Tribblix: manual page: ecb

ECB_CRYPT(3EXT) Extended Library Functions ECB_CRYPT(3EXT)

NAME

ecb_crypt, cbc_crypt, des_setparity, DES_FAILED - fast DES encryption

SYNOPSIS

#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 stat);

DESCRIPTION

ecb_crypt() and cbc_crypt() implement the NBS DES (Data Encryption
Standard). These routines are faster and more general purpose than
crypt(3C). 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.

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 the DES_ENCRYPT
or DES_DECRYPT to specify the encryption direction and DES_HW or
DES_SW to specify software or hardware encryption. 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 8-byte initialization
vector for the chaining. It is updated to the next initialization
vector upon successful return.

RETURN VALUES

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

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 parameter to routine.

ATTRIBUTES

NOTES