DES_CRYPT(3-BSD)    RISC/os Reference Manual     DES_CRYPT(3-BSD)



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

SYNOPSIS
     For -systype svr3 and -systype bsd43:

     #include <des_crypt.h>

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

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

     void des_setparity(key)
     char *key;

DESCRIPTION
     ecb_crypt() and cbc_crypt() implement the NBS DES (Data
     Encryption Standard).  These routines are faster and more
     general purpose than crypt(3).  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 substi-
     tutions 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 routine 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.




                        Printed 11/19/92                   Page 1

DES_CRYPT(3-BSD)    RISC/os Reference Manual     DES_CRYPT(3-BSD)



SEE ALSO
     crypt(3).

DIAGNOSTICS
     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 parameter to routine.

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

RESTRICTIONS
     These routines are not available for export outside the U.S.

ORIGIN
     Sun Microsystems Inc., NFS 4.0.

NOTE
     When these routines are used in a program which is compiled
     in -systype svr3, they are not resolved by libc.a.  See
     intro(3) for more information.






























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