NAME
setkey — set
encoding key (CRYPT)
SYNOPSIS
void setkey(const char *key);
DESCRIPTION
The setkey () function provides access to
an implementation-defined 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 shall be
used with the algorithm to encode a string
block
passed to encrypt(3).
The setkey () function shall not change
the setting of errno if successful. An application wishing
to check for error situations should set errno to 0 before
calling setkey (). If errno is
non-zero on return, an error has occurred.
The setkey () function need not be
reentrant. A function that is not required to be reentrant is not required
to be thread-safe.
RETURN VALUE
No values are returned.
ERRORS
The setkey () function shall 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 government restrictions in some countries on encryption and decryption routines. 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(3) does encoding but not decoding.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
crypt(3), encrypt(3), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), <stdlib.h>
CHANGE HISTORY
First released in Issue 1. Derived from Issue 1 of the SVID.
Issue 5
The DESCRIPTION is updated to indicate that errno is not changed if the function is successful.
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