Create sign/ecdsa package - Second step of crypto refactoring

bls.go

@@ -271,7 +271,11 @@ func (a *blsBLS12381Algo) GeneratePrivateKey(ikm []byte) (sign.PrivateKey, error
 	// HKDF secret = IKM || I2OSP(0, 1)
 	secret := make([]byte, len(ikm)+1)
 	copy(secret, ikm)
-	defer overwrite(secret) // overwrite secret
+	defer func() {
+		for i := range secret {
+			secret[i] = 0
+		}
+	}()
 	// HKDF info = key_info || I2OSP(L, 2)
 	keyInfo := []byte{} // use empty key diversifier. TODO: update header to accept input identifier
 	info := string(append(keyInfo, byte(okmLength>>8), byte(okmLength)))
@@ -283,7 +287,11 @@ func (a *blsBLS12381Algo) GeneratePrivateKey(ikm []byte) (sign.PrivateKey, error
 		if err != nil {
 			return nil, fmt.Errorf("HKDF computation failed: %w", err)
 		}
-		defer overwrite(okm) // overwrite okm
+		defer func() {
+			for i := range okm {
+				okm[i] = 0
+			}
+		}()
 
 		// map the bytes to a private key using modular reduction
 		// SK = OS2IP(OKM) mod r

bls12381_utils_test.go

@@ -29,6 +29,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"github.com/onflow/crypto/sign/testutils"
 )
 
 // Sanity check of G1 and G2 scalar multiplication
@@ -190,7 +192,7 @@ func BenchmarkMapToG1(b *testing.B) {
 
 // test subgroup membership check in G1 and G2
 func TestSubgroupCheck(t *testing.T) {
-	prg := getPRG(t)
+	prg := testutils.GetPRG(t)
 	seed := make([]byte, 192)
 	_, err := prg.Read(seed)
 	require.NoError(t, err)
@@ -242,7 +244,7 @@ func BenchmarkSubgroupCheck(b *testing.B) {
 // specific test of G1 points Encode and decode (BLS signature since the library is set for min_sig).
 // G2 points read and write are implicitly tested by public keys Encode/Decode.
 func TestReadWriteG1(t *testing.T) {
-	prg := getPRG(t)
+	prg := testutils.GetPRG(t)
 	seed := make([]byte, frBytesLen)
 	bytes := make([]byte, g1BytesLen)
 	// generate a random G1 point, encode it, decode it,

bls_test.go

@@ -33,15 +33,16 @@ import (
 
 	"github.com/onflow/crypto/hash"
 	"github.com/onflow/crypto/sign"
+	"github.com/onflow/crypto/sign/testutils"
 )
 
 // TestBLSMainMethods is a sanity check of main signature scheme methods (keyGen, sign, verify)
 func TestBLSMainMethods(t *testing.T) {
 	// test the key generation seed lengths
-	testKeyGenSeed(t, sign.BLSBLS12381, KeyGenSeedMinLen, KeyGenSeedMaxLen)
+	testutils.TestKeyGenSeed(t, sign.BLSBLS12381, KeyGenSeedMinLen, KeyGenSeedMaxLen)
 	// test the consistency with different inputs
 	hasher := NewExpandMsgXOFKMAC128("test tag")
-	testGenSignVerify(t, sign.BLSBLS12381, hasher)
+	testutils.TestGenSignVerify(t, sign.BLSBLS12381, hasher)
 
 	// specific signature test for BLS:
 	// Test a signature with a point encoded with a coordinate x not reduced mod p.
@@ -105,13 +106,13 @@ func TestBLSMainMethods(t *testing.T) {
 // Signing bench
 func BenchmarkBLSSingleSign(b *testing.B) {
 	halg := NewExpandMsgXOFKMAC128("bench tag")
-	benchSign(b, sign.BLSBLS12381, halg)
+	testutils.BenchSign(b, sign.BLSBLS12381, halg)
 }
 
 // Verifying bench
 func BenchmarkBLSSingleVerify(b *testing.B) {
 	halg := NewExpandMsgXOFKMAC128("bench tag")
-	benchVerify(b, sign.BLSBLS12381, halg)
+	testutils.BenchVerify(b, sign.BLSBLS12381, halg)
 }
 
 // utility function to generate a random BLS private key
@@ -138,7 +139,7 @@ func invalidSK(t *testing.T) sign.PrivateKey {
 
 // BLS tests
 func TestBLSBLS12381Hasher(t *testing.T) {
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	// generate a key pair
 	sk := randomSK(t, rand)
 	sig := make([]byte, SignatureLenBLSBLS12381)
@@ -197,7 +198,7 @@ func TestBLSBLS12381Hasher(t *testing.T) {
 // TestBLSEncodeDecode tests encoding and decoding of BLS keys
 func TestBLSEncodeDecode(t *testing.T) {
 	// generic tests
-	testEncodeDecode(t, sign.BLSBLS12381)
+	testutils.TestEncodeDecode(t, sign.BLSBLS12381)
 
 	// specific tests for BLS
 
@@ -276,23 +277,23 @@ func TestBLSEncodeDecode(t *testing.T) {
 
 // TestBLSEquals tests equal for BLS keys
 func TestBLSEquals(t *testing.T) {
-	testEquals(t, sign.BLSBLS12381, sign.ECDSAP256)
+	testutils.TestEquals(t, sign.BLSBLS12381, sign.ECDSAP256)
 }
 
