Info-ZIP's ZCrypt 2.7:  generic C sources.
  C source code add-on to provide PKWARE-
  compatible encryption and decryption sup-
  port for Info-ZIP's Zip 2.2 and UnZip 5.3
  (and later).
This software has been placed in the public
domain (i.e., completely unrestricted.)  It
may be imported into the US but NOT EXPORTED
FROM THE UNITED STATES!  This is a violation
of US law (weird but true).