// Copyright (C) 2005 Open Source Telecom Corp.
//  
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software 
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

#include "engine.h"

namespace ost {
using namespace std;

struct MD5Context {
	uint32 buf[4];
	uint32 bits[2];
	unsigned char in[64];
};

static void MD5Transform(uint32 buf[4], uint32 const in[16]);

#if(__BYTE_ORDER == __LITTLE_ENDIAN)
#define byteReverse(buf, len)	/* Nothing */
#else
static void byteReverse(unsigned char *buf, unsigned longs)
{
    uint32 t;
    do {
	t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
	    ((unsigned) buf[1] << 8 | buf[0]);
	*(uint32 *) buf = t;
	buf += 4;
    } while (--longs);
}
#endif

static void MD5Init(struct MD5Context *ctx)
{
    ctx->buf[0] = 0x67452301;
    ctx->buf[1] = 0xefcdab89;
    ctx->buf[2] = 0x98badcfe;
    ctx->buf[3] = 0x10325476;

    ctx->bits[0] = 0;
    ctx->bits[1] = 0;
}

static void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
{
    uint32 t;

    /* Update bitcount */

    t = ctx->bits[0];
    if ((ctx->bits[0] = t + ((uint32) len << 3)) < t)
	ctx->bits[1]++;		/* Carry from low to high */
    ctx->bits[1] += len >> 29;

    t = (t >> 3) & 0x3f;	/* Bytes already in shsInfo->data */

    /* Handle any leading odd-sized chunks */

    if (t) {
	unsigned char *p = (unsigned char *) ctx->in + t;

	t = 64 - t;
	if (len < t) {
	    memcpy(p, buf, len);
	    return;
	}
	memcpy(p, buf, t);
	byteReverse(ctx->in, 16);
	MD5Transform(ctx->buf, (uint32 *) ctx->in);
	buf += t;
	len -= t;
    }
    /* Process data in 64-byte chunks */

    while (len >= 64) {
	memcpy(ctx->in, buf, 64);
	byteReverse(ctx->in, 16);
	MD5Transform(ctx->buf, (uint32 *) ctx->in);
	buf += 64;
	len -= 64;
    }

    /* Handle any remaining bytes of data. */

    memcpy(ctx->in, buf, len);
}

static void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
{
    unsigned count;
    unsigned char *p;

    /* Compute number of bytes mod 64 */
    count = (ctx->bits[0] >> 3) & 0x3F;

    /* Set the first char of padding to 0x80.  This is safe since there is
       always at least one byte free */
    p = ctx->in + count;
    *p++ = 0x80;

    /* Bytes of padding needed to make 64 bytes */
    count = 64 - 1 - count;

    /* Pad out to 56 mod 64 */
    if (count < 8) {
	/* Two lots of padding:  Pad the first block to 64 bytes */
	memset(p, 0, count);
	byteReverse(ctx->in, 16);
	MD5Transform(ctx->buf, (uint32 *) ctx->in);

	/* Now fill the next block with 56 bytes */
	memset(ctx->in, 0, 56);
    } else {
	/* Pad block to 56 bytes */
	memset(p, 0, count - 8);
    }
    byteReverse(ctx->in, 14);

    /* Append length in bits and transform */
    ((uint32 *) ctx->in)[14] = ctx->bits[0];
    ((uint32 *) ctx->in)[15] = ctx->bits[1];

    MD5Transform(ctx->buf, (uint32 *) ctx->in);
    byteReverse((unsigned char *) ctx->buf, 4);
    memcpy(digest, ctx->buf, 16);
    memset(ctx, 0, sizeof(ctx));	/* In case it's sensitive */
}

#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

#define MD5STEP(f, w, x, y, z, data, s) \
	( w += f /*(x, y, z)*/ + data,  w = w<<s | w>>(32-s),  w += x )

void MD5Transform(uint32 buf[4], uint32 const in[16])
{
    register uint32 a, b, c, d;

    a = buf[0];
    b = buf[1];
    c = buf[2];
    d = buf[3];

