1 // Copyright 2013 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package rand_test 6 7 import ( 8 "crypto/rand" 9 "math/big" 10 mathrand "math/rand" 11 "testing" 12 "time" 13 ) 14 15 // https://golang.org/issue/6849. 16 func TestPrimeSmall(t *testing.T) { 17 for n := 2; n < 10; n++ { 18 p, err := rand.Prime(rand.Reader, n) 19 if err != nil { 20 t.Fatalf("Can't generate %d-bit prime: %v", n, err) 21 } 22 if p.BitLen() != n { 23 t.Fatalf("%v is not %d-bit", p, n) 24 } 25 if !p.ProbablyPrime(32) { 26 t.Fatalf("%v is not prime", p) 27 } 28 } 29 } 30 31 // Test that passing bits < 2 causes Prime to return nil, error 32 func TestPrimeBitsLt2(t *testing.T) { 33 if p, err := rand.Prime(rand.Reader, 1); p != nil || err == nil { 34 t.Errorf("Prime should return nil, error when called with bits < 2") 35 } 36 } 37 38 func TestInt(t *testing.T) { 39 // start at 128 so the case of (max.BitLen() % 8) == 0 is covered 40 for n := 128; n < 140; n++ { 41 b := new(big.Int).SetInt64(int64(n)) 42 if i, err := rand.Int(rand.Reader, b); err != nil { 43 t.Fatalf("Can't generate random value: %v, %v", i, err) 44 } 45 } 46 } 47 48 func testIntPanics(t *testing.T, b *big.Int) { 49 defer func() { 50 if err := recover(); err == nil { 51 t.Errorf("Int should panic when called with max <= 0: %v", b) 52 } 53 }() 54 rand.Int(rand.Reader, b) 55 } 56 57 // Test that passing a new big.Int as max causes Int to panic 58 func TestIntEmptyMaxPanics(t *testing.T) { 59 b := new(big.Int) 60 testIntPanics(t, b) 61 } 62 63 // Test that passing a negative value as max causes Int to panic 64 func TestIntNegativeMaxPanics(t *testing.T) { 65 b := new(big.Int).SetInt64(int64(-1)) 66 testIntPanics(t, b) 67 } 68 69 func BenchmarkPrime(b *testing.B) { 70 r := mathrand.New(mathrand.NewSource(time.Now().UnixNano())) 71 for i := 0; i < b.N; i++ { 72 rand.Prime(r, 1024) 73 } 74 } 75
