What is wrong with gitlab and ssh keys - ssh

having some strange problems with Gitlab and ssh keys.
What I did is
Created a pair of rsa keys
id_rsa_GitLab
id_rsa_GitLab.pub
added the public key to my gitlab account
tried to verify if ssh is able to connect with ssh -Tvvv git#xxxx.xx
when doing so, I got this output
$ ssh -Tvvv git#xxxx.xx
OpenSSH_8.3p1, OpenSSL 1.1.1g 21 Apr 2020
debug1: Reading configuration data /c/Users/Ulrich Waibel/.ssh/config
debug1: /c/Users/Ulrich Waibel/.ssh/config line 2: Applying options for xxxx.xx
debug1: Reading configuration data /etc/ssh/ssh_config
debug2: resolving "xxxx.xx" port 22
debug2: ssh_connect_direct
debug1: Connecting to xxxx.xx [xxx.xxx.xxx.153] port 22.
debug1: Connection established.
debug1: identity file /c/Users/Ulrich Waibel/.ssh/id_rsa_GitLab type 0
debug1: identity file /c/Users/Ulrich Waibel/.ssh/id_rsa_GitLab-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.3
debug1: Remote protocol version 2.0, remote software version mod_sftp
debug1: no match: mod_sftp
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to xxxx.xx:22 as 'git'
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
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-group14-sha256,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,sk-ecdsa-sha2-nistp256-cert-v01#openssh.com,ssh-ed25519-cert-v01#openssh.com,sk-ssh-ed25519-cert-v01#openssh.com,rsa-sha2-512-cert-v01#openssh.com,rsa-sha2-256-cert-v01#openssh.com,ssh-rsa-cert-v01#openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,sk-ecdsa-sha2-nistp256#openssh.com,ssh-ed25519,sk-ssh-ed25519#openssh.com,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,aes128-cbc,3des-cbc,aes256-cbc,aes192-cbc
debug2: ciphers stoc: chacha20-poly1305#openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm#openssh.com,aes256-gcm#openssh.com,aes128-cbc,3des-cbc,aes256-cbc,aes192-cbc
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,zlib
debug2: compression stoc: none,zlib#openssh.com,zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256#libssh.org,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256
debug2: host key algorithms: ssh-rsa
debug2: ciphers ctos: aes192-ctr,aes256-ctr,aes128-ctr,aes192-cbc,aes256-cbc,aes128-cbc
debug2: ciphers stoc: aes192-ctr,aes256-ctr,aes128-ctr,aes192-cbc,aes256-cbc,aes128-cbc
debug2: MACs ctos: hmac-sha2-512,hmac-sha2-256,hmac-sha1
debug2: MACs stoc: hmac-sha2-512,hmac-sha2-256,hmac-sha1
debug2: compression ctos: none
debug2: compression stoc: none
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: curve25519-sha256#libssh.org
debug1: kex: host key algorithm: ssh-rsa
debug1: kex: server->client cipher: aes128-ctr MAC: hmac-sha2-256 compression: none
debug1: kex: client->server cipher: aes128-ctr MAC: hmac-sha2-256 compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ssh-rsa SHA256:jQZlCRVqhjK3w3CQWwpfbsUQaZxL5CGV1wYazbGUc7M
The authenticity of host 'xxxx.xx (xxx.xxx.xxx.153)' can't be established.
RSA key fingerprint is SHA256:jQZlCRVqhjK3w3CQWwpfbsUQaZxL5CGV1wYazbGUc7M.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added 'xxxx.xx,xxx.xxx.xxx.153' (RSA) to the list of known hosts.
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey out after 4294967296 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey in after 4294967296 blocks
debug1: Will attempt key: /c/Users/Ulrich Waibel/.ssh/id_rsa_GitLab RSA SHA256:1vaiihW8GNAzlMgDsoScFqMmxFw3FHScM1x30NboJZw explicit
debug2: pubkey_prepare: done
debug3: send packet: type 5
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password
debug3: start over, passed a different list publickey,password
debug3: preferred publickey
debug3: authmethod_lookup publickey
debug3: remaining preferred:
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /c/Users/Ulrich Waibel/.ssh/id_rsa_GitLab RSA SHA256:1vaiihW8GNAzlMgDsoScFqMmxFw3FHScM1x30NboJZw explicit
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
git#xxxx.xx: Permission denied (publickey,password).
I am using Windows 10, git v2.28.0.windows.1
created the keys with git-bash and did also the ssh -T with git-bash
all files are located in $ser$.ssh
there is also a config file with this content
# GitLab.com
Host xxxx.xx
Preferredauthentications publickey
IdentityFile"/c/users/Ulrich Waibel/.ssh/id_rsa_GitLab"
Any help is appreciated

