// galois multiplication of 8 bit characters a and b
galois_multiplication:function(a,b)
{
var p = 0;
for(var counter = 0; counter < 8; counter++)
{
if((b & 1) == 1)
p ^= a;
if(p > 0x100) p ^= 0x100;
var hi_bit_set = (a & 0x80); //keep p 8 bit
a <<= 1;
if(a > 0x100) a ^= 0x100; //keep a 8 bit
if(hi_bit_set == 0x80)
a ^= 0x1b;
if(a > 0x100) a ^= 0x100; //keep a 8 bit
b >>= 1;
if(b > 0x100) b ^= 0x100; //keep b 8 bit
}
return p;
}