SFTP server not working on Windows Server 2003

[jamescollett]

I am trialling Core FTP Server as a solution to providing an external customer with SFTP access to files generated on a production Windows Server 2003 box.

I have installed Core FTP Pro on my client test machine (Windows XP Pro SP3) and I have generated a key pair for SSH FTP. I have copied the public key to the server and as far as I can tell I have set up everything for the server to behave as an SSH/FTP server.

The client piece says that it is unable to establish a connection. If I have the option "Use Putty compatible SFTP" enabled, it reports:-

[color=blue]Looking up host "myservername"
Connecting to 10.0.0.51 port 22
Server version: SSH-2.0-CoreFTP-0.2.3
version: SSH-2.0-SSH-Local: Oct 22 2009 20:33:56
Using SSH protocol version 2
processing key exchange
Host key fingerprint is:
ssh-rsa 1024 48:f9:7e:76:c5:58:cc:18:45:a3:aa:e8:44:ae:70:57
Initialized AES-256 client->server encryption
Initialized AES-256 server->client encryption
Reading private key file "D:\SFTP for Test\MyPriv"
Unable to use this key file (OpenSSH SSH2 private key)
No supported authentications offered. Disconnecting
Unable to initialize SFTP: ????????t (sftp not enabled?)
Can't establish connection --> RS001512:22 @ Thu Aug 18 11:26:17 2011 (10038-1)[/color]

If I uncheck the optin to use Putty compatible SFTP the error is less verbose. It says:-


[color=blue]Resolving myservername...
RS001512 connecting...
SSH-2.0-CoreFTP-0.2.3
client -> aes128
server -> aes128
4e:e0:f7:71:e9:3b:b9:74:98:d2:b9:0d:57:a8:f6:79
ssh-rsa
Offering public key
Disconnected
key check failed
SFTP connection error[/color]

How is it that the Core FTP client is unable to use the key pair that it created? Why does it think that SFTP is not enabled when I have specifially checked that option on the server?

Is there something problematic with making this work on a Windows Server 2003 server? I have tried other SFTP products, with similar results. The only product that works so far is Titan FTP - but it is really expensive.

Does anyone have any clues?

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UPDATE 2011-08-21
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I have got past this problem. I would document the problem and solution except that there was so much trying one thing after another that I do not know what finally fixed it.

However, I would watch out for the equals sign at the end of the public key. There really must be nothing after it for this product to work. I suspect that his is breaking from the standard but I do not know for sure.