Try with the following %USERPROFILE%.ssh\config file (making sure the eol end of line are LF, not CRLF)
# GitLab.com
Host xxxx.xx
Hostname <correct.hostname>
Preferredauthentications publickey
IdentityFile "/c/users/Ulrich Waibel/.ssh/id_rsa_GitLab"
User git
or
# GitLab.com
Host xxxx.xx
Hostname <correct.hostname>
Preferredauthentications publickey
IdentityFile C:\users\Ulrich Waibel\.ssh\id_rsa_GitLab
User git
or
# GitLab.com
Host xxxx.xx
Hostname <correct.hostname>
Preferredauthentications publickey
IdentityFile "C:\users\Ulrich Waibel\.ssh\id_rsa_GitLab"
User git
You were missing Hostname gitlab.com.
Since you can add User git, the test then becomes:
ssh -Tv xxxx.xx
The OP Uli confirms in the comment: the Host entry has a typo in its "<correct.hostname>"

Related

GitLab Omnibus 14.7.3 ssh "permission denied" error - but specific to "CentOS Stream", works OK on Amazon Linux 2

I have built a brand-new AWS-hosted GitLab Omnibus server (14.7.3-ee) with its own domain name. I have been building this server from Terraform and Ansible for years and never had a problem. But it was based upon CentOS 8, and I’ve just updated it to use "CentOS Stream".
cat /etc/os-release
NAME="CentOS Stream"
VERSION="8"
Since then I cannot seem to get ssh working at all. And I'm pretty sure that the OS is a factor, because if I build the server with the same Ansible and Terraform, but specify Amazon Linux as the OS I don't have this problem.
I’ve created an ssh keypair, again using a script that I’ve had for years. Pasted the pub part into https://gitlab#mydomain.com/-/profile/keys and it has been saved OK. But when I try to use ssh I get the dreaded: “Permission denied (publickey,gssapi-keyex,gssapi-with-mic)”. But I’m completely stumped as to what the problem is.
I’ve tried loads of troubleshooting articles and got nowhere; and I can’t even find the ssh log on the GitLab server as /var/log/auth.log doesn’t exist.
So what I'm really after is any advice on how to troubleshoot this problem further?
ssh -vvvv output shown below.
$ ssh -i /home/peter/.ssh/root-mydomain.com_id_rsa -Tvvvv git#gitlab#mydomain.com
OpenSSH_8.2p1 Ubuntu-4ubuntu0.4, OpenSSL 1.1.1f 31 Mar 2020
debug1: Reading configuration data /home/peter/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug2: resolving "mydomain.com" port 22
debug2: ssh_connect_direct
debug1: Connecting to mydomain.com [3.9.50.219] port 22.
debug1: Connection established.
debug1: identity file /home/peter/.ssh/root-mydomain.com_id_rsa type 0
debug1: identity file /home/peter/.ssh/root-mydomain.com_id_rsa-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_8.0
debug1: match: OpenSSH_8.0 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to mydomain.com:22 as 'git'
debug3: hostkeys_foreach: reading file "/home/peter/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/peter/.ssh/known_hosts:3
debug3: load_hostkeys: loaded 1 keys from mydomain.com
debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-v01#openssh.com,ecdsa-sha2-nistp384-cert-v01#openssh.com,ecdsa-sha2-nistp521-cert-v01#openssh.c
om,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
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,di
ffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,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,ecdsa-sha2-nist
