// NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
// Copyright (C) 2010  Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.


/* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
 */

/* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
   rights reserved.

   License to copy and use this software is granted provided that it
   is identified as the "RSA Data Security, Inc. MD5 Message-Digest
Algorithm" in all material mentioning or referencing this software
or this function.

License is also granted to make and use derivative works provided
that such works are identified as "derived from the RSA Data
Security, Inc. MD5 Message-Digest Algorithm" in all material
mentioning or referencing the derived work.

RSA Data Security, Inc. makes no representations concerning either
the merchantability of this software or the suitability of this
software for any particular purpose. It is provided "as is"
without express or implied warranty of any kind.

These notices must be retained in any copies of any part of this
documentation and/or software.
*/

#include "stdmisc.h"

#include "nel/misc/md5.h"

#include "nel/misc/types_nl.h"
#include "nel/misc/debug.h"
#include "nel/misc/file.h"
#include "nel/misc/path.h"
#include "nel/misc/stream.h"

using namespace std;

namespace NLMISC
{
// ****************************************************************************
// ****************************************************************************
// High Level Routines
// ****************************************************************************
// ****************************************************************************

// ****************************************************************************
CHashKeyMD5 getMD5(const std::string &filename)
{
    CMD5Context	md5ctx;
    CHashKeyMD5 Message_Digest;
	Message_Digest.clear();

	CIFile ifile;
	if (!ifile.open(CPath::lookup(filename)))
	{
		nlwarning ("MD5: Can't open the file '%s'", filename.c_str());
		return Message_Digest;
	}

	md5ctx.init();

	uint8 buffer[1024];
	int bufferSize = 1024;
	sint fs = ifile.getFileSize();
	sint n, read = 0;
	do
	{
		//bs = (int)fread (buffer, 1, bufferSize, fp);
		n = std::min (bufferSize, fs-read);
		//nlinfo ("read %d bytes", n);
		ifile.serialBuffer((uint8 *)buffer, n);

		md5ctx.update(buffer, n);

		read += n;
	}
	while (!ifile.eof());

	ifile.close	();

	md5ctx.final(Message_Digest);

	return Message_Digest;
}

// ****************************************************************************
CHashKeyMD5 getMD5(const uint8 *buffer, uint32 size)
{
    CMD5Context	md5ctx;
    CHashKeyMD5 Message_Digest;
	Message_Digest.clear();

	md5ctx.init();
	md5ctx.update(buffer, size);
	md5ctx.final(Message_Digest);

	return Message_Digest;
}

// ****************************************************************************
// Helper
// ****************************************************************************
static bool fromHex(char c, uint8 &x)
{
	if (c >= '0' && c <= '9')
	{
		x = c - '0';
		return true;
	}
	else if (c >= 'A' && c <= 'F')
	{
		x = c - 'A' + 10;
		return true;
	}
	else if (c >= 'a' && c <= 'f')
	{
		x = c - 'a' + 10;
		return true;
	}

	nlwarning("cannot convert to hexa");
	return false;
}

// ****************************************************************************
// ****************************************************************************
// CHashKeyMD5
// ****************************************************************************
// ****************************************************************************

// ****************************************************************************
void CHashKeyMD5::clear()
{
	for (uint32 i = 0; i < 16; ++i)
		Data[i] = 0;
}

// ****************************************************************************
string CHashKeyMD5::toString() const
{
	string sTmp;
	for (uint32 i = 0; i < 16; ++i)
		sTmp += NLMISC::toString("%02x", Data[i]);
	return sTmp;
}

// ****************************************************************************
bool CHashKeyMD5::fromString(const std::string &in)
{
	if (in.size() != 32)
	{
		nlwarning("bad string size");
		return false;
	}

	for (uint32 i = 0; i < 16; ++i)
	{
		char c1 = in[2*i];
		char c2 = in[2*i+1];
		uint8 x1, x2;
		if (!fromHex(c1, x1)) return false;
		if (!fromHex(c2, x2)) return false;
		Data[i] = (x1 << 4) | x2;
	}
	return true;
}

// ****************************************************************************
bool CHashKeyMD5::operator!=(const CHashKeyMD5 &in) const
{
	for (uint32 i = 0; i < 16; ++i)
		if (Data[i] != in.Data[i])
			return true;
	return false;
}

// ****************************************************************************
bool CHashKeyMD5::operator==(const CHashKeyMD5 &in) const
{
	return !operator!=(in);
}

// ****************************************************************************
bool CHashKeyMD5::operator<(const CHashKeyMD5 &in) const
{
	for (uint32 i = 0; i < 16; ++i)
		if (Data[i] >= in.Data[i])
			return false;
	return true;
}