 // TestBLSUtils tests some utility functions
 func TestBLSUtils(t *testing.T) {
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	// generate a key pair
 	sk := randomSK(t, rand)
 	// test Algorithm()
-	testKeysAlgorithm(t, sk, sign.BLSBLS12381)
+	testutils.TestKeysAlgorithm(t, sk, sign.BLSBLS12381)
 	// test Size()
-	testKeySize(t, sk, PrKeyLenBLSBLS12381, PubKeyLenBLSBLS12381)
+	testutils.TestKeySize(t, sk, PrKeyLenBLSBLS12381, PubKeyLenBLSBLS12381)
 }
 
 // BLS Proof of Possession test
 func TestBLSPOP(t *testing.T) {
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	seed := make([]byte, KeyGenSeedMinLen)
 	input := make([]byte, 100)
 
@@ -347,7 +348,7 @@ func TestBLSPOP(t *testing.T) {
 // Verify the aggregated signature using the multi-signature verification with
 // one message.
 func TestBLSAggregateSignatures(t *testing.T) {
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	// random message
 	input := make([]byte, 100)
 	_, err := rand.Read(input)
@@ -472,7 +473,7 @@ func TestBLSAggregateSignatures(t *testing.T) {
 // the public key of the aggregated private key is equal to the aggregated
 // public key
 func TestBLSAggregatePublicKeys(t *testing.T) {
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	// number of keys to aggregate
 	pkNum := rand.Intn(100) + 1
 	pks := make([]sign.PublicKey, 0, pkNum)
@@ -595,7 +596,7 @@ func TestBLSAggregatePublicKeys(t *testing.T) {
 // BLS multi-signature
 // public keys removal sanity check
 func TestBLSRemovePubKeys(t *testing.T) {
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	// number of keys to aggregate
 	pkNum := rand.Intn(100) + 1
 	pks := make([]sign.PublicKey, 0, pkNum)
@@ -683,7 +684,7 @@ func TestBLSRemovePubKeys(t *testing.T) {
 // batch verification technique and compares the result to verifying each signature
 // separately.
 func TestBLSBatchVerify(t *testing.T) {
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	// random message
 	input := make([]byte, 100)
 	_, err := rand.Read(input)
@@ -920,7 +921,7 @@ func BenchmarkBatchVerify(b *testing.B) {
 // and verify the aggregated signature using the multi-signature verification with
 // many messages.
 func TestBLSAggregateSignaturesManyMessages(t *testing.T) {
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	// number of signatures to aggregate
 	sigsNum := rand.Intn(40) + 1
 	sigs := make([]sign.Signature, 0, sigsNum)
@@ -1035,7 +1036,7 @@ func TestBLSAggregateSignaturesManyMessages(t *testing.T) {
 
 	t.Run("variable number of distinct keys and messages", func(t *testing.T) {
 		// use a specific PRG for easier reproduction
-		prg := getPRG(t)
+		prg := testutils.GetPRG(t)
 		// number of signatures to aggregate
 		N := 100
 		sigs := make([]sign.Signature, 0, N)
@@ -1203,7 +1204,7 @@ func BenchmarkAggregate(b *testing.B) {
 }
 
 func TestBLSIdentity(t *testing.T) {
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 
 	var identitySig []byte
 	msg := []byte("random_message")

bls_thresholdsign_test.go

@@ -33,6 +33,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/onflow/crypto/sign"
+	"github.com/onflow/crypto/sign/testutils"
 )
 
 func TestBLSThresholdSignature(t *testing.T) {
@@ -50,7 +51,7 @@ var thresholdSignatureMessage = []byte("random message")
 
 // centralized test of the stateful threshold signature using the threshold key generation.
 func testCentralizedStatefulAPI(t *testing.T) {
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	seed := make([]byte, KeyGenSeedMinLen)
 	_, err := rand.Read(seed)
 	n := 10
@@ -337,7 +338,7 @@ func testDistributedStatefulAPI_FeldmanVSS(t *testing.T) {
 	log.SetLevel(log.ErrorLevel)
 	log.Info("DKG starts")
 	gt = t
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	// number of participants to test
 	n := 5
 	lead := rand.Intn(n) // random
@@ -397,7 +398,7 @@ func testDistributedStatefulAPI_JointFeldman(t *testing.T) {
 	log.SetLevel(log.ErrorLevel)
 	log.Info("DKG starts")
 	gt = t
-	rand := getPRG(t)
+	rand := testutils.GetPRG(t)
 	// number of participants to test
 	n := 5
 	for threshold := MinimumThreshold; threshold < n; threshold++ {
@@ -569,7 +570,7 @@ func testCentralizedStatelessAPI(t *testing.T) {
 	n := 10
 	for threshold := MinimumThreshold; threshold < n; threshold++ {
 		// generate threshold keys
-		rand := getPRG(t)
+		rand := testutils.GetPRG(t)
 		_, err := rand.Read(seed)
 		require.NoError(t, err)
 		skShares, pkShares, pkGroup, err := BLSThresholdKeyGen(n, threshold, seed)

common.go

@@ -19,7 +19,6 @@
 package crypto
 
 import (
-	"crypto/rand"
 	"errors"
 	"fmt"
 )
@@ -38,18 +37,6 @@ const (
 	KeyGenSeedMaxLen = 256
 )
 
-// TODO: update this code to make sure
-// the function isn't removed by the compiler
-// https://github.com/golang/go/issues/21865
-func overwrite(data []byte) {
-	_, err := rand.Read(data) // checking err is enough
-	if err != nil {
-		// zero the buffer if randomizing failed
-		for i := 0; i < len(data); i++ {
-			data[i] = 0
-		}
-	}
-}
 
 // invalidInputsError is an error returned when a crypto API receives invalid inputs.
 // It allows a function caller differentiate unexpected program errors from errors caused by