83cf7abf8e
Reviewed-by: Richard Levitte <levitte@openssl.org> (Merged from https://github.com/openssl/openssl/pull/6371)
77 lines
2.6 KiB
Text
77 lines
2.6 KiB
Text
=pod
|
|
|
|
=head1 NAME
|
|
|
|
PKCS5_PBKDF2_HMAC, PKCS5_PBKDF2_HMAC_SHA1 - password based derivation routines with salt and iteration count
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/evp.h>
|
|
|
|
int PKCS5_PBKDF2_HMAC(const char *pass, int passlen,
|
|
const unsigned char *salt, int saltlen, int iter,
|
|
const EVP_MD *digest,
|
|
int keylen, unsigned char *out);
|
|
|
|
int PKCS5_PBKDF2_HMAC_SHA1(const char *pass, int passlen,
|
|
const unsigned char *salt, int saltlen, int iter,
|
|
int keylen, unsigned char *out);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
PKCS5_PBKDF2_HMAC() derives a key from a password using a salt and iteration count
|
|
as specified in RFC 2898.
|
|
|
|
B<pass> is the password used in the derivation of length B<passlen>. B<pass>
|
|
is an optional parameter and can be NULL. If B<passlen> is -1, then the
|
|
function will calculate the length of B<pass> using strlen().
|
|
|
|
B<salt> is the salt used in the derivation of length B<saltlen>. If the
|
|
B<salt> is NULL, then B<saltlen> must be 0. The function will not
|
|
attempt to calculate the length of the B<salt> because it is not assumed to
|
|
be NULL terminated.
|
|
|
|
B<iter> is the iteration count and its value should be greater than or
|
|
equal to 1. RFC 2898 suggests an iteration count of at least 1000. Any
|
|
B<iter> less than 1 is treated as a single iteration.
|
|
|
|
B<digest> is the message digest function used in the derivation. Values include
|
|
any of the EVP_* message digests. PKCS5_PBKDF2_HMAC_SHA1() calls
|
|
PKCS5_PBKDF2_HMAC() with EVP_sha1().
|
|
|
|
The derived key will be written to B<out>. The size of the B<out> buffer
|
|
is specified via B<keylen>.
|
|
|
|
=head1 NOTES
|
|
|
|
A typical application of this function is to derive keying material for an
|
|
encryption algorithm from a password in the B<pass>, a salt in B<salt>,
|
|
and an iteration count.
|
|
|
|
Increasing the B<iter> parameter slows down the algorithm which makes it
|
|
harder for an attacker to perform a brute force attack using a large number
|
|
of candidate passwords.
|
|
|
|
These functions make no assumption regarding the given password.
|
|
It will simply be treated as a byte sequence.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
PKCS5_PBKDF2_HMAC() and PBKCS5_PBKDF2_HMAC_SHA1() return 1 on success or 0 on error.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<evp(7)>, L<RAND_bytes(3)>,
|
|
L<EVP_BytesToKey(3)>,
|
|
L<passphrase-encoding(7)>
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2014-2018 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
Licensed under the OpenSSL license (the "License"). You may not use
|
|
this file except in compliance with the License. You can obtain a copy
|
|
in the file LICENSE in the source distribution or at
|
|
L<https://www.openssl.org/source/license.html>.
|
|
|
|
=cut
|