Unable to decompress file after decrypt it

Question

I'm compressing and then encrypting a file. Not problem with this. Problems come when I try to decrypt the file and finally, I try to decompress the decrypted file. In that moment, I get an exception in ReadEndOfCentralDirectory: (Updated)

Offset to Central Directory cannot be held in an Int64.
en System.IO.Compression.ZipArchive.ReadEndOfCentralDirectory()
en System.IO.Compression.ZipArchive.Init(Stream stream, ZipArchiveMode mode, Boolean leaveOpen)
en System.IO.Compression.ZipArchive..ctor(Stream stream, ZipArchiveMode mode, Boolean leaveOpen, Encoding entryNameEncoding)
en System.IO.Compression.ZipFile.Open(String archiveFileName, ZipArchiveMode mode, Encoding entryNameEncoding)
en System.IO.Compression.ZipFile.ExtractToDirectory(String sourceArchiveFileName, String destinationDirectoryName, Encoding entryNameEncoding)
en System.IO.Compression.ZipFile.ExtractToDirectory(String sourceArchiveFileName, String destinationDirectoryName)`

For zip the folder I'm using this

 ZipFile.CreateFromDirectory(sourcePath, pathZipFile, CompressionLevel.Fastest, false);

For encrypt:

            RijndaelManaged key = new RijndaelManaged();

            key.KeySize = 256;
            key.BlockSize = 256;
            key.Padding = System.Security.Cryptography.PaddingMode.ISO10126;
            key.Key = Convert.FromBase64String(aes);
            key.IV = Convert.FromBase64String(aes);

            ICryptoTransform encryptor = key.CreateEncryptor();
            using (FileStream InputFile = new FileStream(sourcePath, FileMode.Open, FileAccess.Read))
            using (FileStream OutputFile = new FileStream(targetPath, FileMode.Create, FileAccess.Write))
            {
                using (CryptoStream csEncrypt = new CryptoStream(OutputFile, encryptor, CryptoStreamMode.Write))
                {

                    long total = InputFile.Length;
                    var buffer = new byte[total];
                    var read = InputFile.Read(buffer, 0, buffer.Length);
                    csEncrypt.Write(buffer, 0, read);
                }
            }

For decrypt:

            RijndaelManaged key = new RijndaelManaged();

            key.KeySize = 256;
            key.BlockSize = 256;
            key.Padding = System.Security.Cryptography.PaddingMode.ISO10126;
            key.Key = Convert.FromBase64String(aes);
            key.IV = Convert.FromBase64String(aes);
            ICryptoTransform cryptor = key.CreateDecryptor();
            using (FileStream InputFile = new FileStream(sourcePath, FileMode.Open, FileAccess.Read))
            {
                CryptoStream csEncrypt = new CryptoStream(InputFile, cryptor, CryptoStreamMode.Read);
                StreamWriter fsDecrypted = new StreamWriter(targetPath);
                fsDecrypted.Write(new StreamReader(csEncrypt).ReadToEnd());
                fsDecrypted.Close();
            }

For unzip:

ZipFile.ExtractToDirectory(zipPath, extractPath);

If I change the whole process and first of all I encrypt file, then compress it, I can decompress it and finally decrypt it without problems. Could be the issue in the encryption/decryption phase (maybe related to encoding, bytes or similar...)? Thanks in advance.

Answer 1

StreamWriter you're writing text. You should write bytes. The conversion is not lossless. Use FileStream.