* 겪고 있는 문제 상황을 최대한 자세하게 작성해주세요.

* 문제 해결을 위해 어떤 시도를 해보았는지 구체적으로 함께 알려주세요.

맥북 터미널에서 AWS 서버 접속시 오류 발생

터미널 작업 내용 :

fdeskui-MacBook-Pro:~ fdesk$ sudo chmod 400/Users/fdesk/Desktop/sparta_mykey.cer 

Password:

usage: chmod [-fhv] [-R [-H | -L | -P]] [-a | +a | =a [i][# [ n]]] mode|entry file ...

chmod [-fhv] [-R [-H | -L | -P]] [-E | -C | -N | -i | -I] file ...

fdeskui-MacBook-Pro:~ fdesk$ ssh -i/Users/fdesk/Desktop/sparta_mykey.cer ubuntu@3.38.212.191

터미널 오류 내용 :

The authenticity of host '3.38.212.191 (3.38.212.191)' can't be established.

ED25519 key fingerprint is SHA256:LIlVN5HVIP4X3+SaoNvHk/qwxyQ5qpK7FOY5bw86cb8.

This key is not known by any other names

Are you sure you want to continue connecting (yes/no/[fingerprint])? yes

Warning: Permanently added '3.38.212.191' (ED25519) to the list of known hosts.

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

@     WARNING: UNPROTECTED PRIVATE KEY FILE!     @

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Permissions 0644 for '/Users/fdesk/Desktop/sparta_mykey.cer' are too open.

It is required that your private key files are NOT accessible by others.

This private key will be ignored.

Load key "/Users/fdesk/Desktop/sparta_mykey.cer": bad permissions

ubuntu@3.38.212.191: Permission denied (publickey).

fdeskui-MacBook-Pro:~ fdesk$