Пример #1
0
        [System.Security.SecurityCritical]  // auto-generated
        private void ProtectMemory(SafeBSTRHandle decryptedBuffer)
        {
            Debug.Assert(!decryptedBuffer.IsInvalid, "Invalid buffer!");

            if (_decryptedLength == 0)
            {
                return;
            }

            try
            {
                SafeBSTRHandle newEncryptedBuffer = null;
                if (Interop.Crypt32.CryptProtectData(decryptedBuffer, out newEncryptedBuffer))
                {
                    _encryptedBuffer.Dispose();
                    _encryptedBuffer = newEncryptedBuffer;
                }
                else
                {
                    throw new CryptographicException(Marshal.GetLastWin32Error());
                }
            }
            finally
            {
                decryptedBuffer.ClearBuffer();
            }
        }
Пример #2
0
        [System.Security.SecuritySafeCritical]  // auto-generated
        private unsafe void InsertAtCore(int index, char c)
        {
            byte *         bufferPtr       = null;
            SafeBSTRHandle decryptedBuffer = null;

            try
            {
                decryptedBuffer = UnProtectMemory();
                EnsureCapacity(ref decryptedBuffer, _decryptedLength + 1);

                decryptedBuffer.AcquirePointer(ref bufferPtr);
                char *pBuffer = (char *)bufferPtr;

                for (int i = _decryptedLength; i > index; i--)
                {
                    pBuffer[i] = pBuffer[i - 1];
                }
                pBuffer[index] = c;
                ++_decryptedLength;
            }
            finally
            {
                ProtectMemory(decryptedBuffer);
                if (bufferPtr != null)
                {
                    decryptedBuffer.ReleasePointer();
                }
            }
        }
Пример #3
0
        internal static SafeBSTRHandle Allocate(String src, uint len)
        {
            SafeBSTRHandle bstr = SysAllocStringLen(src, len);

            bstr.Initialize(len * sizeof(char));
            return(bstr);
        }
Пример #4
0
        internal unsafe static void Copy(SafeBSTRHandle source, SafeBSTRHandle target, uint bytesToCopy)
        {
            if (bytesToCopy == 0)
            {
                return;
            }

            byte* sourcePtr = null, targetPtr = null;
            try
            {
                source.AcquirePointer(ref sourcePtr);
                target.AcquirePointer(ref targetPtr);

                Debug.Assert(source.ByteLength >= bytesToCopy, "Source buffer is too small.");
                Buffer.MemoryCopy(sourcePtr, targetPtr, target.ByteLength, bytesToCopy);
            }
            finally
            {
                if (targetPtr != null)
                {
                    target.ReleasePointer();
                }
                if (sourcePtr != null)
                {
                    source.ReleasePointer();
                }
            }
        }
Пример #5
0
        internal unsafe static void Copy(SafeBSTRHandle source, SafeBSTRHandle target)
        {
            byte *sourcePtr = null, targetPtr = null;

            RuntimeHelpers.PrepareConstrainedRegions();
            try
            {
                source.AcquirePointer(ref sourcePtr);
                target.AcquirePointer(ref targetPtr);

                Contract.Assert(Win32Native.SysStringLen((IntPtr)targetPtr) >= Win32Native.SysStringLen((IntPtr)sourcePtr), "Target buffer is not large enough!");

                Buffer.Memcpy(targetPtr, sourcePtr, (int)Win32Native.SysStringLen((IntPtr)sourcePtr) * 2);
            }
            finally
            {
                if (sourcePtr != null)
                {
                    source.ReleasePointer();
                }
                if (targetPtr != null)
                {
                    target.ReleasePointer();
                }
            }
        }
Пример #6
0
        [System.Security.SecuritySafeCritical]  // auto-generated
        private unsafe void RemoveAtCore(int index)
        {
            byte *         bufferPtr       = null;
            SafeBSTRHandle decryptedBuffer = null;

            try
            {
                decryptedBuffer = UnProtectMemory();
                decryptedBuffer.AcquirePointer(ref bufferPtr);
                char *pBuffer = (char *)bufferPtr;

                for (int i = index; i < _decryptedLength - 1; i++)
                {
                    pBuffer[i] = pBuffer[i + 1];
                }
                pBuffer[--_decryptedLength] = (char)0;
            }
            finally
            {
                ProtectMemory(decryptedBuffer);
                if (bufferPtr != null)
                {
                    decryptedBuffer.ReleasePointer();
                }
            }
        }
Пример #7
0
        [System.Security.SecuritySafeCritical]  // auto-generated
        public void SetAt(int index, char c)
        {
            lock (_methodLock)
            {
                if (index < 0 || index >= _decryptedLength)
                {
                    throw new ArgumentOutOfRangeException("index", SR.ArgumentOutOfRange_IndexString);
                }
                Debug.Assert(index <= Int32.MaxValue / sizeof(char));

