static FFelem FFpow(FFelem b, int e)
{
if (e == 0) return 1;
if (e < 0) return FFpow(FFdiv(1, b), -e);
if (e == 1) return b;
if (e&1) return FFmul(b, FFpow(FFmul(b, b), (e-1)/2));
return FFpow(FFmul(b, b), e/2);
}
DUPFF DUPFFexgcd(DUPFF *fcofac, DUPFF *gcofac, const DUPFF f, const DUPFF g)
{
DUPFF u, v, uf, ug, vf, vg;
FFelem q, lcu, lcvrecip, p;
int df, dg, du, dv;
if (DUPFFdeg(f) < DUPFFdeg(g)) return DUPFFexgcd(gcofac, fcofac, g, f);
if (DUPFFdeg(f) != 2 || DUPFFdeg(g) != 1) abort();
if (f->coeffs[0] == 0) return f;
p = 2;
df = DUPFFdeg(f); if (df < 0) df = 0; /* both inputs are zero */
dg = DUPFFdeg(g); if (dg < 0) dg = 0; /* one input is zero */
u = DUPFFcopy(f);
v = DUPFFcopy(g);
uf = DUPFFnew(dg); uf->coeffs[0] = 1; uf->deg = 0;
ug = DUPFFnew(df);
vf = DUPFFnew(dg);
vg = DUPFFnew(df); vg->coeffs[0] = 1; vg->deg = 0;
while (DUPFFdeg(v) > 0)
{
dv = DUPFFdeg(v);
lcvrecip = FFmul(1, v->coeffs[dv]);
while (DUPFFdeg(u) >= dv)
{
du = DUPFFdeg(u);
lcu = u->coeffs[du];
q = FFmul(lcu, lcvrecip);
DUPFFshift_add(u, v, du-dv, p-q);
DUPFFshift_add(uf, vf, du-dv, p-q);
DUPFFshift_add(ug, vg, du-dv, p-q);
}
DUPFFswap(u, v);
DUPFFswap(uf, vf);
DUPFFswap(ug, vg);
}
if (DUPFFdeg(v) == 0)
{
DUPFFswap(u, v);
DUPFFswap(uf, vf);
DUPFFswap(ug, vg);
}
DUPFFfree(vf);
DUPFFfree(vg);
DUPFFfree(v);
*fcofac = uf;
*gcofac = ug;
return u;
}
void DUPFFformal_deriv2(DUPFF fprime, const DUPFF f)
/* fprime and f may be identical */
{
int df, dans, j, p;
p = CurrentFF.prime;
df = DUPFFdeg(f);
/* find degree of the answer */
for (dans=df; dans >= 1; dans--)
if (f->coeffs[dans] != 0 && (dans%p != 0)) break;
dans--;
if (dans < 0)
{
fprime->deg = -1;
return;
}
if (fprime->maxdeg < dans)
{
JERROR(JERROR_DEG_TOO_LOW);
return;
}
fprime->deg = dans;
for (j = 1; j <= dans+1; j++)
fprime->coeffs[j-1] = FFmul(j%p, f->coeffs[j]);
return;
}
void AES::InvMixColumns(unsigned char state[][4])
{
unsigned char t[4];
int r,c;
for(c=0; c< 4; c++)
{
for(r=0; r<4; r++)
{
t[r] = state[r][c];
}
for(r=0; r<4; r++)
{
state[r][c] = FFmul(0x0e, t[r])
^ FFmul(0x0b, t[(r+1)%4])
^ FFmul(0x0d, t[(r+2)%4])
^ FFmul(0x09, t[(r+3)%4]);
}
}
}
void CBm53AES::MixColumns(unsigned char state[][4])
{
unsigned char t[4];
int r,c;
for(c=0; c< 4; c++)
{
for(r=0; r<4; r++)
{
t[r] = state[r][c];
}
for(r=0; r<4; r++)
{
state[r][c] = FFmul(0x02, t[r])
^ FFmul(0x03, t[(r+1)%4])
^ FFmul(0x01, t[(r+2)%4])
^ FFmul(0x01, t[(r+3)%4]);
}
}
}
static void InvMixColumns(unsigned char data[bytes_row_size][bytes_columns_size])
{
unsigned char v[bytes_columns_size];
for(size_t col = 0; col < bytes_columns_size; ++col)
{
//提取一列数据
for(size_t row = 0; row < bytes_row_size; ++row)
{
v[row] = data[row][col];
}
//列混淆
for(size_t row = 0; row < bytes_row_size; ++row)
{
data[row][col] = FFmul(0x0e, v[row])
^ FFmul(0x0b, v[(row+1)%4])
^ FFmul(0x0d, v[(row+2)%4])
^ FFmul(0x09, v[(row+3)%4]);
}
}
}
void InvMixColumns(unsigned int *state){
unsigned int b[16]={0};
int i=0;
for(i=0;i<4;i++){
b[i*4]=(state[i]&0xff000000)>>24;
b[i*4+1]=(state[i]&0xff0000)>>16;
b[i*4+2]=(state[i]&0xff00)>>8;
b[i*4+3]=state[i]&0xff;
}
for(i=0;i<4;i++){
state[i]=0;
int j=0;
for(j=0;j<4;j++){
state[i] += FFmul(b[i*4],InvMC_Matrix[j*4]) ^
FFmul(b[i*4+1],InvMC_Matrix[j*4+1]) ^
FFmul(b[i*4+2],InvMC_Matrix[j*4+2]) ^
FFmul(b[i*4+3],InvMC_Matrix[j*4+3]);
if(j<3)
state[i] <<= 8;
}
}
}
DUPFF DMPZ_to_DUPFF(DMPZ f, int var, int *substitution)
{
FFelem p = CurrentFF.prime;
int df, d, c, i;
DUPFF ans;
DMPZ iter;
df = DMPZdeg(f, var);
ans = DUPFFnew(df);
for(i=0; i<=df;i++) ans->coeffs[i] = 0;
for(iter=f;iter;iter = iter->next)
{
d = iter->exps[var];
c = mpz_fdiv_ui(iter->coeff, p);
for(i=0; c!=0 && i<NVARS;i++)
if (i != var)
c = FFmul(c, FFpow(substitution[i], iter->exps[i]));
ans->coeffs[d] += c;
if (ans->coeffs[d] >= p) ans->coeffs[d] -= p;
}
for(i=df;i>=0;i--) if (ans->coeffs[i] != 0) break;
ans->deg = i;
return ans;
}
