How do I remotely get a checksum for a file on a Windows machine?

I'm trying to check, using an automated discovery tool, when JAR files in remote J2EE application servers have changed content. Currently, the system downloads the whole JAR using WMI to checksum it locally, which is slow for large JARs.

For UNIXy servers (and Windows servers with Cygwin), I can just log in over SSH and run md5sum foo.jar. Ideally, I'd like to avoid installing extra software on the remote servers (there may be thousands), so is there a good way to do this on vanilla Windows servers?

From stackoverflow Will Harris

• You could try the Sysinternals PSExec tool. You would need a checksum utility available on the remote machine. Unfortunately since they became part of Microsoft they don't make any source code available.

  Alternatively, you could install the Cygwin SSH daemon on the remote machines and use ssh but that's a bit more involved.

  From Dave Webb

• Microsoft has a free checksum tool you could run with PSExec above.

  From agnul