I’m running into this with keys generated by MobaKeyGen (MobaXTerm SSH Key generator utility). It creates keys in ppk format, but with an option to export as OpenSSH and OpenSSH (new file format). I’m not sure what the difference is, only a few of the base64 characters are different when exported using either one.
If I use ssh-keygen it works fine, of course. I’ll put a test private key here (WHICH I AM NOT USING ANYWHERE) so devs can maybe see what’s wrong with this format.
-----BEGIN OPENSSH PRIVATE KEY-----
b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAMwAAAAtz
c2gtZWQyNTUxOQAAACBz2Mlzce/O8/NTMlUBeBR2Tbt3Wd0BRMRfCEl8YnZUwgAA
AKBMecrrTHnK6wAAAAtzc2gtZWQyNTUxOQAAACBz2Mlzce/O8/NTMlUBeBR2Tbt3
Wd0BRMRfCEl8YnZUwgAAAEAQUqjBjjTpjP1m8ISUoWrEjpGr/iLCmPBlRhG/cT7y
X3PYyXNx787z81MyVQF4FHZNu3dZ3QFExF8ISXxidlTCAAAAEnRlc3RfZm9yX2Jp
dHdhcmRlbgECAwQFBgcICQoL
-----END OPENSSH PRIVATE KEY-----
