# phpman > man > des_crypt(3)

[DES_CRYPT(3)](https://www.chedong.com/phpMan.php/man/DESCRYPT/3/markdown)             BSD Library Functions Manual             [DES_CRYPT(3)](https://www.chedong.com/phpMan.php/man/DESCRYPT/3/markdown)

## NAME
     **des**___**crypt**, **ecb**___**crypt**, **cbc**___**crypt**, **des**___**setparity** — 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_);

## DESCRIPTION
     The **ecb**___**crypt**() and **cbc**___**crypt**() functions implement the NBS DES (Data Encryption Standard).
     These routines are faster and more general purpose than [crypt(3)](https://www.chedong.com/phpMan.php/man/crypt/3/markdown).  They also are able to uti‐
     lize DES hardware if it is available.  The **ecb**___**crypt**() function encrypts in ECB (Electronic
     Code Book) mode, which encrypts blocks of data independently.  The **cbc**___**crypt**() function en‐
     crypts 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 _OR_'ing together some things.  For the encryption direc‐
     tion _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 _ivec_
     argument is the 8-byte initialization vector for the chaining.  It is updated to the next ini‐
     tialization vector upon return.

## ERRORS
     [DESERR_NONE]        No error.
     [DESERR_NOHWDEVICE]  Encryption succeeded, but done in software instead of the requested hard‐
                          ware.
     [DESERR_HWERR]       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 sta‐
     tuses.

## AVAILABILITY
     The **ecb**___**crypt**(), **cbc**___**crypt**(), and **des**___**setparity**() functions are part of libtirpc.

## SEE ALSO
     [crypt(3)](https://www.chedong.com/phpMan.php/man/crypt/3/markdown)

## RESTRICTIONS
     These routines are not available in RPCSRC 4.0.  This information is provided to describe the
     DES interface expected by Secure RPC.

BSD                             October 6, 1987                            BSD