NAME

setkey - set encoding key (CRYPT)

 SYNOPSIS

#include <stdlib.h>

void setkey(const char *key);

 DESCRIPTION

The setkey() function provides (rather primitive) access to an implementation-dependent encoding algorithm. The argument of setkey() is an array of length 64 bytes containing only the bytes with numerical value of 0 and 1. If this string is divided into groups of 8, the low-order bit in each group is ignored; this gives a 56-bit key which is used by the algorithm. This is the key that will be used with the algorithm to encode a string block passed to encrypt().

The setkey() function will not change the setting of errno if successful.

This interface need not be reentrant.

 RETURN VALUE

No values are returned.

 ERRORS

The setkey() function will fail if:

[ENOSYS]

The functionality is not supported on this implementation.

 EXAMPLES

None.

 APPLICATION USAGE

Decoding need not be implemented in all environments. This is related to U.S. Government restrictions on encryption and decryption routines: the DES decryption algorithm cannot be exported outside the U.S.A. Historical practice has been to ship a different version of the encryption library without the decryption feature in the routines supplied. Thus the exported version of encrypt() does encoding but not decoding.

 FUTURE DIRECTIONS

None.

 SEE ALSO

crypt(), encrypt(), <stdlib.h>.

DERIVATION

Derived from Issue 1 of the SVID.