// This file is dual-licensed.  Choose whichever licence you want from
// the two licences listed below.
//
// The first licence is a regular 2-clause BSD licence.  The second licence
// is the CC-0 from Creative Commons. It is intended to release Monocypher
// to the public domain.  The BSD licence serves as a fallback option.
//
// SPDX-License-Identifier: BSD-2-Clause OR CC0-1.0
//
// ------------------------------------------------------------------------
//
// Copyright (c) 2017-2019, 2023 Loup Vaillant
// All rights reserved.
//
//
// 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 COPYRIGHT HOLDERS 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 COPYRIGHT
// HOLDER 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.
//
// ------------------------------------------------------------------------
//
// Written in 2017-2019, 2023 by Loup Vaillant
//
// To the extent possible under law, the author(s) have dedicated all copyright
// and related neighboring rights to this software to the public domain
// worldwide.  This software is distributed without any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication along
// with this software.  If not, see
// <https://creativecommons.org/publicdomain/zero/1.0/>

#include "utils.h"
#include <stdio.h>

static void store64_le(u8 out[8], u64 in)
{
	out[0] =  in        & 0xff;
	out[1] = (in >>  8) & 0xff;
	out[2] = (in >> 16) & 0xff;
	out[3] = (in >> 24) & 0xff;
	out[4] = (in >> 32) & 0xff;
	out[5] = (in >> 40) & 0xff;
	out[6] = (in >> 48) & 0xff;
	out[7] = (in >> 56) & 0xff;
}

// Must be seeded with a nonzero value.
// Accessible from the outside so we can modify it
u64 random_state = 12345;

// Pseudo-random 64 bit number, based on xorshift*
u64 rand64(void)
{
	random_state ^= random_state >> 12;
	random_state ^= random_state << 25;
	random_state ^= random_state >> 27;
	return random_state * 0x2545F4914F6CDD1D; // magic constant
}

void p_random(u8 *stream, size_t size)
{
	FOR (i, 0, size) {
		stream[i] = (u8)rand64();
	}
}

void print_vector(const u8 *buf, size_t size)
{
	FOR (i, 0, size) {
		printf("%x%x", buf[i] >> 4, buf[i] & 0x0f);
	}
	printf(":\n");
}

void print_number(u64 n)
{
	u8 buf[8];
	store64_le(buf, n);
	print_vector(buf, 8);
}