SSH into AWS EC2 instance gives Permission denied (publickey)

I created a new EC2 Instance form my AWS Console and tried to ssh using my keyfile

ssh -i "myKeypair.pem" [e-mail]

I was able to login into the server and did these things :

installed httpd. isntalled php. installed mysql.

created a new group “web” and added user apache and ec2-user to this group.Changed my default home directory /home/ec2-user/ ownership to ec2-user:web

Set up FTP for my instance as explained in this answer.

then i installed OPencart in my home directory.

After this is logged out from the SSH using the exit command

but now when i try to login again using the same pem file i get this error:

prince@devilDevice:~$ ssh -v -i "mypemFile.pem" [e-mail]
OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to instancepublicDNS.amazonaws.com [Public IP] port 22.
debug1: Connection established.
debug1: identity file mypemFile.pem type -1
debug1: identity file mypemFile.pem-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.4
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: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr [e-mail] none
debug1: kex: client->server aes128-ctr [e-mail] none
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA {somefingerprinthere}
debug1: Host 'instancepublicDNS.amazonaws.com' is known and matches the ECDSA host key.
debug1: Found key in /home/prince/.ssh/known_hosts:18
debug1: ssh_ecdsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: {my_email_address}
debug1: Authentications that can continue: publickey
debug1: Trying private key: mypemFile.pem
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type RSA
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
Permission denied (publickey).

Please Help.

Answer

This is the culprit.

Changed my default home directory /home/ec2-user/ ownership to ec2-user:web

sshd tried to get the public key from /home/ec2-user/.ssh/authorized_keys file but couldn’t because you changed the owner. So you are denied access.