devilution/2020_03_31/Source/sha.cpp

#include "diablo.h"

SHA1Context sgSHA1[3];

void SHA1Clear()
{
	memset(sgSHA1, 0, 0x114u);
}

void SHA1Result(int n, char Message_Digest[SHA1HashSize])
{
	char *v2; // eax
	SHA1Context *v3; // ecx
	signed int i; // edx
	int v5; // esi

	v2 = Message_Digest;
	if ( Message_Digest )
	{
		v3 = &sgSHA1[n];
		i = 5;
		do
		{
			v5 = v3->state[0];
			v3 = (SHA1Context *)((char *)v3 + 4);
			*(_DWORD *)v2 = v5;
			v2 += 4;
			--i;
		}
		while ( i );
	}
}

void SHA1Calculate(int n, const char *data, char Message_Digest[SHA1HashSize])
{
	int v3; // esi

	v3 = n;
	SHA1Input(&sgSHA1[n], data, 64);
	if ( Message_Digest )
		SHA1Result(v3, (char *)Message_Digest);
}

void SHA1Input(SHA1Context *context, const char *message_array, int len)
{
	SHA1Context *v3; // esi
	const char *v4; // ebx
	int v5; // ecx
	int v6; // edx
	unsigned int v7; // ebp

	v3 = context;
	v4 = message_array;
	v5 = context->count[0];
	v6 = v5 + 8 * len;
	if ( v6 < v5 )
		++v3->count[1];
	v3->count[0] = v6;
	v3->count[1] += len >> 29;
	if ( len >= 64 )
	{
		v7 = (unsigned int)len >> 6;
		do
		{
			memcpy(v3->buffer, v4, 0x40u);
			SHA1ProcessMessageBlock(v3);
			v4 += 64;
			--v7;
		}
		while ( v7 );
	}
}

void SHA1ProcessMessageBlock(SHA1Context *context)
{
	int i; // [esp+158h] [ebp-4h]
	int temp; // esi
	int W[80]; // [esp+Ch] [ebp-150h]
	int A, B, C, D, E; // [esp+150h] [ebp-Ch]

	qmemcpy(W, context->buffer, 0x40u);

	for(i = 16; i < 80; i++)
	{
		W[i] = W[i-16] ^ W[i-14] ^ W[i-8] ^ W[i-3];
	}

	A = context->state[0];
	B = context->state[1];
	C = context->state[2];
	D = context->state[3];
	E = context->state[4];

	for(i = 0; i < 20; i++)
	{
		temp = SHA1CircularShift(5,A) + ((B & C) | ((~B) & D)) + E + W[i] + 0x5A827999;
		E = D;
		D = C;
		C = SHA1CircularShift(30,B);
		B = A;
		A = temp;
	}

	for(i = 20; i < 40; i++)
	{
		temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[i] + 0x6ED9EBA1;
		E = D;
		D = C;
		C = SHA1CircularShift(30,B);
		B = A;
		A = temp;
	}

	for(i = 40; i < 60; i++)
	{
		temp = SHA1CircularShift(5,A) + ((B & C) | (B & D) | (C & D)) + E + W[i] + 0x8F1BBCDC;
		E = D;
		D = C;
		C = SHA1CircularShift(30,B);
		B = A;
		A = temp;
	}

	for(i = 60; i < 80; i++)
	{
		temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[i] + 0xCA62C1D6;
		E = D;
		D = C;
		C = SHA1CircularShift(30,B);
		B = A;
		A = temp;
	}

	context->state[0] += A;
	context->state[1] += B;
	context->state[2] += C;
	context->state[3] += D;
	context->state[4] += E;
}

void SHA1Reset(int n)
{
	sgSHA1[n].count[0] = 0;
	sgSHA1[n].count[1] = 0;
	sgSHA1[n].state[0] = 0x67452301;
	sgSHA1[n].state[1] = 0xEFCDAB89;
	sgSHA1[n].state[2] = 0x98BADCFE;
	sgSHA1[n].state[3] = 0x10325476;
	sgSHA1[n].state[4] = 0xC3D2E1F0;
}