des_crypt, ecb_crypt, cbc_crypt, des_setparity, DES_FAILED - fast DES encryption
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,
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,
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(),
ivec is the 8-byte initialization vector for the
chaining. It is updated to the next initialization vector upon
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, the macro
stat) is false
only for the first two statuses.
4.3BSD. Not in POSIX.1.
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