/*
 * This file is part of the GROMACS molecular simulation package.
 *
 * Copyright 2009- The GROMACS Authors
 * and the project initiators Erik Lindahl, Berk Hess and David van der Spoel.
 * Consult the AUTHORS/COPYING files and https://www.gromacs.org for details.
 *
 * GROMACS is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1
 * of the License, or (at your option) any later version.
 *
 * GROMACS 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with GROMACS; if not, see
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 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA.
 *
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 */
/* This software has been altered by GROMACS for its use, including
 * the renaming of the functions md5_init, md5_append and md5_finish
 * to have a gmx_ prefix, and the #include guard md5_INCLUDED to have
 * a GMX_ prefix (both to avoid name clashes). */
/*
   Copyright (C) 1999, 2000, 2002 Aladdin Enterprises.  All rights reserved.

   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
   arising from the use of this software.

   Permission is granted to anyone to use this software for any purpose,
   including commercial applications, and to alter it and redistribute it
   freely, subject to the following restrictions:

   1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
   2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
   3. This notice may not be removed or altered from any source distribution.

   L. Peter Deutsch
   ghost@aladdin.com

 */
/*
   Independent implementation of MD5 (RFC 1321).

   This code implements the MD5 Algorithm defined in RFC 1321, whose
   text is available at
    http://www.ietf.org/rfc/rfc1321.txt
   The code is derived from the text of the RFC, including the test suite
   (section A.5) but excluding the rest of Appendix A.  It does not include
   any code or documentation that is identified in the RFC as being
   copyrighted.

   The original and principal author of md5.h is L. Peter Deutsch
   <ghost@aladdin.com>.  Other authors are noted in the change history
   that follows (in reverse chronological order):

   2002-04-13 lpd Removed support for non-ANSI compilers; removed
    references to Ghostscript; clarified derivation from RFC 1321;
    now handles byte order either statically or dynamically.
   1999-11-04 lpd Edited comments slightly for automatic TOC extraction.
   1999-10-18 lpd Fixed typo in header comment (ansi2knr rather than md5);
    added conditionalization for C++ compilation from Martin
    Purschke <purschke@bnl.gov>.
   1999-05-03 lpd Original version.
 */

#ifndef GMX_md5_INCLUDED
#define GMX_md5_INCLUDED

#include <array>

/*
 * This package supports both compile-time and run-time determination of CPU
 * byte order.  If ARCH_IS_BIG_ENDIAN is defined as 0, the code will be
 * compiled to run only on little-endian CPUs; if ARCH_IS_BIG_ENDIAN is
 * defined as non-zero, the code will be compiled to run only on big-endian
 * CPUs; if ARCH_IS_BIG_ENDIAN is not defined, the code will be compiled to
 * run on either big- or little-endian CPUs, but will run slightly less
 * efficiently on either one than if ARCH_IS_BIG_ENDIAN is defined.
 */

typedef unsigned char md5_byte_t; /* 8-bit byte */
typedef unsigned int  md5_word_t; /* 32-bit word */

/* Define the state of the MD5 Algorithm. */
typedef struct md5_state_s
{
    md5_word_t count[2]; /* message length in bits, lsw first */
    md5_word_t abcd[4];  /* digest buffer */
    md5_byte_t buf[64];  /* accumulate block */
} md5_state_t;

/* Initialize the algorithm. */
void gmx_md5_init(md5_state_t* pms);

/* Append a string to the message. */
void gmx_md5_append(md5_state_t* pms, const md5_byte_t* data, int nbytes);

/* Finish the message and return the digest. */
std::array<unsigned char, 16> gmx_md5_finish(md5_state_t* pms);

#endif