p256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,sk-ecdsa-sha2-nistp256-cert-v01#openssh.com,ssh-ed25519-cert-v01#openssh.com,sk-ssh-ed25519-cert-v01#openssh.com,rsa-sha2-
512-cert-v01#openssh.com,rsa-sha2-256-cert-v01#openssh.com,ssh-rsa-cert-v01#openssh.com,sk-ecdsa-sha2-nistp256#openssh.com,ssh-ed25519,sk-ssh-ed25519#openssh.com,rsa-s
ha2-512,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#opens
sh.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#opens
sh.com,umac-128#openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,zlib#openssh.com,zlib
debug2: compression stoc: none,zlib#openssh.com,zlib
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,di
ffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1
debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256,ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: aes256-gcm#openssh.com,chacha20-poly1305#openssh.com,aes256-ctr,aes256-cbc,aes128-gcm#openssh.com,aes128-ctr,aes128-cbc
debug2: ciphers stoc: aes256-gcm#openssh.com,chacha20-poly1305#openssh.com,aes256-ctr,aes256-cbc,aes128-gcm#openssh.com,aes128-ctr,aes128-cbc
debug2: MACs ctos: hmac-sha2-256-etm#openssh.com,hmac-sha1-etm#openssh.com,umac-128-etm#openssh.com,hmac-sha2-512-etm#openssh.com,hmac-sha2-256,hmac-sha1,umac-128#open
ssh.com,hmac-sha2-512
debug2: MACs stoc: hmac-sha2-256-etm#openssh.com,hmac-sha1-etm#openssh.com,umac-128-etm#openssh.com,hmac-sha2-512-etm#openssh.com,hmac-sha2-256,hmac-sha1,umac-128#open
ssh.com,hmac-sha2-512
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
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:ruhWAao5k3Y9OCJVphXBc1I8WkqRXeRu6p5LQmdbXCU
debug3: hostkeys_foreach: reading file "/home/peter/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/peter/.ssh/known_hosts:3
debug3: load_hostkeys: loaded 1 keys from mydomain.com
debug3: hostkeys_foreach: reading file "/home/peter/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/peter/.ssh/known_hosts:4
debug3: load_hostkeys: loaded 1 keys from 3.9.50.219
debug1: Host 'mydomain.com' is known and matches the ECDSA host key.
debug1: Found key in /home/peter/.ssh/known_hosts:3
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey in after 134217728 blocks
debug1: Will attempt key: /home/peter/.ssh/root-mydomain.com_id_rsa RSA SHA256:foPG+FSppSKdlcygi8+FuqMsfPJO5VaVs7ZqvuBsaLI explicit
debug2: pubkey_prepare: done
debug3: send packet: type 5
debug3: receive packet: type 7
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>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic
debug3: start over, passed a different list publickey,gssapi-keyex,gssapi-with-mic
debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup gssapi-with-mic
debug3: remaining preferred: publickey,keyboard-interactive,password
debug3: authmethod_is_enabled gssapi-with-mic
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available (default cache: FILE:/tmp/krb5cc_1000)
debug1: Unspecified GSS failure. Minor code may provide more information
No Kerberos credentials available (default cache: FILE:/tmp/krb5cc_1000)
debug2: we did not send a packet, disable method
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /home/peter/.ssh/root-mydomain.com_id_rsa RSA SHA256:foPG+FSppSKdlcygi8+FuqMsfPJO5VaVs7ZqvuBsaLI explicit
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
git#mydomain.com: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).