                EnsureNotDisposed();
                EnsureNotReadOnly();

                SafeBSTRHandle decryptedBuffer = null;
                try
                {
                    decryptedBuffer = UnProtectMemory();
                    decryptedBuffer.Write <char>((uint)index * sizeof(char), c);
                }
                finally
                {
                    ProtectMemory(decryptedBuffer);
                }
            }
        }
Пример #8
0
 [System.Security.SecurityCritical]  // auto-generated
 internal SecureString(SecureString str)
 {
     AllocateBuffer(str.BufferLength);
     SafeBSTRHandle.Copy(str.m_buffer, this.m_buffer);
     m_length    = str.m_length;
     m_encrypted = str.m_encrypted;
 }
Пример #9
0
        internal static SafeBSTRHandle Allocate(string src, uint len)
        {
            SafeBSTRHandle handle = SysAllocStringLen(src, len);

            handle.Initialize((ulong)(len * 2));
            return(handle);
        }
Пример #10
0
        [System.Security.SecurityCritical]  // auto-generated
        private unsafe void InitializeSecureString(char *value, int length)
        {
            if (length == 0)
            {
                AllocateBuffer(0);
                _decryptedLength = 0;
                return;
            }

            _encryptedBuffer = SafeBSTRHandle.Allocate(null, 0);
            SafeBSTRHandle decryptedBuffer = SafeBSTRHandle.Allocate(null, (uint)length);

            _decryptedLength = length;

            byte *bufferPtr = null;

            try
            {
                decryptedBuffer.AcquirePointer(ref bufferPtr);
                Buffer.MemoryCopy((byte *)value, bufferPtr, decryptedBuffer.Length * sizeof(char), length * sizeof(char));
            }
            finally
            {
                if (bufferPtr != null)
                {
                    decryptedBuffer.ReleasePointer();
                }
            }

            ProtectMemory(decryptedBuffer);
        }
Пример #11
0
        internal static unsafe bool CryptProtectData(SafeBSTRHandle uncryptedBuffer, out SafeBSTRHandle cryptedBuffer)
        {
            byte* uncryptedBufferPtr = null;
            DATA_BLOB pDataOut = default(DATA_BLOB);
            try
            {
                uncryptedBuffer.AcquirePointer(ref uncryptedBufferPtr);
                DATA_BLOB pDataIn = new DATA_BLOB((IntPtr)uncryptedBufferPtr, uncryptedBuffer.Length * 2);
                if (CryptProtectData(new IntPtr(&pDataIn), String.Empty, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, CRYPTPROTECTMEMORY_SAME_PROCESS, new IntPtr(&pDataOut)))
                {
                    SafeBSTRHandle newHandle = SafeBSTRHandle.Allocate(pDataOut.pbData, pDataOut.cbData);
                    cryptedBuffer = newHandle;
                    return true;
                }
                else
                {
                    cryptedBuffer = SafeBSTRHandle.Allocate(null, 0);
                    return false;
                }
            }
            finally
            {
                if (uncryptedBufferPtr != null)
                    uncryptedBuffer.ReleasePointer();

                if (pDataOut.pbData != IntPtr.Zero)
                {
                    NtDll.ZeroMemory(pDataOut.pbData, (UIntPtr)pDataOut.cbData);
                    Marshal.FreeHGlobal(pDataOut.pbData);
                }
            }
        }
Пример #12
0
        internal unsafe static void Copy(SafeBSTRHandle source, SafeBSTRHandle target, uint bytesToCopy)
        {
            if (bytesToCopy == 0)
            {
                return;
            }

            byte *sourcePtr = null, targetPtr = null;

            try
            {
                source.AcquirePointer(ref sourcePtr);
                target.AcquirePointer(ref targetPtr);

