SCP failed with "Permission denied" and error not reported to user code.

[gantzm]

Version

2.10.0

Bug description

I'm attempting to scp a file from a Dropbear instance. I don't have permissions to copy the file. Dropbear reports permission denied, but that failure is never reported up to the calling code.

Actual behavior

The ScpHelper class logged this:

receiveNextCmd - ACK=1: scp: /directory1/directory2/file.xml: Permission denied

But this error appears to get ignored and never reported back to my calling code. I don't receive any calls to my instance of ScpTransferEventListener. The call to download on the ScpClient just returns, no exceptions or anything.

When I look at the code in ScpHelper it appears to just log the error ACK and continue on:

    // NOTE: we rely on the fact that an SCP command does not start with an ACK code
    protected int receiveNextCmd() throws IOException {
        int c = in.read();
        if (c == -1) {
            return c;
        }

        if (c == ScpAckInfo.OK) {
            return c;
        }

        if ((c == ScpAckInfo.WARNING) || (c == ScpAckInfo.ERROR)) {
            String line = ScpIoUtils.readLine(in, csIn, true);
            if (log.isDebugEnabled()) {
                log.debug("receiveNextCmd - ACK={}", new ScpAckInfo(c, line));
            }
        }

        return c;
    }

Expected behavior

I would expect this information to show up in the ScpAckInfo parameter of a call to handleFileEventAckInfo. Or possibly an exception thrown to indicate a failure.

Relevant log output

receiveNextCmd - ACK=1: scp: /directory1/directory2/file.xml: Permission denied

Other information

No response

[lgoldstein]

See also #428

[lgoldstein]

See my reply for PR#428 - it may be the case that the server is signalling the permissions problem as a WARNING rather than an ERROR (see also the proposed fix for next version). Thank you though for helping focus the problematic code block - it helped a lot in diagnosing this issue as weel as PR#428

[tomaswolf]

Should have been fixed by commit f908189.