Why is ssh on WSL1 asking for a passphrase although the key has no passphrase

On Arch Linux I can login to my server with an ssh-key with no passphrase.
I copied the ssh-key into my WSL1 .ssh Folder and added the server/key configuration to .ssh/config. Now when I want to login into my server from within WSL I am asked to enter a passphrase, which, obviously, I am not able to do and the login fails.
Why am I supposed to enter a passphrase for a key that has no passphrase and works well on Linux?
ssh -vvv melusinapress.lu
OpenSSH_8.2p1 Ubuntu-4ubuntu0.1, OpenSSL 1.1.1f 31 Mar 2020
debug1: Reading configuration data /home/niels/.ssh/config
debug1: /home/niels/.ssh/config line 6: Applying options for melusinapress.lu
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug2: resolving "melusinapress.lu" port 22
debug2: ssh_connect_direct
debug1: Connecting to melusinapress.lu [104.248.135.159] port 22.
debug1: Connection established.
debug1: identity file /home/niels/.ssh/id_rsa_do_mp type 0
debug1: identity file /home/niels/.ssh/id_rsa_do_mp-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.1
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_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
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to melusinapress.lu:22 as 'XXXXXXXXXXXX'
debug3: hostkeys_foreach: reading file "/home/niels/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/niels/.ssh/known_hosts:10
debug3: load_hostkeys: loaded 1 keys from melusinapress.lu
debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-v01#openssh.com,ecdsa-sha2-nistp384-cert-v01#openssh.com,ecdsa-sha2-nistp521-cert-v01#openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
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-group14-sha256,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,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,sk-ecdsa-sha2-nistp256-cert-v01#openssh.com,ssh-ed25519-cert-v01#openssh.com,sk-ssh-ed25519-cert-v01#openssh.com,rsa-sha2-512-cert-v01#openssh.com,rsa-sha2-256-cert-v01#openssh.com,ssh-rsa-cert-v01#openssh.com,sk-ecdsa-sha2-nistp256#openssh.com,ssh-ed25519,sk-ssh-ed25519#openssh.com,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,zlib#openssh.com,zlib
debug2: compression stoc: none,zlib#openssh.com,zlib
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
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:6tsDRZFslPDOZRjFw84fSoqHQMpX5i9Ewkn70DVtFVk
debug3: hostkeys_foreach: reading file "/home/niels/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/niels/.ssh/known_hosts:10
debug3: load_hostkeys: loaded 1 keys from melusinapress.lu
debug3: hostkeys_foreach: reading file "/home/niels/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/niels/.ssh/known_hosts:8
debug3: load_hostkeys: loaded 1 keys from 104.248.135.159
debug1: Host 'melusinapress.lu' is known and matches the ECDSA host key.
debug1: Found key in /home/niels/.ssh/known_hosts:10
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey in after 134217728 blocks
debug1: Will attempt key: /home/niels/.ssh/id_rsa_do_mp RSA SHA256:yAL0xd2pAuyso0lk4rHd1IKkAtOVtoLV366NdPwfj/U explicit
debug2: pubkey_prepare: done
debug3: send packet: type 5
debug3: receive packet: type 7
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>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey
debug3: start over, passed a different list publickey
debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /home/niels/.ssh/id_rsa_do_mp RSA SHA256:yAL0xd2pAuyso0lk4rHd1IKkAtOVtoLV366NdPwfj/U explicit
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 60
debug1: Server accepts key: /home/niels/.ssh/id_rsa_do_mp RSA SHA256:yAL0xd2pAuyso0lk4rHd1IKkAtOVtoLV366NdPwfj/U explicit
debug3: sign_and_send_pubkey: RSA SHA256:yAL0xd2pAuyso0lk4rHd1IKkAtOVtoLV366NdPwfj/U
debug3: sign_and_send_pubkey: signing using rsa-sha2-512 SHA256:yAL0xd2pAuyso0lk4rHd1IKkAtOVtoLV366NdPwfj/U
Enter passphrase for key '/home/niels/.ssh/id_rsa_do_mp':
(Disclaimer: the key once had a passphrase but I eliminated the passphrase for that key. There were never any problems on Arch Linux with it. Of cause, I tried out the old passphrase, just to see what happens, but the login fails anyway; likewise just hitting return fails.)

