AWS EC2 unable to SSH with Key Pair

Question

I'm having some problems using SSH to get into my running AWS EC2 instance. According to the instructions, I need to create a Key Pair, which downloads a .pem private key file, which I have named QARTH.pem. From the directory where this file has been saved, I'm supposed to execute command:

ssh -i "QARTH.pem" [email protected]

However, I get the error:

Permission denied (publickey).

I'm using the auto-generated launch-wizard security group, which allows port 22 incoming access to all IPs.

I've also used the example procedure to convert the .pem file to a PuTTy private key .ppk file, and used the PuTTy client. I get the same error.

This seems like a pretty straightforward procedure, so I don't know what I could be doing wrong. If you have any ideas, I'd love to hear them. However, I'm not strong in network security, so please make responses lay-person friendly.

Answer 1

You are either using the wrong key pair (QARTH.pem), the wrong username, connecting to the wrong system or QARTH.pem is not set to be read-only.

STEP 1: Add debugging options to ssh to help determine what is wrong:

ssh -v -i QARTH.pem [email protected]

STEP 2: Make sure that the key pair file is read-only.

LINUX: To make the key pair file read-only execute this command: chmod 400 QARTH.pem while in the same directory as the file.

WINDOWS: Commands to run on a Windows system (as administrator) to make a key pair read-only and satisfy ssh:

Note replace %USERNAME% with your user name.

REM Disable inheritance on QARTH.pem
icacls QARTH.pem /inheritance:d

REM Delete "NT AUTHORITY\Authenticated Users" from having any rights
icacls QARTH.pem /remove "NT AUTHORITY\Authenticated Users"

REM Delete "BUILTIN\Users" from having any rights
icacls QARTH.pem /remove "BUILTIN\Users"

REM Grant Read-Only rights to me
icacls QARTH.pem /GRANT:R "%USERNAME%:(R)"

STEP 3: Make sure that you are using the correct username for the EC2 AMI:

Usernames for popular EC2 AMIs:

• For Amazon Linux 2 or the Amazon Linux AMI, the user name is ec2-user.
• For a Centos AMI, the user name is centos.
• For a Debian AMI, the user name is admin or root.
• For a Fedora AMI, the user name is ec2-user or fedora.
• For a RHEL AMI, the user name is ec2-user or root.
• For a SUSE AMI, the user name is ec2-user or root.
• For an Ubuntu AMI, the user name is ubuntu.
• Otherwise, if ec2-user and root don't work, check with the AMI provider.

Answer 2

Try changing the permission of key file

sudo chmod 400 rsa_key_file_name.pem

put you key file name and enter and you are done