                Debug.Assert(Interop.OleAut32.SysStringLen((IntPtr)sourcePtr) * sizeof(char) >= bytesToCopy, "Source buffer is too small.");
                Buffer.MemoryCopy(sourcePtr, targetPtr, Interop.OleAut32.SysStringLen((IntPtr)targetPtr) * sizeof(char), bytesToCopy);
            }
            finally
            {
                if (sourcePtr != null)
                {
                    source.ReleasePointer();
                }
                if (targetPtr != null)
                {
                    target.ReleasePointer();
                }
            }
        }
Пример #13
0
        internal static unsafe void Copy(SafeBSTRHandle source, SafeBSTRHandle target, uint bytesToCopy)
        {
            if (bytesToCopy == 0)
            {
                return;
            }

            byte *sourcePtr = null, targetPtr = null;

            try
            {
                source.AcquirePointer(ref sourcePtr);
                target.AcquirePointer(ref targetPtr);

                Debug.Assert(source.ByteLength >= bytesToCopy, "Source buffer is too small.");
                Buffer.MemoryCopy(sourcePtr, targetPtr, target.ByteLength, bytesToCopy);
            }
            finally
            {
                if (targetPtr != null)
                {
                    target.ReleasePointer();
                }
                if (sourcePtr != null)
                {
                    source.ReleasePointer();
                }
            }
        }
Пример #14
0
        internal static SafeBSTRHandle Allocate(IntPtr src, uint lenInBytes)
        {
            SafeBSTRHandle bstr = Interop.OleAut32.SysAllocStringLen(src, lenInBytes / sizeof(char));

            bstr.Initialize(lenInBytes);
            return(bstr);
        }
Пример #15
0
        private void AllocateBuffer(int size) {
            uint alignedSize = GetAlignedSize(size);

            m_buffer = SafeBSTRHandle.Allocate(null, alignedSize);
            if (m_buffer.IsInvalid) {
                throw new OutOfMemoryException();
            }
        }
Пример #16
0
        internal static SafeBSTRHandle Allocate(string src, uint len)
        {
            SafeBSTRHandle safeBstrHandle = SafeBSTRHandle.SysAllocStringLen(src, len);
            long           num            = (long)(len * 2U);

            safeBstrHandle.Initialize((ulong)num);
            return(safeBstrHandle);
        }
 public void Dispose()
 {
     if ((this.m_buffer != null) && !this.m_buffer.IsInvalid)
     {
         this.m_buffer.Close();
         this.m_buffer = null;
     }
 }
Пример #18
0
 private void AllocateBuffer(int size)
 {
     this.m_buffer = SafeBSTRHandle.Allocate((string)null, SecureString.GetAlignedSize(size));
     if (this.m_buffer.IsInvalid)
     {
         throw new OutOfMemoryException();
     }
 }
Пример #19
0
 [System.Security.SecurityCritical]  // auto-generated
 private void AllocateBuffer(uint size)
 {
     _encryptedBuffer = SafeBSTRHandle.Allocate(null, size);
     if (_encryptedBuffer.IsInvalid)
     {
         throw new OutOfMemoryException();
     }
 }
Пример #20
0
 public void Dispose()
 {
     if (m_buffer != null && !m_buffer.IsInvalid)
     {
         m_buffer.Close();
         m_buffer = null;
     }
 }
Пример #21
0
 public void Dispose()
 {
     if (this.m_buffer == null || this.m_buffer.IsInvalid)
     {
         return;
     }
     this.m_buffer.Close();
     this.m_buffer = (SafeBSTRHandle)null;
 }
 private void AllocateBuffer(int size)
 {
     uint alignedSize = GetAlignedSize(size);
     this.m_buffer = SafeBSTRHandle.Allocate(null, alignedSize);
     if (this.m_buffer.IsInvalid)
     {
         throw new OutOfMemoryException();
     }
 }
Пример #23
0
 [System.Security.SecuritySafeCritical]  // auto-generated
 public void Dispose()
 {
     lock (_methodLock)
     {
         if (_encryptedBuffer != null && !_encryptedBuffer.IsInvalid)
         {
             _encryptedBuffer.Dispose();
             _encryptedBuffer = null;
         }
     }
 }
Пример #24
0
        internal static SafeBSTRHandle Allocate(string src, uint lenInChars)
        {
            SafeBSTRHandle bstr = Interop.OleAut32.SysAllocStringLen(src, lenInChars);

