SSH 权限被拒绝（公钥）

Question

I am stuck trying to get SSH to work from my iMac to my desktop running Ubuntu. I've combed through the forums for a solution but nothing has worked for me so far.

Strangely, I can SSH in from my MacBook running a near identical version of macOS. This perhaps rules out any issues with the SSH server?

ssh debug output indicates that the public key was denied. But in my server's /var/log/auth.log I don't see any login attempts

I've attached the client SSH debug output below:

 $ ssh -vvv <user@hosturl>
OpenSSH_7.7p1, LibreSSL 2.7.3
debug1: Reading configuration data /Users/xx/.ssh/config
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 <hosturl> port 22.
debug1: Connection established.
debug1: identity file /Users/xx/.ssh/id_rsa type 0
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_rsa-cert type -1
debug1: identity file /Users/xx/.ssh/id_dsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_ed25519-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_xmss type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_7.7
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH_5* compat 0x0c000000
debug3: fd 5 is O_NONBLOCK
debug1: Authenticating to <hosturl>:22 as 'foobar'
debug3: hostkeys_foreach: reading file "/Users/xx/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /Users/xx/.ssh/known_hosts:14
debug3: load_hostkeys: loaded 1 keys from <hosturl>
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,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
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: 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-sha2-512,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-sha2-512,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: diffie-hellman-group-exchange-sha256
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 34
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(2048<3072<8192) sent
debug3: receive packet: type 31
debug1: got SSH2_MSG_KEX_DH_GEX_GROUP
debug2: bits set: 1558/3072
debug3: send packet: type 32
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug3: receive packet: type 33
debug1: got SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Server host key: ssh-rsa SHA256:f0XcxK1EZCYB0LVN5oqDMyBLc4H6KwGTulMx2otmW34
debug3: hostkeys_foreach: reading file "/Users/xx/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /Users/xx/.ssh/known_hosts:14
debug3: load_hostkeys: loaded 1 keys from <hosturl>
debug3: hostkeys_foreach: reading file "/Users/xx/.ssh/known_hosts"
debug3: record_hostkey: found key type RSA in file /Users/xx/.ssh/known_hosts:14
debug3: load_hostkeys: loaded 1 keys from 17.168.114.134
debug1: Host '<hosturl>' is known and matches the RSA host key.
debug1: Found key in /Users/xx/.ssh/known_hosts:14
debug2: bits set: 1526/3072
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: /Users/xx/.ssh/id_rsa (0x7f996de099e0)
debug1: Skipping ssh-dss key /Users/xx/.ssh/id_dsa - not in PubkeyAcceptedKeyTypes
debug2: key: /Users/xx/.ssh/id_ecdsa (0x0)
debug2: key: /Users/xx/.ssh/id_ed25519 (0x0)
debug2: key: /Users/xx/.ssh/id_xmss (0x0)
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,gssapi-keyex,gssapi-with-mic
debug3: start over, passed a different list publickey,gssapi-keyex,gssapi-with-mic
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 public key: RSA SHA256:mVvMEiNFJDCDKBKFsL62+VQ8PMf1l8ddk1baPUXEzFg /Users/xx/.ssh/id_rsa
debug3: send_pubkey_test
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
debug1: Trying private key: /Users/xx/.ssh/id_ecdsa
debug3: no such identity: /Users/xx/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /Users/xx/.ssh/id_ed25519
debug3: no such identity: /Users/xx/.ssh/id_ed25519: No such file or directory
debug1: Trying private key: /Users/xx/.ssh/id_xmss
debug3: no such identity: /Users/xx/.ssh/id_xmss: No such file or directory
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
xx@foobarlinux1.hopto.org: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).

As a contrast, here's the ssh output from my MacBook which does work:

OpenSSH_7.7p1, LibreSSL 2.7.3
debug1: Reading configuration data /Users/xx/.ssh/config
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 <hosturl> port 22.
debug1: Connection established.
debug1: identity file /Users/xx/.ssh/id_rsa type 0
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_ed25519-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_xmss type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/xx/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_7.7
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.6p1 Ubuntu-4
debug1: match: OpenSSH_7.6p1 Ubuntu-4 pat OpenSSH* compat 0x04000000
debug3: fd 5 is O_NONBLOCK
debug1: Authenticating to <hosturl>:22 as 'xx'
debug3: hostkeys_foreach: reading file "/Users/xx/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/xx/.ssh/known_hosts:14
debug3: load_hostkeys: loaded 1 keys from <hosturl>
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:c+GVdzOd5tiog2l2SoZt9b2XhitOpXrTmXtqb+jd+YM
debug3: hostkeys_foreach: reading file "/Users/xx/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/xx/.ssh/known_hosts:14
debug3: load_hostkeys: loaded 1 keys from <hosturl>
debug3: hostkeys_foreach: reading file "/Users/xx/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/xx/.ssh/known_hosts:14
debug2: channel 0: window 997745 sent adjust 50831
debug3: load_hostkeys: loaded 1 keys from 24.130.30.176
debug1: Host '<hosturl>' is known and matches the ECDSA host key.
debug1: Found key in /Users/xx/.ssh/known_hosts:14
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/xx/.ssh/id_rsa (0x7fcb22d01120)
debug2: key: /Users/xx/.ssh/id_dsa (0x0)
debug2: key: /Users/xx/.ssh/id_ecdsa (0x0)
debug2: key: /Users/xx/.ssh/id_ed25519 (0x0)
debug2: key: /Users/xx/.ssh/id_xmss (0x0)
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 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: RSA SHA256:7oi1SUngV0UmBMeHVXNLjPwtDHO8oumGEuu5vy18b1s /Users/xx/.ssh/id_rsa
debug3: send_pubkey_test
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 60
debug1: Server accepts key: pkalg rsa-sha2-512 blen 279
debug2: input_userauth_pk_ok: fp SHA256:7oi1SUngV0UmBMeHVXNLjPwtDHO8oumGEuu5vy18b1s
debug3: sign_and_send_pubkey: RSA SHA256:7oi1SUngV0UmBMeHVXNLjPwtDHO8oumGEuu5vy18b1s
debug3: send packet: type 50
debug3: receive packet: type 52
debug1: Authentication succeeded (publickey).
Authenticated to <hosturl> ([24.130.30.176]:22).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug3: send packet: type 90
debug1: Requesting no-more-sessions@openssh.com
debug3: send packet: type 80
debug1: Entering interactive session.
debug1: pledge: network
debug3: receive packet: type 80
debug1: client_input_global_request: rtype hostkeys-00@openssh.com want_reply 0
debug3: receive packet: type 91
debug2: channel_input_open_confirmation: channel 0: callback start
debug2: fd 5 setting TCP_NODELAY
debug3: ssh_packet_set_tos: set IP_TOS 0x10
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 1
debug3: send packet: type 98
debug1: Sending environment.
debug3: Ignored env TERM_SESSION_ID
debug3: Ignored env SSH_AUTH_SOCK
debug3: Ignored env Apple_PubSub_Socket_Render
debug3: Ignored env COLORFGBG
debug3: Ignored env ITERM_PROFILE
debug3: Ignored env SQLITE_EXEMPT_PATH_FROM_VNODE_GUARDS
debug3: Ignored env XPC_FLAGS
debug1: Sending env LANG = en_US.UTF-8
debug2: channel 0: request env confirm 0
debug3: send packet: type 98
debug3: Ignored env PWD
debug3: Ignored env SHELL
debug3: Ignored env SECURITYSESSIONID
debug3: Ignored env TERM_PROGRAM_VERSION
debug3: Ignored env TERM_PROGRAM
debug3: Ignored env PATH
debug3: Ignored env DISPLAY
debug3: Ignored env COLORTERM
debug3: Ignored env COMMAND_MODE
debug3: Ignored env TERM
debug3: Ignored env HOME
debug3: Ignored env TMPDIR
debug3: Ignored env USER
debug3: Ignored env XPC_SERVICE_NAME
debug3: Ignored env LOGNAME
debug3: Ignored env __CF_USER_TEXT_ENCODING
debug3: Ignored env ITERM_SESSION_ID
debug3: Ignored env SHLVL
debug3: Ignored env OLDPWD
debug3: Ignored env ZSH
debug3: Ignored env PAGER
debug3: Ignored env LESS
debug1: Sending env LC_CTYPE = en_US.UTF-8
debug2: channel 0: request env confirm 0
debug3: send packet: type 98
debug3: Ignored env LSCOLORS
debug3: Ignored env _
debug2: channel 0: request shell confirm 1
debug3: send packet: type 98
debug2: channel_input_open_confirmation: channel 0: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: PTY allocation request accepted on channel 0
debug2: channel 0: rcvd adjust 2097152
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: shell request accepted on channel 0

Any help is really appreciated!

Answer 1

You are try to log in to two different servers, as can be seen from the server versions:

debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3

This is distinct from the second log, so the machines cannot be the same:

debug1: Remote protocol version 2.0, remote software version OpenSSH_7.6p1 Ubuntu-4

You should compare the DNS configuration and also make sure that you do not have defined any Host aliases in ~/.ssh/config .

Answer 2

For anyone else who stumbles on similar error and above answer does not help, confirm the remote device still has the public ssh key.

• Login to the remote device and cat ~/.ssh/authorized_keys
• Compare with the public ssh key xxxxxx.pub on the local device

Answer 3

Your MacBook is connecting with a valid private SSH key as indicated by:

debug1: Next authentication method: publickey
debug1: Offering public key: RSA SHA256:7oi1SUngV0UmBMeHVXNLjPwtDHO8oumGEuu5vy18b1s /Users/xx/.ssh/id_rsa

...snip...

debug1: Server accepts key: pkalg rsa-sha2-512 blen 279

and

debug1: Authentication succeeded (publickey).

While the first PC tries to authenticate using the default key names, but none of them exist. The server's sshd_config likely has password authentication disabled.

debug1: Trying private key: /Users/xx/.ssh/id_ecdsa
debug3: no such identity: /Users/xx/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /Users/xx/.ssh/id_ed25519
debug3: no such identity: /Users/xx/.ssh/id_ed25519: No such file or directory
debug1: Trying private key: /Users/xx/.ssh/id_xmss
debug3: no such identity: /Users/xx/.ssh/id_xmss: No such file or directory
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
xx@foobarlinux1.hopto.org: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).

Check the file $HOME/.ssh/authorized_keys on your destination server to see the public keys that are saved there.