/*

MD5 collision generator
=======================
Source code files:
  block0.cpp
  block1.cpp
  main.cpp
  main.hpp
  md5.cpp
  block1wang.cpp
  block1stevens00.cpp
  block1stevens01.cpp
  block1stevens10.cpp
  block1stevens11.cpp
Win32 executable:
  fastcoll_v1.0.0.5.exe

Version
=======
version 1.0.0.5-1, April 2006.

Copyright
=========
© M. Stevens, 2006. All rights reserved.

Disclaimer
==========
This software is provided as is. Use is at the user's risk.
No guarantee whatsoever is given on how it may function or malfunction.
Support cannot be expected.
This software is meant for scientific and educational purposes only.
It is forbidden to use it for other than scientific or educational purposes.
In particular, commercial and malicious use is not allowed.
Further distribution of this software, by whatever means, is not allowed
without our consent.
This includes publication of source code or executables in printed form,
on websites, newsgroups, CD-ROM's, etc.
Changing the (source) code without our consent is not allowed.
In all versions of the source code this disclaimer, the copyright
notice and the version number should be present.

*/

#include <iostream>
#include <vector>
#include "main.hpp"

uint32 seed32_1, seed32_2;

void find_block0(uint32 block[], const uint32 IV[])
{
	uint32 Q[68] = { IV[0], IV[3], IV[2], IV[1] };

	std::vector<uint32> q4mask(1<<4);
	for (unsigned k = 0; k < q4mask.size(); ++k)
		q4mask[k] = ((k<<2) ^ (k<<26)) & 0x38000004;

	std::vector<uint32> q9q10mask(1<<3);
	for (unsigned k = 0; k < q9q10mask.size(); ++k)
		q9q10mask[k] = ((k<<13) ^ (k<<4)) & 0x2060;
		
	std::vector<uint32> q9mask(1<<16);
	for (unsigned k = 0; k < q9mask.size(); ++k)
		q9mask[k] = ((k<<1) ^ (k<<2) ^ (k<<5) ^ (k<<7) ^ (k<<8) ^ (k<<10) ^ (k<<11) ^ (k<<13)) & 0x0eb94f16;

	while (true)
	{
		Q[Qoff + 1] = xrng64();
		Q[Qoff + 3] = (xrng64() & 0xfe87bc3f) | 0x017841c0;
		Q[Qoff + 4] = (xrng64() & 0x44000033) | 0x000002c0 | (Q[Qoff + 3] & 0x0287bc00);
		Q[Qoff + 5] = 0x41ffffc8 | (Q[Qoff + 4] & 0x04000033);
		Q[Qoff + 6] = 0xb84b82d6;
		Q[Qoff + 7] = (xrng64() & 0x68000084) | 0x02401b43;
		Q[Qoff + 8] = (xrng64() & 0x2b8f6e04) | 0x005090d3 | (~Q[Qoff + 7] & 0x40000000);
		Q[Qoff + 9] = 0x20040068 | (Q[Qoff + 8] & 0x00020000) | (~Q[Qoff + 8] & 0x40000000);
		Q[Qoff + 10] = (xrng64() & 0x40000000) | 0x1040b089;
		Q[Qoff + 11] = (xrng64() & 0x10408008) | 0x0fbb7f16 | (~Q[Qoff + 10] & 0x40000000);
		Q[Qoff + 12] = (xrng64() & 0x1ed9df7f) | 0x00022080 | (~Q[Qoff + 11] & 0x40200000);
		Q[Qoff + 13] = (xrng64() & 0x5efb4f77) | 0x20049008;
		Q[Qoff + 14] = (xrng64() & 0x1fff5f77) | 0x0000a088 | (~Q[Qoff + 13] & 0x40000000);
		Q[Qoff + 15] = (xrng64() & 0x5efe7ff7) | 0x80008000 | (~Q[Qoff + 14] & 0x00010000);
		Q[Qoff + 16] = (xrng64() & 0x1ffdffff) | 0xa0000000 | (~Q[Qoff + 15] & 0x40020000);