            if (bstr.IsInvalid) // SysAllocStringLen returns a NULL ptr when there's insufficient memory
            {
                throw new OutOfMemoryException();
            }
            bstr.Initialize(lenInChars * sizeof(char));
            return(bstr);
        }
Пример #25
0
        internal static SafeBSTRHandle Allocate(IntPtr src, uint lenInBytes)
        {
            Debug.Assert(lenInBytes % sizeof(char) == 0);
            SafeBSTRHandle bstr = Interop.OleAut32.SysAllocStringLen(src, lenInBytes / sizeof(char));

            if (bstr.IsInvalid) // SysAllocStringLen returns a NULL ptr when there's insufficient memory
            {
                throw new OutOfMemoryException();
            }
            bstr.Initialize(lenInBytes);
            return(bstr);
        }
Пример #26
0
        internal SecureString(SecureString str)
        {
            Debug.Assert(str != null, "Expected non-null SecureString");
            Debug.Assert(str._buffer != null, "Expected other SecureString's buffer to be non-null");
            Debug.Assert(str._encrypted, "Expected to be used only on encrypted SecureStrings");

            AllocateBuffer(str._buffer.Length);
            SafeBSTRHandle.Copy(str._buffer, _buffer, str._buffer.Length * sizeof(char));

            _decryptedLength = str._decryptedLength;
            _encrypted       = str._encrypted;
        }
        private static bool EncryptionSupported()
        {
            bool flag = true;

            try
            {
                Win32Native.SystemFunction041(SafeBSTRHandle.Allocate(null, 0x10), 0x10, 0);
            }
            catch (EntryPointNotFoundException)
            {
                flag = false;
            }
            return(flag);
        }
Пример #28
0
        private static bool EncryptionSupported()
        {
            bool flag = true;

            try
            {
                Win32Native.SystemFunction041(SafeBSTRHandle.Allocate((string)null, 16U), 16U, 0U);
            }
            catch (EntryPointNotFoundException ex)
            {
                flag = false;
            }
            return(flag);
        }
Пример #29
0
 [System.Security.SecurityCritical]  // auto-generated
 unsafe static bool EncryptionSupported() {
     // check if the enrypt/decrypt function is supported on current OS
     bool supported = true;                        
     try {
         Win32Native.SystemFunction041(
             SafeBSTRHandle.Allocate(null , (int)Win32Native.CRYPTPROTECTMEMORY_BLOCK_SIZE),
             Win32Native.CRYPTPROTECTMEMORY_BLOCK_SIZE, 
             Win32Native.CRYPTPROTECTMEMORY_SAME_PROCESS);
     }
     catch (EntryPointNotFoundException) {
         supported = false;
     }            
     return supported;
 }
Пример #30
0
        [System.Security.SecuritySafeCritical]  // auto-generated
        private void SetAtCore(int index, char c)
        {
            SafeBSTRHandle decryptedBuffer = null;

            try
            {
                decryptedBuffer = UnProtectMemory();
                decryptedBuffer.Write <char>((uint)index * sizeof(char), c);
            }
            finally
            {
                ProtectMemory(decryptedBuffer);
            }
        }
Пример #31
0
        private static bool EncryptionSupported()
        {
            bool result = true;

            try
            {
                Win32Native.SystemFunction041(SafeBSTRHandle.Allocate(null, 16U), 16U, 0U);
            }
            catch (EntryPointNotFoundException)
            {
                result = false;
            }
            return(result);
        }
Пример #32
0
        [System.Security.SecuritySafeCritical]  // auto-generated
        private void AppendCharCore(char c)
        {
            SafeBSTRHandle decryptedBuffer = null;

            try
            {
                decryptedBuffer = UnProtectMemory();
                EnsureCapacity(ref decryptedBuffer, _decryptedLength + 1);
                decryptedBuffer.Write <char>((uint)_decryptedLength * sizeof(char), c);
                _decryptedLength++;
            }
            finally
            {
                ProtectMemory(decryptedBuffer);
            }
        }
Пример #33
0
        [System.Security.SecurityCritical]  // auto-generated
        internal unsafe IntPtr ToUniStr()
        {
            lock (_methodLock)
            {
                EnsureNotDisposed();
                int    length    = _decryptedLength;
                IntPtr ptr       = IntPtr.Zero;
                IntPtr result    = IntPtr.Zero;
                byte * bufferPtr = null;

