Biztalk Server 2016 : PGP decryption using Bouncy Castle

Question

Hi All,

I am using bouncy castle for decryption in custom pipeline cxomponent.

At this point in code i am getting null reference error. what could be possible reason and workaround for this.

foreach (PgpPublicKeyEncryptedData pubKeyDataItem in encryptedData.GetEncryptedDataObjects())

Please advise. Thanks in advance.

Regards,
Pooja

Answer 1

Hi,

Unfortunately it's impossible to say without more code or a stacktrace.

But the only thing that could be null in the code you provided is the variable encryptedData.

Br,
Leo

Answer 2

This is method :

public static string DecryptPgpData(Stream inputStream, Stream privateKeyStream, string passPhrase)
{
string output;

        PgpObjectFactory pgpFactory = new PgpObjectFactory(PgpUtilities.GetDecoderStream(inputStream));
        // find secret key
        PgpSecretKeyRingBundle pgpKeyRing = new PgpSecretKeyRingBundle(PgpUtilities.GetDecoderStream(privateKeyStream));

        PgpObject pgp = null;
        if (pgpFactory != null)
        {
            pgp = pgpFactory.NextPgpObject();
        }

        // the first object might be a PGP marker packet.
        PgpEncryptedDataList encryptedData = null;
        if (pgp is PgpEncryptedDataList)
        {
            encryptedData = (PgpEncryptedDataList)pgp;
        }
        else
        {
            encryptedData = (PgpEncryptedDataList)pgpFactory.NextPgpObject();
        }

        // decrypt
        PgpPrivateKey privateKey = null;
        PgpPublicKeyEncryptedData pubKeyData = null;
        ***foreach (PgpPublicKeyEncryptedData pubKeyDataItem in encryptedData.GetEncryptedDataObjects())***
        {
            privateKey = FindSecretKey(pgpKeyRing, pubKeyDataItem.KeyId, passPhrase.ToCharArray());

            if (privateKey != null)
            {
                pubKeyData = pubKeyDataItem;
                break;
            }
        }

        if (privateKey == null)
        {
            throw new ArgumentException("Secret key for message not found.");
        }

        PgpObjectFactory plainFact = null;
        using (Stream clear = pubKeyData.GetDataStream(privateKey))
        {
            plainFact = new PgpObjectFactory(clear);
        }

        PgpObject message = plainFact.NextPgpObject();

        if (message is PgpCompressedData)
        {
            PgpCompressedData compressedData = (PgpCompressedData)message;
            PgpObjectFactory pgpCompressedFactory = null;

            using (Stream compDataIn = compressedData.GetDataStream())
            {
                pgpCompressedFactory = new PgpObjectFactory(compDataIn);
            }

            message = pgpCompressedFactory.NextPgpObject();
            PgpLiteralData literalData = null;
            if (message is PgpOnePassSignatureList)
            {
                message = pgpCompressedFactory.NextPgpObject();
            }

            literalData = (PgpLiteralData)message;
            using (Stream unc = literalData.GetInputStream())
            {
                output = IoHelper.GetString(unc);
            }

        }
        else if (message is PgpLiteralData)
        {
            PgpLiteralData literalData = (PgpLiteralData)message;
            using (Stream unc = literalData.GetInputStream())
            {
                output = IoHelper.GetString(unc);
            }
        }
        else if (message is PgpOnePassSignatureList)
        {
            throw new PgpException("Encrypted message contains a signed message - not literal data.");
        }
        else
        {
            throw new PgpException("Message is not a simple encrypted file - type unknown.");
        }

        return output;
    }

Answer 3

This issue seems since long time but no body posted solution to this.

PSB links:

https://social.msdn.microsoft.com/Forums/vstudio/en-US/d42b0708-a06b-417e-a834-754f0dcfde92/pgp-encryption-using-visual-studio-2005?forum=csharpgeneral

https://gist.github.com/tekmaven/03fddd1b156f0149f28e66a7c675d94e