Hello
Anyone having problems with SecureFTPConnection and Filezilla server 1.3.0? With an insecure setup, the connection is OK. With Explicit only setup there is no way to connect.
The client debug mode :
Testing your ftp settings...
Set LocalDirectory to D:\Projects\
waitOnShutdownSSL=True
StrictReturnCodes=False
Setting socket timeout=120000
SecureSocket timeout=120000
SecureSocket timeout=120000
Command encoding=System.Text.SBCSCodePageEncoding
Setting socket buffer sizes=-1
220-FileZilla Server 1.3.0
220 Please visit https://filezilla-project.org/
SetSSLProtocol: min=DETECT, max=DETECT
---> AUTH TLS
234 Using authentication type TLS.
Starting handshake
ECDHE_RSA_AES_128_SHA
ECDHE_RSA_AES_256_SHA
RSA_AES_128_GCM_SHA256
RSA_AES_256_GCM_SHA384
DHE_RSA_AES_128_GCM_SHA256
DHE_RSA_AES_256_GCM_SHA384
ECDHE_RSA_AES_128_GCM_SHA256
ECDHE_RSA_AES_256_GCM_SHA384
DHE_RSA_AES_128_SHA
DHE_RSA_AES_128_SHA256
DHE_RSA_AES_256_SHA
DHE_RSA_AES_256_SHA256
DHE_RSA_AES_256_SHA256
RSA_AES_128_SHA
RSA_AES_128_SHA256
RSA_AES_256_SHA256
RSA_AES_256_SHA
ECDHE_RSA_3DES_SHA
DHE_RSA_3DES_SHA
RSA_3DES_168_SHA
DHE_RSA_DES_SHA
Handshake started
Waiting for handshake completion
OnReceive closing (size == 0)
CloseConnection(e=null)
Shut down socket
Closed socket
Close() called when open
OnReceive - caught exception - closing: Socket closed before handshake is complete (2)
CloseConnection(e=Socket closed before handshake is complete (2))
OnHandshakeComplete - waiting for lock
OnHandshakeComplete - in lock
OnHandshakeComplete - exiting lock
OnHandshakeComplete - exit
Exception during handshake
Socket closed before handshake is complete (2)
On the server side I got:
2022-03-24T19:31:12.791Z II [FTP Session 25 127.0.0.1] Session 0x1d6a3247930 with ID 25 created.
2022-03-24T19:31:12.854Z >> [FTP Session 25 127.0.0.1] AUTH TLS
2022-03-24T19:31:12.854Z DD [FTP Session 25 127.0.0.1] securer(1) ENTERING state = 0
2022-03-24T19:31:12.854Z DD [FTP Session 25 127.0.0.1] calling tls_layer_->set_certificate_file("C:\Windows\system32\config\systemprofile\AppData\Local\filezilla-server\certificates\cc4c3012da89d57f85610ff2c14d26483cf9352a4c0e4a0e8c2e9502299de874\key.pem", "C:\Windows\system32\config\systemprofile\AppData\Local\filezilla-server\certificates\cc4c3012da89d57f85610ff2c14d26483cf9352a4c0e4a0e8c2e9502299de874\cert.pem", "****")
2022-03-24T19:31:12.854Z DD [FTP Session 25 127.0.0.1] securer(1) EXITING state = 1
2022-03-24T19:31:12.854Z << [FTP Session 25 127.0.0.1] 234 Using authentication type TLS.
2022-03-24T19:31:12.854Z DD [FTP Session 25 127.0.0.1] ~securer(1) ENTERING state = 1
2022-03-24T19:31:12.854Z DD [FTP Session 25 127.0.0.1] calling tls_layer_->set_alpn()
2022-03-24T19:31:12.854Z VV [FTP Session 25 127.0.0.1] tls_layer_impl::server_handshake()
2022-03-24T19:31:12.854Z VV [FTP Session 25 127.0.0.1] tls_layer_impl::continue_handshake()
2022-03-24T19:31:12.854Z DD [FTP Session 25 127.0.0.1] ~securer(1) EXITING state = 2
2022-03-24T19:31:12.854Z DD [FTP Session 25 127.0.0.1] tls_layer_impl::on_send()
2022-03-24T19:31:12.854Z VV [FTP Session 25 127.0.0.1] tls_layer_impl::continue_handshake()
2022-03-24T19:31:13.148Z DD [FTP Session 25 127.0.0.1] tls_layer_impl::on_read()
2022-03-24T19:31:13.148Z VV [FTP Session 25 127.0.0.1] tls_layer_impl::continue_handshake()
2022-03-24T19:31:13.148Z DD [FTP Session 25 127.0.0.1] TLS handshakep: Received CLIENT HELLO
2022-03-24T19:31:13.148Z DD [FTP Session 25 127.0.0.1] tls_layer_impl::failure(-347)
2022-03-24T19:31:13.148Z !! [FTP Session 25 127.0.0.1] GnuTLS error -347: A connection with inappropriate fallback was attempted.
2022-03-24T19:31:13.148Z !! [FTP Session 25 127.0.0.1] Control channel closed with error from source 0. Reason: ECONNABORTED - Connection aborted.
2022-03-24T19:31:13.149Z !! [FTP Server] Session 25 ended with error from source 0. Reason: ECONNABORTED - Connection aborted.
2022-03-24T19:31:13.149Z II [FTP Session 25 127.0.0.1] Session 0x1d6a3247930 with ID 25 destroyed.
-347: A connection with inappropriate fallback was attempted. seems to be the problem here. The server is at minimum TLS 1.2 and the client is using all possible cipher methods.
