From aa20a9518118d8aed2dcab8f1c6dae711c4eb569 Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Tue, 3 Dec 2019 16:17:04 +0300
Subject: [PATCH] util: add Uint256DecodeStringBE()

---
 pkg/util/uint256.go      | 15 +++++++++++++++
 pkg/util/uint256_test.go | 10 ++++++++++
 2 files changed, 25 insertions(+)

diff --git a/pkg/util/uint256.go b/pkg/util/uint256.go
index 8a859b42b..10dcfe0a5 100644
--- a/pkg/util/uint256.go
+++ b/pkg/util/uint256.go
@@ -28,6 +28,21 @@ func Uint256DecodeStringLE(s string) (u Uint256, err error) {
 	return Uint256DecodeBytesLE(b)
 }
 
+// Uint256DecodeStringBE attempts to decode the given string (in BE representation)
+// into an Uint256.
+func Uint256DecodeStringBE(s string) (u Uint256, err error) {
+	if len(s) != Uint256Size*2 {
+		return u, fmt.Errorf("expected string size of %d got %d", Uint256Size*2, len(s))
+	}
+
+	b, err := hex.DecodeString(s)
+	if err != nil {
+		return u, err
+	}
+
+	return Uint256DecodeBytesBE(b)
+}
+
 // Uint256DecodeBytesBE attempts to decode the given string (in BE representation) into an Uint256.
 func Uint256DecodeBytesBE(b []byte) (u Uint256, err error) {
 	if len(b) != Uint256Size {
diff --git a/pkg/util/uint256_test.go b/pkg/util/uint256_test.go
index 4d5ba4178..9fc8bf1c0 100644
--- a/pkg/util/uint256_test.go
+++ b/pkg/util/uint256_test.go
@@ -37,6 +37,10 @@ func TestUint256DecodeString(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, hexStr, val.StringLE())
 
+	valBE, err := Uint256DecodeStringBE(hexStr)
+	require.NoError(t, err)
+	assert.Equal(t, val, valBE.Reverse())
+
 	bs, err := hex.DecodeString(hexStr)
 	require.NoError(t, err)
 
@@ -48,9 +52,15 @@ func TestUint256DecodeString(t *testing.T) {
 	_, err = Uint256DecodeStringLE(hexStr[1:])
 	assert.Error(t, err)
 
+	_, err = Uint256DecodeStringBE(hexStr[1:])
+	assert.Error(t, err)
+
 	hexStr = "zzz7308fa0ab18155bccfc08485468c112409ea5064595699e98c545f245f32d"
 	_, err = Uint256DecodeStringLE(hexStr)
 	assert.Error(t, err)
+
+	_, err = Uint256DecodeStringBE(hexStr)
+	assert.Error(t, err)
 }
 
 func TestUint256DecodeBytes(t *testing.T) {