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 . Simply run this shell script and fill in the information. Nevertheless you can still send bug reports to as normal electronic mails. The add-on is free software. See the file COPYING.LIB for copying conditions.