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Technical Reference: Communications, Volume 1
Implements Data Encryption
Standard (DES) encryption routines.
DES library
(libdes.a)
# 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;
The ecb_crypt and
cbc_crypt subroutines implement DES encryption routines, set by the
National Bureau of Standards.
- The ecb_crypt
subroutine encrypts in ECB (Electronic Code Book) mode, which encrypts blocks
of data independently.
- The cbc_crypt
subroutine 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.
Note: The DES library must be installed to use these
subroutines.
data
| Specifies that the data is to be either encrypted or decrypted.
|
datalen
| Specifies the length in bytes of data. The length must be a
multiple of 8.
|
key
| Specifies the 8-byte encryption key with parity. To set the parity
for the key, which for DES is in the low bit of each byte, use the
des_setparity subroutine.
|
ivec
| Initializes the vector for the chaining in 8-byte. This is updated
to the next initialization vector upon return.
|
mode
| Specifies whether data is to be encrypted or decrypted. This
parameter is formed by logically ORing the DES_ENCRYPT or
DES_DECRYPT symbols. For software versus hardware
encryption, logically OR the DES_HW or DES_SW
symbols. These four symbols are defined in the
/usr/include/des_crypt.h file.
|
DESERR_BADPARAM
| Specifies that a bad parameter was passed to routine.
|
DESERR_HWERR
| Specifies that an error occurred in the hardware or driver.
|
DESERR_NOHWDEVICE
| Specifies that encryption succeeded, but was done in software instead of
the requested hardware.
|
DESERR_NONE
| Specifies no error.
|
Note: Given
the stat variable, for example, which contains the return value for
either the ecb_crypt or cbc_crypt subroutine, the
DES_FAILED(stat) macro is false only for the DESERR_NONE
and DESERR_NOHWDEVICE return values.
These subroutines are not
available for export outside the United States.
/usr/include/des_crypt.h
| Defines macros and needed symbols for the mode
parameter.
|
Secure NFS
in AIX 5L Version 5.1 System Management Guide:
Communications and Networks.
Example Using
DES Authentication in AIX 5L Version 5.1 Communications
Programming Concepts.
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