Porting getShareableUrl from Java to PERL (Linux)

I'm a Solutions Engineer with EMC.  I'm trying to port getShareableUrl into a PERL script that I'm working on.  I've read the source code on:

http://code.google.com/p/atmos-java/source/browse/trunk/api/src/com/emc/esu/api/rest/EsuRestApi.java?r=2

The function is straightforward except I can't find the sign() function documented:

          String signature = sign( sb.toString() );

I'm hoping to find a comparable Linux executable or PERL library to create the SSH HMAC signature.

Any help is appreciated.

Jason Thornbrugh
Principal Solutions Engineer
GSC Demo Cloud