81 lines
2.4 KiB
C
81 lines
2.4 KiB
C
/*
|
|
* Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation; either version 2 of the
|
|
* License, or any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
* 02110-1301, USA.
|
|
*
|
|
* You can also choose to distribute this program under the terms of
|
|
* the Unmodified Binary Distribution Licence (as given in the file
|
|
* COPYING.UBDL), provided that you have satisfied its requirements.
|
|
*/
|
|
|
|
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
|
|
|
|
/** @file
|
|
*
|
|
* Random non-zero bytes
|
|
*
|
|
* The RSA algorithm requires the generation of random non-zero bytes,
|
|
* i.e. bytes in the range [0x01,0xff].
|
|
*
|
|
* This algorithm is designed to comply with ANS X9.82 Part 1-2006
|
|
* Section 9.2.1. This standard is not freely available, but most of
|
|
* the text appears to be shared with NIST SP 800-90, which can be
|
|
* downloaded from
|
|
*
|
|
* http://csrc.nist.gov/publications/nistpubs/800-90/SP800-90revised_March2007.pdf
|
|
*
|
|
* Where possible, references are given to both documents. In the
|
|
* case of any disagreement, ANS X9.82 takes priority over NIST SP
|
|
* 800-90. (In particular, note that some algorithms that are
|
|
* Approved by NIST SP 800-90 are not Approved by ANS X9.82.)
|
|
*/
|
|
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
#include <ipxe/rbg.h>
|
|
#include <ipxe/random_nz.h>
|
|
|
|
/**
|
|
* Get random non-zero bytes
|
|
*
|
|
* @v data Output buffer
|
|
* @v len Length of output buffer
|
|
* @ret rc Return status code
|
|
*
|
|
* This algorithm is designed to be isomorphic to the Simple Discard
|
|
* Method described in ANS X9.82 Part 1-2006 Section 9.2.1 (NIST SP
|
|
* 800-90 Section B.5.1.1).
|
|
*/
|
|
int get_random_nz ( void *data, size_t len ) {
|
|
uint8_t *bytes = data;
|
|
int rc;
|
|
|
|
while ( len ) {
|
|
|
|
/* Generate random byte */
|
|
if ( ( rc = rbg_generate ( NULL, 0, 0, bytes, 1 ) ) != 0 )
|
|
return rc;
|
|
|
|
/* Move to next byte if this byte is acceptable */
|
|
if ( *bytes != 0 ) {
|
|
bytes++;
|
|
len--;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|