From 49147e170a36738075f731c0cc03b1dc2a4419b0 Mon Sep 17 00:00:00 2001
From: h5law <53987565+h5law@users.noreply.github.com>
Date: Mon, 1 Jan 2024 00:40:49 +0000
Subject: [PATCH] chore: replace BigEndian encoding with LittleEndian in the
 SMST

---
 benchmarks/bench_utils_test.go | 8 ++++----
 benchmarks/proof_sizes_test.go | 8 ++++----
 docs/MerkleSumTrie.md          | 2 +-
 fuzz_test.go                   | 2 +-
 hasher.go                      | 6 +++---
 proofs.go                      | 4 ++--
 smst.go                        | 6 +++---
 smst_proofs_test.go            | 8 ++++----
 smst_test.go                   | 2 +-
 smst_utils_test.go             | 4 ++--
 utils.go                       | 4 ++--
 11 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/benchmarks/bench_utils_test.go b/benchmarks/bench_utils_test.go
index 5a360aa..0083ffa 100644
--- a/benchmarks/bench_utils_test.go
+++ b/benchmarks/bench_utils_test.go
@@ -30,24 +30,24 @@ var (
 
 	updSMST = func(s *smt.SMST, i uint64) error {
 		b := make([]byte, 8)
-		binary.BigEndian.PutUint64(b, i)
+		binary.LittleEndian.PutUint64(b, i)
 		return s.Update(b, b, i)
 	}
 	getSMST = func(s *smt.SMST, i uint64) error {
 		b := make([]byte, 8)
-		binary.BigEndian.PutUint64(b, i)
+		binary.LittleEndian.PutUint64(b, i)
 		_, _, err := s.Get(b)
 		return err
 	}
 	proSMST = func(s *smt.SMST, i uint64) error {
 		b := make([]byte, 8)
-		binary.BigEndian.PutUint64(b, i)
+		binary.LittleEndian.PutUint64(b, i)
 		_, err := s.Prove(b)
 		return err
 	}
 	delSMST = func(s *smt.SMST, i uint64) error {
 		b := make([]byte, 8)
-		binary.BigEndian.PutUint64(b, i)
+		binary.LittleEndian.PutUint64(b, i)
 		return s.Delete(b)
 	}
 )
diff --git a/benchmarks/proof_sizes_test.go b/benchmarks/proof_sizes_test.go
index e020fad..d103abe 100644
--- a/benchmarks/proof_sizes_test.go
+++ b/benchmarks/proof_sizes_test.go
@@ -43,7 +43,7 @@ func TestSMT_ProofSizes(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			for i := 0; i < tc.trieSize; i++ {
 				b := make([]byte, 8)
-				binary.BigEndian.PutUint64(b, uint64(i))
+				binary.LittleEndian.PutUint64(b, uint64(i))
 				require.NoError(t, trie.Update(b, b))
 			}
 			require.NoError(t, trie.Commit())
@@ -55,7 +55,7 @@ func TestSMT_ProofSizes(t *testing.T) {
 			minCompact := uint64(0)
 			for i := 0; i < tc.trieSize; i++ {
 				b := make([]byte, 8)
-				binary.BigEndian.PutUint64(b, uint64(i))
+				binary.LittleEndian.PutUint64(b, uint64(i))
 				proof, err := trie.Prove(b)
 				require.NoError(t, err)
 				require.NotNil(t, proof)
@@ -132,7 +132,7 @@ func TestSMST_ProofSizes(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			for i := 0; i < tc.trieSize; i++ {
 				b := make([]byte, 8)
-				binary.BigEndian.PutUint64(b, uint64(i))
+				binary.LittleEndian.PutUint64(b, uint64(i))
 				require.NoError(t, trie.Update(b, b, uint64(i)))
 			}
 			require.NoError(t, trie.Commit())
@@ -144,7 +144,7 @@ func TestSMST_ProofSizes(t *testing.T) {
 			minCompact := uint64(0)
 			for i := 0; i < tc.trieSize; i++ {
 				b := make([]byte, 8)
-				binary.BigEndian.PutUint64(b, uint64(i))
+				binary.LittleEndian.PutUint64(b, uint64(i))
 				proof, err := trie.Prove(b)
 				require.NoError(t, err)
 				require.NotNil(t, proof)
diff --git a/docs/MerkleSumTrie.md b/docs/MerkleSumTrie.md
index a72017c..cecf46e 100644
--- a/docs/MerkleSumTrie.md
+++ b/docs/MerkleSumTrie.md
@@ -61,7 +61,7 @@ The majority of the code relating to the SMST can be found in:
 The sum for any node is encoded in a byte array with a fixed size (`[8]byte`)
 this allows for the sum to fully represent a `uint64` value in binary form.
 The golang `encoding/binary` package is used to encode the sum with
-`binary.BigEndian.PutUint64(sumBz[:], sum)` into a byte array `sumBz`.
+`binary.LittleEndian.PutUint64(sumBz[:], sum)` into a byte array `sumBz`.
 
