Cannot ssh into server: Permission Denied (Public Key)

Question

I created a new user on my server, and generated a public (id_rsa.pub) and private key (id_rsa), which I copied to my laptop's .ssh directory. I then created a config file like so:

Host xxx.xxx.xxx
RSAAuthentication yes
IdentityFile ~/.ssh/id_rsa
User xxx 

I then attempted to ssh into the server, but got the following error instead:

OpenSSH_7.4p1, LibreSSL 2.5.0
debug1: Reading configuration data /Users/xxx/.ssh/config
debug1: /Users/xxx/.ssh/config line 1: Applying options for xxx.xxx.xxx
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to xxx.xxx.xxx [xx.xxx.xx.xx] port 22.
debug1: Connection established.
debug1: identity file /Users/xxx/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xxx/.ssh/id_rsa-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.1
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.1 pat OpenSSH* compat 0x04000000
debug1: Authenticating to xxx.xxx.xxx:22 as 'xxx'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:n+rA9cq8RQTcnh19HlV2/ASXuktvPF2NhZkxNmZTzBE
debug1: Host 'analytics.selfscore.com' is known and matches the ECDSA host key.
debug1: Found key in /Users/xxx/.ssh/known_hosts:1
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: Offering RSA public key: /Users/xxx/.ssh/id_rsa
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
Permission denied (publickey).

Any ideas?

Answer 1

Looks like you have not added your public key to your new users ~/.ssh/authorized_keys file on the remote server.

Log in normally to the server, copy your public key from your local machine then:

echo "your public key here" >> ~/.ssh/authorized_keys"

Then open a new terminal window to verify you can ssh in using the method you are already have.

If successful I would then disable password based auth altogether:

vi /etc/ssh/sshd_config

change

PasswordAuthentication yes

to

PasswordAuthentication no

then

sudo service sshd restart

Verify this:

ssh user@domain should give you a permission denied error without even asking for a PW

Also double check all file permissions on your remote and local key dirs and files: https://superuser.com/questions/215504/permissions-on-private-key-in-ssh-folder

NOTE: the above is based on Ubuntu remote server, the premise is the same for any remote Linux box.