#!/usr/bin/perl
# 	$OpenBSD: bn_prime.pl,v 1.12 2023/03/26 08:04:57 tb Exp $
#
# Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
# All rights reserved.
#
# This package is an SSL implementation written
# by Eric Young (eay@cryptsoft.com).
# The implementation was written so as to conform with Netscapes SSL.
#
# This library is free for commercial and non-commercial use as long as
# the following conditions are aheared to.  The following conditions
# apply to all code found in this distribution, be it the RC4, RSA,
# lhash, DES, etc., code; not just the SSL code.  The SSL documentation
# included with this distribution is covered by the same copyright terms
# except that the holder is Tim Hudson (tjh@cryptsoft.com).
#
# Copyright remains Eric Young's, and as such any Copyright notices in
# the code are not to be removed.
# If this package is used in a product, Eric Young should be given attribution
# as the author of the parts of the library used.
# This can be in the form of a textual message at program startup or
# in documentation (online or textual) provided with the package.
#
# 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 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.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#    "This product includes cryptographic software written by
#     Eric Young (eay@cryptsoft.com)"
#    The word 'cryptographic' can be left out if the rouines from the library
#    being used are not cryptographic related :-).
# 4. If you include any Windows specific code (or a derivative thereof) from
#    the apps directory (application code) you must include an acknowledgement:
#    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
#
# THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
#
# The licence and distribution terms for any publically available version or
# derivative of this code cannot be changed.  i.e. this code cannot simply be
# copied and put under another distribution licence
# [including the GNU Public Licence.]

use strict;
use warnings;

my ($i, $num, $p, $s, @primes);

$num = 2048;
$num = $ARGV[0] if $#ARGV >= 0;

# The 6543rd prime is 2^16 + 1.
die "$num must be smaller than 6543" if $num >= 6543;

push(@primes, 2);
$p = 1;

loop:
while ($#primes < $num - 1) {
	$p += 2;
	$s = int(sqrt($p));

	for ($i = 0; defined($primes[$i]) && $primes[$i] <= $s; $i++) {
		next loop if $p % $primes[$i] == 0;
	}

	die "\$primes[$i] is too large: $primes[$i]" if $primes[$i] > 65535;
	push(@primes, $p);
}

printf("/*\t\$" . "OpenBSD" . "\$ */\n");
print <<\EOF;
/*
 * Public domain, generated by bn_prime.pl.
 */

EOF

print "#include \"bn_prime.h\"\n\n";
print "const uint16_t primes[NUMPRIMES] = {";
for ($i = 0; $i <= $#primes; $i++) {
	printf("%s%5d,", $i % 8 == 0 ? "\n\t" : " ", $primes[$i]);
}
print "\n};\n";