		MD5_REVERSE_STEP(0, 0xd76aa478, 7);
		MD5_REVERSE_STEP(6, 0xa8304613, 17);
		MD5_REVERSE_STEP(7, 0xfd469501, 22);
		MD5_REVERSE_STEP(11, 0x895cd7be, 22);
		MD5_REVERSE_STEP(14, 0xa679438e, 17);
		MD5_REVERSE_STEP(15, 0x49b40821, 22);

		const uint32 tt1 = FF(Q[Qoff + 1], Q[Qoff + 0], Q[Qoff - 1]) + Q[Qoff - 2] + 0xe8c7b756;		
		const uint32 tt17 = GG(Q[Qoff + 16], Q[Qoff + 15], Q[Qoff + 14]) + Q[Qoff + 13] + 0xf61e2562;
		const uint32 tt18 = Q[Qoff + 14] + 0xc040b340 + block[6];
		const uint32 tt19 = Q[Qoff + 15] + 0x265e5a51 + block[11];
		const uint32 tt20 = Q[Qoff + 16] + 0xe9b6c7aa + block[0];
		const uint32 tt5 = RR(Q[Qoff + 6] - Q[Qoff + 5], 12) - FF(Q[Qoff + 5], Q[Qoff + 4], Q[Qoff + 3]) - 0x4787c62a;

		// change q17 until conditions are met on q18, q19 and q20
		unsigned counter = 0;
		while (counter < (1 << 7))
		{
			const uint32 q16 = Q[Qoff + 16];
			uint32 q17 = ((xrng64() & 0x3ffd7ff7) | (q16&0xc0008008)) ^ 0x40000000;
			++counter;

			uint32 q18 = GG(q17, q16, Q[Qoff + 15]) + tt18;
			q18 = RL(q18, 9); q18 += q17;
			if (0x00020000 != ((q18^q17)&0xa0020000))
				continue;

			uint32 q19 = GG(q18, q17, q16) + tt19;
			q19 = RL(q19, 14); q19 += q18;
			if (0x80000000 != (q19 & 0x80020000))
				continue;
			
			uint32 q20 = GG(q19, q18, q17) + tt20;
			q20 = RL(q20, 20); q20 += q19;
			if (0x00040000 != ((q20^q19) & 0x80040000))
				continue;

			block[1] = q17-q16; block[1] = RR(block[1], 5); block[1] -= tt17;
			uint32 q2 = block[1] + tt1; q2 = RL(q2, 12); q2 += Q[Qoff + 1];
			block[5] = tt5 - q2;

			Q[Qoff + 2] = q2;
			Q[Qoff + 17] = q17;
			Q[Qoff + 18] = q18;
			Q[Qoff + 19] = q19;
			Q[Qoff + 20] = q20;
			MD5_REVERSE_STEP(2, 0x242070db, 17);

			counter = 0;
			break;
		}
		if (counter != 0)
			continue;

		const uint32 q4 = Q[Qoff + 4];
		const uint32 q9backup = Q[Qoff + 9];
		const uint32 tt21 = GG(Q[Qoff+20], Q[Qoff+19], Q[Qoff+18]) + Q[Qoff+17] + 0xd62f105d;

		// iterate over possible changes of q4 
		// while keeping all conditions on q1-q20 intact
		// this changes m3, m4, m5 and m7
		unsigned counter2 = 0;
		while (counter2 < (1<<4))
		{
			Q[Qoff+4] = q4 ^ q4mask[counter2];
			++counter2;
			MD5_REVERSE_STEP(5, 0x4787c62a, 12);
			uint32 q21 = tt21 + block[5];
			q21 = RL(q21,5); q21 += Q[Qoff+20];
			if (0 != ((q21^Q[Qoff+20]) & 0x80020000))
				continue;

			Q[Qoff + 21] = q21;
			MD5_REVERSE_STEP(3, 0xc1bdceee, 22);
			MD5_REVERSE_STEP(4, 0xf57c0faf, 7);
			MD5_REVERSE_STEP(7, 0xfd469501, 22);
			
			const uint32 tt22 = GG(Q[Qoff + 21], Q[Qoff + 20], Q[Qoff + 19]) + Q[Qoff + 18] + 0x02441453;
			const uint32 tt23 = Q[Qoff + 19] + 0xd8a1e681 + block[15];
			const uint32 tt24 = Q[Qoff + 20] + 0xe7d3fbc8 + block[4];

			const uint32 tt9 = Q[Qoff + 6] + 0x8b44f7af;
			const uint32 tt10 = Q[Qoff + 7] + 0xffff5bb1;
			const uint32 tt8 = FF(Q[Qoff + 8], Q[Qoff + 7], Q[Qoff + 6]) + Q[Qoff + 5] + 0x698098d8;		
			const uint32 tt12 = RR(Q[Qoff+13]-Q[Qoff+12],7) - 0x6b901122;
			const uint32 tt13 = RR(Q[Qoff+14]-Q[Qoff+13],12) - FF(Q[Qoff+13],Q[Qoff+12],Q[Qoff+11]) - 0xfd987193;

