Improvements to the test random library. (#1029)

Signed-off-by: Cody Littley <[email protected]>

common/testutils/random/test_random.go

@@ -1,19 +1,38 @@
 package random
 
 import (
+	"crypto/ecdsa"
+	crand "crypto/rand"
 	"fmt"
+	"github.com/Layr-Labs/eigenda/core"
+	"github.com/consensys/gnark-crypto/ecc/bn254/fr"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/stretchr/testify/require"
+	"io"
+	"math/big"
 	"math/rand"
+	"testing"
 	"time"
 )
 
+// charset is the set of characters that can be used to generate random strings
+const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+
 // TestRandom provides all the functionality of math/rand.Rand, plus additional randomness functionality useful for testing
 type TestRandom struct {
+	// The source of randomness
 	*rand.Rand
+
+	// The testing object
+	t *testing.T
+
+	// The seed used to initialize the random number generator
+	seed int64
 }
 
 // NewTestRandom creates a new instance of TestRandom
 // This method may either be seeded, or not seeded. If no seed is provided, then current unix nano time is used.
-func NewTestRandom(fixedSeed ...int64) *TestRandom {
+func NewTestRandom(t *testing.T, fixedSeed ...int64) *TestRandom {
 	var seed int64
 	if len(fixedSeed) == 0 {
 		seed = time.Now().UnixNano()
@@ -25,12 +44,20 @@ func NewTestRandom(fixedSeed ...int64) *TestRandom {
 
 	fmt.Printf("Random seed: %d\n", seed)
 	return &TestRandom{
-		rand.New(rand.NewSource(seed)),
+		Rand: rand.New(rand.NewSource(seed)),
+		t:    t,
+		seed: seed,
 	}
 }
 
-// RandomBytes generates a random byte slice of a given length.
-func (r *TestRandom) RandomBytes(length int) []byte {
+// Reset resets the random number generator to the state it was in when it was first created.
+// This method is not thread safe with respect to other methods in this struct.
+func (r *TestRandom) Reset() {
+	r.Seed(r.seed)
+}
+
+// Bytes generates a random byte slice of a given length.
+func (r *TestRandom) Bytes(length int) []byte {
 	bytes := make([]byte, length)
 	_, err := r.Read(bytes)
 	if err != nil {
@@ -39,17 +66,59 @@ func (r *TestRandom) RandomBytes(length int) []byte {
 	return bytes
 }
 
-// RandomTime generates a random time.
-func (r *TestRandom) RandomTime() time.Time {
+// Time generates a random time.
+func (r *TestRandom) Time() time.Time {
 	return time.Unix(r.Int63(), r.Int63())
 }
 
-// RandomString generates a random string out of printable ASCII characters.
-func (r *TestRandom) RandomString(length int) string {
-	const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+// String generates a random string out of printable ASCII characters.
+func (r *TestRandom) String(length int) string {
 	b := make([]byte, length)
 	for i := range b {
 		b[i] = charset[r.Intn(len(charset))]
 	}
 	return string(b)
 }
+
+var _ io.Reader = &randIOReader{}
+
+// randIOReader is an io.Reader that reads from a random number generator.
+type randIOReader struct {
+	rand *TestRandom
+}
+
+// Read reads random bytes into the provided buffer, returning the number of bytes read.
+func (i *randIOReader) Read(p []byte) (n int, err error) {
+	return i.rand.Read(p)
+}
+
+// IOReader creates an io.Reader that reads from a random number generator.
+func (r *TestRandom) IOReader() io.Reader {
+	return &randIOReader{r}
+}
+
+// ECDSA generates a random ECDSA key. Note that the returned keys are not deterministic due to limitations
+// **intentionally** imposed by the Go standard libraries. (╯°□°)╯︵ ┻━┻
+//
+// NOT CRYPTOGRAPHICALLY SECURE!!! FOR TESTING PURPOSES ONLY. DO NOT USE THESE KEYS FOR SECURITY PURPOSES.
+func (r *TestRandom) ECDSA() (*ecdsa.PublicKey, *ecdsa.PrivateKey) {
+	key, err := ecdsa.GenerateKey(crypto.S256(), crand.Reader)
+	require.NoError(r.t, err)
+	return &key.PublicKey, key
+}
+
+// BLS generates a random BLS key pair.
+//
+// NOT CRYPTOGRAPHICALLY SECURE!!! FOR TESTING PURPOSES ONLY. DO NOT USE THESE KEYS FOR SECURITY PURPOSES.
+func (r *TestRandom) BLS() *core.KeyPair {
+	//Max random value is order of the curve
+	maxValue := new(big.Int)
+	maxValue.SetString(fr.Modulus().String(), 10)
+
+	//Generate cryptographically strong pseudo-random between 0 - max
+	n, err := crand.Int(r.IOReader(), maxValue)
+	require.NoError(r.t, err)
+
+	sk := new(core.PrivateKey).SetBigInt(n)
+	return core.MakeKeyPair(sk)
+}

