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I have Ubuntu running on Windows (app) where I have created SSH key pair and added to Ubuntu server (Cloud) for the user.

Whenever I try to SSH from Ubuntu sandbox (Windows) to Ubuntu server (Cloud), authentication fails with following logs in /var/log/auth.log

Connection closed by #.#.#.# [preauth]

Verbose logs for SSH are here from sandbox:

$ ssh prod-bastion -vvv
OpenSSH_8.9p1 Ubuntu-3, OpenSSL 3.0.2 15 Mar 2022
debug1: Reading configuration data /home/jane/.ssh/config
debug1: /home/jane/.ssh/config line 1: Applying options for prod-bastion
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 *
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts' -> '/home/jane/.ssh/known_hosts'
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts2' -> '/home/jane/.ssh/known_hosts2'
debug1: auto-mux: Trying existing master
debug1: Control socket "/home/jane/.ssh/jane@prod-bastion.example.net:22" does not exist
debug2: resolving "prod-bastion.example.net" port 22
debug3: resolve_host: lookup prod-bastion.example.net:22
debug3: ssh_connect_direct: entering
debug1: Connecting to prod-bastion.example.net [52.37.167.176] port 22.
debug3: set_sock_tos: set socket 3 IP_TOS 0x10
debug1: Connection established.
debug1: identity file /home/jane/.ssh/id_rsa type 0
debug1: identity file /home/jane/.ssh/id_rsa-cert type -1
debug1: identity file /home/jane/.ssh/id_ecdsa type -1
debug1: identity file /home/jane/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/jane/.ssh/id_ecdsa_sk type -1
debug1: identity file /home/jane/.ssh/id_ecdsa_sk-cert type -1
debug1: identity file /home/jane/.ssh/id_ed25519 type -1
debug1: identity file /home/jane/.ssh/id_ed25519-cert type -1
debug1: identity file /home/jane/.ssh/id_ed25519_sk type -1
debug1: identity file /home/jane/.ssh/id_ed25519_sk-cert type -1
debug1: identity file /home/jane/.ssh/id_xmss type -1
debug1: identity file /home/jane/.ssh/id_xmss-cert type -1
debug1: identity file /home/jane/.ssh/id_dsa type -1
debug1: identity file /home/jane/.ssh/id_dsa-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.9p1 Ubuntu-3
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8
debug1: compat_banner: match: OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8 pat OpenSSH_6.6.1* compat 0x04000002
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to prod-bastion.example.net:22 as 'jane'
debug3: record_hostkey: found key type ED25519 in file /home/jane/.ssh/known_hosts:1
debug3: load_hostkeys_file: loaded 1 keys from prod-bastion.example.net
debug1: load_hostkeys: fopen /home/jane/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug3: order_hostkeyalgs: have matching best-preference key type ssh-ed25519-cert-v01@openssh.com, using HostkeyAlgorithms verbatim
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,sntrup761x25519-sha512@openssh.com,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,ext-info-c
debug2: host key algorithms: ssh-ed25519-cert-v01@openssh.com,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,sk-ssh-ed25519-cert-v01@openssh.com,sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,rsa-sha2-512-cert-v01@openssh.com,rsa-sha2-256-cert-v01@openssh.com,ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,sk-ssh-ed25519@openssh.com,sk-ecdsa-sha2-nistp256@openssh.com,rsa-sha2-512,rsa-sha2-256
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@libssh.org,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,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: aes128-ctr,aes192-ctr,aes256-ctr
debug2: ciphers stoc: aes128-ctr,aes192-ctr,aes256-ctr
debug2: MACs ctos: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@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-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@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: curve25519-sha256@libssh.org
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: aes128-ctr MAC: umac-64-etm@openssh.com compression: none
debug1: kex: client->server cipher: aes128-ctr MAC: umac-64-etm@openssh.com compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: SSH2_MSG_KEX_ECDH_REPLY received
debug1: Server host key: ssh-ed25519 SHA256:A1GFTbRvBgWebh+N7XxFam9Ke7QG731QdQRjwYXUbmo
debug3: record_hostkey: found key type ED25519 in file /home/jane/.ssh/known_hosts:1
debug3: load_hostkeys_file: loaded 1 keys from prod-bastion.example.net
debug1: load_hostkeys: fopen /home/jane/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug1: Host 'prod-bastion.example.net' is known and matches the ED25519 host key.
debug1: Found key in /home/jane/.ssh/known_hosts:1
debug3: send packet: type 21
debug2: ssh_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: ssh_set_newkeys: mode 0
debug1: rekey in after 4294967296 blocks
debug1: Will attempt key: /home/jane/.ssh/id_rsa RSA SHA256:5ER+G702M2aLEQq4PP5a8opGM0W0ZLfhm2aHIbfxZpU
debug1: Will attempt key: /home/jane/.ssh/id_ecdsa
debug1: Will attempt key: /home/jane/.ssh/id_ecdsa_sk
debug1: Will attempt key: /home/jane/.ssh/id_ed25519
debug1: Will attempt key: /home/jane/.ssh/id_ed25519_sk
debug1: Will attempt key: /home/jane/.ssh/id_xmss
debug1: Will attempt key: /home/jane/.ssh/id_dsa
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
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/jane/.ssh/id_rsa RSA SHA256:5ER+G702M2aLEQq4PP5a8opGM0W0ZLfhm2aHIbfxZpU
debug1: send_pubkey_test: no mutual signature algorithm
debug1: Trying private key: /home/jane/.ssh/id_ecdsa
debug3: no such identity: /home/jane/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /home/jane/.ssh/id_ecdsa_sk
debug3: no such identity: /home/jane/.ssh/id_ecdsa_sk: No such file or directory
debug1: Trying private key: /home/jane/.ssh/id_ed25519
debug3: no such identity: /home/jane/.ssh/id_ed25519: No such file or directory
debug1: Trying private key: /home/jane/.ssh/id_ed25519_sk
debug3: no such identity: /home/jane/.ssh/id_ed25519_sk: No such file or directory
debug1: Trying private key: /home/jane/.ssh/id_xmss
debug3: no such identity: /home/jane/.ssh/id_xmss: No such file or directory
debug1: Trying private key: /home/jane/.ssh/id_dsa
debug3: no such identity: /home/jane/.ssh/id_dsa: No such file or directory
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
jane@prod-bastion.example.net: Permission denied (publickey).