    MD5STEP(F1(b,c,d), a, b, c, d, in[0] + 0xd76aa478L, 7);
    MD5STEP(F1(a,b,c), d, a, b, c, in[1] + 0xe8c7b756L, 12);
    MD5STEP(F1(d,a,b), c, d, a, b, in[2] + 0x242070dbL, 17);
    MD5STEP(F1(c,d,a), b, c, d, a, in[3] + 0xc1bdceeeL, 22);
    MD5STEP(F1(b,c,d), a, b, c, d, in[4] + 0xf57c0fafL, 7);
    MD5STEP(F1(a,b,c), d, a, b, c, in[5] + 0x4787c62aL, 12);
    MD5STEP(F1(d,a,b), c, d, a, b, in[6] + 0xa8304613L, 17);
    MD5STEP(F1(c,d,a), b, c, d, a, in[7] + 0xfd469501L, 22);
    MD5STEP(F1(b,c,d), a, b, c, d, in[8] + 0x698098d8L, 7);
    MD5STEP(F1(a,b,c), d, a, b, c, in[9] + 0x8b44f7afL, 12);
    MD5STEP(F1(d,a,b), c, d, a, b, in[10] + 0xffff5bb1L, 17);
    MD5STEP(F1(c,d,a), b, c, d, a, in[11] + 0x895cd7beL, 22);
    MD5STEP(F1(b,c,d), a, b, c, d, in[12] + 0x6b901122L, 7);
    MD5STEP(F1(a,b,c), d, a, b, c, in[13] + 0xfd987193L, 12);
    MD5STEP(F1(d,a,b), c, d, a, b, in[14] + 0xa679438eL, 17);
    MD5STEP(F1(c,d,a), b, c, d, a, in[15] + 0x49b40821L, 22);

    MD5STEP(F2(b,c,d), a, b, c, d, in[1] + 0xf61e2562L, 5);
    MD5STEP(F2(a,b,c), d, a, b, c, in[6] + 0xc040b340L, 9);
    MD5STEP(F2(d,a,b), c, d, a, b, in[11] + 0x265e5a51L, 14);
    MD5STEP(F2(c,d,a), b, c, d, a, in[0] + 0xe9b6c7aaL, 20);
    MD5STEP(F2(b,c,d), a, b, c, d, in[5] + 0xd62f105dL, 5);
    MD5STEP(F2(a,b,c), d, a, b, c, in[10] + 0x02441453L, 9);
    MD5STEP(F2(d,a,b), c, d, a, b, in[15] + 0xd8a1e681L, 14);
    MD5STEP(F2(c,d,a), b, c, d, a, in[4] + 0xe7d3fbc8L, 20);
    MD5STEP(F2(b,c,d), a, b, c, d, in[9] + 0x21e1cde6L, 5);
    MD5STEP(F2(a,b,c), d, a, b, c, in[14] + 0xc33707d6L, 9);
    MD5STEP(F2(d,a,b), c, d, a, b, in[3] + 0xf4d50d87L, 14);
    MD5STEP(F2(c,d,a), b, c, d, a, in[8] + 0x455a14edL, 20);
    MD5STEP(F2(b,c,d), a, b, c, d, in[13] + 0xa9e3e905L, 5);
    MD5STEP(F2(a,b,c), d, a, b, c, in[2] + 0xfcefa3f8L, 9);
    MD5STEP(F2(d,a,b), c, d, a, b, in[7] + 0x676f02d9L, 14);
    MD5STEP(F2(c,d,a), b, c, d, a, in[12] + 0x8d2a4c8aL, 20);

