NAME    [Toc]    [Back]

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

LIBRARY    [Toc]    [Back]

     Standard C Library (libc, -lc)

SYNOPSIS    [Toc]    [Back]

     #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    [Toc]    [Back]

     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).  They also are able to utilize 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 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 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 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 initialization
 vector upon return.

ERRORS    [Toc]    [Back]

     [DESERR_NONE]	  No error.
     [DESERR_NOHWDEVICE]  Encryption succeeded, but done in software instead
			  of the requested hardware.
     [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 statuses.

SEE ALSO    [Toc]    [Back]

     crypt(3)

RESTRICTIONS    [Toc]    [Back]

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


FreeBSD 5.2.1			October 6, 1987 		 FreeBSD 5.2.1