Warning: the ECDSA host key for 'bitbucket.org' differs

[Manjunath B_V_]

Hi Team,
     When i try to push code using git push cmd, I'm getting below error:

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@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
SHA256:46OSHA1Rmj8E8ERTC6xkNcmGOw9oFxYr0WF6zWW8l1E.
Please contact your system administrator.
Add correct host key in /home/manju/.ssh/known_hosts to get rid of this message.
Offending RSA key in /home/manju/.ssh/known_hosts:5
remove with:
ssh-keygen -f "/home/manju/.ssh/known_hosts" -R "bitbucket.org"
RSA host key for bitbucket.org has changed and you have requested strict checking.
Host key verification failed.
fatal: Could not read from remote repository.

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

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Then i ran a cmd as below:
git ls-remote -h git@bitbucket.org:manjunathbv/cirrus-erp.git HEAD

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After above cmd, i got the same worning and now when i push code i get a msg:
Warning: the ECDSA host key for 'bitbucket.org' differs from the key for the IP address '2406:da00:ff00::22cd:e0db'
Offending key for IP in /home/manju/.ssh/known_hosts:21
Matching host key in /home/manju/.ssh/known_hosts:29
Are you sure you want to continue connecting (yes/no)?

could you please help me with the same?

[LynnG]

This is a classic SSH host key mismatch issue. It usually happens when:

• Bitbucket has rotated/changed its SSH host keys, or
• You previously connected to a different server/IP that had a different key cached in known_hosts.

The important thing is to verify the new key is legitimate before accepting it.

What happened?

Initially SSH reported:

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Offending RSA key in /home/manju/.ssh/known_hosts:5

2

remove with:

3

ssh-keygen -f "/home/manju/.ssh/known_hosts" -R "bitbucket.org"

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After running additional commands, SSH now sees:

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Warning: the ECDSA host key for 'bitbucket.org' differs from the key for the IP address '2406:da00:ff00::22cd:e0db'

2

Offending key for IP in /home/manju/.ssh/known_hosts:21

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Matching host key in /home/manju/.ssh/known_hosts:29

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This means your known_hosts file contains entries for both:

• bitbucket.org
• the resolved IPv6 address 2406:da00:ff00::22cd:e0db

and they don't match.

Fix

Remove the old Bitbucket entries:

Shell

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ssh-keygen -R bitbucket.org

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ssh-keygen -R 2406:da00:ff00::22cd:e0db

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``

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Or manually edit:

Shell

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vi ~/.ssh/known_hosts

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and delete the offending lines (21 and any old Bitbucket entries).

Re-add the host key

Test the connection:

Shell

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ssh -T git@bitbucket.org

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You should get something similar to:

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The authenticity of host 'bitbucket.org' can't be established.

2

ECDSA key fingerprint is ...

3

Are you sure you want to continue connecting (yes/no)?

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Before typing yes, compare the fingerprint shown with the official Bitbucket SSH fingerprints published by Atlassian:

https://support.atlassian.com/bitbucket-cloud/docs/configure-ssh-and-two-step-verification/

If the fingerprint matches Atlassian's documentation, type:

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yes

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This will create a fresh entry in ~/.ssh/known_hosts.

Verify

Run:

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ssh -T git@bitbucket.org

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You should see a successful authentication message.

Then try:

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git push

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again.

If it still fails

Please share the output of:

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grep bitbucket ~/.ssh/known_hosts

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and

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ssh -vT git@bitbucket.org

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(with any sensitive information removed), and I can pinpoint exactly which host key entry is causing the conflict.