SSH authentication suddenly stopped working

[Eric Kivuti]

I am using Git for Windows x64 2.22.0. I successfully setup SSH access a few weeks ago, and have been pushing and pulling with no issues. Today, none of the connections are working. I followed the troubleshoot and got nothing to work. Also searched for an answer here as well as elsewhere.

The following is my log:

$ ssh -v personal
OpenSSH_8.0p1, OpenSSL 1.1.1c 28 May 2019
debug1: Reading configuration data /c/Users/Someone/.ssh/config
debug1: /c/Users/Someone/.ssh/config line 1: Applying options for personal
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to bitbucket.org [18.205.93.0] port 22.
debug1: Connection established.
debug1: identity file /c/Users/Someone/.ssh/git type 0
debug1: identity file /c/Users/Someone/.ssh/git-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.0
debug1: Remote protocol version 2.0, remote software version conker_1.1.87-0aaf585 app-154
debug1: no match: conker_1.1.87-0aaf585 app-154
debug1: Authenticating to bitbucket.org:22 as 'someone'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256@libssh.org
debug1: kex: host key algorithm: ssh-rsa
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ssh-rsa SHA256:zzXQ...Gp1A
debug1: Host 'bitbucket.org' is known and matches the RSA host key.
debug1: Found key in /c/Users/Someone/.ssh/known_hosts:1
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: rekey in after 134217728 blocks
debug1: Will attempt key: /c/Users/Someone/.ssh/git RSA SHA256:+dq6F...2lTk explicit agent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /c/Users/Someone/.ssh/git RSA SHA256:+dq6F...2lTk explicit agent
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
someone@bitbucket.org: Permission denied (publickey).

What broke? What needs to be updated? 

[Daniil Penkin]

Hello @Eric Kivuti,

There have been no recent changes around authentication in Bitbucket that I'm aware of.

From the output of ssh command you posted I can say that the key you have in /c/Users/Someone/.ssh/git is not registered with Bitbucket, so the login attempt is declined.

Without specific account details I can only really guess what might be causing this, here're some ideas:

• Is /c/Users/Someone/.ssh/git the right key? Maybe you updated your local SSH client configuration recently and changed this?
• Can you check your SSH configuration in Bitbucket? Maybe you accidentally removed the key there?
• Have you generated any keys recently on that box? Maybe you've accidentally overridden the correct key?

If everything looks correct on your side and you believe Bitbucket is behaving incorrectly, please open a support case here so that we can look specifically into your account settings and discuss the issue privately.

Hope this helps.

Cheers,
Daniil