                SafeBSTRHandle decryptedBuffer = null;
                try
                {
                    ptr = Marshal.AllocCoTaskMem((length + 1) * 2);

                    if (ptr == IntPtr.Zero)
                    {
                        throw new OutOfMemoryException();
                    }

                    decryptedBuffer = UnProtectMemory();
                    decryptedBuffer.AcquirePointer(ref bufferPtr);
                    Buffer.MemoryCopy(bufferPtr, (byte *)ptr.ToPointer(), ((length + 1) * 2), length * 2);
                    char *endptr = (char *)ptr.ToPointer();
                    *(endptr + length) = '\0';
                    result             = ptr;
                }
                finally
                {
                    if (result == IntPtr.Zero)
                    {
                        // If we failed for any reason, free the new buffer
                        if (ptr != IntPtr.Zero)
                        {
                            Interop.NtDll.ZeroMemory(ptr, (UIntPtr)(length * 2));
                            Marshal.FreeCoTaskMem(ptr);
                        }
                    }

                    if (bufferPtr != null)
                    {
                        decryptedBuffer.ReleasePointer();
                    }
                }
                return(result);
            }
        }
Пример #34
0
        internal unsafe static void Copy(SafeBSTRHandle source, SafeBSTRHandle target, uint bytesToCopy)
        {
            if (bytesToCopy == 0)
                return;

            byte* sourcePtr = null, targetPtr = null;
            try
            {
                source.AcquirePointer(ref sourcePtr);
                target.AcquirePointer(ref targetPtr);

                Debug.Assert(Interop.OleAut32.SysStringLen((IntPtr)sourcePtr) * sizeof(char) >= bytesToCopy, "Source buffer is too small.");
                Buffer.MemoryCopy(sourcePtr, targetPtr, Interop.OleAut32.SysStringLen((IntPtr)targetPtr) * sizeof(char), bytesToCopy);
            }
            finally
            {
                if (sourcePtr != null)
                    source.ReleasePointer();
                if (targetPtr != null)
                    target.ReleasePointer();
            }
        }
 internal static unsafe void Copy(SafeBSTRHandle source, SafeBSTRHandle target)
 {
     byte* pointer = null;
     byte* numPtr2 = null;
     RuntimeHelpers.PrepareConstrainedRegions();
     try
     {
         source.AcquirePointer(ref pointer);
         target.AcquirePointer(ref numPtr2);
         Buffer.memcpyimpl(pointer, numPtr2, Win32Native.SysStringLen((IntPtr) pointer) * 2);
     }
     finally
     {
         if (pointer != null)
         {
             source.ReleasePointer();
         }
         if (numPtr2 != null)
         {
             target.ReleasePointer();
         }
     }
 }
Пример #36
0
        private void EnsureCapacity(int capacity)
        {
            if (capacity > MaxLength)
            {
                throw new ArgumentOutOfRangeException(nameof(capacity), SR.ArgumentOutOfRange_Capacity);
            }

            if (((uint)capacity * sizeof(char)) <= _buffer.ByteLength)
            {
                return;
            }

            var oldBuffer = _buffer;
            SafeBSTRHandle newBuffer = SafeBSTRHandle.Allocate(GetAlignedSize((uint)capacity));
            SafeBSTRHandle.Copy(oldBuffer, newBuffer, (uint)_decryptedLength * sizeof(char));
            _buffer = newBuffer;
            oldBuffer.Dispose();
        }
Пример #37
0
        internal unsafe static void Copy(SafeBSTRHandle source, SafeBSTRHandle target) {
            byte* sourcePtr = null, targetPtr = null;
            RuntimeHelpers.PrepareConstrainedRegions();
            try
            {
                source.AcquirePointer(ref sourcePtr);
                target.AcquirePointer(ref targetPtr);

                Contract.Assert(Win32Native.SysStringLen((IntPtr)targetPtr) >= Win32Native.SysStringLen((IntPtr)sourcePtr), "Target buffer is not large enough!");

