From 2aa3ee46e7ccc55868b9fb06de968cf753719471 Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <e.stratonikov@yadro.com>
Date: Wed, 3 May 2023 14:09:17 +0300
Subject: [PATCH] [#27] util/signature: Fix staticcheck warning

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
---
 util/signature/buffer.go  | 22 +++++++++++++---------
 util/signature/data.go    |  4 ++--
 util/signature/options.go |  8 ++++----
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/util/signature/buffer.go b/util/signature/buffer.go
index 2a7f1e0..c2fa855 100644
--- a/util/signature/buffer.go
+++ b/util/signature/buffer.go
@@ -4,26 +4,30 @@ import "sync"
 
 const poolSliceMaxSize = 64 * 1024
 
+type buffer struct {
+	data []byte
+}
+
 var buffersPool = sync.Pool{
 	New: func() any {
-		return make([]byte, 0)
+		return new(buffer)
 	},
 }
 
-func newBufferFromPool(size int) []byte {
-	result := buffersPool.Get().([]byte)
-	if cap(result) < size {
-		result = make([]byte, size)
+func newBufferFromPool(size int) *buffer {
+	result := buffersPool.Get().(*buffer)
+	if cap(result.data) < size {
+		result.data = make([]byte, size)
 	} else {
-		result = result[:size]
+		result.data = result.data[:size]
 	}
 	return result
 }
 
-func returnBufferToPool(buf []byte) {
-	if cap(buf) > poolSliceMaxSize {
+func returnBufferToPool(buf *buffer) {
+	if cap(buf.data) > poolSliceMaxSize {
 		return
 	}
-	buf = buf[:0]
+	buf.data = buf.data[:0]
 	buffersPool.Put(buf)
 }
diff --git a/util/signature/data.go b/util/signature/data.go
index d2bf1dc..1db46dc 100644
--- a/util/signature/data.go
+++ b/util/signature/data.go
@@ -38,7 +38,7 @@ func SignDataWithHandler(key *ecdsa.PrivateKey, src DataSource, handler KeySigna
 	buffer := newBufferFromPool(src.SignedDataSize())
 	defer returnBufferToPool(buffer)
 
-	data, err := src.ReadSignedData(buffer)
+	data, err := src.ReadSignedData(buffer.data)
 	if err != nil {
 		return err
 	}
@@ -67,7 +67,7 @@ func VerifyDataWithSource(dataSrc DataSource, sigSrc KeySignatureSource, opts ..
 	buffer := newBufferFromPool(dataSrc.SignedDataSize())
 	defer returnBufferToPool(buffer)
 
-	data, err := dataSrc.ReadSignedData(buffer)
+	data, err := dataSrc.ReadSignedData(buffer.data)
 	if err != nil {
 		return err
 	}
diff --git a/util/signature/options.go b/util/signature/options.go
index a8a3522..b9bf68d 100644
--- a/util/signature/options.go
+++ b/util/signature/options.go
@@ -37,8 +37,8 @@ func verify(cfg *cfg, data []byte, sig *refs.Signature) error {
 	case refs.ECDSA_RFC6979_SHA256_WALLET_CONNECT:
 		buffer := newBufferFromPool(base64.StdEncoding.EncodedLen(len(data)))
 		defer returnBufferToPool(buffer)
-		base64.StdEncoding.Encode(buffer, data)
-		if !walletconnect.Verify(pub, buffer, sig.GetSign()) {
+		base64.StdEncoding.Encode(buffer.data, data)
+		if !walletconnect.Verify(pub, buffer.data, sig.GetSign()) {
 			return crypto.ErrInvalidSignature
 		}
 		return nil
@@ -56,8 +56,8 @@ func sign(cfg *cfg, key *ecdsa.PrivateKey, data []byte) ([]byte, error) {
 	case refs.ECDSA_RFC6979_SHA256_WALLET_CONNECT:
 		buffer := newBufferFromPool(base64.StdEncoding.EncodedLen(len(data)))
 		defer returnBufferToPool(buffer)
-		base64.StdEncoding.Encode(buffer, data)
-		return walletconnect.Sign(key, buffer)
+		base64.StdEncoding.Encode(buffer.data, data)
+		return walletconnect.Sign(key, buffer.data)
 	default:
 		panic(fmt.Sprintf("unsupported scheme %s", cfg.scheme))
 	}