refactor(share/sha-256): Consolidate SHA-256 Hash Function Usage

blob/service_test.go

@@ -3,7 +3,6 @@ package blob
 import (
 	"bytes"
 	"context"
-	"crypto/sha256"
 	"encoding/json"
 	"fmt"
 	"sort"
@@ -203,7 +202,7 @@ func TestBlobService_Get(t *testing.T) {
 						for _, p := range *proof {
 							from := to
 							to = p.End() - p.Start() + from
-							eq := p.VerifyInclusion(sha256.New(), namespace.ToNMT(), rawShares[from:to], row)
+							eq := p.VerifyInclusion(share.NewSHA256Hasher(), namespace.ToNMT(), rawShares[from:to], row)
 							if eq == true {
 								return
 							}

share/eds/byzantine/bad_encoding_test.go

@@ -2,7 +2,6 @@ package byzantine
 
 import (
 	"context"
-	"crypto/sha256"
 	"hash"
 	"testing"
 	"time"
@@ -253,7 +252,7 @@ func newNamespacedBlockService() *namespacedBlockService {
 	sha256NamespaceFlagged := uint64(0x7701)
 	// register the nmt hasher to validate the order of namespaces
 	mhcore.Register(sha256NamespaceFlagged, func() hash.Hash {
-		nh := nmt.NewNmtHasher(sha256.New(), share.NamespaceSize, true)
+		nh := nmt.NewNmtHasher(share.NewSHA256Hasher(), share.NamespaceSize, true)
 		nh.Reset()
 		return nh
 	})
@@ -266,7 +265,7 @@ func newNamespacedBlockService() *namespacedBlockService {
 		Codec:   sha256NamespaceFlagged,
 		MhType:  sha256NamespaceFlagged,
 		// equals to NmtHasher.Size()
-		MhLength: sha256.New().Size() + 2*share.NamespaceSize,
+		MhLength: share.NewSHA256Hasher().Size() + 2*share.NamespaceSize,
 	}
 	return bs
 }

share/eds/byzantine/share_proof.go

@@ -2,7 +2,6 @@ package byzantine
 
 import (
 	"context"
-	"crypto/sha256"
 
 	"github.com/ipfs/boxo/blockservice"
 	"github.com/ipfs/go-cid"
@@ -45,7 +44,7 @@ func NewShareWithProof(index int, share share.Share, pathToLeaf []cid.Cid) *Shar
 // Validate validates inclusion of the share under the given root CID.
 func (s *ShareWithProof) Validate(root cid.Cid) bool {
 	return s.Proof.VerifyInclusion(
-		sha256.New(), // TODO(@Wondertan): This should be defined somewhere globally
+		share.NewSHA256Hasher(),
 		share.GetNamespace(s.Share).ToNMT(),
 		[][]byte{share.GetData(s.Share)},
 		ipld.NamespacedSha256FromCID(root),

share/eds/eds.go

@@ -3,7 +3,6 @@ package eds
 import (
 	"bytes"
 	"context"
-	"crypto/sha256"
 	"errors"
 	"fmt"
 	"io"
@@ -68,7 +67,7 @@ func writeHeader(eds *rsmt2d.ExtendedDataSquare, w io.Writer) error {
 
 // writeQuadrants reorders the shares to quadrant order and writes them to the CARv1 file.
 func writeQuadrants(eds *rsmt2d.ExtendedDataSquare, w io.Writer) error {
-	hasher := nmt.NewNmtHasher(sha256.New(), share.NamespaceSize, ipld.NMTIgnoreMaxNamespace)
+	hasher := nmt.NewNmtHasher(share.NewSHA256Hasher(), share.NamespaceSize, ipld.NMTIgnoreMaxNamespace)
 	shares := quadrantOrder(eds)
 	for _, share := range shares {
 		leaf, err := hasher.HashLeaf(share)

share/getter.go

@@ -2,7 +2,6 @@ package share
 
 import (
 	"context"
-	"crypto/sha256"
 	"errors"
 	"fmt"
 
@@ -90,7 +89,7 @@ func (row *NamespacedRow) verify(rowRoot []byte, namespace Namespace) bool {
 
 	// verify namespace
 	return row.Proof.VerifyNamespace(
-		sha256.New(),
+		NewSHA256Hasher(),
 		namespace.ToNMT(),
 		leaves,
 		rowRoot,

share/hashutils.go

@@ -0,0 +1,11 @@
+package share
+
+import (
+	"crypto/sha256"
+	"hash"
+)
+
+// NewSHA256Hasher returns a new instance of a SHA-256 hasher.
+func NewSHA256Hasher() hash.Hash {
+	return sha256.New()
+}

share/ipld/get_shares_test.go

@@ -3,7 +3,6 @@ package ipld
 import (
 	"bytes"
 	"context"
-	"crypto/sha256"
 	"errors"
 	mrand "math/rand"
 	"sort"
@@ -384,15 +383,15 @@ func TestGetSharesWithProofsByNamespace(t *testing.T) {
 
 					// verify namespace
 					verified := proof.VerifyNamespace(
-						sha256.New(),
+						share.NewSHA256Hasher(),
 						namespace.ToNMT(),
 						leaves,
 						NamespacedSha256FromCID(rcid))
 					require.True(t, verified)
 
 					// verify inclusion
 					verified = proof.VerifyInclusion(
-						sha256.New(),
+						share.NewSHA256Hasher(),
 						namespace.ToNMT(),
 						rowShares,
 						NamespacedSha256FromCID(rcid))
@@ -483,7 +482,7 @@ func assertNoRowContainsNID(
 
 		// if no error returned, check absence proof
 		foundAbsenceRows++
-		verified := data.Proof().VerifyNamespace(sha256.New(), namespace.ToNMT(), nil, rowRoot)
+		verified := data.Proof().VerifyNamespace(share.NewSHA256Hasher(), namespace.ToNMT(), nil, rowRoot)
 		require.True(t, verified)
 	}
 

share/ipld/nmt.go

@@ -61,7 +61,7 @@ const (
 func init() {
 	// required for Bitswap to hash and verify inbound data correctly
 	mhcore.Register(sha256NamespaceFlagged, func() hash.Hash {
-		nh := nmt.NewNmtHasher(sha256.New(), share.NamespaceSize, true)
+		nh := nmt.NewNmtHasher(share.NewSHA256Hasher(), share.NamespaceSize, true)
 		nh.Reset()
 		return nh
 	})