NAME

       des_crypt, ecb_crypt, cbc_crypt, des_setparity, DES_FAILED - fast DES encryption

SYNOPSIS

       #include <rpc/des_crypt.h>

       int ecb_crypt(char *key, char *data, unsigned datalen,
                     unsigned mode);

       int cbc_crypt(char *key, char *data, unsigned datalen,
                     unsigned mode, char *ivec);

       void des_setparity(char *key);

       int DES_FAILED(int status);

DESCRIPTION

       ecb_crypt()  and cbc_crypt() implement the NBS DES (Data Encryption Standard).  These routines are faster
       and more general purpose than crypt(3).  They also are able to utilize DES hardware if it  is  available.
       ecb_crypt()  encrypts  in  ECB  (Electronic Code Book) mode, which encrypts blocks of data independently.
       cbc_crypt() encrypts in CBC (Cipher Block Chaining) mode, which chains together successive  blocks.   CBC
       mode protects against insertions, deletions and substitutions of blocks.  Also, regularities in the clear
       text will not appear in the cipher text.

       Here is how to use these routines.  The first argument, key, is the 8-byte encryption  key  with  parity.
       To  set  the key's parity, which for DES is in the low bit of each byte, use des_setparity().  The second
       argument, data, contains the data to be encrypted or decrypted.  The  third  argument,  datalen,  is  the
       length  in  bytes  of data, which must be a multiple of 8.  The fourth argument, mode, is formed by ORing
       together some things.  For the encryption  direction  OR  in  either  DES_ENCRYPT  or  DES_DECRYPT.   For
       software versus hardware encryption, OR in either DES_HW or DES_SW.  If DES_HW is specified, and there is
       no hardware, then the encryption is performed in software and the routine returns DESERR_NOHWDEVICE.  For
       cbc_crypt(),  the  argument  ivec is the 8-byte initialization vector for the chaining.  It is updated to
       the next initialization vector upon return.

RETURN VALUE

       DESERR_NONE         No error.
       DESERR_NOHWDEVICE   Encryption succeeded, but done in software instead of the requested hardware.
       DESERR_HWERROR      An error occurred in the hardware or driver.
       DESERR_BADPARAM     Bad argument to routine.

       Given a result status stat, the macro DES_FAILED(stat) is false only for the first two statuses.

VERSIONS

       These routines are present in libc 4.6.27 and later, and in glibc 2.1 and later.

CONFORMING TO

       4.3BSD.  Not in POSIX.1-2001.

SEE ALSO

       des(1), crypt(3), xcrypt(3)

COLOPHON

       This page is part of release 3.54 of the Linux man-pages project.  A  description  of  the  project,  and
       information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.

                                                   2007-05-18                                       DES_CRYPT(3)