| NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | VERSIONS | CONFORMING TO | SEE ALSO | COLOPHON | The Linux Programming Interface |
DES_CRYPT(3) Linux Programmer's Manual DES_CRYPT(3)
des_crypt, ecb_crypt, cbc_crypt, des_setparity, DES_FAILED - fast DES encryp-
tion
#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);
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 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 argument ivec is the
8-byte initialization vector for the chaining. It is updated to the next
initialization vector upon return.
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.
These routines are present in libc 4.6.27 and later, and in glibc 2.1 and
later.
4.3BSD. Not in POSIX.1-2001.
des(1), crypt(3), xcrypt(3)
This page is part of release 3.32 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
2007-05-18 DES_CRYPT(3)
HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface