// sha.cpp - modified by Wei Dai from Steve Reid's public domain sha1.c

// Steve Reid implemented SHA-1. Wei Dai implemented SHA-2.
// Both are in the public domain.

#include "pch.h"
#include "sha.h"
#include "misc.h"

NAMESPACE_BEGIN(CryptoPP)

void SHA::Init()
{
	m_digest[0] = 0x67452301L;
	m_digest[1] = 0xEFCDAB89L;
	m_digest[2] = 0x98BADCFEL;
	m_digest[3] = 0x10325476L;
	m_digest[4] = 0xC3D2E1F0L;
}

// start of Steve Reid's code

#define blk0(i) (W[i] = data[i])
#define blk1(i) (W[i&15] = rotlFixed(W[(i+13)&15]^W[(i+8)&15]^W[(i+2)&15]^W[i&15],1))

#define f1(x,y,z) (z^(x&(y^z)))
#define f2(x,y,z) (x^y^z)
#define f3(x,y,z) ((x&y)|(z&(x|y)))
#define f4(x,y,z) (x^y^z)

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
#define R0(v,w,x,y,z,i) z+=f1(w,x,y)+blk0(i)+0x5A827999+rotlFixed(v,5);w=rotlFixed(w,30);
#define R1(v,w,x,y,z,i) z+=f1(w,x,y)+blk1(i)+0x5A827999+rotlFixed(v,5);w=rotlFixed(w,30);
#define R2(v,w,x,y,z,i) z+=f2(w,x,y)+blk1(i)+0x6ED9EBA1+rotlFixed(v,5);w=rotlFixed(w,30);
#define R3(v,w,x,y,z,i) z+=f3(w,x,y)+blk1(i)+0x8F1BBCDC+rotlFixed(v,5);w=rotlFixed(w,30);
#define R4(v,w,x,y,z,i) z+=f4(w,x,y)+blk1(i)+0xCA62C1D6+rotlFixed(v,5);w=rotlFixed(w,30);

void SHA::Transform(word32 *state, const word32 *data)
{
	word32 W[16];
    /* Copy context->state[] to working vars */
    word32 a = state[0];
    word32 b = state[1];
    word32 c = state[2];
    word32 d = state[3];
    word32 e = state[4];
    /* 4 rounds of 20 operations each. Loop unrolled. */
    R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
    R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
    R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
    R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
    R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
    R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
    R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
    R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
    R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
    R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
    R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
    R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
    R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
    R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
    R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
    R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
    R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
    R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
    R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
    R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
    /* Add the working vars back into context.state[] */
    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;
    /* Wipe variables */
    a = b = c = d = e = 0;
	memset(W, 0, sizeof(W));
}

// end of Steve Reid's code

// *************************************************************

NAMESPACE_END