byte array compression

using System.IO;
using System.IO.Compression;

public static byte[] Compress(byte[] buffer)
        {
            MemoryStream ms = new MemoryStream();
            GZipStream zip = new GZipStream(ms, CompressionMode.Compress, true);
            zip.Write(buffer, 0, buffer.Length);
            zip.Close();
            ms.Position = 0;

            MemoryStream outStream = new MemoryStream();

            byte[] compressed = new byte[ms.Length];
            ms.Read(compressed, 0, compressed.Length);

            byte[] gzBuffer = new byte[compressed.Length + 4];
            Buffer.BlockCopy(compressed, 0, gzBuffer, 4, compressed.Length);
            Buffer.BlockCopy(BitConverter.GetBytes(buffer.Length), 0, gzBuffer, 0, 4);
            return gzBuffer;
        }

        public static byte[] Decompress(byte[] gzBuffer)
        {
            MemoryStream ms = new MemoryStream();
            int msgLength = BitConverter.ToInt32(gzBuffer, 0);
            ms.Write(gzBuffer, 4, gzBuffer.Length - 4);

            byte[] buffer = new byte[msgLength];

            ms.Position = 0;
            GZipStream zip = new GZipStream(ms, CompressionMode.Decompress);
            zip.Read(buffer, 0, buffer.Length);

            return buffer;
        }