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void A3A8(/* in */ unsigned char rand[16], /* in */ unsigned char key[16],
/* out */ unsigned char simoutput[12])
{
unsigned char x[32], bit[128];
int i, j, k, l, m, n, y, z, next_bit;
/* ( Load RAND into last 16 bytes of input ) */
for (i=16; i<32; i++)
x[i] = rand[i-16];
/* ( Loop eight times ) */
for (i=1; i<9; i++) {
/* ( Load key into first 16 bytes of input ) */
for (j=0; j<16; j++)
x[j] = key[j];
/* ( Perform substitutions ) */
for (j=0; j<5; j++)
for (k=0; k<(1<<j); k++)
for (l=0; l<(1<<(4-j)); l++) {
m = l + k*(1<<(5-j));
n = m + (1<<(4-j));
y = (x[m]+2*x[n]) % (1<<(9-j));
z = (2*x[m]+x[n]) % (1<<(9-j));
x[m] = table[j][y];
x[n] = table[j][z];
}
/* ( Form bits from bytes ) */
for (j=0; j<32; j++)
for (k=0; k<4; k++)
bit[4*j+k] = (x[j]>>(3-k)) & 1;
/* ( Permutation but not on the last loop ) */
if (i < 8)
for (j=0; j<16; j++) {
x[j+16] = 0;
for (k=0; k<8; k++) {
next_bit = ((8*j + k)*17) % 128;
x[j+16] |= bit[next_bit] << (7-k);
}
}
}
/*
* ( At this stage the vector x[] consists of 32 nibbles.
* The first 8 of these are taken as the output SRES. )
*/
/* The remainder of the code is not given explicitly in the
* standard, but was derived by reverse-engineering.
*/
for (i=0; i<4; i++)
simoutput[i] = (x[2*i]<<4) | x[2*i+1];
for (i=0; i<6; i++)
simoutput[4+i] = (x[2*i+18]<<6) | (x[2*i+18+1]<<2)
| (x[2*i+18+2]>>2);
simoutput[4+6] = (x[2*6+18]<<6) | (x[2*6+18+1]<<2);
simoutput[4+7] = 0;
}
/* out */ unsigned char simoutput[12])
{
unsigned char x[32], bit[128];
int i, j, k, l, m, n, y, z, next_bit;
/* ( Load RAND into last 16 bytes of input ) */
for (i=16; i<32; i++)
x[i] = rand[i-16];
/* ( Loop eight times ) */
for (i=1; i<9; i++) {
/* ( Load key into first 16 bytes of input ) */
for (j=0; j<16; j++)
x[j] = key[j];
/* ( Perform substitutions ) */
for (j=0; j<5; j++)
for (k=0; k<(1<<j); k++)
for (l=0; l<(1<<(4-j)); l++) {
m = l + k*(1<<(5-j));
n = m + (1<<(4-j));
y = (x[m]+2*x[n]) % (1<<(9-j));
z = (2*x[m]+x[n]) % (1<<(9-j));
x[m] = table[j][y];
x[n] = table[j][z];
}
/* ( Form bits from bytes ) */
for (j=0; j<32; j++)
for (k=0; k<4; k++)
bit[4*j+k] = (x[j]>>(3-k)) & 1;
/* ( Permutation but not on the last loop ) */
if (i < 8)
for (j=0; j<16; j++) {
x[j+16] = 0;
for (k=0; k<8; k++) {
next_bit = ((8*j + k)*17) % 128;
x[j+16] |= bit[next_bit] << (7-k);
}
}
}
/*
* ( At this stage the vector x[] consists of 32 nibbles.
* The first 8 of these are taken as the output SRES. )
*/
/* The remainder of the code is not given explicitly in the
* standard, but was derived by reverse-engineering.
*/
for (i=0; i<4; i++)
simoutput[i] = (x[2*i]<<4) | x[2*i+1];
for (i=0; i<6; i++)
simoutput[4+i] = (x[2*i+18]<<6) | (x[2*i+18+1]<<2)
| (x[2*i+18+2]>>2);
simoutput[4+6] = (x[2*6+18]<<6) | (x[2*6+18+1]<<2);
simoutput[4+7] = 0;
}
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