Allow more SSH key algorithms (ecdsa-sha2-*)

Hello,

please allow other SSH key algorithms, e.g. ecdsa-sha2-nistp521.

1. Go to /Users/UserEdit?name=root
2. Under "SSH authorized keys", paste a ecdsa-sha2-nistp521 public key
3. Click save
4. Get error message "[1] ecdsa-sha2-nistp521: Syntax of the key is incorrect!"

The source code of the page contains the "checkKey" function, which only checks for a few algorithms (ssh-ed25519, [email protected], ssh-rsa). Please revise this function so that it works more generally. Perhaps as a blocklist rather than an allowlist.

Unraid 6.12.6

Greetings