF-8
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug1: client_input_channel_req: channel 0 rtype eow@openssh.com reply 0
Hi guinslym! You've successfully authenticated, but GitHub does not provide shell access.
debug1: channel 0: free: client-session, nchannels 1
Transferred: sent 2664, received 2688 bytes, in 0.1 seconds
Bytes per second: sent 21363.1, received 21555.6
debug1: Exit status 1
guinslym@ubuntu:~/Documents/rails_tuto/first_app$ 

Here I did setup an private key to use but I'm still having error when I want to push. I did follow this stackoverflow answer (the first answer)

guinslym@ubuntu:~/.ssh$ ls
id_rsa  id_rsa.pub  known_hosts
guinslym@ubuntu:~/.ssh$ ssh -i id_rsa.pub -vT git@github.com
    ...
Hi guinslym! You've successfully authenticated, but GitHub does not provide shell access.
    debug1: channel 0: free: client-session, nchannels 1
    Transferred: sent 2664, received 2688 bytes, in 0.1 seconds
    Bytes per second: sent 22659.2, received 22863.4
    debug1: Exit status 1

Answer 1

If you need to change your ssh url by an http one for your remote 'origin', use:

git remote set-url origin https://guinslym@github.com/guinslym/first_app.git

It will ask for your GitHub password on the git push.

Answer 2

A possible cause is that you are sshing in to the box your trying to push from and you have agent forwarding enabled.

E.g:

user@box-a:~ ssh box-b
user@box-b:~ git -C path/to/repo push
Access denied.
fatal: Could not read from remote repository.

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

In this case it would be trying to use keys from box-a to authenticate. Solutions are:

• Add key from box-a to github
• Disable agent forwarding on box-a

To disable agent forwarding, add this to your ~/.ssh/config file:

Host *github.com
    ForwardAgent no