1DES_CRYPT(3)             BSD Library Functions Manual             DES_CRYPT(3)
2

NAME

4     des_crypt, ecb_crypt, cbc_crypt, des_setparity — fast DES encryption
5

LIBRARY

7     Standard C Library (libc, -lc)
8

SYNOPSIS

10     #include <rpc/des_crypt.h>
11
12     int
13     ecb_crypt(char *key, char *data, unsigned datalen, unsigned mode);
14
15     int
16     cbc_crypt(char *key, char *data, unsigned datalen, unsigned mode,
17         char *ivec);
18
19     void
20     des_setparity(char *key);
21

DESCRIPTION

23     The ecb_crypt() and cbc_crypt() functions implement the NBS DES (Data
24     Encryption Standard).  These routines are faster and more general purpose
25     than crypt(3).  They also are able to utilize DES hardware if it is
26     available.  The ecb_crypt() function encrypts in ECB (Electronic Code
27     Book) mode, which encrypts blocks of data independently.  The cbc_crypt()
28     function encrypts in CBC (Cipher Block Chaining) mode, which chains
29     together successive blocks.  CBC mode protects against insertions, dele‐
30     tions and substitutions of blocks.  Also, regularities in the clear text
31     will not appear in the cipher text.
32
33     Here is how to use these routines.  The first argument, key, is the
34     8-byte encryption key with parity.  To set the key's parity, which for
35     DES is in the low bit of each byte, use des_setparity().  The second
36     argument, data, contains the data to be encrypted or decrypted.  The
37     third argument, datalen, is the length in bytes of data, which must be a
38     multiple of 8.  The fourth argument, mode, is formed by OR'ing together
39     some things.  For the encryption direction OR in either DES_ENCRYPT or
40     DES_DECRYPT.  For software versus hardware encryption, OR in either
41     DES_HW or DES_SW.  If DES_HW is specified, and there is no hardware, then
42     the encryption is performed in software and the routine returns
43     DESERR_NOHWDEVICE.  For cbc_crypt(), the ivec argument is the 8-byte ini‐
44     tialization vector for the chaining.  It is updated to the next initial‐
45     ization vector upon return.
46

ERRORS

48     [DESERR_NONE]        No error.
49     [DESERR_NOHWDEVICE]  Encryption succeeded, but done in software instead
50                          of the requested hardware.
51     [DESERR_HWERR]       An error occurred in the hardware or driver.
52     [DESERR_BADPARAM]    Bad argument to routine.
53
54     Given a result status stat, the macro DES_FAILED(stat) is false only for
55     the first two statuses.
56

SEE ALSO

58     crypt(3)
59

RESTRICTIONS

61     These routines are not available in RPCSRC 4.0.  This information is pro‐
62     vided to describe the DES interface expected by Secure RPC.
63
64BSD                             October 6, 1987                            BSD