 In order for the SMST to include the sum into a leaf node the SMT the SMST
 initialises the SMT with the `WithValueHasher(nil)` option so that the SMT does
diff --git a/fuzz_test.go b/fuzz_test.go
index 98ce5dc..91a2233 100644
--- a/fuzz_test.go
+++ b/fuzz_test.go
@@ -72,7 +72,7 @@ func FuzzSMT_DetectUnexpectedFailures(f *testing.F) {
 				require.Equal(t, originalRoot, newRoot, "root changed while getting")
 			case Update:
 				value := make([]byte, 32)
-				binary.BigEndian.PutUint64(value, uint64(i))
+				binary.LittleEndian.PutUint64(value, uint64(i))
 				err := trie.Update(key(), value)
 				require.NoErrorf(t, err, "unknown error occured while updating")
 				newRoot := trie.Root()
diff --git a/hasher.go b/hasher.go
index 1b9b2cd..08b3b2c 100644
--- a/hasher.go
+++ b/hasher.go
@@ -167,12 +167,12 @@ func encodeSumInner(leftData []byte, rightData []byte) []byte {
 	leftSumBz := leftData[len(leftData)-sumSize:]
 	rightSumBz := rightData[len(rightData)-sumSize:]
 	if !bytes.Equal(leftSumBz, defaultSum[:]) {
-		leftSum = binary.BigEndian.Uint64(leftSumBz)
+		leftSum = binary.LittleEndian.Uint64(leftSumBz)
 	}
 	if !bytes.Equal(rightSumBz, defaultSum[:]) {
-		rightSum = binary.BigEndian.Uint64(rightSumBz)
+		rightSum = binary.LittleEndian.Uint64(rightSumBz)
 	}
-	binary.BigEndian.PutUint64(sum[:], leftSum+rightSum)
+	binary.LittleEndian.PutUint64(sum[:], leftSum+rightSum)
 	value = append(value, sum[:]...)
 	return value
 }
diff --git a/proofs.go b/proofs.go
index 32983a9..d7e2f64 100644
--- a/proofs.go
+++ b/proofs.go
@@ -285,7 +285,7 @@ func VerifyProof(proof *SparseMerkleProof, root, key, value []byte, spec *TrieSp
 // VerifySumProof verifies a Merkle proof for a sum trie.
 func VerifySumProof(proof *SparseMerkleProof, root, key, value []byte, sum uint64, spec *TrieSpec) (bool, error) {
 	var sumBz [sumSize]byte
-	binary.BigEndian.PutUint64(sumBz[:], sum)
+	binary.LittleEndian.PutUint64(sumBz[:], sum)
 	valueHash := spec.digestValue(value)
 	valueHash = append(valueHash, sumBz[:]...)
 	if bytes.Equal(value, defaultValue) && sum == 0 {
@@ -318,7 +318,7 @@ func VerifyClosestProof(proof *SparseMerkleClosestProof, root []byte, spec *Trie
 		return VerifySumProof(proof.ClosestProof, root, proof.ClosestPath, nil, 0, spec)
 	}
 	sumBz := proof.ClosestValueHash[len(proof.ClosestValueHash)-sumSize:]
-	sum := binary.BigEndian.Uint64(sumBz)
+	sum := binary.LittleEndian.Uint64(sumBz)
 	valueHash := proof.ClosestValueHash[:len(proof.ClosestValueHash)-sumSize]
 	return VerifySumProof(proof.ClosestProof, root, proof.ClosestPath, valueHash, sum, spec)
 }
diff --git a/smst.go b/smst.go
index 9f571cc..0e90422 100644
--- a/smst.go
+++ b/smst.go
@@ -59,7 +59,7 @@ func (smst *SMST) Get(key []byte) ([]byte, uint64, error) {
 	}
 	var weightBz [sumSize]byte
 	copy(weightBz[:], valueHash[len(valueHash)-sumSize:])
-	weight := binary.BigEndian.Uint64(weightBz[:])
+	weight := binary.LittleEndian.Uint64(weightBz[:])
 	return valueHash[:len(valueHash)-sumSize], weight, nil
 }
 
@@ -69,7 +69,7 @@ func (smst *SMST) Get(key []byte) ([]byte, uint64, error) {
 func (smst *SMST) Update(key, value []byte, weight uint64) error {
 	valueHash := smst.digestValue(value)
 	var weightBz [sumSize]byte
-	binary.BigEndian.PutUint64(weightBz[:], weight)
+	binary.LittleEndian.PutUint64(weightBz[:], weight)
 	valueHash = append(valueHash, weightBz[:]...)
 	return smst.SMT.Update(key, valueHash)
 }
@@ -109,5 +109,5 @@ func (smst *SMST) Sum() uint64 {
 	var sumBz [sumSize]byte
 	digest := smst.Root()
 	copy(sumBz[:], digest[len(digest)-sumSize:])
-	return binary.BigEndian.Uint64(sumBz[:])
+	return binary.LittleEndian.Uint64(sumBz[:])
 }
diff --git a/smst_proofs_test.go b/smst_proofs_test.go
index f113a0b..b9c7625 100644
--- a/smst_proofs_test.go
+++ b/smst_proofs_test.go
@@ -101,7 +101,7 @@ func TestSMST_Proof_Operations(t *testing.T) {
 
