Permission denied (publickey) while accessing aws through ssh - amazon-web-services

Question

I am trying to connect to my ec-2 free(t2.micro) instance through ssh from my PC.
I have created instance with default VPC. I am not able to connect it from my PC.
It is throwing me permission denied error.
I have checked the rules in the security group.
I have gone through the below url's to check the answer but no success.
AWS SSH connection error: Permission denied (publickey)
Troubleshooting Connecting to Your Instance
SSH: Permission denied (publickey)
Also when I run below command
sudo ssh -v -i tep-keyPair.pem ubuntu#ec2-52-XX-XXX-XX.us-west-2.compute.amazonaws.com
The below error came:
OpenSSH_7.3p1, LibreSSL 2.4.1
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 20: Applying options for *
debug1: Connecting to ec2-52-XX-XXX-XX.us-west-2.compute.amazonaws.com [52.XX.XXX.XX] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: key_load_public: No such file or directory
debug1: identity file tep-keyPair.pem type -1
debug1: key_load_public: No such file or directory
debug1: identity file tep-keyPair.pem-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.3
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1
debug1: match: OpenSSH_6.6.1 pat OpenSSH_6.6.1* compat 0x04000000
debug1: Authenticating to ec2-52-XX-XXX-XX.us-west-2.compute.amazonaws.com:22 as 'ubuntu'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256#libssh.org
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: chacha20-poly1305#openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305#openssh.com MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:ZeJ4XQUfgLkaMUEvjGohL/6FWKN9Gq4AXrPwL/i9t3M
debug1: Host 'ec2-52-XX-XXX-XX.us-west-2.compute.amazonaws.com' is known and matches the ECDSA host key.
debug1: Found key in /var/root/.ssh/known_hosts:3
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: tep-keyPair.pem
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
Permission denied (publickey).
Please help me.. I am really stuck here

Answer 1

The fact that you are receiving a Permission denied (publickey) error indicates that you are successfully communicating with the instance, so the problem is not related to networking nor security groups.
Rather, the instance is not accepting a connection via the keypair you are providing. Therefore, you either need to provide it with the keypair it expects, or you can copy a new keypair to the instance.
To copy a different keypair to the instance, follow instructions on this StackOverflow answer, which is written for Ubuntu: Change key pair for ec2 instance