Could not upload data to blob - The argument must not be empty string

[Nisden]

Enabling SendBigMessagesAsAttachments together with StoreInBlobStorage throws an exception that says "The argument must not be empty string"

Our configuration is pretty basic

var dataBusOptions = d.StoreInBlobStorage(configuration.GetConnectionString("AzureStorage"), storageOptions.DataBusContainer);
d.SendBigMessagesAsAttachments(0); // When we approach the limit of Azure Storage Queues we want to transfer to blob storage
d.EnableEncryption(); // Encrypted while stored

if (!storageOptions.AllowAutoCreate)
    dataBusOptions.DoNotCreateContainer();

Full exception

Rebus.Exceptions.RebusApplicationException: Could not create (automatic claim check) attachment for outgoing message with ID 83b2a3fe-a812-4874-9da2-41b747691db5
 ---> System.IO.IOException: Could not upload data to blob named 'data-5c7c7972-b94c-4b53-a249-225b2e69f627.dat' in the 'databus' container
 ---> Microsoft.Azure.Storage.StorageException: The argument must not be empty string.
 ---> System.ArgumentException: The argument must not be empty string.
   at Microsoft.Azure.Storage.Shared.Protocol.HttpRequestMessageFactory.AddMetadata(StorageRequestMessage request, String name, String value)
   at Microsoft.Azure.Storage.Shared.Protocol.HttpRequestMessageFactory.AddMetadata(StorageRequestMessage request, IDictionary`2 metadata)
   at Microsoft.Azure.Storage.Blob.Protocol.BlobHttpRequestMessageFactory.AddMetadata(StorageRequestMessage request, IDictionary`2 metadata)
   at Microsoft.Azure.Storage.Blob.CloudBlockBlob.<>c__DisplayClass145_0.<PutBlobImpl>b__1(RESTCommand`1 cmd, Uri uri, UriQueryBuilder builder, HttpContent cnt, Nullable`1 serverTimeout, OperationContext ctx)
   at Microsoft.Azure.Storage.Core.Executor.Executor.ProcessStartOfRequest[T](ExecutionState`1 executionState, String startLogMessage, CancellationTokenSource timeoutTokenSource)
   at Microsoft.Azure.Storage.Core.Executor.Executor.ExecuteAsync[T](RESTCommand`1 cmd, IRetryPolicy policy, OperationContext operationContext, CancellationToken token)
   --- End of inner exception stack trace ---
   at Microsoft.Azure.Storage.Core.Executor.Executor.ExecuteAsync[T](RESTCommand`1 cmd, IRetryPolicy policy, OperationContext operationContext, CancellationToken token)
   at Microsoft.Azure.Storage.Blob.CloudBlockBlob.UploadFromStreamAsyncHelper(Stream source, Nullable`1 length, AccessCondition accessCondition, BlobRequestOptions options, OperationContext operationContext, AggregatingProgressIncrementer progressIncrementer, CancellationToken cancellationToken)
   at Rebus.AzureBlobs.DataBus.AzureBlobsDataBusStorage.Save(String id, Stream source, Dictionary`2 metadata)
Request Information
RequestID:
RequestDate:
StatusMessage:
ErrorCode:

   --- End of inner exception stack trace ---
   at Rebus.AzureBlobs.DataBus.AzureBlobsDataBusStorage.Save(String id, Stream source, Dictionary`2 metadata)
   at Rebus.Encryption.EncryptingDataBusStorageDecorator.Save(String id, Stream source, Dictionary`2 metadata)
   at Rebus.DataBus.DefaultDataBus.CreateAttachment(Stream source, Dictionary`2 optionalMetadata)
   at Rebus.DataBus.ClaimCheck.DehydrateOutgoingMessageStep.DehydrateTransportMessage(OutgoingStepContext context, TransportMessage transportMessage)
   --- End of inner exception stack trace ---
   at Rebus.DataBus.ClaimCheck.DehydrateOutgoingMessageStep.DehydrateTransportMessage(OutgoingStepContext context, TransportMessage transportMessage)
   at Rebus.DataBus.ClaimCheck.DehydrateOutgoingMessageStep.Process(OutgoingStepContext context, Func`1 next)
   at Rebus.Encryption.EncryptMessagesOutgoingStep.Process(OutgoingStepContext context, Func`1 next)
   at Rebus.Pipeline.Send.SerializeOutgoingMessageStep.Process(OutgoingStepContext context, Func`1 next)
   at Rebus.Pipeline.Send.AutoHeadersOutgoingStep.Process(OutgoingStepContext context, Func`1 next)
   at Rebus.Pipeline.Send.FlowCorrelationIdStep.Process(OutgoingStepContext context, Func`1 next)
   at Rebus.Pipeline.Send.AssignDefaultHeadersStep.Process(OutgoingStepContext context, Func`1 next)
   at Rebus.ServiceProvider.ServiceProviderProviderStep.Process(OutgoingStepContext context, Func`1 next)
   at Rebus.Bus.RebusBus.SendUsingTransactionContext(IEnumerable`1 destinationAddresses, Message logicalMessage, ITransactionContext transactionContext)
   at Rebus.Bus.RebusBus.InnerSend(IEnumerable`1 destinationAddresses, Message logicalMessage)
   at Rebus.Bus.RebusBus.Send(Object commandMessage, IDictionary`2 optionalHeaders)

[Nisden]

Might have found the bug (And will be testing it very soon), I think its because my custom encryption have an empty IV.

[mookid8000]

I've tried to reproduce it, but without success.

The test is here: https://github.com/rebus-org/Rebus.AzureBlobs/blob/master/Rebus.AzureBlobs.Tests/Bugs/ReproduceDataBusNullReferenceException.cs

Can you see if there's anything different in your code?

[Nisden]

Just confirmed it, my issue was my custom encryption based on a DataProtectionProvider

internal sealed class RebusDataProtectionEncryption : IEncryptor
{
    private readonly IDataProtector dataProtector;

    public string ContentEncryptionValue => "dataprotection";

    public RebusDataProtectionEncryption(IDataProtectionProvider dataProtectionProvider)
    {
        dataProtector = dataProtectionProvider.CreateProtector("Rebus");
    }

    public byte[] Decrypt(EncryptedData encryptedData)
    {
        return dataProtector.Unprotect(encryptedData.Bytes);
    }

    public EncryptedData Encrypt(byte[] bytes)
    {
        return new EncryptedData(dataProtector.Protect(bytes), Array.Empty<byte>());
    }
}

Having added an "dummy" IV it works now, instead of Array.Empty