ssh-add : Invalid key length

Question

After my mac upgraded automatically, I try ssh-add fail:

>ssh-add
Enter passphrase for /Users/dan/.ssh/id_rsa:
Error loading key "/Users/dan/.ssh/id_rsa": Invalid key length

>ssh -V
OpenSSH_7.6p1, LibreSSL 2.6.2

But how can I fix this issue?

Thanks!

Answer 1

As per the release notes for OpenSSH 7.6:

Refuse RSA keys <1024 bits in length and improve reporting
for keys that do not meet this requirement.

So it's likely that the key you're trying to import is too short (weak). Your best bet is to generate a new key.