Exemplo n.º 1
0
// randomN creates a random integer in [0..limit), using the space in z if
// possible. n is the bit length of limit.
func randomN(z []Word, rand *rand.Rand, limit []Word, n int) []Word {
	bitLengthOfMSW := uint(n % _W)
	if bitLengthOfMSW == 0 {
		bitLengthOfMSW = _W
	}
	mask := Word((1 << bitLengthOfMSW) - 1)
	z = makeN(z, len(limit), false)

	for {
		for i := range z {
			switch _W {
			case 32:
				z[i] = Word(rand.Uint32())
			case 64:
				z[i] = Word(rand.Uint32()) | Word(rand.Uint32())<<32
			}
		}

		z[len(limit)-1] &= mask

		if cmpNN(z, limit) < 0 {
			break
		}
	}

	return normN(z)
}
Exemplo n.º 2
0
Arquivo: nat.go Projeto: radhermit/gcc
// random creates a random integer in [0..limit), using the space in z if
// possible. n is the bit length of limit.
func (z nat) random(rand *rand.Rand, limit nat, n int) nat {
	bitLengthOfMSW := uint(n % _W)
	if bitLengthOfMSW == 0 {
		bitLengthOfMSW = _W
	}
	mask := Word((1 << bitLengthOfMSW) - 1)
	z = z.make(len(limit))

	for {
		for i := range z {
			switch _W {
			case 32:
				z[i] = Word(rand.Uint32())
			case 64:
				z[i] = Word(rand.Uint32()) | Word(rand.Uint32())<<32
			}
		}

		z[len(limit)-1] &= mask

		if z.cmp(limit) < 0 {
			break
		}
	}

	return z.norm()
}
Exemplo n.º 3
0
func randomInt(rand *rand.Rand) *big.Int {
	return new(big.Int).SetInt64(int64(int32(rand.Uint32())))
}