Fix cyclical dependency (#15248)

* fix cyclical dependency

* fix bazel file

* fix comments

* fix: Break cyclical dependency by importing GetRandBlob directly from crypto/random

* add changelog

beacon-chain/blockchain/kzg/BUILD.bazel

@@ -29,9 +29,8 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//consensus-types/blocks:go_default_library",
+        "//crypto/random:go_default_library",
         "//testing/require:go_default_library",
-        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
         "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
-        "@com_github_sirupsen_logrus//:go_default_library",
     ],
 )

beacon-chain/blockchain/kzg/validation_test.go

@@ -1,16 +1,12 @@
 package kzg
 
 import (
-	"bytes"
-	"crypto/sha256"
-	"encoding/binary"
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/crypto/random"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
-	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
-	"github.com/sirupsen/logrus"
 )
 
 func GenerateCommitmentAndProof(blob GoKZG.Blob) (GoKZG.KZGCommitment, GoKZG.KZGProof, error) {
@@ -41,7 +37,7 @@ func TestBytesToAny(t *testing.T) {
 }
 
 func TestGenerateCommitmentAndProof(t *testing.T) {
-	blob := getRandBlob(123)
+	blob := random.GetRandBlob(123)
 	commitment, proof, err := GenerateCommitmentAndProof(blob)
 	require.NoError(t, err)
 	expectedCommitment := GoKZG.KZGCommitment{180, 218, 156, 194, 59, 20, 10, 189, 186, 254, 132, 93, 7, 127, 104, 172, 238, 240, 237, 70, 83, 89, 1, 152, 99, 0, 165, 65, 143, 62, 20, 215, 230, 14, 205, 95, 28, 245, 54, 25, 160, 16, 178, 31, 232, 207, 38, 85}
@@ -49,36 +45,3 @@ func TestGenerateCommitmentAndProof(t *testing.T) {
 	require.Equal(t, expectedCommitment, commitment)
 	require.Equal(t, expectedProof, proof)
 }
-
-func deterministicRandomness(seed int64) [32]byte {
-	// Converts an int64 to a byte slice
-	buf := new(bytes.Buffer)
-	err := binary.Write(buf, binary.BigEndian, seed)
-	if err != nil {
-		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
-		return [32]byte{}
-	}
-	bytes := buf.Bytes()
-
-	return sha256.Sum256(bytes)
-}
-
-// Returns a serialized random field element in big-endian
-func getRandFieldElement(seed int64) [32]byte {
-	bytes := deterministicRandomness(seed)
-	var r fr.Element
-	r.SetBytes(bytes[:])
-
-	return GoKZG.SerializeScalar(r)
-}
-
-// Returns a random blob using the passed seed as entropy
-func getRandBlob(seed int64) GoKZG.Blob {
-	var blob GoKZG.Blob
-	bytesPerBlob := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
-	for i := 0; i < bytesPerBlob; i += GoKZG.SerializedScalarSize {
-		fieldElementBytes := getRandFieldElement(seed + int64(i))
-		copy(blob[i:i+GoKZG.SerializedScalarSize], fieldElementBytes[:])
-	}
-	return blob
-}

changelog/gerceboss_testing-util-reuse.md

@@ -0,0 +1,3 @@
+### Fixed
+
+- Fix cyclical dependencies issue when using testing/util package

crypto/random/BUILD.bazel

@@ -0,0 +1,24 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["random.go"],
+    importpath = "github.com/OffchainLabs/prysm/v6/crypto/random",
+    visibility = ["//visibility:public"],
+    deps = [
+        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
+        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["random_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
+        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
+    ],
+)

crypto/random/random.go

@@ -0,0 +1,45 @@
+package random
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
+
+	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
+	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	"github.com/sirupsen/logrus"
+)
+
+// DeterministicRandomness creates a deterministic 32 byte array from a seed
+func DeterministicRandomness(seed int64) [32]byte {
+	// Converts an int64 to a byte slice
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.BigEndian, seed)
+	if err != nil {
+		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
+		return [32]byte{}
+	}
+	bytes := buf.Bytes()
+
+	return sha256.Sum256(bytes)
+}
+
+// GetRandFieldElement returns a serialized random field element in big-endian
+func GetRandFieldElement(seed int64) [32]byte {
+	bytes := DeterministicRandomness(seed)
+	var r fr.Element
+	r.SetBytes(bytes[:])
+
+	return GoKZG.SerializeScalar(r)
+}
+
+// GetRandBlob returns a random blob using the passed seed as entropy
+func GetRandBlob(seed int64) GoKZG.Blob {
+	var blob GoKZG.Blob
+	bytesPerBlob := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
+	for i := 0; i < bytesPerBlob; i += GoKZG.SerializedScalarSize {
+		fieldElementBytes := GetRandFieldElement(seed + int64(i))
+		copy(blob[i:i+GoKZG.SerializedScalarSize], fieldElementBytes[:])
+	}
+	return blob
+}

