SFTP private key (ppk) not loaded when file name has special characters

[Igor Akkerman]

In some cases a private key file (ppk) cannot be loaded from the file system to be used for SFTP authentification.

This happens when the ppk file name or the path to the ppk file have special characters like German Umlauts.

Whether the ppk file name is provided by the FileZilla or PuTTY settings is irrelevant.

Only exception: If 'iso-8859-1' is set as the charset of a connection in the Site Manager, the ppk file name is interpreted correctly.

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Corresponding log output:

Trace:	CControlSocket::DoClose(64)
Trace:	CControlSocket::DoClose(64)
Status:	Connecting to myserver...
Trace:	Going to execute "C:\Program Files (x86)\FileZilla FTP Client\fzsftp.exe"
Response:	fzSftp started
Trace:	CSftpControlSocket::ConnectParseResponse(fzSftp started)
Trace:	CSftpControlSocket::SendNextCommand()
Trace:	CSftpControlSocket::ConnectSend()
Command:	open "myuser@myserver" 22
Trace:	Looking up host "myserver"
Trace:	Connecting to 1xx.1xx.1x.x port 22
Trace:	Server version: SSH-2.0-Sun_SSH_1.1.3
Trace:	Using SSH protocol version 2
Trace:	We claim version: SSH-2.0-PuTTY_Local:_Mar_27_2011_22:10:31
Trace:	Doing Diffie-Hellman group exchange
Trace:	Doing Diffie-Hellman key exchange with hash SHA-1
Trace:	Host key fingerprint is:
Trace:	ssh-rsa 1024 xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx
Trace:	Initialised AES-256 SDCTR client->server encryption
Trace:	Initialised HMAC-SHA1 client->server MAC algorithm
Trace:	Initialised AES-256 SDCTR server->client encryption
Trace:	Initialised HMAC-SHA1 server->client MAC algorithm
Trace:	Reading private key file "C:\Temp\schlüssel.ppk"
Trace:	Unable to use this key file (unable to open file)
Trace:	Keyboard-interactive authentication refused
Command:	Pass: 
Trace:	Sent password
Trace:	Access denied
Error:	Authentication failed.
Trace:	CControlSocket::DoClose(1030)
Trace:	CSftpControlSocket::ResetOperation(1094)
Trace:	CControlSocket::ResetOperation(1094)
Error:	Critical error
Error:	Could not connect to server
Trace:	CFileZillaEnginePrivate::ResetOperation(1094)