common/testutils/random/test_random_test.go

@@ -1,27 +1,104 @@
 package random
 
 import (
+	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"math/rand"
 	"testing"
 )
 
 // Tests that random seeding produces random results, and that consistent seeding produces consistent results
 func TestSetup(t *testing.T) {
-	testRandom1 := NewTestRandom()
+	testRandom1 := NewTestRandom(t)
 	x := testRandom1.Int()
 
-	testRandom2 := NewTestRandom()
+	testRandom2 := NewTestRandom(t)
 	y := testRandom2.Int()
 
-	assert.NotEqual(t, x, y)
+	require.NotEqual(t, x, y)
 
 	seed := rand.Int63()
-	testRandom3 := NewTestRandom(seed)
+	testRandom3 := NewTestRandom(t, seed)
 	a := testRandom3.Int()
 
-	testRandom4 := NewTestRandom(seed)
+	testRandom4 := NewTestRandom(t, seed)
 	b := testRandom4.Int()
 
-	assert.Equal(t, a, b)
+	require.Equal(t, a, b)
+}
+
+func TestReset(t *testing.T) {
+	random := NewTestRandom(t)
+
+	a := random.Uint64()
+	b := random.Uint64()
+	c := random.Uint64()
+	d := random.Uint64()
+
+	random.Reset()
+
+	require.Equal(t, a, random.Uint64())
+	require.Equal(t, b, random.Uint64())
+	require.Equal(t, c, random.Uint64())
+	require.Equal(t, d, random.Uint64())
+}
+
+func TestECDSAKeyGeneration(t *testing.T) {
+	random := NewTestRandom(t)
+
+	// We should not get the same key pair twice in a row
+	public1, private1 := random.ECDSA()
+	public2, private2 := random.ECDSA()
+
+	assert.NotEqual(t, &public1, &public2)
+	assert.NotEqual(t, &private1, &private2)
+
+	// Getting keys should result in deterministic generator state.
+	generatorState := random.Uint64()
+	random.Reset()
+	random.ECDSA()
+	random.ECDSA()
+	require.Equal(t, generatorState, random.Uint64())
+
+	// Keypair should be valid.
+	data := random.Bytes(32)
+
+	signature, err := crypto.Sign(data, private1)
+	require.NoError(t, err)
+
+	signingPublicKey, err := crypto.SigToPub(data, signature)
+	require.NoError(t, err)
+	require.Equal(t, &public1, &signingPublicKey)
+}
+
+func TestBLSKeyGeneration(t *testing.T) {
+	random := NewTestRandom(t)
+
+	// We should not get the same key pair twice in a row
+	keypair1 := random.BLS()
+	keypair2 := random.BLS()
+
+	require.False(t, keypair1.PrivKey.Equal(keypair2.PrivKey))
+	require.False(t, keypair1.PubKey.Equal(keypair2.PubKey.G1Affine))
+
+	// Getting keys should result in deterministic generator state.
+	generatorState := random.Uint64()
+	random.Reset()
+	random.BLS()
+	random.BLS()
+	require.Equal(t, generatorState, random.Uint64())
+
+	// Keys should be deterministic.
+	random.Reset()
+	keypair3 := random.BLS()
+	require.True(t, keypair1.PrivKey.Equal(keypair3.PrivKey))
+	require.True(t, keypair1.PubKey.Equal(keypair3.PubKey.G1Affine))
+
+	// Keypair should be valid.
+	data := random.Bytes(32)
+	signature := keypair1.SignMessage(([32]byte)(data))
+
+	isValid := signature.Verify(keypair1.GetPubKeyG2(), ([32]byte)(data))
+	require.True(t, isValid)
 }