Permissions error when connecting to EC2 via SSH on Mac OSx

Two possibilities I can think of, although they are both mentioned in the link you referenced:

1. You're not specifying the correct SSH keypair file or user name in the ssh command you're using to log into the server:

   ssh -i [full path to keypair file] root@[EC2 instance hostname or IP address]

2. You don't have the correct permissions on the keypair file; you should use

   chmod 600 [keypair file]

to ensure that only you can read or write the file.

Try using the -v option with ssh to get more info on where exactly it's failing, and post back here if you''d like more help.

[Update]: OK, so this is what you should have seen if everything was set up properly:

debug1: Authentications that can continue: publickey,gssapi-with-mic
debug1: Next authentication method: publickey
debug1: Trying private key: ec2-keypair
debug1: read PEM private key done: type RSA
debug1: Authentication succeeded (publickey).

Are you running the ssh command from the directory containing the ec2-keypair file ? If so, try specifying -i ./ec2-keypair just to eliminate path problems. Also check "ls -l [full path to ec2-keypair]" file and make sure the permissions are 600 (displayed as rw-------). If none of that works, I'd suspect the contents of the keypair file, so try recreating it using the steps in your link.

The key for me to be able to connect was to use the "ec2-user" user rather than root. I.e.:

ssh -i [full path to keypair file] ec2-user@[EC2 instance hostname or IP address]