SSH Error: trying to get more bytes 4 than in buffer 0

I ran across this cryptic error message in an SSH log file today:

Feb  7 03:33:21 hostname sshd[19439]: error: buffer_get_ret: trying to get more bytes 4 than in buffer 0
Feb  7 03:33:21 hostname sshd[19439]: fatal: buffer_get_int: buffer error

The problem is actually a corrupt line in a users ~/.ssh/authorized_keys file. This user had copy/pasted a new key into his authorized_keys file and it had a newline after the ssh-rsa. Strangely enough, people were still able to authenticate if their key was above the corrupted line. Users whose key was listed below the corrupt line were not able to log in.

7 thoughts on “SSH Error: trying to get more bytes 4 than in buffer 0”

  1. This happened for me when there was a rouge new line character in the known_host file on the CLIENT side

  2. This can also happen if your key file permissions are not strict enough. In Linux, this command should fix it…
    sudo chmod 600 ~/.ssh/id_rsa

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