trouble connecting to AWS Lightsail via SSH with keys other than default - amazon-web-services

Question

I have downloaded the default private key and am able to connect via SSH with no problem using that private key. In my Lightsail instance, I went to the SSH Keys tab, created a new key pair and downloaded the new private key (savng it in the correct location on my local machine with proper permissions). However, i am unable to connect using that new private key. Here is the output I get from the command: ssh -v -i ~/.ssh/test.pem me#x.x.x.x
OpenSSH_7.8p1, LibreSSL 2.6.2
debug1: Reading configuration data /Volumes/Norman Data/daveh0/.ssh/config
debug1: /Volumes/Norman Data/daveh0/.ssh/config line 1: Applying options for *
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 48: Applying options for *
debug1: Connecting to x.x.x.x port 22.
debug1: Connection established.
debug1: identity file .ssh/test.pem type -1
debug1: identity file .ssh/test.pem-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_7.8
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.8
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.8 pat OpenSSH_7.0*,OpenSSH_7.1*,OpenSSH_7.2*,OpenSSH_7.3*,OpenSSH_7.4*,OpenSSH_7.5*,OpenSSH_7.6*,OpenSSH_7.7* compat 0x04000002
debug1: Authenticating to x.x.x.x:22 as 'me'
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:Bajjqc9SJlMHTB/OrEWKl4ATi6/wI+fB1C351fi5Iwk
debug1: Host 'x.x.x.x' is known and matches the ECDSA host key.
debug1: Found key in /Volumes/Norman Data/daveh0/.ssh/known_hosts:10
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: .ssh/test.pem
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
me#x.x.x.x : Permission denied (publickey).
I've got to be missing a step on the SSH Keys screen, but I can't seem to figure out what it would be. Can anyone help?

Answer 1

Keypairs are a feature of Linux. The way it works is:
Somebody tries to connect to the Linux computer using SSH, eg ssh -i key.pem username#IP-ADDRESS
The Linux computer looks in /home/USERNAME/.ssh/authorized_keys
If it finds a public key that matches the private key supplied in key.pem, then the connection is permitted
Therefore, since you created a new keypair, you will need to add the new keypair to the appropriate user's ~/.ssh/authorized_keys file.
Your example shows you as logging in as a user called me, so the public keypair should be added to /home/me/.ssh/authorized_keys.
When first launching a Lightsail or EC2 instance, you can specify a keypair and software on the instance will automatically add the associated public key to the authorized_keys file. However, you will need to do this step manually for an already-running instance.

Answer 2

For AWS Lightsail, I was able to login via SSH by appending my public key id_rsa.pub to remote authorized_keys, I used SFTP (Filezilla) to update authorized_keys file. For SFTP connection I downloaded ssh key from Accounts page.