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Is there a way to unzip a DynaZip Max file with another library? FE DotNetZip

I have a database in which we saved pdf files compressed with DynaZip Max Secure using the following code:

MemoryStream msIN = new System.IO.MemoryStream(); //Input MemoryStream MemoryStream msZip = new System.IO.MemoryStream(); //Compressed MemoryStream BinaryReader objBinaryReader; BinaryWriter objBinaryWriter; public MemoryStream CompressStream(byte[] vbuf) { System.IO.BinaryWriter bw = new System.IO.BinaryWriter(msIN); bw.Write(vbuf); CDZipSNET dz1 = new CDZipSNET(); dz1.ZipMemToMemCallback += new CDZipSNET.OnZipMemToMemCallback(this.ZipMemToMemCallback_event); dz1.ActionDZ = CDZipSNET.DZACTION.ZIP_MEMTOMEM; return msZip; }

And this is the ZipMemToMemCallback_event code:

 public void ZipMemToMemCallback_event(CDZipSNET.MEMTOMEMACTION lAction,ref byte[] lpMemBuf,ref uint pdwSize,uint dwTotalReadL,uint dwTotalReadH,uint dwTotalWrittenL,uint dwTotalWrittenH,ref CDZipSNET.MEMTOMEMRESPONSE plRet) { int bytesToRead; switch(lAction) { case CDZipSNET.MEMTOMEMACTION.MEM_READ_DATA: if((dwTotalReadL == 0) && (dwTotalReadH == 0)) { msIN.Seek(0, System.IO.SeekOrigin.Begin); objBinaryReader = new System.IO.BinaryReader(msIN); } try { bytesToRead = (int)(objBinaryReader.BaseStream.Length - dwTotalReadL); if(bytesToRead > pdwSize) { bytesToRead = (int)pdwSize; plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_CONTINUE; } else { plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_DONE; } pdwSize = (uint)bytesToRead; if(bytesToRead > 0) { objBinaryReader.Read(lpMemBuf, 0, bytesToRead); } } catch { plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_ERROR; } break; case CDZipSNET.MEMTOMEMACTION.MEM_WRITE_DATA: if((dwTotalWrittenL == 0) && (dwTotalWrittenH == 0)) { objBinaryWriter = new System.IO.BinaryWriter(msZip); } try { objBinaryWriter.Write(lpMemBuf, 0, (int)pdwSize); plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_CONTINUE; } catch (System.Exception) { plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_ERROR; } break; default: plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_ERROR; break; } } byte [] lpMemBuf, ref uint pdwSize, uint dwTotalReadL, uint dwTotalReadH, uint dwTotalWrittenL, uint dwTotalWrittenH, ref CDZipSNET.MEMTOMEMRESPONSE plRet) public void ZipMemToMemCallback_event(CDZipSNET.MEMTOMEMACTION lAction,ref byte[] lpMemBuf,ref uint pdwSize,uint dwTotalReadL,uint dwTotalReadH,uint dwTotalWrittenL,uint dwTotalWrittenH,ref CDZipSNET.MEMTOMEMRESPONSE plRet) { int bytesToRead; switch(lAction) { case CDZipSNET.MEMTOMEMACTION.MEM_READ_DATA: if((dwTotalReadL == 0) && (dwTotalReadH == 0)) { msIN.Seek(0, System.IO.SeekOrigin.Begin); objBinaryReader = new System.IO.BinaryReader(msIN); } try { bytesToRead = (int)(objBinaryReader.BaseStream.Length - dwTotalReadL); if(bytesToRead > pdwSize) { bytesToRead = (int)pdwSize; plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_CONTINUE; } else { plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_DONE; } pdwSize = (uint)bytesToRead; if(bytesToRead > 0) { objBinaryReader.Read(lpMemBuf, 0, bytesToRead); } } catch { plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_ERROR; } break; case CDZipSNET.MEMTOMEMACTION.MEM_WRITE_DATA: if((dwTotalWrittenL == 0) && (dwTotalWrittenH == 0)) { objBinaryWriter = new System.IO.BinaryWriter(msZip); } try { objBinaryWriter.Write(lpMemBuf, 0, (int)pdwSize); plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_CONTINUE; } catch (System.Exception) { plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_ERROR; } break; default: plRet = CDZipSNET.MEMTOMEMRESPONSE.MEM_ERROR; break; } }

I provided everything that was necessary to answer this riddle, I tried the usual unpacking of Zip, Zlib, Gzip to no avail. I would appreciate any help. Thanks.

Edit: The problem is that DinaZip is a proprietary library with discontinued access, without the help or troubleshooting of the company that released it. I am tasked with unpacking a bunch of files that were previously compressed using this library (with avobe code), and I no longer have a library available for decompression. I wonder if anyone knows how to unzip these files using another library or method.

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This code is from https://zlibnet.codeplex.com and can decompress unencrypted DynaZip streams:

 public static class DynazipCompressor { const int DZ_DEFLATE_POS = 46; public static bool IsDynazip(byte[] source) { return source.Length >= 4 && BitConverter.ToInt32(source, 0) == 0x02014b50; } public static byte[] DeCompress(byte[] source) { if (!IsDynazip(source)) throw new InvalidDataException("not dynazip header"); using (MemoryStream srcStream = new MemoryStream(source, DZ_DEFLATE_POS, source.Length - DZ_DEFLATE_POS)) using (MemoryStream dstStream = DeCompress(srcStream)) return dstStream.ToArray(); } private static MemoryStream DeCompress(Stream source) { MemoryStream dest = new MemoryStream(); DeCompress(source, dest); dest.Position = 0; return dest; } private static void DeCompress(Stream source, Stream dest) { using (DeflateStream zsSource = new DeflateStream(source, CompressionMode.Decompress, true)) { zsSource.CopyTo(dest); } } }

The DynaZip stream is just a DeflateStream with a PKZIP header, so this code just skips the header.

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