.\"
.\" Sun Microsystems, Inc. gratefully acknowledges The Open Group for
.\" permission to reproduce portions of its copyrighted documentation.
.\" Original documentation from The Open Group can be obtained online at
.\" http://www.opengroup.org/bookstore/.
.\"
.\" The Institute of Electrical and Electronics Engineers and The Open
.\" Group, have given us permission to reprint portions of their
.\" documentation.
.\"
.\" In the following statement, the phrase ``this text'' refers to portions
.\" of the system documentation.
.\"
.\" Portions of this text are reprinted and reproduced in electronic form
.\" in the SunOS Reference Manual, from IEEE Std 1003.1, 2004 Edition,
.\" Standard for Information Technology -- Portable Operating System
.\" Interface (POSIX), The Open Group Base Specifications Issue 6,
.\" Copyright (C) 2001-2004 by the Institute of Electrical and Electronics
.\" Engineers, Inc and The Open Group.  In the event of any discrepancy
.\" between these versions 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.opengroup.org/unix/online.html.
.\"
.\" This notice shall appear on any product containing this material.
.\"
.\" The contents of this file are subject to the terms of the
.\" Common Development and Distribution License (the "License").
.\" You may not use this file except in compliance with the License.
.\"
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
.\" or http://www.opensolaris.org/os/licensing.
.\" See the License for the specific language governing permissions
.\" and limitations under the License.
.\"
.\" When distributing Covered Code, include this CDDL HEADER in each
.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE.
.\" If applicable, add the following below this CDDL HEADER, with the
.\" fields enclosed by brackets "[]" replaced with your own identifying
.\" information: Portions Copyright [yyyy] [name of copyright owner]
.\"
.\"
.\" Copyright 1989 AT&T.
.\" Portions Copyright (c) 1992, X/Open Company Limited.  All Rights Reserved.
.\" Copyright (c) 2004, Sun Microsystems, Inc.  All Rights Reserved.
.\"
.TH CRYPT 3C "Sep 28, 2004"
.SH NAME
crypt \- string encoding function
.SH SYNOPSIS
.LP
.nf
#include <crypt.h>

\fBchar *\fR\fBcrypt\fR(\fBconst char *\fR\fIkey\fR, \fBconst char *\fR\fIsalt\fR);
.fi

.SS "Standard conforming"
.LP
.nf
#include <unistd.h>

\fBchar *\fR\fBcrypt\fR(\fBconst char *\fR\fIkey\fR, \fBconst char *\fR\fIsalt\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBcrypt()\fR function encodes strings suitable for secure storage as
passwords. It generates the password hash given the \fIkey\fR and \fIsalt\fR.
.sp
.LP
The \fIkey\fR argument is the plain text password to be encrypted.
.sp
.LP
If the first character of \fIsalt\fR is "$", \fBcrypt()\fR uses
\fBcrypt.conf\fR(4) to determine which shared module to load for the encryption
algorithm.  The algorithm name \fBcrypt()\fR uses to search in \fBcrypt.conf\fR
is the string between the first and second "$", or between the first "$" and
first "," if a "," comes before the second "$".
.sp
.LP
If the first character of \fIsalt\fR is not "$", the algorithm described on
\fBcrypt_unix\fR(5) is used.
.SH RETURN VALUES
.sp
.LP
Upon successful completion, \fBcrypt()\fR returns a pointer to the encoded
string. Otherwise it returns a null pointer and sets \fBerrno\fR to indicate
the error.
.sp
.LP
The return value points to static data that is overwritten by each call.
.SH ERRORS
.sp
.LP
The \fBcrypt()\fR function will fail if:
.sp
.ne 2
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 11n
An entry in \fBcrypt.conf\fR is invalid.
.RE

.sp
.ne 2
.na
\fB\fBELIBACC\fR\fR
.ad
.RS 11n
The required shared library was not found.
.RE

.sp
.ne 2
.na
\fB\fBENOMEM\fR\fR
.ad
.RS 11n
There is insufficient memory to generate the hash.
.RE

.sp
.ne 2
.na
\fB\fBENOSYS\fR\fR
.ad
.RS 11n
The functionality is not supported on this system.
.RE

.SH USAGE
.sp
.LP
The values returned by this function might not be portable among
standard-conforming systems. See \fBstandards\fR(5).
.sp
.LP
Applications should not use \fBcrypt()\fR to store or verify user passwords but
should use the functions described on \fBpam\fR(3PAM) instead.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Standard
_
MT-Level	MT-Safe
.TE

.SH SEE ALSO
.sp
.LP
\fBpasswd\fR(1), \fBcrypt_genhash_impl\fR(3C), \fBcrypt_gensalt\fR(3C),
\fBcrypt_gensalt_impl\fR(3C), \fBgetpassphrase\fR(3C), \fBpam\fR(3PAM),
\fBpasswd\fR(4), \fBpolicy.conf\fR(4), \fBattributes\fR(5),
\fBcrypt_unix\fR(5), \fBstandards\fR(5)