// ****************************************************************************
void CHashKeyMD5::serial (NLMISC::IStream &s)
{
	s.serialBuffer(Data,16);
}


// ****************************************************************************
// ****************************************************************************
// CMD5Context
// ****************************************************************************
// ****************************************************************************

uint8 CMD5Context::Padding[64] = {
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

// ****************************************************************************
void CMD5Context::init()
{
    Count[0] = Count[1] = 0;
    // Load magic initialization constants.
    State[0] = 0x67452301;
    State[1] = 0xefcdab89;
    State[2] = 0x98badcfe;
    State[3] = 0x10325476;
}

// ****************************************************************************
void CMD5Context::update (const uint8 *pBufIn, uint32 nBufLength)
{
    uint i, index, partLen;

    // Compute number of bytes mod 64
    index = (uint)((Count[0] >> 3) & 0x3F);

    // Update number of bits
    if ((Count[0] += (nBufLength << 3)) < (nBufLength << 3))
	Count[1]++;
    Count[1] += (nBufLength >> 29);

    partLen = 64 - index;

    // Transform as many times as possible.
    if (nBufLength >= partLen)
	{
		memcpy((uint8*)&Buffer[index], pBufIn, partLen);
		transform (State, Buffer);

		for (i = partLen; i + 63 < nBufLength; i += 64)
			transform (State, &pBufIn[i]);

		index = 0;
    }
	else
	{
		i = 0;
	}

    // Buffer remaining input
    memcpy((uint8*)&Buffer[index], &pBufIn[i], nBufLength-i);
}

// ****************************************************************************
void CMD5Context::final (CHashKeyMD5 &out)
{
	uint8 bits[8];
	uint index, padLen;

	// Save number of bits
	encode (&bits[0], Count, 8);

	// Pad out to 56 mod 64.
	index = (unsigned int)((Count[0] >> 3) & 0x3f);
	padLen = (index < 56) ? (56 - index) : (120 - index);
	update (Padding, padLen);

	// Append length (before padding)
	update (&bits[0], 8);
	// Store state in digest
	encode (out.Data, State, 16);

	// Zeroize sensitive information.
	uint i;
	for (i = 0; i < 4; ++i) State[i] = 0;
    for (i = 0; i < 2; ++i) Count[i] = 0;
    for (i = 0; i < 64; ++i) Buffer[i] = 0;
}

// Constants for MD5Transform routine.
// ****************************************************************************
#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

// F, G, H and I are basic MD5 functions.
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

// ROTATE_LEFT rotates x left n bits.
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

// FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
// Rotation is separate from addition to prevent recomputation.
#define FF(a, b, c, d, x, s, ac) { \
      (a) += F ((b), (c), (d)) + (x) + (uint32)(ac); \
      (a) = ROTATE_LEFT ((a), (s)); \
      (a) += (b); \
			       }
#define GG(a, b, c, d, x, s, ac) { \
      (a) += G ((b), (c), (d)) + (x) + (uint32)(ac); \
      (a) = ROTATE_LEFT ((a), (s)); \
      (a) += (b); \
     }
#define HH(a, b, c, d, x, s, ac) { \
      (a) += H ((b), (c), (d)) + (x) + (uint32)(ac); \
      (a) = ROTATE_LEFT ((a), (s)); \
      (a) += (b); \
     }
#define II(a, b, c, d, x, s, ac) { \
      (a) += I ((b), (c), (d)) + (x) + (uint32)(ac); \
      (a) = ROTATE_LEFT ((a), (s)); \
      (a) += (b); \
     }


// MD5 basic transformation. Transforms state based on block.
// ****************************************************************************
void CMD5Context::transform (uint32 state[4], const uint8 block[64])
{
    uint32 a = state[0], b = state[1], c = state[2], d = state[3], x[16];

    decode (&x[0], &block[0], 64);

    // Round 1
    FF (a, b, c, d, x[ 0], S11, 0xd76aa478); // 1
    FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); // 2
    FF (c, d, a, b, x[ 2], S13, 0x242070db); // 3
    FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); // 4
    FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); // 5
    FF (d, a, b, c, x[ 5], S12, 0x4787c62a); // 6
    FF (c, d, a, b, x[ 6], S13, 0xa8304613); // 7
    FF (b, c, d, a, x[ 7], S14, 0xfd469501); // 8
    FF (a, b, c, d, x[ 8], S11, 0x698098d8); // 9
    FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); // 10
    FF (c, d, a, b, x[10], S13, 0xffff5bb1); // 11
    FF (b, c, d, a, x[11], S14, 0x895cd7be); // 12
    FF (a, b, c, d, x[12], S11, 0x6b901122); // 13
    FF (d, a, b, c, x[13], S12, 0xfd987193); // 14
    FF (c, d, a, b, x[14], S13, 0xa679438e); // 15
    FF (b, c, d, a, x[15], S14, 0x49b40821); // 16

