[SSHD-765] SFTP client fails to retrieve a binary file using an InputStream

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.6.0
• Fix Version/s: 1.7.0
• Assignee: Lyor Goldstein
• Reporter: Michael Binder
• Created: 23/Aug/17 14:37
• Updated: 24/Aug/17 11:36
• Resolved: 23/Aug/17 17:27

Description

The SFTP client fails to retrieve a binary file from an SFTP server using the InputStream returned by the SftpClient.read (String) method.

In my case the binary file was actually a gzipped XML file. So I wrapped the returned InputStream in a java.util.zip.GZIPInputStream object. When reading from the stream I received an IOException with following message:
"org.apache.sshd.client.subsystem.sftp.SftpInputStreamWithChannel.read() returned value out of range -1..255: -117".

I think that this method violates the contract given in java.io.InputStream: "The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned."

After I patched line 130 in SftpInputStreamWithChannel.java to

            return bb[0] & 0xFF;

retrieving the file seemed to have worked fine.