From bcda00d8c93184c7c5c29c11313217f54767f7c2 Mon Sep 17 00:00:00 2001
From: Yi Ding <yi.ding5@nio.com>
Date: Tue, 10 Jan 2023 22:14:22 +0800
Subject: [PATCH] Fix over-iterating buffer in hex string utility.

---
 Sources/Crypto/Util/PrettyBytes.swift         | 10 +++---
 Tests/CryptoTests/Utils/PrettyBytes.swift     | 10 +++---
 .../CryptoTests/Utils/PrettyBytesTests.swift  | 33 +++++++++++++++++++
 .../_CryptoExtrasTests/Utils/BytesUtil.swift  | 10 +++---
 4 files changed, 45 insertions(+), 18 deletions(-)
 create mode 100644 Tests/CryptoTests/Utils/PrettyBytesTests.swift

diff --git a/Sources/Crypto/Util/PrettyBytes.swift b/Sources/Crypto/Util/PrettyBytes.swift
index 2733f9ed..0d0ccc28 100644
--- a/Sources/Crypto/Util/PrettyBytes.swift
+++ b/Sources/Crypto/Util/PrettyBytes.swift
@@ -42,12 +42,10 @@ extension DataProtocol {
         var hexChars = [UInt8](repeating: 0, count: hexLen)
         var offset = 0
         
-        self.regions.forEach { (_) in
-            for i in self {
-                hexChars[Int(offset * 2)] = itoh((i >> 4) & 0xF)
-                hexChars[Int(offset * 2 + 1)] = itoh(i & 0xF)
-                offset += 1
-            }
+        for i in self {
+            hexChars[Int(offset * 2)] = itoh((i >> 4) & 0xF)
+            hexChars[Int(offset * 2 + 1)] = itoh(i & 0xF)
+            offset += 1
         }
         
         return String(bytes: hexChars, encoding: .utf8)!
diff --git a/Tests/CryptoTests/Utils/PrettyBytes.swift b/Tests/CryptoTests/Utils/PrettyBytes.swift
index 2733f9ed..0d0ccc28 100644
--- a/Tests/CryptoTests/Utils/PrettyBytes.swift
+++ b/Tests/CryptoTests/Utils/PrettyBytes.swift
@@ -42,12 +42,10 @@ extension DataProtocol {
         var hexChars = [UInt8](repeating: 0, count: hexLen)
         var offset = 0
         
-        self.regions.forEach { (_) in
-            for i in self {
-                hexChars[Int(offset * 2)] = itoh((i >> 4) & 0xF)
-                hexChars[Int(offset * 2 + 1)] = itoh(i & 0xF)
-                offset += 1
-            }
+        for i in self {
+            hexChars[Int(offset * 2)] = itoh((i >> 4) & 0xF)
+            hexChars[Int(offset * 2 + 1)] = itoh(i & 0xF)
+            offset += 1
         }
         
         return String(bytes: hexChars, encoding: .utf8)!
diff --git a/Tests/CryptoTests/Utils/PrettyBytesTests.swift b/Tests/CryptoTests/Utils/PrettyBytesTests.swift
new file mode 100644
index 00000000..2f98d3a0
--- /dev/null
+++ b/Tests/CryptoTests/Utils/PrettyBytesTests.swift
@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftCrypto open source project
+//
+// Copyright (c) 2019-2020 Apple Inc. and the SwiftCrypto project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.md for the list of SwiftCrypto project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+import Foundation
+import XCTest
+
+// Not sure if NSString-bridged "String.init(format:_:)" is available on Linux/Windows.
+#if (os(macOS) || os(iOS) || os(tvOS) || os(watchOS)) && CRYPTO_IN_SWIFTPM_FORCE_BUILD_API
+
+@testable import Crypto
+
+class PrettyBytesTests: XCTestCase {
+    func testHexString() {
+        let random = Data((1...64).map { _ in UInt8.random(in: UInt8.min...UInt8.max)})
+
+        let hexString = random.hexString
+        let target = random.map { String(format: "%02x", $0) }.joined()
+
+        XCTAssertEqual(hexString, target)
+    }
+}
+
+#endif
diff --git a/Tests/_CryptoExtrasTests/Utils/BytesUtil.swift b/Tests/_CryptoExtrasTests/Utils/BytesUtil.swift
index 1d6f7daf..17c5c14a 100644
--- a/Tests/_CryptoExtrasTests/Utils/BytesUtil.swift
+++ b/Tests/_CryptoExtrasTests/Utils/BytesUtil.swift
@@ -63,12 +63,10 @@ extension DataProtocol {
             let ptr = UnsafeMutablePointer<UInt8>.allocate(capacity: hexLen)
             var offset = 0
 
-            self.regions.forEach { (_) in
-                for i in self {
-                    ptr[Int(offset * 2)] = itoh((i >> 4) & 0xF)
-                    ptr[Int(offset * 2 + 1)] = itoh(i & 0xF)
-                    offset += 1
-                }
+            for i in self {
+                ptr[Int(offset * 2)] = itoh((i >> 4) & 0xF)
+                ptr[Int(offset * 2 + 1)] = itoh(i & 0xF)
+                offset += 1
             }
 
             return String(bytesNoCopy: ptr, length: hexLen, encoding: .utf8, freeWhenDone: true)!