ecb_crypt

DES_CRYPT(3)							 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  avail-
       able.   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 parameter, 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
       parameter,  data,  contains the data to be encrypted or decrypted. The
       third parameter, datalen, is the length in bytes of data,  which	 must
       be  a  multiple	of 8. The fourth parameter, mode, is formed by OR’ing
       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 rou-
       tine returns DESERR_NOHWDEVICE.	For cbc_crypt, the parameter ivec  is
       the  the 8-byte initialization vector for the chaining.	It is updated
       to the next initialization vector upon return.


SEE ALSO
       des(1), crypt(3) and xcrypt(3)

DIAGNOSTICS
       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 parameter to routine.

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


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



				6 October 1987			 DES_CRYPT(3)