crypto/random/random_test.go

@@ -0,0 +1,61 @@
+package random
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/testing/assert"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	GoKZG "github.com/crate-crypto/go-kzg-4844"
+)
+
+func TestDeterministicRandomness(t *testing.T) {
+	seed := int64(123)
+	r1 := DeterministicRandomness(seed)
+	r2 := DeterministicRandomness(seed)
+	assert.DeepEqual(t, r1, r2, "Same seed should produce same output")
+
+	// Test different seeds produce different outputs
+	r3 := DeterministicRandomness(seed + 1)
+	assert.NotEqual(t, r1, r3, "Different seeds should produce different outputs")
+}
+
+func TestGetRandFieldElement(t *testing.T) {
+	seed := int64(123)
+	r1 := GetRandFieldElement(seed)
+	r2 := GetRandFieldElement(seed)
+	assert.DeepEqual(t, r1, r2, "Same seed should produce same output")
+
+	// Test different seeds produce different outputs
+	r3 := GetRandFieldElement(seed + 1)
+	assert.NotEqual(t, r1, r3, "Different seeds should produce different outputs")
+}
+
+func TestGetRandBlob(t *testing.T) {
+	seed := int64(123)
+	r1 := GetRandBlob(seed)
+	r2 := GetRandBlob(seed)
+	assert.DeepEqual(t, r1, r2, "Same seed should produce same blob")
+
+	expectedSize := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
+	assert.Equal(t, expectedSize, len(r1), "Blob should have correct size")
+
+	r3 := GetRandBlob(seed + 1)
+	assert.NotEqual(t, r1, r3, "Different seeds should produce different blobs")
+}
+
+func TestGetRandBlobElements(t *testing.T) {
+	seed := int64(123)
+	blob := GetRandBlob(seed)
+
+	// Check that each field element in the blob matches what we'd get from GetRandFieldElement
+	for i := 0; i < GoKZG.ScalarsPerBlob; i++ {
+		start := i * GoKZG.SerializedScalarSize
+		end := start + GoKZG.SerializedScalarSize
+
+		blobElement := [32]byte{}
+		copy(blobElement[:], blob[start:end])
+
+		expectedElement := GetRandFieldElement(seed + int64(i*GoKZG.SerializedScalarSize))
+		require.DeepEqual(t, expectedElement, blobElement, "Field element in blob doesn't match expected value")
+	}
+}

testing/util/BUILD.bazel

@@ -54,6 +54,7 @@ go_library(
         "//crypto/bls:go_default_library",
         "//crypto/hash:go_default_library",
         "//crypto/rand:go_default_library",
+        "//crypto/random:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//encoding/ssz:go_default_library",
         "//network/forks:go_default_library",
@@ -65,7 +66,6 @@ go_library(
         "//testing/assertions:go_default_library",
         "//testing/require:go_default_library",
         "//time/slots:go_default_library",
-        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
         "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",

testing/util/deneb.go

@@ -1,8 +1,6 @@
 package util
 
 import (
-	"bytes"
-	"crypto/sha256"
 	"encoding/binary"
 	"math/big"
 	"testing"
@@ -13,17 +11,16 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/crypto/bls"
+	"github.com/OffchainLabs/prysm/v6/crypto/random"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/network/forks"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
-	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
 	"github.com/ethereum/go-ethereum/common"
 	gethTypes "github.com/ethereum/go-ethereum/core/types"
-	"github.com/sirupsen/logrus"
 )
 
 type DenebBlockGeneratorOption func(*denebBlockGenerator)
@@ -203,35 +200,16 @@ func ExtendBlocksPlusBlobs(t *testing.T, blks []blocks.ROBlock, size int) ([]blo
 	return blks, blobs
 }
 
-func deterministicRandomness(seed int64) [32]byte {
-	// Converts an int64 to a byte slice
-	buf := new(bytes.Buffer)
-	err := binary.Write(buf, binary.BigEndian, seed)
-	if err != nil {
-		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
-		return [32]byte{}
-	}
-	bytes := buf.Bytes()
-
-	return sha256.Sum256(bytes)
+func DeterministicRandomness(seed int64) [32]byte {
+	return random.DeterministicRandomness(seed)
 }
 
 // Returns a serialized random field element in big-endian
 func GetRandFieldElement(seed int64) [32]byte {
-	bytes := deterministicRandomness(seed)
-	var r fr.Element
-	r.SetBytes(bytes[:])
-
-	return GoKZG.SerializeScalar(r)
+	return random.GetRandFieldElement(seed)
 }
 
 // Returns a random blob using the passed seed as entropy
 func GetRandBlob(seed int64) GoKZG.Blob {
-	var blob GoKZG.Blob
-	bytesPerBlob := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
-	for i := 0; i < bytesPerBlob; i += GoKZG.SerializedScalarSize {
-		fieldElementBytes := GetRandFieldElement(seed + int64(i))
-		copy(blob[i:i+GoKZG.SerializedScalarSize], fieldElementBytes[:])
-	}
-	return blob
+	return random.GetRandBlob(seed)
 }