SSH – Load key “/Users/username/.ssh/id_rsa.pub”: invalid format

Suddenly the git push via SSH failed, and the remote server returned something like invalid format for the public key id_rsa.pub?

git push

Load key "/Users/username/.ssh/id_rsa.pub": invalid format
[email protected]: Permission denied (publickey).
fatal: Could not read from remote repository.

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

Last week, everything still working fine, unsure what is the root cause of it?

1. Check ~/.ssh/config

Review the ~/.ssh/config file and ensure the IdentityFile points to the private key id_rsa, not the public key id_rsa.pub. The common mistake is put the public key id_rsa.pub as the IdentityFile value.

cat ~/.ssh/config

Host *
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_rsa.pub  

2. Solution

Open the ~/.ssh/config file, update the IdentityFile, and ensure it points it to the private key id_rsa.

nano ~/.ssh/config

Host *
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_rsa

References

• Configure SSH and two-step verification
• Git on the Server – Generating Your SSH Public Key