/*

 * Hedgewars, a worms-like game

 * Copyright (c) 2005 Andrey Korotaev <unC0Rr@gmail.com>

 *

 * Distributed under the terms of the BSD-modified licence:

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * with the Software without restriction, including without limitation the

 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or

 * sell copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * 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.

 * 3. The name of the author may not be used to endorse or promote products

 *    derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.

 */

#include <QDateTime>

#include "rndstr.h"

const char * letters = "qwertyuiopasdfghjklzxcvbnm" \

                       "QWERTYUIOPASDFGHJKLZXCVBNM" \

                       "0123456789";

const quint8 letterscnt = 62;

const char * upd = "/hw!/";

const quint8 updcnt = 5;

RNDStr::RNDStr()

{

	SHA1Init(&ctx);

	QDateTime now = QDateTime::currentDateTime();

	QDateTime zero;

	int secs = now.secsTo(zero);

	SHA1Update(&ctx, (quint8 *)&secs, sizeof(int));

}

void RNDStr::GenRNDStr(QString & str, quint32 len)

{

	str = "";

	sha1_ctxt tmpctx;

	sha1_digest digest;

	for(quint32 i = 0; i < len; i++)

	{

		SHA1Update(&ctx, (quint8 *)upd, updcnt);

		qMemCopy(&tmpctx, &ctx, sizeof(sha1_ctxt));

		SHA1Final(digest, &tmpctx);

		int index = (digest[3] + digest[11] + digest[17]) % letterscnt;

		str += letters[index];

	}

}