fix(work): 修复指针 Double Free 问题

src/SKIT.FlurlHttpClient.Wechat.Work/SDK/Finance/InteropServices/FinanceDllLinuxPInvoker.cs

@@ -32,8 +32,7 @@ namespace SKIT.FlurlHttpClient.Wechat.Work.SDK.Finance.InteropServices
         public static extern void FreeSlice([In] IntPtr slice);
 
         [DllImport(DLL_NAME, SetLastError = true, CallingConvention = CallingConvention.Cdecl)]
-        [return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(UTF8Marshaler))]
+        public static extern IntPtr GetContentFromSlice([In] IntPtr slice);
-        public static extern string GetContentFromSlice([In] IntPtr slice);
 
         [DllImport(DLL_NAME, SetLastError = true, CallingConvention = CallingConvention.Cdecl)]
         public static extern int GetSliceLen([In] IntPtr slice);
@@ -45,7 +44,7 @@ namespace SKIT.FlurlHttpClient.Wechat.Work.SDK.Finance.InteropServices
         public static extern void FreeMediaData([In] IntPtr mediaData);
 
         [DllImport(DLL_NAME, SetLastError = true, CallingConvention = CallingConvention.Cdecl)]
-        public static extern string GetOutIndexBuf([In] IntPtr mediaData);
+        public static extern IntPtr GetOutIndexBuf([In] IntPtr mediaData);
 
         [DllImport(DLL_NAME, SetLastError = true, CallingConvention = CallingConvention.Cdecl)]
         public static extern IntPtr GetData([In] IntPtr mediaData);

src/SKIT.FlurlHttpClient.Wechat.Work/SDK/Finance/InteropServices/FinanceDllWindowsPInvoker.cs

@@ -42,8 +42,7 @@ namespace SKIT.FlurlHttpClient.Wechat.Work.SDK.Finance.InteropServices
 
         [DllImport(DLL_NAME, SetLastError = true, CallingConvention = CallingConvention.Cdecl)]
         [SuppressUnmanagedCodeSecurity]
-        [return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(UTF8Marshaler))]
+        public static extern IntPtr GetContentFromSlice([In] IntPtr slice);
-        public static extern string GetContentFromSlice([In] IntPtr slice);
 
         [DllImport(DLL_NAME, SetLastError = true, CallingConvention = CallingConvention.Cdecl)]
         [SuppressUnmanagedCodeSecurity]
@@ -59,7 +58,7 @@ namespace SKIT.FlurlHttpClient.Wechat.Work.SDK.Finance.InteropServices
 
         [DllImport(DLL_NAME, SetLastError = true, CallingConvention = CallingConvention.Cdecl)]
         [SuppressUnmanagedCodeSecurity]
-        public static extern string GetOutIndexBuf([In] IntPtr mediaData);
+        public static extern IntPtr GetOutIndexBuf([In] IntPtr mediaData);
 
         [DllImport(DLL_NAME, SetLastError = true, CallingConvention = CallingConvention.Cdecl)]
         [SuppressUnmanagedCodeSecurity]

src/SKIT.FlurlHttpClient.Wechat.Work/SDK/Finance/InteropServices/MarshalerHelper.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace SKIT.FlurlHttpClient.Wechat.Work.SDK.Finance.InteropServices
+{
+    internal static class MarshalerHelper
+    {
+        public static string PtrToStringAnsi(IntPtr ptr)
+        {
+            if (ptr == IntPtr.Zero)
+                return default!;
+
+            return Marshal.PtrToStringAnsi(ptr)!;
+        }
+
+        public static string PtrToStringUTF8(IntPtr ptr)
+        {
+            if (ptr == IntPtr.Zero)
+                return default!;
+
+#if NETCOREAPP || NET5_0_OR_GREATER
+            return Marshal.PtrToStringUTF8(ptr)!;
+#else
+            byte b;
+            int offset = 0;
+
+            do
+            {
+                b = Marshal.ReadByte(ptr, offset);
+                offset++;
+            }
+            while (b != 0);
+
+            byte[] bytes = new byte[offset - 1];
+            Marshal.Copy(ptr, bytes, 0, bytes.Length);
+            return Encoding.UTF8.GetString(bytes);
+#endif
+        }
+    }
+}

src/SKIT.FlurlHttpClient.Wechat.Work/SDK/Finance/InteropServices/UTF8Marshaler.cs

