Section (3) des_crypt
des_crypt, ecb_crypt, cbc_crypt, des_setparity, DES_FAILED — fast DES encryption
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_zsingle_quotesz_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
DES_DECRYPT. For software
versus hardware encryption, OR in either
DES_HW is specified, and there is no
hardware, then the encryption is performed in software and
the routine returns
cbc_crypt(), the argument
ivec is the 8-byte
initialization vector for the chaining. It is updated to the
next initialization vector upon return.
Encryption succeeded, but done in software instead of the requested hardware.
An error occurred in the hardware or driver.
Bad argument to routine.
Given a result status
stat) is false only for the
first two statuses.
Because they employ the DES block cipher, which is no
longer considered secure,
des_setparity() were removed in glibc 2.28.
Applications should switch to a modern cryptography library,
For an explanation of the terms used in this section, see attributes(7).
This page is part of release 5.04 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
(#)des_crypt.3 2.1 88/08/11 4.0 RPCSRC; from 1.16 88/03/02 SMI;
Taken from libc4 sources, which say:
Copyright (C) 1993 Eric Young - can be distributed under GPL.
However, the above header line suggests that this file in fact is
Copyright Sun Microsystems, Inc (and is provided for unrestricted use,
see other Sun RPC sources).
can be distributed under GPL.