Class SignedCloudEventExtensions

Namespace

Savvyio.EventDriven.Messaging.CloudEvents.Cryptography

Assembly

Savvyio.EventDriven.Messaging.dll

Extension methods for the ICloudEvent<T> interface.

public static class SignedCloudEventExtensions

Inheritance

object

SignedCloudEventExtensions

Examples

This example shows how to verify a signed CloudEvent before deserializing it into application-level event processing.

using System;
using Savvyio;
using Savvyio.EventDriven;
using Savvyio.EventDriven.Messaging.CloudEvents;
using Savvyio.EventDriven.Messaging.CloudEvents.Cryptography;
using Savvyio.Messaging;

namespace ExampleApp;

using System;
using System.IO;
using System.Text;
using Savvyio;

public sealed class DemoMarshaller : IMarshaller
{
    public Stream Serialize<TValue>(TValue value) => new MemoryStream(Encoding.UTF8.GetBytes(value?.ToString() ?? string.Empty));
    public Stream Serialize(object value, Type inputType) => Serialize(value?.ToString() ?? string.Empty);
    public TValue Deserialize<TValue>(Stream data) => throw new NotSupportedException();
    public object Deserialize(Stream data, Type returnType) => throw new NotSupportedException();
}

public sealed class SignedCloudEventExtensionsExample
{
    public void Verify()
    {
        var message = new Message<MemberCreatedEvent>("msg-42", new Uri("https://api.example.com/members"), "members.created", new MemberCreatedEvent("MEM-42"));
        var signed = message.ToCloudEvent().SignCloudEvent(new DemoMarshaller(), options => options.SignatureSecret = new byte[] { 1, 2, 3 });
        signed.CheckCloudEventSignature(new DemoMarshaller(), options => options.SignatureSecret = new byte[] { 1, 2, 3 });
    }
}

public sealed record MemberCreatedEvent(string MemberId) : Request, IIntegrationEvent;

Methods

CheckCloudEventSignature<T>(ISignedCloudEvent<T>, IMarshaller, Action<SignedMessageOptions>)

Verifies the digital signature of the ISignedCloudEvent<T> message.

public static void CheckCloudEventSignature<T>(this ISignedCloudEvent<T> cloudEvent, IMarshaller marshaller, Action<SignedMessageOptions> setup) where T : IIntegrationEvent

Parameters

cloudEvent ISignedCloudEvent<T>

The IRequest message to cryptographically verify.

marshaller IMarshaller

The IMarshaller that is used when converting the cloudEvent into an ISignedCloudEvent<T>.

setup Action<SignedMessageOptions>

The SignedMessageOptions that must be configured.

Type Parameters

T

The type of the payload constraint to the IRequest interface.

Remarks

This method throws an ArgumentOutOfRangeException if the verification of the digital signature fails.

Exceptions

ArgumentNullException

cloudEvent cannot be null -or- marshaller cannot be null.

ArgumentException

setup failed to configure an instance of SignedMessageOptions in a valid state.

ArgumentOutOfRangeException

cloudEvent signature did not match the cryptographically calculated value.