\"      $NetBSD: pw_gensalt.3,v 1.8 2021/10/12 12:03:47 nia Exp $
\"
\" Copyright (c) 2020 The NetBSD Foundation, Inc.
\" All rights reserved.
\"
\" This code is derived from software contributed to The NetBSD Foundation
\" by Christos Zoulas.
\"
\" Redistribution and use in source and binary forms, with or without
\" modification, are permitted provided that the following conditions
\" are met:
\" 1. Redistributions of source code must retain the above copyright
\"    notice, this list of conditions and the following disclaimer.
\" 2. Redistributions in binary form must reproduce the above copyright
\"    notice, this list of conditions and the following disclaimer in the
\"    documentation and/or other materials provided with the distribution.
\"
\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
\" POSSIBILITY OF SUCH DAMAGE.
\"
\"
Dd October 12, 2021
Dt PW_GENSALT 3
Os
Sh NAME
Nm pw_gensalt
Nd passwd salt generation function
Sh LIBRARY
Lb libcrypt
Sh SYNOPSIS
In pwd.h
Ft int
Fn pw_gensalt "char *salt" "size_t saltlen" "const char *type" "const char *option"
Sh DESCRIPTION
The
Fn pw_gensalt
function generates a
Dq salt
to be added to a password hashing function to guarantee uniqueness and
slow down dictionary and brute force attacks.
The function places a random array of
Ar saltlen
bytes in
Ar salt
using the hash function specified in
Ar type
with the function-specific
Ar option .
Pp
The new salt types follow the
Dq Modular Crypt Format
(MCF) standard and are of the form:
Bd -literal -offset indent
Li $<id>[$<param>=<value>(,<param>=<value>)*][$<salt>[$<hash>]]
Ed
Pp
The characters allowed in the password salt are alphanumeric and
include a forward slash and a period (are in the regular expression
format
Li [A-Za-z0-9/.] ) .
Pp
The following types are available:
Bl -tag -width blowfish -offset indent
It old
The original Unix implementation.
This is of the form
Li _Gl/.???? ,
where
Li \&?
denotes a random alphanumeric character.
The minimum salt size is
Dv 3 .
It new
The Seventh Edition Unix 12 bit salt.
This has the same form as the
Sq old .
The minimum salt size is
Dv 10 .
The number of rounds can be specified in
Ar option
and is enforced to be between
Dv 7250
and
Dv 16777215 .
It newsalt
An alias for
Sq new .
It md5
A salt generated using the
Xr md5 1
algorithm.
This is of the form
Li $1$????????$ .
The minimum salt size is
Dv 13 .
It sha1
A salt generated using the
Xr sha1 1
algorithm.
This is of the form
Li $sha1$nrounds$????????$ ,
where
Ar nrounds
is the number of rounds to be used.
The number of rounds can be specified in
Ar option ,
and defaults to random if
Dv NULL .
The minimum salt size is
Dv 8
and the maximum is
Dv 64 .
It blowfish
A salt generated using the
Sq blowfish
algorithm.
The minimum salt size is
Dv 30
and the number of rounds needs to be specified in
Ar option .
This is of the form:
Li $2a$nrounds$?????????????????????? .
The
Li 2
in the salt string indicates the current blowfish version.
It argon2d
This is of the form:
Li $argon2d$v=19$m=MEMORY,t=TIME,p=THREADS$????????????????$
It argon2i
This is of the form:
Li $argon2i$v=19$m=MEMORY,t=TIME,p=THREADS$????????????????$
It argon2id
This is of the form:
Li $argon2id$v=19$m=MEMORY,t=TIME,p=THREADS$????????????????$
It argon2
An alias for
Dq argon2id .
Pp
See
Xr crypt 3
for details on the Argon2 parameters.
El
Sh RETURN VALUES
Upon successful completion, a value of 0 is returned.
Otherwise, a value of \-1 is returned and
Va errno
is set to indicate the error.
Sh ERRORS
Fn pw_gensalt
will fail if:
Bl -tag -width Er
It Bq Er EINVAL
If the
Ar option
is not specified or has an illegal value.
It Bq Er ENOSPC
The
Ar saltlen
was not large enough to fit the salt for the specified
Ar type .
El
Sh SEE ALSO
Xr passwd 1 ,
Xr pwhash 1
Sh HISTORY
The
Fn pw_gensalt
function was written in 1997 by
An Niels Provos Aq Mt [email protected] .
Pp
The
Lk https://passlib.readthedocs.io/en/stable/modular_crypt_format.html "Modular Crypt Format (MCF)" .
Pp
The
Lk https://github.com/P-H-C/phc-string-format/blob/master/phc-sf-spec.md "Password Hashing Competition (PHC) format" .

You are viewing proxied material from ftp.icm.edu.pl. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.