Update: I added following lines to ~/.ssh/config & /etc/ssh/sshd_config::

HostkeyAlgorithms +ssh-rsa
PubkeyAcceptedAlgorithms +ssh-rsa

And am still facing same issue. Following was the client logs:

$ ssh prod-bastion -vvv
OpenSSH_8.9p1 Ubuntu-3, OpenSSL 3.0.2 15 Mar 2022
debug1: Reading configuration data /home/jane/.ssh/config
debug1: /home/jane/.ssh/config line 5: Applying options for prod-bastion
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 *
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts' -> '/home/jane/.ssh/known_hosts'
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts2' -> '/home/jane/.ssh/known_hosts2'
debug1: auto-mux: Trying existing master
debug1: Control socket "/home/jane/.ssh/jane@prod-bastion.example.net:22" does not exist
debug2: resolving "prod-bastion.example.net" port 22
debug3: resolve_host: lookup prod-bastion.example.net:22
debug3: ssh_connect_direct: entering
debug1: Connecting to prod-bastion.example.net [52.37.167.176] port 22.
debug3: set_sock_tos: set socket 3 IP_TOS 0x10
debug1: Connection established.
debug1: identity file /home/jane/.ssh/id_rsa type 0
debug1: identity file /home/jane/.ssh/id_rsa-cert type -1
debug1: identity file /home/jane/.ssh/id_ecdsa type -1
debug1: identity file /home/jane/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/jane/.ssh/id_ecdsa_sk type -1
debug1: identity file /home/jane/.ssh/id_ecdsa_sk-cert type -1
debug1: identity file /home/jane/.ssh/id_ed25519 type -1
debug1: identity file /home/jane/.ssh/id_ed25519-cert type -1
debug1: identity file /home/jane/.ssh/id_ed25519_sk type -1
debug1: identity file /home/jane/.ssh/id_ed25519_sk-cert type -1
debug1: identity file /home/jane/.ssh/id_xmss type -1
debug1: identity file /home/jane/.ssh/id_xmss-cert type -1
debug1: identity file /home/jane/.ssh/id_dsa type -1
debug1: identity file /home/jane/.ssh/id_dsa-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.9p1 Ubuntu-3
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8
debug1: compat_banner: match: OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8 pat OpenSSH_6.6.1* compat 0x04000002
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to prod-bastion.example.net:22 as 'jane'
debug3: record_hostkey: found key type ED25519 in file /home/jane/.ssh/known_hosts:2
debug3: load_hostkeys_file: loaded 1 keys from prod-bastion.example.net
debug1: load_hostkeys: fopen /home/jane/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug3: order_hostkeyalgs: have matching best-preference key type ssh-ed25519-cert-v01@openssh.com, using HostkeyAlgorithms verbatim
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,sntrup761x25519-sha512@openssh.com,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,ext-info-c
debug2: host key algorithms: ssh-ed25519-cert-v01@openssh.com,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,sk-ssh-ed25519-cert-v01@openssh.com,sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,rsa-sha2-512-cert-v01@openssh.com,rsa-sha2-256-cert-v01@openssh.com,ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,sk-ssh-ed25519@openssh.com,sk-ecdsa-sha2-nistp256@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@libssh.org,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,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: aes128-ctr,aes192-ctr,aes256-ctr
debug2: ciphers stoc: aes128-ctr,aes192-ctr,aes256-ctr
