I am trying to connect to a remote server using SSH from client running ubuntu 22.04
Server is a cloud instance of OVH ISP, running ubuntu 23.04.
In OVH doc, it is mentioned: "You can only store RSA and ECDSA encrypted keys; ED25519 is currently not supported.". So I created, as they propose, an RSA key on my client, using:
ssh-keygen -b 4096, and copied the key to the cloud instance server.
Now, when I try to connect, using:
ssh [email protected]
I get:
The authenticity of host '135.125.94.203' can't be established. ED25519 key fingerprint is SHA256:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx. This key is not known by any other names Are you sure you want to continue connecting (yes/no/[fingerprint])?
When I answer yes, I get: [email protected]: Permission denied (publickey).
I read different messages about that, but in the first place I don't understand why ED25519 is mentioned, since I created an RSA key.
I tried to add: PubkeyAcceptedKeyTypes +ssh-rsa at the end of /etc/ssh/sshd_config and restart ssh, but it didn't help.
Below is the log of ssh -vvv [email protected]
OpenSSH_8.9p1 Ubuntu-3ubuntu0.1, OpenSSL 3.0.2 15 Mar 2022
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: resolve_canonicalize: hostname 135.125.94.203 is address
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts' -> '/home/mp/.ssh/known_hosts'
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts2' -> '/home/mp/.ssh/known_hosts2'
debug3: ssh_connect_direct: entering
debug1: Connecting to 135.125.94.203 [135.125.94.203] port 22.
debug3: set_sock_tos: set socket 3 IP_TOS 0x10
debug1: Connection established.
debug1: identity file /home/mp/.ssh/id_rsa type 0
debug1: identity file /home/mp/.ssh/id_rsa-cert type -1
debug1: identity file /home/mp/.ssh/id_ecdsa type -1
debug1: identity file /home/mp/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/mp/.ssh/id_ecdsa_sk type -1
debug1: identity file /home/mp/.ssh/id_ecdsa_sk-cert type -1
debug1: identity file /home/mp/.ssh/id_ed25519 type -1
debug1: identity file /home/mp/.ssh/id_ed25519-cert type -1
debug1: identity file /home/mp/.ssh/id_ed25519_sk type -1
debug1: identity file /home/mp/.ssh/id_ed25519_sk-cert type -1
debug1: identity file /home/mp/.ssh/id_xmss type -1
debug1: identity file /home/mp/.ssh/id_xmss-cert type -1
debug1: identity file /home/mp/.ssh/id_dsa type -1
debug1: identity file /home/mp/.ssh/id_dsa-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.9p1 Ubuntu-3ubuntu0.1
debug1: Remote protocol version 2.0, remote software version OpenSSH_9.0p1 Ubuntu-1ubuntu8
debug1: compat_banner: match: OpenSSH_9.0p1 Ubuntu-1ubuntu8 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to 135.125.94.203:22 as 'ubuntu'
debug3: record_hostkey: found key type ED25519 in file /home/mp/.ssh/known_hosts:1
debug3: load_hostkeys_file: loaded 1 keys from 135.125.94.203
debug1: load_hostkeys: fopen /home/mp/.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 [email protected], 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,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,[email protected],diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,ext-info-c
debug2: host key algorithms: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],rsa-sha2-512,rsa-sha2-256
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected],zlib
debug2: compression stoc: none,[email protected],zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: [email protected],curve25519-sha256,[email protected],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
debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected]
debug2: compression stoc: none,[email protected]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> 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 SHA256:78sCXM8oOJ0H7mq/mhlVw6N/iLgtGSf6ua3Fr91j0Lo
debug3: record_hostkey: found key type ED25519 in file /home/mp/.ssh/known_hosts:1
debug3: load_hostkeys_file: loaded 1 keys from 135.125.94.203
debug1: load_hostkeys: fopen /home/mp/.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 '135.125.94.203' is known and matches the ED25519 host key.
debug1: Found key in /home/mp/.ssh/known_hosts:1
debug3: send packet: type 21
debug2: ssh_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: ssh_set_newkeys: mode 0
debug1: rekey in after 134217728 blocks
debug1: get_agent_identities: bound agent to hostkey
debug1: get_agent_identities: agent returned 1 keys
debug1: Will attempt key: /home/mp/.ssh/id_rsa RSA SHA256:k1ZxU52fxS6qcGnXNplNGShPZdv4aqFYR30JHvSoeeo agent
debug1: Will attempt key: /home/mp/.ssh/id_ecdsa
debug1: Will attempt key: /home/mp/.ssh/id_ecdsa_sk
debug1: Will attempt key: /home/mp/.ssh/id_ed25519
debug1: Will attempt key: /home/mp/.ssh/id_ed25519_sk
debug1: Will attempt key: /home/mp/.ssh/id_xmss
debug1: Will attempt key: /home/mp/.ssh/id_dsa
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,[email protected],ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected]>
debug1: kex_input_ext_info: [email protected]=<0>
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/mp/.ssh/id_rsa RSA SHA256:k1ZxU52fxS6qcGnXNplNGShPZdv4aqFYR30JHvSoeeo 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/mp/.ssh/id_ecdsa
debug3: no such identity: /home/mp/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /home/mp/.ssh/id_ecdsa_sk
debug3: no such identity: /home/mp/.ssh/id_ecdsa_sk: No such file or directory
debug1: Trying private key: /home/mp/.ssh/id_ed25519
debug3: no such identity: /home/mp/.ssh/id_ed25519: No such file or directory
debug1: Trying private key: /home/mp/.ssh/id_ed25519_sk
debug3: no such identity: /home/mp/.ssh/id_ed25519_sk: No such file or directory
debug1: Trying private key: /home/mp/.ssh/id_xmss
debug3: no such identity: /home/mp/.ssh/id_xmss: No such file or directory
debug1: Trying private key: /home/mp/.ssh/id_dsa
debug3: no such identity: /home/mp/.ssh/id_dsa: No such file or directory
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
[email protected]: Permission denied (publickey).`
