On Apr 29, 2010, at 3:23 PM, Gregg Wonderly wrote:

> Peter Firmstone wrote:
>> I don't know how to enable the Service to specify a constraint on the signer 
>> of the downloaded codebase if not originating from the service, any ideas?
> 
> The HTTPMD protocol handler (URLStreamHandler) does this by requiring that 
> you know the MD5 sum of the jar that you want to download.  If you try and 
> download the jar, and the sum is different, you can know that the content is 
> not what you originally knew it to be.
> 
> Not directly signing, but a mechanism that is similar and provides a fairly 
> secured indication of "source" based on what you knew at the moment you 
> acquired the MD5 sum.

As long as you use a strong enough message digest -- SHA-1 or something still 
stronger would be better choices these days now that the safety of MD5 is 
uncertain -- the security of HTTPMD is just as good as that of code signing.

- Tim

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