debug2: MACs ctos: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@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-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@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: curve25519-sha256@libssh.org
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: aes128-ctr MAC: umac-64-etm@openssh.com compression: none
debug1: kex: client->server cipher: aes128-ctr MAC: umac-64-etm@openssh.com compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: SSH2_MSG_KEX_ECDH_REPLY received
debug1: Server host key: ssh-ed25519 SHA256:A1GFTbRvBgWebh+N7XxFam9Ke7QG731QdQRjwYXUbmo
debug3: record_hostkey: found key type ED25519 in file /home/jane/.ssh/known_hosts:2
debug3: load_hostkeys_file: loaded 1 keys from prod-bastion.example.net
debug1: load_hostkeys: fopen /home/jane/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug1: Host 'prod-bastion.example.net' is known and matches the ED25519 host key.
debug1: Found key in /home/jane/.ssh/known_hosts:2
debug3: send packet: type 21
debug2: ssh_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: ssh_set_newkeys: mode 0
debug1: rekey in after 4294967296 blocks
debug1: get_agent_identities: bound agent to hostkey
debug1: get_agent_identities: agent returned 1 keys
debug1: Will attempt key: /home/jane/.ssh/id_rsa RSA SHA256:MdIotJIPz/SIVid25XfX+B8T9g1C6CxHGwTxnnuCRe8 agent
debug1: Will attempt key: /home/jane/.ssh/id_ecdsa 
debug1: Will attempt key: /home/jane/.ssh/id_ecdsa_sk 
debug1: Will attempt key: /home/jane/.ssh/id_ed25519 
debug1: Will attempt key: /home/jane/.ssh/id_ed25519_sk 
debug1: Will attempt key: /home/jane/.ssh/id_xmss 
debug1: Will attempt key: /home/jane/.ssh/id_dsa 
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
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/jane/.ssh/id_rsa RSA SHA256:MdIotJIPz/SIVid25XfX+B8T9g1C6CxHGwTxnnuCRe8 agent
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
debug1: Trying private key: /home/jane/.ssh/id_ecdsa
debug3: no such identity: /home/jane/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /home/jane/.ssh/id_ecdsa_sk
debug3: no such identity: /home/jane/.ssh/id_ecdsa_sk: No such file or directory
debug1: Trying private key: /home/jane/.ssh/id_ed25519
debug3: no such identity: /home/jane/.ssh/id_ed25519: No such file or directory
debug1: Trying private key: /home/jane/.ssh/id_ed25519_sk
debug3: no such identity: /home/jane/.ssh/id_ed25519_sk: No such file or directory
debug1: Trying private key: /home/jane/.ssh/id_xmss
debug3: no such identity: /home/jane/.ssh/id_xmss: No such file or directory
debug1: Trying private key: /home/jane/.ssh/id_dsa
debug3: no such identity: /home/jane/.ssh/id_dsa: No such file or directory
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
jane@prod-bastion.example.net: Permission denied (publickey).

What I am missing here?

Giacomo1968
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rp346
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1 Answers1

0

Your OpenSSH client is recent (8.9) which no longer by default supports the old, unsafe type of RSA signature (ssh-rsa) while your server is ancient (6.6) which only supports ssh-rsa not the newer rsa-sha2*, hence "no mutual signature algorithm".

Either use -o PubKeyAcceptedAlgorithms=+ssh-rsa (below 8.5 you would need the older less-precise name PubKeyAcceptedKeyTypes) or use an ecdsa or ed25519 key (which you don't currently have in the default locations, so it would probably need to be created and configured on the server).