SSH – Fix Public Key Authentication Denied on Ubuntu

I am trying to connect to a virtual machine via SSH.

I can login to an account with a password.

I created another user without a password, generated a ssh key on my host machine (Windows), and placed the public key inside the user/.ssh/authorized_keys, and set the permission to read only, with full ownership of the user.

However, when I try to ssh, from localhost on the VM OR from my host machine, the public key is always denied. I have configured the ssh server to accept only public key authentication.

This is the error that I get when I run ssh -vv user@localhost -i privatekey

PS C:\Users\gicum\.ssh> ssh -vv mironica@192.168.230.129 -p 2222 -i mironica
OpenSSH_for_Windows_7.7p1, LibreSSL 2.6.5
debug1: Reading configuration data C:\\Users\\gicum/.ssh/config
debug1: C:\\Users\\gicum/.ssh/config line 1: Applying options for 192.168.230.129
debug2: resolve_canonicalize: hostname 192.168.230.129 is address
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to 192.168.230.129 [192.168.230.129] port 2222.
debug1: Connection established.
debug1: identity file mironica.pub type 0
debug1: key_load_public: No such file or directory
debug1: identity file mironica.pub-cert type -1
debug1: identity file C:\\Users\\gicum/.ssh/mironica type 0
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\gicum/.ssh/mironica-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_for_Windows_7.7
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.6p1 Ubuntu-4ubuntu0.3
debug1: match: OpenSSH_7.6p1 Ubuntu-4ubuntu0.3 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to 192.168.230.129:2222 as 'mironica'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,ext-info-c
debug2: host key algorithms: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ssh-ed25519-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com
debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com
debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none
debug2: compression stoc: none
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1
debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com
debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com
debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,zlib@openssh.com
debug2: compression stoc: none,zlib@openssh.com
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: curve25519-sha256
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:gS6dFKtHfhm8j4RkJ41ISAn0XS5KLrGlAD+QCHMp8qc
debug1: checking without port identifier
debug1: Host '192.168.230.129' is known and matches the ECDSA host key.
debug1: Found key in C:\\Users\\gicum/.ssh/known_hosts:10
debug1: found matching key w/out port
debug2: set_newkeys: mode 1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
debug2: key: mironica.pub (00000266CA181500), explicit, agent
debug2: key: C:\\Users\\gicum/.ssh/mironica (00000266CA181030), explicit
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<ssh-ed25519,ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521>
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering public key: RSA SHA256:JbiX5u8cO0CxDtwgv258/TLUWyG/xh4XwTvGIQjdXrc mironica.pub
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey
debug1: Offering public key: RSA SHA256:JbiX5u8cO0CxDtwgv258/TLUWyG/xh4XwTvGIQjdXrc C:\\Users\\gicum/.ssh/mironica
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
mironica@192.168.230.129: Permission denied (publickey).

The issue is similar when trying via localhost as mentioned above.
I can't figure out what could possibly be my problem here?

The public key

ssh-rsa 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 gicum@bosslife

/var/log/auth.log

Sep 15 14:03:45 ubuntu sshd[9423]: Received SIGHUP; restarting.
Sep 15 14:03:45 ubuntu sshd[9423]: Server listening on 0.0.0.0 port 22.
Sep 15 14:03:45 ubuntu sshd[9423]: Server listening on :: port 22.
Sep 15 14:17:02 ubuntu CRON[11586]: pam_unix(cron:session): session opened for user root by (uid=0)
Sep 15 14:17:02 ubuntu CRON[11586]: pam_unix(cron:session): session closed for user root
Sep 15 14:24:49 ubuntu sshd[11884]: Connection reset by authenticating user mironica 192.168.230.1 port 50138 [preauth]
Sep 15 14:25:16 ubuntu sshd[11904]: Connection reset by authenticating user mironica 192.168.230.1 port 50141 [preauth]
Sep 15 14:26:47 ubuntu sshd[11955]: Connection reset by authenticating user mironica 192.168.230.1 port 50173 [preauth]
Sep 15 14:27:01 ubuntu sshd[11965]: Connection reset by authenticating user mironica 192.168.230.1 port 50182 [preauth]
Sep 15 14:27:20 ubuntu sshd[11980]: Connection reset by authenticating user mironica 192.168.230.1 port 50194 [preauth]
Sep 15 14:42:48 ubuntu gdm-password]: gkr-pam: unlocked login keyring