SSH keeps asking for password in spite of authorized_key

I created such a key pair:
ssh-keygen -t ed25519 -C "my key to go to X" -f ~/.ssh/keyname
Then added this to my .ssh/config
# Name
Host name login.name.com
User USERNAMEHERE
Hostname login.name.com
IdentityFile ~/.ssh/keyname
PreferredAuthentications publickey,password
Port 8001
ServerAliveInterval 120
ServerAliveCountMax 5
I put keyname.pub in the remote's .ssh/authorized_keys
...
ssh-ed25519 AAAAC3NzaC1lZD...XxQlAX my key to go to X
with on remote: chmod 600 .ssh/authorized_keys and chmod 700 .ssh
Now I still get asked for USERNAMEHERE's password... logs to ssh -vvv name (which I can't decrypt) :
╍ᗇ ssh -vvv name
OpenSSH_7.6p1, LibreSSL 2.6.2
debug1: Reading configuration data /Users/myname/.ssh/config
debug1: /Users/myname/.ssh/config line 1: Applying options for *
debug1: /Users/myname/.ssh/config line 7: Applying options for name
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 48: Applying options for *
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to login.name.com port 8002.
debug1: Connection established.
debug1: identity file /Users/myname/.ssh/name type 3
debug1: key_load_public: No such file or directory
debug1: identity file /Users/myname/.ssh/name-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_7.6
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.6p1 Ubuntu-4ubuntu0.1
debug1: match: OpenSSH_7.6p1 Ubuntu-4ubuntu0.1 pat OpenSSH* compat 0x04000000
debug3: fd 5 is O_NONBLOCK
debug1: Authenticating to login.name.com:8002 as 'USERNAMEHERE'
debug3: put_host_port: [login.name.com]:8002
debug3: hostkeys_foreach: reading file "/Users/myname/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/myname/.ssh/known_hosts:84
debug3: load_hostkeys: loaded 1 keys from [login.name.com]:8002
debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-v01#openssh.com,ecdsa-sha2-nistp384-cert-v01#openssh.com,ecdsa-sha2-nistp521-cert-v01#openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
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,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519-cert-v01#openssh.com,ssh-rsa-cert-v01#openssh.com,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,zlib#openssh.com,zlib
debug2: compression stoc: none,zlib#openssh.com,zlib
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
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:epXBPgPUxN859nWsyfeOA9ie8dFezoed7d1dsHtdDCk
debug3: put_host_port: [69.28.236.4]:8002
debug3: put_host_port: [login.name.com]:8002
debug3: hostkeys_foreach: reading file "/Users/myname/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/myname/.ssh/known_hosts:84
debug3: load_hostkeys: loaded 1 keys from [login.name.com]:8002
debug3: hostkeys_foreach: reading file "/Users/myname/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/myname/.ssh/known_hosts:77
debug3: load_hostkeys: loaded 1 keys from [69.28.236.4]:8002
debug1: Host '[login.name.com]:8002' is known and matches the ECDSA host key.
debug1: Found key in /Users/myname/.ssh/known_hosts:84
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
debug2: key: /Users/myname/.ssh/name (0x7f93396034b0), explicit
debug3: send packet: type 5
debug3: receive packet: type 7
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>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: gssapi-keyex,gssapi-with-mic,password,keyboard-interactive
debug3: start over, passed a different list gssapi-keyex,gssapi-with-mic,password,keyboard-interactive
debug3: preferred publickey,password
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
USERNAMEHERE#login.name.com's password:
You're using the wrong key file. The log shows this:
debug2: key: /Users/myname/.ssh/name (0x7f93396034b0), explicit
but you specified ~/.ssh/keyname in your .ssh/config file.

