PGP Compress and Encrypt

Question

I’m using Bouncy Castles to compress and encrypt some data. The compress method fails with a null reference exception. The following method performs compression:

private byte[] Compress(byte[] data)
        {
            using (MemoryStream outStream = new MemoryStream())
            {
                PgpCompressedDataGenerator pgpCompressedDataGenerator = new PgpCompressedDataGenerator(CompressionAlgorithmTag.Zip);
                using (Stream compressedStream = pgpCompressedDataGenerator.Open(outStream))
                {
                    PgpLiteralDataGenerator pgpLiteralDataGenerator = new PgpLiteralDataGenerator();

                    using (Stream literalDataStream = pgpLiteralDataGenerator.Open(compressedStream, PgpLiteralData.Binary, null, data.Length, DateTime.UtcNow))
                    {
                        literalDataStream.Write(data, 0, data.Length);

                        literalDataStream.Close();

                        pgpCompressedDataGenerator.Close();

                        return outStream.ToArray();
                    }
                }
            }
        }

The following line causes the bulk reference exception:

pgpLiteralDataGenerator.Open(compressedStream, PgpLiteralData.Binary, null, data.Length, DateTime.UtcNow))

However I don’t know why - if I leave compression out, the encryption part works as expected. Do I need another library to perform the compression,

Mark

Answer 1

It turns out the null parameter in the call below was causing the problem:

pgpLiteralDataGenerator.Open(compressedStream, PgpLiteralData.Binary, null, data.Length, DateTime.UtcNow))

This code was a direct copy from another project, however in that project the Bouncy Castles API was brought in with iTextSharp - I'm assuming there's a slight difference in implementation.