DES_CRYPT(3)						     Linux Programmer's Manual						      DES_CRYPT(3)

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 3.44 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)