			// iterate over possible changes of q9 and q10
			// while keeping conditions on q1-q21 intact
			// this changes m8, m9, m10, m12 and m13 (and not m11!)
			// the possible changes of q9 that also do not change m10 are used below
			for (unsigned counter3 = 0; counter3 < (1<<3);)
			{
				uint32 q10 = Q[Qoff+10] ^ (q9q10mask[counter3] & 0x60);
				Q[Qoff + 9] = q9backup ^ (q9q10mask[counter3] & 0x2000);
				++counter3;
				uint32 m10 = RR(Q[Qoff+11]-q10,17);
				m10 -= FF(q10, Q[Qoff+9], Q[Qoff+8]) + tt10;

				uint32 aa = Q[Qoff + 21];
				uint32 dd = tt22+m10; dd = RL(dd, 9) + aa;
				if (0x80000000 != (dd & 0x80000000)) continue;

				uint32 bb = Q[Qoff + 20];
				uint32 cc = tt23 + GG(dd, aa, bb); 
				if (0 != (cc & 0x20000)) continue;
				cc = RL(cc, 14) + dd;
				if (0 != (cc & 0x80000000)) continue;

				bb = tt24 + GG(cc, dd, aa); bb = RL(bb, 20) + cc;
				if (0 == (bb & 0x80000000)) continue;

				block[10] = m10;
				block[13] = tt13 - q10;

				// iterate over possible changes of q9
				// while keeping intact conditions on q1-q24
				// this changes m8, m9 and m12 (but not m10!)
				for (unsigned counter4 = 0; counter4 < (1<<16); ++counter4)
				{
					uint32 q9 = Q[Qoff + 9] ^ q9mask[counter4];
					block[12] = tt12 - FF(Q[Qoff + 12], Q[Qoff + 11], q10) - q9;
					uint32 m8 = q9 - Q[Qoff + 8];
					block[8] = RR(m8, 7) - tt8; 
					uint32 m9 = q10 - q9;
					block[9] = RR(m9, 12) - FF(q9, Q[Qoff + 8], Q[Qoff + 7]) - tt9; 

					uint32 a = aa, b = bb, c = cc, d = dd;
					MD5_STEP(GG, a, b, c, d, block[9], 0x21e1cde6, 5);
					MD5_STEP(GG, d, a, b, c, block[14], 0xc33707d6, 9);
					MD5_STEP(GG, c, d, a, b, block[3], 0xf4d50d87, 14);
					MD5_STEP(GG, b, c, d, a, block[8], 0x455a14ed, 20);
					MD5_STEP(GG, a, b, c, d, block[13], 0xa9e3e905, 5);
					MD5_STEP(GG, d, a, b, c, block[2], 0xfcefa3f8, 9);
					MD5_STEP(GG, c, d, a, b, block[7], 0x676f02d9, 14);
					MD5_STEP(GG, b, c, d, a, block[12], 0x8d2a4c8a, 20);
					MD5_STEP(HH, a, b, c, d, block[5], 0xfffa3942, 4);
					MD5_STEP(HH, d, a, b, c, block[8], 0x8771f681, 11);

					c += HH(d, a, b) + block[11] + 0x6d9d6122;
					if (0 != (c & (1 << 15))) 
						continue;
					c = (c<<16 | c>>16) + d;
					
					MD5_STEP(HH, b, c, d, a, block[14], 0xfde5380c, 23);
					MD5_STEP(HH, a, b, c, d, block[1], 0xa4beea44, 4);
					MD5_STEP(HH, d, a, b, c, block[4], 0x4bdecfa9, 11);
					MD5_STEP(HH, c, d, a, b, block[7], 0xf6bb4b60, 16);
					MD5_STEP(HH, b, c, d, a, block[10], 0xbebfbc70, 23);
					MD5_STEP(HH, a, b, c, d, block[13], 0x289b7ec6, 4);
					MD5_STEP(HH, d, a, b, c, block[0], 0xeaa127fa, 11);
					MD5_STEP(HH, c, d, a, b, block[3], 0xd4ef3085, 16);
					MD5_STEP(HH, b, c, d, a, block[6], 0x04881d05, 23);
					MD5_STEP(HH, a, b, c, d, block[9], 0xd9d4d039, 4);
					MD5_STEP(HH, d, a, b, c, block[12], 0xe6db99e5, 11);
					MD5_STEP(HH, c, d, a, b, block[15], 0x1fa27cf8, 16);
					MD5_STEP(HH, b, c, d, a, block[2], 0xc4ac5665, 23);
					if (0 != ((b^d) & 0x80000000))
						continue;