    // Round 2
    GG (a, b, c, d, x[ 1], S21, 0xf61e2562); // 17
    GG (d, a, b, c, x[ 6], S22, 0xc040b340); // 18
    GG (c, d, a, b, x[11], S23, 0x265e5a51); // 19
    GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); // 20
    GG (a, b, c, d, x[ 5], S21, 0xd62f105d); // 21
    GG (d, a, b, c, x[10], S22,  0x2441453); // 22
    GG (c, d, a, b, x[15], S23, 0xd8a1e681); // 23
    GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); // 24
    GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); // 25
    GG (d, a, b, c, x[14], S22, 0xc33707d6); // 26
    GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); // 27
    GG (b, c, d, a, x[ 8], S24, 0x455a14ed); // 28
    GG (a, b, c, d, x[13], S21, 0xa9e3e905); // 29
    GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); // 30
    GG (c, d, a, b, x[ 7], S23, 0x676f02d9); // 31
    GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); // 32

    // Round 3
    HH (a, b, c, d, x[ 5], S31, 0xfffa3942); // 33
    HH (d, a, b, c, x[ 8], S32, 0x8771f681); // 34
    HH (c, d, a, b, x[11], S33, 0x6d9d6122); // 35
    HH (b, c, d, a, x[14], S34, 0xfde5380c); // 36
    HH (a, b, c, d, x[ 1], S31, 0xa4beea44); // 37
    HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); // 38
    HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); // 39
    HH (b, c, d, a, x[10], S34, 0xbebfbc70); // 40
    HH (a, b, c, d, x[13], S31, 0x289b7ec6); // 41
    HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); // 42
    HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); // 43
    HH (b, c, d, a, x[ 6], S34,  0x4881d05); // 44
    HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); // 45
    HH (d, a, b, c, x[12], S32, 0xe6db99e5); // 46
    HH (c, d, a, b, x[15], S33, 0x1fa27cf8); // 47
    HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); // 48

    // Round 4
    II (a, b, c, d, x[ 0], S41, 0xf4292244); // 49
    II (d, a, b, c, x[ 7], S42, 0x432aff97); // 50
    II (c, d, a, b, x[14], S43, 0xab9423a7); // 51
    II (b, c, d, a, x[ 5], S44, 0xfc93a039); // 52
    II (a, b, c, d, x[12], S41, 0x655b59c3); // 53
    II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); // 54
    II (c, d, a, b, x[10], S43, 0xffeff47d); // 55
    II (b, c, d, a, x[ 1], S44, 0x85845dd1); // 56
    II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); // 57
    II (d, a, b, c, x[15], S42, 0xfe2ce6e0); // 58
    II (c, d, a, b, x[ 6], S43, 0xa3014314); // 59
    II (b, c, d, a, x[13], S44, 0x4e0811a1); // 60
    II (a, b, c, d, x[ 4], S41, 0xf7537e82); // 61
    II (d, a, b, c, x[11], S42, 0xbd3af235); // 62
    II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); // 63
    II (b, c, d, a, x[ 9], S44, 0xeb86d391); // 64

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
}

// Encodes input (guint32) into output (unsigned char). Assumes len is a multiple of 4.
// ****************************************************************************
void CMD5Context::encode (uint8 *output, const uint32 *input, uint len)
{
	uint i, j;

	for (i = 0, j = 0; j < len; i++, j += 4)
	{
		output[j] = (uint8)(input[i] & 0xff);
		output[j+1] = (uint8)((input[i] >> 8) & 0xff);
		output[j+2] = (uint8)((input[i] >> 16) & 0xff);
		output[j+3] = (uint8)((input[i] >> 24) & 0xff);
	}
}

// Decodes input (unsigned char) into output (guint32). Assumes len is a multiple of 4.
// ****************************************************************************
void CMD5Context::decode (uint32 *output, const uint8 *input, uint len)
{
	uint i, j;

	for (i = 0, j = 0; j < len; i++, j += 4)
		output[i] = ((uint32)input[j]) | (((uint32)input[j+1]) << 8) |
					(((uint32)input[j+2]) << 16) | (((uint32)input[j+3]) << 24);
}


} // namespace NLMISC