NAME
encrypt — encoding
function (CRYPT)
SYNOPSIS
void encrypt(char block[64], int edflag);
DESCRIPTION
The encrypt () function shall provide
access to an implementation-defined encoding algorithm. The key generated by
setkey(3) is used to encrypt the string
block with encrypt ().
The block argument to
encrypt () shall be an array of length 64 bytes
containing only the bytes with values of 0 and 1. The array is modified in
place to a similar array using the key set by setkey(3).
If edflag is 0, the argument is encoded. If
edflag is 1, the argument may be decoded (see the
APPLICATION USAGE section); if the argument is not decoded,
errno shall be set to [ENOSYS].
The encrypt () 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 encrypt (). If errno is
non-zero on return, an error has occurred.
The encrypt () function need not be
thread-safe.
RETURN VALUE
The encrypt () function shall not return a
value.
ERRORS
The encrypt () function shall fail if:
- [ENOSYS]
- The functionality is not supported on this implementation.
EXAMPLES
None.
APPLICATION USAGE
Historical implementations of the encrypt
() function used a rather primitive encoding algorithm.
In some environments, decoding might not be implemented. This is
related to some Government restrictions 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 () does
encoding but not decoding.
RATIONALE
None.
FUTURE DIRECTIONS
A future version of the standard may mark this interface as obsolete or remove it altogether.
SEE ALSO
XBD <unistd.h>
CHANGE HISTORY
First released in Issue 1. Derived from Issue 1 of the SVID.
Issue 5
A note indicating that this function need not be reentrant is added to the DESCRIPTION.
Issue 6
In the DESCRIPTION, the note about reentrancy is expanded to cover thread-safety.
Issue 7
Austin Group Interpretation 1003.1-2001 #156 is applied.
POSIX.1-2008, Technical Corrigendum 2, XSH/TC2-2008/0085 [899] is applied.