NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | VERSIONS | ATTRIBUTES | CONFORMING TO | SEE ALSO | COLOPHON

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

NAME         top

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

SYNOPSIS         top

       #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         top

       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         top

       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         top

       These functions are present in glibc 2.1 and later.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).

       ┌──────────────────────────┬───────────────┬─────────┐
       │Interface                 Attribute     Value   │
       ├──────────────────────────┼───────────────┼─────────┤
       │ecb_crypt(), cbc_crypt(), │ Thread safety │ MT-Safe │
       │des_setparity()           │               │         │
       └──────────────────────────┴───────────────┴─────────┘

CONFORMING TO         top

       4.3BSD.  Not in POSIX.1.

SEE ALSO         top

       des(1), crypt(3), xcrypt(3)

COLOPHON         top

       This page is part of release 4.07 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.

                                 2015-03-02                     DES_CRYPT(3)