/** @com.intel.drl.spec_ref */
public ECFieldF2m(int m, BigInteger rp) {
this.m = m;
if (this.m <= 0) {
throw new IllegalArgumentException(Messages.getString("security.75")); // $NON-NLS-1$
}
this.rp = rp;
if (this.rp == null) {
throw new NullPointerException(Messages.getString("security.76")); // $NON-NLS-1$
}
// the leftmost bit must be (m+1)-th one,
// set bits count must be 3 or 5,
// bits 0 and m must be set
int rp_bc = this.rp.bitCount();
if ((this.rp.bitLength() != (m + 1))
|| (rp_bc != TPB_LEN && rp_bc != PPB_LEN)
|| (!this.rp.testBit(0) || !this.rp.testBit(m))) {
throw new IllegalArgumentException(Messages.getString("security.77")); // $NON-NLS-1$
}
// setup ks using rp:
// allocate for mid terms only
ks = new int[rp_bc - 2];
// find midterm orders and set ks accordingly
BigInteger rpTmp = rp.clearBit(0);
for (int i = ks.length - 1; i >= 0; i--) {
ks[i] = rpTmp.getLowestSetBit();
rpTmp = rpTmp.clearBit(ks[i]);
}
}
public static void bitOps(int order) {
int failCount1 = 0, failCount2 = 0, failCount3 = 0;
for (int i = 0; i < size * 5; i++) {
BigInteger x = fetchNumber(order);
BigInteger y;
/* Test setBit and clearBit (and testBit) */
if (x.signum() < 0) {
y = BigInteger.valueOf(-1);
for (int j = 0; j < x.bitLength(); j++) if (!x.testBit(j)) y = y.clearBit(j);
} else {
y = BigInteger.ZERO;
for (int j = 0; j < x.bitLength(); j++) if (x.testBit(j)) y = y.setBit(j);
}
if (!x.equals(y)) failCount1++;
/* Test flipBit (and testBit) */
y = BigInteger.valueOf(x.signum() < 0 ? -1 : 0);
for (int j = 0; j < x.bitLength(); j++) if (x.signum() < 0 ^ x.testBit(j)) y = y.flipBit(j);
if (!x.equals(y)) failCount2++;
}
report("clearBit/testBit", failCount1);
report("flipBit/testBit", failCount2);
for (int i = 0; i < size * 5; i++) {
BigInteger x = fetchNumber(order);
/* Test getLowestSetBit() */
int k = x.getLowestSetBit();
if (x.signum() == 0) {
if (k != -1) failCount3++;
} else {
BigInteger z = x.and(x.negate());
int j;
for (j = 0; j < z.bitLength() && !z.testBit(j); j++) ;
if (k != j) failCount3++;
}
}
report("getLowestSetBit", failCount3);
}