This is the distribution tar file for the cryptography add-on to the
GNU C library.  For the version number, see the file "Banner".

The add-on is not included in the main distribution of the GNU C
library because some governments, most notably those of France,
Russia, and the US, have very restrictive rules governing the
distribution and use of encryption software.  Please read the node
"Legal Problems" in the manual for more details.  

In particular, the US does not allow export of this software without a
licence, including via the Internet.  So please do not download it
from the main FSF FTP site at ftp.gnu.org if you are outside
the US.  This software was completely developed outside the US.

To install the add-on, unpack the tar file in the top level of the GNU
C library distribution.  Then build GNU C library like this:

configure --enable-add-ons
make
make install

It is not presently possible to add the add-on to the GNU C library
without recompiling the GNU C library.

The additional functionality provided by the add-on consists of:

* DES-based crypt().  This is only for backwards compatibility;
  for new installations the MD5-based crypt(), provided with the main
  GNU C library distribution, should be used instead.

* The AUTH_DES RPC authentication method.  In a given situation, this
  may be more or less secure than the AUTH_UNIX authentication method
  which is provided with the main GNU C library distribution.

* User-visible DES encryption routines.  Note that DES by itself is
  not now considered a very secure encryption method.

The add-on also includes a manual, the file "crypt.texi".  The manual
will be integrated with the GNU C library manual when the GNU C
library is installed.

Report bugs in this library (or its manual) in the same way as for the
GNU C library; that is, using the `glibcbug' shell script to send
e-mail to <bugs@gnu.org>.  Simply run this shell script and fill in
the information.  Nevertheless you can still send bug reports to
<bug-glibc@gnu.org> as normal electronic mails.

The add-on is free software.  See the file COPYING.LIB for copying
conditions.