RtlCompressBuffer API in C#
本文关键字:in API RtlCompressBuffer | 更新日期: 2023-09-27 18:02:14
我正在尝试在c#项目中使用RtlGetCompressionWorkSpaceSize和RtlCompressBuffer函数。
到目前为止我写的是:
class Program
{
const uint COMPRESSION_FORMAT_LZNT1 = 2;
const uint COMPRESSION_ENGINE_MAXIMUM = 0x100;
[DllImport("ntdll.dll")]
static extern uint RtlGetCompressionWorkSpaceSize(uint CompressionFormat, out uint pNeededBufferSize, out uint Unknown);
[DllImport("ntdll.dll")]
static extern uint RtlCompressBuffer(uint CompressionFormat, byte[] SourceBuffer, uint SourceBufferLength, out byte[] DestinationBuffer,
uint DestinationBufferLength, uint Unknown, out uint pDestinationSize, IntPtr WorkspaceBuffer);
static void Main(string[] args)
{
uint dwSize = 0;
uint dwRet = 0;
uint ret = RtlGetCompressionWorkSpaceSize(COMPRESSION_FORMAT_LZNT1 | COMPRESSION_ENGINE_MAXIMUM, out dwSize, out dwRet);
IntPtr pMem = Marshal.AllocHGlobal((int)dwSize);
byte[] buffer = new byte[1024];
byte[] outBuf = new byte[1024];
uint destSize = 0;
ret = RtlCompressBuffer(COMPRESSION_FORMAT_LZNT1 | COMPRESSION_ENGINE_MAXIMUM, buffer, 1024, out outBuf, 1024, 0, out destSize, pMem);
Console.Write(ret.ToString());
Console.Read();
}
}
RtlGetCompressionWorkSpaceSize工作,因为它返回0 (NT成功代码),但当我调用RtlCompressBuffer时,我得到内存访问冲突错误。
编辑:在David的回答的帮助下,我已经修复了这个问题,正确的代码如下。 const ushort COMPRESSION_FORMAT_LZNT1 = 2;
const ushort COMPRESSION_ENGINE_MAXIMUM = 0x100;
[DllImport("ntdll.dll")]
static extern uint RtlGetCompressionWorkSpaceSize(ushort CompressionFormat, out uint pNeededBufferSize, out uint Unknown);
[DllImport("ntdll.dll")]
static extern uint RtlCompressBuffer(ushort CompressionFormat, byte[] SourceBuffer, int SourceBufferLength, byte[] DestinationBuffer,
int DestinationBufferLength, uint Unknown, out int pDestinationSize, IntPtr WorkspaceBuffer);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
internal static extern IntPtr LocalAlloc(int uFlags, IntPtr sizetdwBytes);
[DllImport("kernel32.dll", SetLastError = true)]
static extern IntPtr LocalFree(IntPtr hMem);
internal static byte[] Compress(byte[] buffer)
{
var outBuf = new byte[buffer.Length * 6];
uint dwSize = 0, dwRet = 0;
uint ret = RtlGetCompressionWorkSpaceSize(COMPRESSION_FORMAT_LZNT1 | COMPRESSION_ENGINE_MAXIMUM, out dwSize, out dwRet);
if (ret != 0)
{
return null;
}
int dstSize = 0;
IntPtr hWork = LocalAlloc(0, new IntPtr(dwSize));
ret = RtlCompressBuffer(COMPRESSION_FORMAT_LZNT1 | COMPRESSION_ENGINE_MAXIMUM, buffer,
buffer.Length, outBuf, outBuf.Length, 0, out dstSize, hWork);
if (ret != 0)
{
return null;
}
LocalFree(hWork);
Array.Resize(ref outBuf, dstSize);
return outBuf;
}
你就快成功了。问题是RtlCompressBuffer
的P/调用的这一部分:
out byte[] DestinationBuffer
byte[]
的默认封送是对数组内容在两个方向上进行封送,从托管到非托管,然后在函数返回时再返回。RtlCompressBuffer
的C定义用__out
注释,但这意味着数组内容是__out
而不是指针是__out
。
将p/invoke更改为
byte[] DestinationBuffer
,同样在RtlCompressBuffer
的调用中,将out outBuf
更改为outBuf
,您应该可以很好地运行。
请注意,您的代码将返回状态码STATUS_BUFFER_ALL_ZEROS
,因此不要误以为此非零返回值表示失败。
最后一点,两个p/调用的第一个参数CompressionFormat
应该声明为ushort
。