					MD5_STEP(II, a, b, c, d, block[0], 0xf4292244, 6);
					if (0 != ((a^c) >> 31)) continue;
					MD5_STEP(II, d, a, b, c, block[7], 0x432aff97, 10);
					if (0 == ((b^d) >> 31)) continue;
					MD5_STEP(II, c, d, a, b, block[14], 0xab9423a7, 15);
					if (0 != ((a^c) >> 31)) continue;
					MD5_STEP(II, b, c, d, a, block[5], 0xfc93a039, 21);
					if (0 != ((b^d) >> 31)) continue;
					MD5_STEP(II, a, b, c, d, block[12], 0x655b59c3, 6);
					if (0 != ((a^c) >> 31)) continue;
					MD5_STEP(II, d, a, b, c, block[3], 0x8f0ccc92, 10);
					if (0 != ((b^d) >> 31)) continue;
					MD5_STEP(II, c, d, a, b, block[10], 0xffeff47d, 15);
					if (0 != ((a^c) >> 31)) continue;
					MD5_STEP(II, b, c, d, a, block[1], 0x85845dd1, 21);
					if (0 != ((b^d) >> 31)) continue;
					MD5_STEP(II, a, b, c, d, block[8], 0x6fa87e4f, 6);
					if (0 != ((a^c) >> 31)) continue;
					MD5_STEP(II, d, a, b, c, block[15], 0xfe2ce6e0, 10);
					if (0 != ((b^d) >> 31)) continue;
					MD5_STEP(II, c, d, a, b, block[6], 0xa3014314, 15);
					if (0 != ((a^c) >> 31)) continue;
					MD5_STEP(II, b, c, d, a, block[13], 0x4e0811a1, 21);
					if (0 == ((b^d) >> 31)) continue;
					MD5_STEP(II, a, b, c, d, block[4], 0xf7537e82, 6);
					if (0 != ((a^c) >> 31)) continue;
					MD5_STEP(II, d, a, b, c, block[11], 0xbd3af235, 10);
					if (0 != ((b^d) >> 31)) continue;
					MD5_STEP(II, c, d, a, b, block[2], 0x2ad7d2bb, 15);
					if (0 != ((a^c) >> 31)) continue;
					MD5_STEP(II, b, c, d, a, block[9], 0xeb86d391, 21);

					uint32 IHV1 = b + IV[1];
					uint32 IHV2 = c + IV[2];
					uint32 IHV3 = d + IV[3];

					bool wang = true;
					if (0x02000000 != ((IHV2^IHV1) & 0x86000000)) wang = false;
					if (0 != ((IHV1^IHV3) & 0x82000000)) wang = false;
					if (0 != (IHV1 & 0x06000020)) wang = false;
					
					bool stevens = true;
					if ( ((IHV1^IHV2)>>31)!=0 || ((IHV1^IHV3)>>31)!= 0 ) stevens = false;
					if ( (IHV3&(1<<25))!=0 || (IHV2&(1<<25))!=0 || (IHV1&(1<<25))!=0 
						|| ((IHV2^IHV1)&1)!=0) stevens = false;
										
					if (!(wang || stevens)) continue;

					std::cout << "." << std::flush;

					uint32 IV1[4], IV2[4];
					for (int t = 0; t < 4; ++t)
						IV2[t] = IV1[t] = IV[t];

					uint32 block2[16];
					for (int t = 0; t < 16; ++t)
						block2[t] = block[t];
					block2[4] += 1<<31;
					block2[11] += 1<<15;
					block2[14] += 1<<31;

					md5_compress(IV1, block);
					md5_compress(IV2, block2);
					if (	   (IV2[0] == IV1[0] + (1<<31))
							&& (IV2[1] == IV1[1] + (1<<31) + (1<<25))
							&& (IV2[2] == IV1[2] + (1<<31) + (1<<25))
							&& (IV2[3] == IV1[3] + (1<<31) + (1<<25)))
						return;

					if (IV2[0] != IV1[0] + (1<<31))
						std::cout << "!" << std::flush;
				}
			}
		}
	}
}