No supported authentication methods available in 3.48, work fine with 3.47

[tzorattoa]

Hi, connecting to the same remote SFTP server (proftpd) it works fine with filezilla 3.47, and doesn't work with 3.48, with the exact same configuration.

Client logs :
Status: Waiting to retry...
Trace: CControlSocket::SendNextCommand()
Trace: CSftpConnectOpData::Send() in state 0
Status: Connecting to some-sftp.server.com...
Trace: Going to execute C:\Program Files (x86)\FileZilla FTP Client\fzsftp.exe
Response: fzSftp started, protocol_version=9
Trace: CSftpConnectOpData::ParseResponse() in state 0
Trace: CControlSocket::SendNextCommand()
Trace: CSftpConnectOpData::Send() in state 3
Command: open "someuser@…" 22
Trace: Looking up host "some-sftp.server.com" for SSH connection
Trace: Connecting to XX.XX.XX.XX port 22
Trace: We claim version: SSH-2.0-FileZilla_3.48.0
Trace: Remote version: SSH-2.0-SFTP SERVER
Trace: Using SSH protocol version 2
Trace: Doing Diffie-Hellman group exchange
Trace: Doing Diffie-Hellman key exchange using 4096-bit modulus and hash SHA-256 (unaccelerated) with a server-supplied group
Trace: Host key fingerprint is:
Trace: ssh-rsa 4096 dd:9b:bf:e7:a8:d1:41:8d:db:69:26:06:a1:dc:76:3a c7eFbbeLQB8Vd5gOrtj6GZzdoQ6aWGOtCxu5HoFd66E=
Trace: CSftpControlSocket::SetAsyncRequestReply
Command: Trust new Hostkey: Once
Trace: Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption
Trace: Initialised HMAC-SHA-256 (unaccelerated) outbound MAC algorithm
Trace: Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption
Trace: Initialised HMAC-SHA-256 (unaccelerated) inbound MAC algorithm
Status: Using username "someuser".
Command: Pass:
Trace: Sent password
Trace: Remote side sent disconnect message type 14 (no more auth methods available): "No other authentication mechanisms available"
Error: FATAL ERROR: Remote side sent disconnect message
Error: type 14 (no more auth methods available):
Error: "No other authentication mechanisms available"
Trace: CSftpControlSocket::OnTerminate without error
Trace: CControlSocket::DoClose(66)
Trace: CControlSocket::ResetOperation(66)
Trace: CSftpConnectOpData::Reset(66) in state 3
Error: Could not connect to server
Trace: CFileZillaEnginePrivate::ResetOperation(66)
Status: Waiting to retry...

Server logs:
2020-07-16 11:42:26,512 mod_sftp/1.0.0[10141]: sent server version 'SSH-2.0-SFTP SERVER'
2020-07-16 11:38:00,342 mod_sftp/1.0.0[9832]: received client version 'SSH-2.0-FileZilla_3.48.0'
2020-07-16 11:38:00,342 mod_sftp/1.0.0[9832]: handling connection from SSH2 client 'FileZilla_3.48.0'
2020-07-16 11:38:00,363 mod_sftp/1.0.0[9832]: + Session key exchange: diffie-hellman-group-exchange-sha256
2020-07-16 11:38:00,363 mod_sftp/1.0.0[9832]: + Session server hostkey: ssh-rsa
2020-07-16 11:38:00,363 mod_sftp/1.0.0[9832]: + Session client-to-server encryption: aes256-ctr
2020-07-16 11:38:00,363 mod_sftp/1.0.0[9832]: + Session server-to-client encryption: aes256-ctr
2020-07-16 11:38:00,363 mod_sftp/1.0.0[9832]: + Session client-to-server MAC: hmac-sha2-256
2020-07-16 11:38:00,363 mod_sftp/1.0.0[9832]: + Session server-to-client MAC: hmac-sha2-256
2020-07-16 11:38:00,363 mod_sftp/1.0.0[9832]: + Session client-to-server compression: none
2020-07-16 11:38:00,363 mod_sftp/1.0.0[9832]: + Session server-to-client compression: none
2020-07-16 11:38:00,915 mod_sftp/1.0.0[9832]: sending acceptable userauth methods: password
2020-07-16 11:38:00,934 mod_sftp/1.0.0[9832]: client sent SSH_MSG_IGNORE message (13 bytes)
2020-07-16 11:38:00,934 mod_sftp/1.0.0[9832]: cipher algorithm 'USERAUTH_REQUEST someuser' or MAC algorithm 'none' unacceptable for password authentication, denying password authentication request
2020-07-16 11:38:00,934 mod_sftp/1.0.0[9832]: no more auth methods available, disconnecting
2020-07-16 11:38:00,934 mod_sftp/1.0.0[9832]: disconnecting YY.YY.YY.YY (No other authentication mechanisms available)

It works both with 3.47 and 3.48 connecting to a remote OpenSSH server instead of proftpd. I suppose there are some differences in the supported algorithms but the error messages are not crystal clear and I didn't found any related changes in the changelog for 3.48 on https://filezilla-project.org/versions.php.

As a workaround we now use another SFTP client.