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.TH ENCRYPT "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"

.SH PROLOG

This manual page is part of the POSIX Programmer's Manual.

The Linux implementation of this interface may differ (consult

the corresponding Linux manual page for details of Linux behavior),

or the interface may not be implemented on Linux.

.SH NAME

encrypt

\(em encoding function

(\fBCRYPT\fP)

.SH SYNOPSIS

.LP

.nf

#include <unistd.h>

.P

void encrypt(char \fIblock\fP[64], int \fIedflag\fP);

.fi

.SH DESCRIPTION

The

\fIencrypt\fR()

function shall provide access to an implementation-defined encoding

algorithm. The key generated by

\fIsetkey\fR()

is used to encrypt the string

.IR block

with

\fIencrypt\fR().

.P

The

.IR block

argument to

\fIencrypt\fR()

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

\fIsetkey\fR().

If

.IR edflag

is 0, the argument is encoded. If

.IR edflag

is 1, the argument may be decoded (see the APPLICATION USAGE section);

if the argument is not decoded,

.IR errno

shall be set to

.BR [ENOSYS] .

.P

The

\fIencrypt\fR()

function shall not change the setting of

.IR errno

if successful. An application wishing to check for error situations

should set

.IR errno

to 0 before calling

\fIencrypt\fR().

If

.IR errno

is non-zero on return, an error has occurred.

.P

The

\fIencrypt\fR()

function need not be thread-safe.

.SH "RETURN VALUE"

The

\fIencrypt\fR()

function shall not return a value.

.SH ERRORS

The

\fIencrypt\fR()

function shall fail if:

.TP

.BR ENOSYS

The functionality is not supported on this implementation.

.LP

.IR "The following sections are informative."

.SH EXAMPLES

None.

.SH "APPLICATION USAGE"

Historical implementations of the

\fIencrypt\fR()

function used a rather primitive encoding algorithm.

.P

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

\fIencrypt\fR()

does encoding but not decoding.

.SH RATIONALE

None.

.SH "FUTURE DIRECTIONS"

None.

.SH "SEE ALSO"

.IR "\fIcrypt\fR\^(\|)",

.IR "\fIsetkey\fR\^(\|)"

.P

The Base Definitions volume of POSIX.1\(hy2008,

.IR "\fB<unistd.h>\fP"

.SH COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form

from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology

-- Portable Operating System Interface (POSIX), The Open Group Base

Specifications Issue 7, Copyright (C) 2013 by the Institute of

Electrical and Electronics Engineers, Inc and The Open Group.

(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the

event of any discrepancy between this version and the original IEEE and

The Open Group Standard, the original IEEE and The Open Group Standard

is the referee document. The original Standard can be obtained online at

http://www.unix.org/online.html .

Any typographical or formatting errors that appear

in this page are most likely

to have been introduced during the conversion of the source files to

man page format. To report such errors, see

https://www.kernel.org/doc/man-pages/reporting_bugs.html .