ssh shows no prompt and authentication fails

I have a VPS running Debian 7 which I use to access through ssh for as long as 4 years.
Now, suddenly, when I try to connect to it, no prompt for password is shown, although the connection to remote sshd is open. And after a few seconds, I get the message "Authentication failed", so that I just can't login to and get a shell prompt.
Does anybody have seen this problem before? Does anybody have any hint on how I may circumvent this issue?
Thanks in advance,
Angico
Edit: I am including the full output of ssh -vvv in order to make it clearer for you to see any detail that may be escaping my attention and/or is out of my poor knowledge:
OpenSSH_7.4p1 Debian-10+deb9u3, OpenSSL 1.0.2l 25 May 2017
debug1: Reading configuration data /home/xyz/.ssh/config
debug1: /home/xyz/.ssh/config line 1: Applying options for xyz.net
debug3: kex names ok: [diffie-hellman-group1-sha1]
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: resolving "xyz.net" port 22
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to xyz.net [12.34.56.78] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /dev/null type -1
debug1: key_load_public: No such file or directory
debug1: identity file /dev/null-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.4p1 Debian-10+deb9u3
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.0p1 Debian-4+deb7u4
debug1: match: OpenSSH_6.0p1 Debian-4+deb7u4 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to xyz.net:22 as 'xyz'
debug3: put_host_port: [xyz.net]:22
debug3: hostkeys_foreach: reading file "/home/xyz/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /home/xyz/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys from [xyz.net]:22
debug3: order_hostkeyalgs: prefer hostkeyalgs: ssh-rsa-cert-v01#openssh.com,rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
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,diffie-hellman-group1-sha1,ext-info-c
debug2: host key algorithms: ssh-rsa-cert-v01#openssh.com,rsa-sha2-512,rsa-sha2-256,ssh-rsa,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,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519
debug2: ciphers ctos: chacha20-poly1305#openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm#openssh.com,aes256-gcm#openssh.com,aes128-cbc,aes192-cbc,aes256-cbc
debug2: ciphers stoc: chacha20-poly1305#openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm#openssh.com,aes256-gcm#openssh.com,aes128-cbc,aes192-cbc,aes256-cbc
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,zlib
debug2: compression stoc: none,zlib#openssh.com,zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: host key algorithms: ssh-rsa,ssh-dss
debug2: ciphers ctos: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc#lysator.liu.se
debug2: ciphers stoc: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc#lysator.liu.se
debug2: MACs ctos: hmac-md5,hmac-sha1,umac-64#openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd160#openssh.com,hmac-sha1-96,hmac-md5-96
debug2: MACs stoc: hmac-md5,hmac-sha1,umac-64#openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd160#openssh.com,hmac-sha1-96,hmac-md5-96
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: ecdh-sha2-nistp256
debug1: kex: host key algorithm: ssh-rsa
debug1: kex: server->client cipher: aes128-ctr MAC: umac-64#openssh.com compression: none
debug1: kex: client->server cipher: aes128-ctr MAC: umac-64#openssh.com compression: none
debug3: send packet: type 30
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ssh-rsa SHA256:abcdefghugklmnop+qrstuvwxyzabcdefghi+jklmnop
debug3: put_host_port: [12.34.56.78]:22
debug3: put_host_port: [xyz.net]:22
debug3: hostkeys_foreach: reading file "/home/xyz/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /home/xyz/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys from [xyz.net]:22
debug3: hostkeys_foreach: reading file "/home/xyz/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /home/xyz/.ssh/known_hosts:2
debug3: load_hostkeys: loaded 1 keys from [12.34.56.78]:22
debug1: Host '[xyz.net]:22' is known and matches the RSA host key.
debug1: Found key in /home/xyz/.ssh/known_hosts:1
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 4294967296 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey after 4294967296 blocks
debug2: key: /dev/null ((nil)), explicit
debug3: send packet: type 5
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
And here, after some time...
Authentication failed.
Your ssh client is trying to use an already defined connection. Do you have any ssh connection configured in .ssh/config? Does it match the connection you want to use?
Also, do you have defined any public or private key in the folder .ssh? if you have some keys there, the ssh clien will try to attempt to use it for connecting and after some tries, will fail. If it is the case, as described here you can use:
ssh -o PreferredAuthentications=password -o PubkeyAuthentication=no example.com
to skip the use of any existing key.