                Buffer.Memcpy(targetPtr, sourcePtr, (int) Win32Native.SysStringLen((IntPtr)sourcePtr) * 2);
            }
            finally
            {
                if (sourcePtr != null)
                    source.ReleasePointer();
                if (targetPtr != null)
                    target.ReleasePointer();
            }
        }
 internal static extern bool CryptUnprotectMemory(SafeBSTRHandle pData, uint cbData, uint dwFlags);
Пример #39
0
 [System.Security.SecurityCritical]  // auto-generated
 private void AllocateBuffer(uint size)
 {
     _encryptedBuffer = SafeBSTRHandle.Allocate(null, size);
 }
Пример #40
0
 internal static extern uint SysStringLen(SafeBSTRHandle bstr);
Пример #41
0
        [System.Security.SecurityCritical]  // auto-generated
        private void EnsureCapacity(ref SafeBSTRHandle decryptedBuffer, int capacity)
        {
            if (capacity > MaxLength)
            {
                throw new ArgumentOutOfRangeException("capacity", SR.ArgumentOutOfRange_Capacity);
            }

            if (capacity <= _decryptedLength)
            {
                return;
            }

            SafeBSTRHandle newBuffer = SafeBSTRHandle.Allocate(null, (uint)capacity);
            SafeBSTRHandle.Copy(decryptedBuffer, newBuffer, (uint)_decryptedLength * sizeof(char));
            decryptedBuffer.Dispose();
            decryptedBuffer = newBuffer;
        }
Пример #42
0
        [System.Security.SecurityCritical]  // auto-generated
        private void ProtectMemory(SafeBSTRHandle decryptedBuffer)
        {
            Debug.Assert(!decryptedBuffer.IsInvalid, "Invalid buffer!");

            if (_decryptedLength == 0)
            {
                return;
            }

            try
            {
                SafeBSTRHandle newEncryptedBuffer = null;
                if (Interop.Crypt32.CryptProtectData(decryptedBuffer, out newEncryptedBuffer))
                {
                    _encryptedBuffer.Dispose();
                    _encryptedBuffer = newEncryptedBuffer;
                }
                else
                {
                    throw new CryptographicException(Marshal.GetLastWin32Error());
                }
            }
            finally
            {
                decryptedBuffer.ClearBuffer();
                decryptedBuffer.Dispose();
            }
        }
Пример #43
0
 private void AllocateBuffer(uint size)
 {
     _buffer = SafeBSTRHandle.Allocate(GetAlignedSize(size));
 }
Пример #44
0
 internal static extern void ZeroMemory(SafeBSTRHandle address, uint length);
Пример #45
0
 public void Dispose() {
     if(m_buffer != null && !m_buffer.IsInvalid) {
         m_buffer.Close();
         m_buffer = null;   
     }            
 }
 private void EnsureCapacity(int capacity)
 {
     if (capacity > 0x10000)
     {
         throw new ArgumentOutOfRangeException("capacity", Environment.GetResourceString("ArgumentOutOfRange_Capacity"));
     }
     if (capacity > this.m_buffer.Length)
     {
         SafeBSTRHandle target = SafeBSTRHandle.Allocate(null, GetAlignedSize(capacity));
         if (target.IsInvalid)
         {
             throw new OutOfMemoryException();
         }
         SafeBSTRHandle.Copy(this.m_buffer, target);
         this.m_buffer.Close();
         this.m_buffer = target;
     }
 }
Пример #47
0
        [System.Security.SecurityCritical]  // auto-generated
        private void EnsureCapacity(int capacity) {            
            if( capacity > MaxLength) {
                throw new ArgumentOutOfRangeException("capacity", Environment.GetResourceString("ArgumentOutOfRange_Capacity"));
            }
            Contract.EndContractBlock();

            if( capacity <= m_buffer.Length) {
                return;
            }

            SafeBSTRHandle newBuffer = SafeBSTRHandle.Allocate(null, GetAlignedSize(capacity));

            if (newBuffer.IsInvalid) {
                throw new OutOfMemoryException();
            }                

            SafeBSTRHandle.Copy(m_buffer, newBuffer);
            m_buffer.Close();
            m_buffer = newBuffer;                
        }
 public void Dispose()
 {
     if ((this.m_buffer != null) && !this.m_buffer.IsInvalid)
     {
         this.m_buffer.Close();
         this.m_buffer = null;
     }
 }