    MD5STEP(F3(b,c,d), a, b, c, d, in[5] + 0xfffa3942L, 4);
    MD5STEP(F3(a,b,c), d, a, b, c, in[8] + 0x8771f681L, 11);
    MD5STEP(F3(d,a,b), c, d, a, b, in[11] + 0x6d9d6122L, 16);
    MD5STEP(F3(c,d,a), b, c, d, a, in[14] + 0xfde5380cL, 23);
    MD5STEP(F3(b,c,d), a, b, c, d, in[1] + 0xa4beea44L, 4);
    MD5STEP(F3(a,b,c), d, a, b, c, in[4] + 0x4bdecfa9L, 11);
    MD5STEP(F3(d,a,b), c, d, a, b, in[7] + 0xf6bb4b60L, 16);
    MD5STEP(F3(c,d,a), b, c, d, a, in[10] + 0xbebfbc70L, 23);
    MD5STEP(F3(b,c,d), a, b, c, d, in[13] + 0x289b7ec6L, 4);
    MD5STEP(F3(a,b,c), d, a, b, c, in[0] + 0xeaa127faL, 11);
    MD5STEP(F3(d,a,b), c, d, a, b, in[3] + 0xd4ef3085L, 16);
    MD5STEP(F3(c,d,a), b, c, d, a, in[6] + 0x04881d05L, 23);
    MD5STEP(F3(b,c,d), a, b, c, d, in[9] + 0xd9d4d039L, 4);
    MD5STEP(F3(a,b,c), d, a, b, c, in[12] + 0xe6db99e5L, 11);
    MD5STEP(F3(d,a,b), c, d, a, b, in[15] + 0x1fa27cf8L, 16);
    MD5STEP(F3(c,d,a), b, c, d, a, in[2] + 0xc4ac5665L, 23);

    MD5STEP(F4(b,c,d), a, b, c, d, in[0] + 0xf4292244L, 6);
    MD5STEP(F4(a,b,c), d, a, b, c, in[7] + 0x432aff97L, 10);
    MD5STEP(F4(d,a,b), c, d, a, b, in[14] + 0xab9423a7L, 15);
    MD5STEP(F4(c,d,a), b, c, d, a, in[5] + 0xfc93a039L, 21);
    MD5STEP(F4(b,c,d), a, b, c, d, in[12] + 0x655b59c3L, 6);
    MD5STEP(F4(a,b,c), d, a, b, c, in[3] + 0x8f0ccc92L, 10);
    MD5STEP(F4(d,a,b), c, d, a, b, in[10] + 0xffeff47dL, 15);
    MD5STEP(F4(c,d,a), b, c, d, a, in[1] + 0x85845dd1L, 21);
    MD5STEP(F4(b,c,d), a, b, c, d, in[8] + 0x6fa87e4fL, 6);
    MD5STEP(F4(a,b,c), d, a, b, c, in[15] + 0xfe2ce6e0L, 10);
    MD5STEP(F4(d,a,b), c, d, a, b, in[6] + 0xa3014314L, 15);
    MD5STEP(F4(c,d,a), b, c, d, a, in[13] + 0x4e0811a1L, 21);
    MD5STEP(F4(b,c,d), a, b, c, d, in[4] + 0xf7537e82L, 6);
    MD5STEP(F4(a,b,c), d, a, b, c, in[11] + 0xbd3af235L, 10);
    MD5STEP(F4(d,a,b), c, d, a, b, in[2] + 0x2ad7d2bbL, 15);
    MD5STEP(F4(c,d,a), b, c, d, a, in[9] + 0xeb86d391L, 21);

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

void Bayonne::md5_hash(char *out, const char *source)
{
	struct MD5Context md5;
	unsigned char digest[16];
	unsigned p = 0;
	
	MD5Init(&md5);
	MD5Update(&md5, (unsigned char *)source, strlen(source));
	MD5Final(digest, &md5);

	while(p < 16)
	{
		snprintf(&out[p * 2], 3, "%2.2x", digest[p]);
		++p;
	}
}
		
} // namespace