Ssh dsa key authentication fails

I'm trying to log to openssh server installed in cygwin using a dsa key file generated using:
ssh-keygen -t dsa
I have copied my key to authorized_keys using:
ssh-copy-id -i ~/.ssh/id_dsa ltonon#localhost
I also configured ssh server in /etc/sshd_config (everything else was commented out by default):
PubkeyAuthentication yes
AuthorizedKeysFile .ssh/authorized_keys
PasswordAuthentication yes
PubkeyAcceptedKeyTypes=+ssh-dss
In /etc/ssh_config (everything else was commented out by default):
Host *
PubkeyAcceptedKeyTypes=+ssh-dss
Now when I try to log in using:
ssh -vvvv -i .ssh/id_dsa ltonon#localhost
I have the following:
OpenSSH_7.5p1, OpenSSL 1.0.2k 26 Jan 2017
debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 20: Applying options for *
debug2: resolving "localhost" port 22
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to localhost [::1] port 22.
debug1: Connection established.
debug1: identity file .ssh/id_dsa type 2
debug1: key_load_public: No such file or directory
debug1: identity file .ssh/id_dsa-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.5
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.5
debug1: match: OpenSSH_7.5 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to localhost:22 as 'ltonon'
debug3: hostkeys_foreach: reading file "/home/ltonon/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/ltonon/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys from localhost
debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-v01#openssh.com,ecdsa-sha2-nistp384-cert-v01#openssh.com,ecdsa-sha2-nistp521-cert-v01#openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
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,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519-cert-v01#openssh.com,ssh-rsa-cert-v01#openssh.com,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,aes128-cbc,aes192-cbc,aes256-cbc
debug2: ciphers stoc: chacha20-poly1305#openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm#openssh.com,aes256-gcm#openssh.com,aes128-cbc,aes192-cbc,aes256-cbc
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,zlib
debug2: compression stoc: none,zlib#openssh.com,zlib
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
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:3kIsOo83GqltRfLJY2uSGhsQZDVcY+BoTgl+YqvWYns
debug3: hostkeys_foreach: reading file "/home/ltonon/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/ltonon/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys from localhost
debug1: Host 'localhost' is known and matches the ECDSA host key.
debug1: Found key in /home/ltonon/.ssh/known_hosts:1
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
debug2: key: .ssh/id_dsa (0x60005ff20), explicit
debug3: send packet: type 5
debug3: receive packet: type 7
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>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug3: start over, passed a different list publickey,password,keyboard-interactive
debug3: preferred publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering DSA public key: .ssh/id_dsa
debug3: send_pubkey_test
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
Authentication failed.
I'm lost here... Can you help me checking what I missed?
Thanks a lot
The client is configured correctly -- the key is successfully tried:
debug1: Offering DSA public key: .ssh/id_dsa
debug3: send_pubkey_test
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
but the key is rejected by server. Check that the file ~/.ssh/authorized_keys is in the server and it has correct permissions (andalso the parent directories) and that you restarted the sshd service on the server after changing the configuration.
If that will not help, open the server sshd_config, put there LogLevel DEBUG3, restart the sshd service, try to connect once more and have a look into the logs.
But really, you SHOULD NOT be using DSA keys!