imported from https://bitbucket.org/ustraca/crypto

utils_test.go

@@ -0,0 +1,55 @@
+package paillier
+
+import (
+	"crypto/rand"
+	"math/big"
+	"testing"
+)
+
+func b(i int) *big.Int {
+	return big.NewInt(int64(i))
+}
+
+func n(i *big.Int) int {
+	return int(i.Int64())
+}
+
+func areRelativelyPrime(a, b int) bool {
+	if b == 0 {
+		return a == 1
+	}
+	return areRelativelyPrime(b, a%b)
+}
+
+func TestConstants(t *testing.T) {
+	if n(ZERO) != 0 {
+		t.Fail()
+	}
+
+	if n(ONE) != 1 {
+		t.Fail()
+	}
+
+	if n(TWO) != 2 {
+		t.Fail()
+	}
+
+	if n(FOUR) != 4 {
+		t.Fail()
+	}
+}
+
+func TestGetRandomNumberInMultiplicativeGroup(t *testing.T) {
+	k := b(2 * 3 * 5 * 7)
+	for i := 0; i < 100; i++ {
+		m, err := GetRandomNumberInMultiplicativeGroup(k, rand.Reader)
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		if !areRelativelyPrime(n(k), n(m)) {
+			t.Fail()
+		}
+	}
+
+}