 	// Try proving a default value for a non-default leaf.
 	var sum [sumSize]byte
-	binary.BigEndian.PutUint64(sum[:], 5)
+	binary.LittleEndian.PutUint64(sum[:], 5)
 	tval := base.digestValue([]byte("testValue"))
 	tval = append(tval, sum[:]...)
 	_, leafData := base.th.digestSumLeaf(base.ph.Path([]byte("testKey2")), tval)
@@ -321,7 +321,7 @@ func TestSMST_ProveClosest(t *testing.T) {
 	require.NotEqual(t, proof, &SparseMerkleClosestProof{})
 	closestPath := sha256.Sum256([]byte("testKey2"))
 	closestValueHash := []byte("testValue2")
-	binary.BigEndian.PutUint64(sumBz[:], 24)
+	binary.LittleEndian.PutUint64(sumBz[:], 24)
 	closestValueHash = append(closestValueHash, sumBz[:]...)
 	require.Equal(t, proof, &SparseMerkleClosestProof{
 		Path:             path[:],
@@ -347,7 +347,7 @@ func TestSMST_ProveClosest(t *testing.T) {
 	require.NotEqual(t, proof, &SparseMerkleClosestProof{})
 	closestPath = sha256.Sum256([]byte("testKey4"))
 	closestValueHash = []byte("testValue4")
-	binary.BigEndian.PutUint64(sumBz[:], 30)
+	binary.LittleEndian.PutUint64(sumBz[:], 30)
 	closestValueHash = append(closestValueHash, sumBz[:]...)
 	require.Equal(t, proof, &SparseMerkleClosestProof{
 		Path:             path2[:],
@@ -418,7 +418,7 @@ func TestSMST_ProveClosest_OneNode(t *testing.T) {
 	closestPath := sha256.Sum256([]byte("foo"))
 	closestValueHash := []byte("bar")
 	var sumBz [sumSize]byte
-	binary.BigEndian.PutUint64(sumBz[:], 5)
+	binary.LittleEndian.PutUint64(sumBz[:], 5)
 	closestValueHash = append(closestValueHash, sumBz[:]...)
 	require.Equal(t, proof, &SparseMerkleClosestProof{
 		Path:             path[:],
diff --git a/smst_test.go b/smst_test.go
index ca40dfa..5246883 100644
--- a/smst_test.go
+++ b/smst_test.go
@@ -460,7 +460,7 @@ func TestSMST_TotalSum(t *testing.T) {
 	// Check root hash contains the correct hex sum
 	root1 := smst.Root()
 	sumBz := root1[len(root1)-sumSize:]
-	rootSum := binary.BigEndian.Uint64(sumBz)
+	rootSum := binary.LittleEndian.Uint64(sumBz)
 	require.NoError(t, err)
 
 	// Calculate total sum of the trie
diff --git a/smst_utils_test.go b/smst_utils_test.go
index 9accaa1..ca37941 100644
--- a/smst_utils_test.go
+++ b/smst_utils_test.go
@@ -23,7 +23,7 @@ func (smst *SMSTWithStorage) Update(key, value []byte, sum uint64) error {
 	}
 	valueHash := smst.digestValue(value)
 	var sumBz [sumSize]byte
-	binary.BigEndian.PutUint64(sumBz[:], sum)
+	binary.LittleEndian.PutUint64(sumBz[:], sum)
 	value = append(value, sumBz[:]...)
 	return smst.preimages.Set(valueHash, value)
 }
@@ -54,7 +54,7 @@ func (smst *SMSTWithStorage) GetValueSum(key []byte) ([]byte, uint64, error) {
 	}
 	var sumBz [sumSize]byte
 	copy(sumBz[:], value[len(value)-sumSize:])
-	storedSum := binary.BigEndian.Uint64(sumBz[:])
+	storedSum := binary.LittleEndian.Uint64(sumBz[:])
 	if storedSum != sum {
 		return nil, 0, fmt.Errorf("sum mismatch for %s: got %d, expected %d", string(key), storedSum, sum)
 	}
diff --git a/utils.go b/utils.go
index cc5bca8..ea4466f 100644
--- a/utils.go
+++ b/utils.go
@@ -103,7 +103,7 @@ func minBytes(i int) int {
 // intToBytes converts an int to a byte slice
 func intToBytes(i int) []byte {
 	b := make([]byte, 8)
-	binary.BigEndian.PutUint64(b, uint64(i))
+	binary.LittleEndian.PutUint64(b, uint64(i))
 	d := minBytes(i)
 	return b[8-d:]
 }
@@ -113,7 +113,7 @@ func bytesToInt(bz []byte) int {
 	b := make([]byte, 8) // allocate space for a 64-bit unsigned integer
 	d := 8 - len(bz)     // determine how much padding is necessary
 	copy(b[d:], bz)      // copy over the non-zero bytes
-	u := binary.BigEndian.Uint64(b)
+	u := binary.LittleEndian.Uint64(b)
 	return int(u)
 }