@@ -1,83 +0,0 @@
-using System;
-using System.Runtime.InteropServices;
-using System.Text;
-
-namespace SKIT.FlurlHttpClient.Wechat.Work.SDK.Finance.InteropServices
-{
-    internal sealed class UTF8Marshaler : ICustomMarshaler
-    {
-        private static readonly Lazy<UTF8Marshaler> _instance = new Lazy<UTF8Marshaler>(() => new UTF8Marshaler());
-
-        public static ICustomMarshaler GetInstance(string pstrCookie)
-        {
-            return _instance.Value;
-        }
-
-        public static string? PtrToStringUTF8(IntPtr pNativeData)
-        {
-            return _instance.Value.MarshalNativeToManaged(pNativeData) as string;
-        }
-
-        public IntPtr MarshalManagedToNative(object managedObj)
-        {
-            if (managedObj is null)
-                return IntPtr.Zero;
-            if (!(managedObj is string))
-                throw new InvalidOperationException();
-
-            byte[] bytes = Encoding.UTF8.GetBytes((string)managedObj);
-            IntPtr pNativeData = Marshal.AllocHGlobal(bytes.Length + 1);
-            Marshal.Copy(bytes, 0, pNativeData, bytes.Length);
-            Marshal.WriteByte(pNativeData, bytes.Length, 0);
-            return pNativeData;
-        }
-
-        public object MarshalNativeToManaged(IntPtr pNativeData)
-        {
-            if (pNativeData == IntPtr.Zero)
-                return default!;
-
-#if NETCOREAPP || NET5_0_OR_GREATER
-            return Marshal.PtrToStringUTF8(pNativeData)!;
-#else
-            byte b;
-            int offset = 0;
-
-            do
-            {
-                b = Marshal.ReadByte(pNativeData, offset);
-                offset++;
-            }
-            while (b != 0);
-
-            byte[] bytes = new byte[offset - 1];
-            Marshal.Copy(pNativeData, bytes, 0, bytes.Length);
-            return Encoding.UTF8.GetString(bytes);
-#endif
-        }
-
-        public void CleanUpManagedData(object managedObj)
-        {
-        }
-
-        public void CleanUpNativeData(IntPtr pNativeData)
-        {
-            if (pNativeData == IntPtr.Zero)
-            {
-                return;
-            }
-
-            /**
-             * NOTICE:
-             *   这里释放内存会导致外部 P/Invoke 调用 FreeSlice() 方法时抛出异常
-             *   因此请注释下面的代码
-             */
-            // Marshal.FreeHGlobal(pNativeData);
-        }
-
-        public int GetNativeDataSize()
-        {
-            return -1;
-        }
-    }
-}

src/SKIT.FlurlHttpClient.Wechat.Work/SDK/Finance/WechatWorkFinanceClient.cs

@@ -129,10 +129,11 @@ namespace SKIT.FlurlHttpClient.Wechat.Work.SDK.Finance
                         //    IsRunOnWindows() ? FinanceDllWindowsPInvoker.GetSliceLen(dataPtr) :
                         //    IsRunOnLinux() ? FinanceDllLinuxPInvoker.GetSliceLen(dataPtr) :
                         //    throw new PlatformNotSupportedException();
-                        string dataContent = /* 获取聊天记录数据内容 */
+                        IntPtr dataContentPtr = /* 获取聊天记录数据内容 */
                             IsRunOnWindows() ? FinanceDllWindowsPInvoker.GetContentFromSlice(dataPtr) :
                             IsRunOnLinux() ? FinanceDllLinuxPInvoker.GetContentFromSlice(dataPtr) :
                             throw new PlatformNotSupportedException();
+                        string dataContent = MarshalerHelper.PtrToStringUTF8(dataContentPtr);
 
                         response = JsonSerializer.Deserialize<Models.GetChatRecordsResponse>(dataContent);
                         response.RawBytes = Encoding.UTF8.GetBytes(dataContent);
@@ -220,10 +221,11 @@ namespace SKIT.FlurlHttpClient.Wechat.Work.SDK.Finance
                         //    IsRunOnWindows() ? FinanceDllWindowsPInvoker.GetSliceLen(dataPtr) :
                         //    IsRunOnLinux() ? FinanceDllLinuxPInvoker.GetSliceLen(dataPtr) :
                         //    throw new PlatformNotSupportedException();
-                        string dataContent = /* 获取聊天记录数据内容 */
+                        IntPtr dataContentPtr = /* 获取聊天记录数据内容 */
                             IsRunOnWindows() ? FinanceDllWindowsPInvoker.GetContentFromSlice(dataPtr) :
                             IsRunOnLinux() ? FinanceDllLinuxPInvoker.GetContentFromSlice(dataPtr) :
                             throw new PlatformNotSupportedException();
+                        string dataContent = MarshalerHelper.PtrToStringUTF8(dataContentPtr);
 
                         response = JsonSerializer.Deserialize<Models.DecryptChatRecordResponse>(dataContent);
                         response.RawBytes = Encoding.UTF8.GetBytes(dataContent);
@@ -293,7 +295,7 @@ namespace SKIT.FlurlHttpClient.Wechat.Work.SDK.Finance
                             IsRunOnWindows() ? FinanceDllWindowsPInvoker.GetData(dataPtr) :
                             IsRunOnLinux() ? FinanceDllLinuxPInvoker.GetData(dataPtr) :
                             throw new PlatformNotSupportedException();
-                        string dataNextBufferIndex = /* 获取媒体文件数据内容缓冲标识 */
+                        IntPtr dataNextBufferIndex = /* 获取媒体文件数据内容缓冲标识 */
                             IsRunOnWindows() ? FinanceDllWindowsPInvoker.GetOutIndexBuf(dataPtr) :
                             IsRunOnLinux() ? FinanceDllLinuxPInvoker.GetOutIndexBuf(dataPtr) :
                             throw new PlatformNotSupportedException();
@@ -304,10 +306,9 @@ namespace SKIT.FlurlHttpClient.Wechat.Work.SDK.Finance
 
                         byte[] bytes = new byte[dataSize];
                         Marshal.Copy(dataContentPtr, bytes, 0, bytes.Length);
-                        Marshal.FreeHGlobal(dataContentPtr);
 
                         response.FileBufferBytes = bytes;
-                        response.NextBufferIndex = dataNextBufferIndex;
+                        response.NextBufferIndex = MarshalerHelper.PtrToStringAnsi(dataNextBufferIndex);
                         response.IsFinished = dataIsFinishFlag != 0;
                     }