#### [Abblix\.SecurityEvents](https://www.abblix.com/en/docs/api/abblix-securityevents 'index') ### [Abblix\.SecurityEvents\.Delivery](https://www.abblix.com/en/docs/api/abblix-securityevents/Abblix.SecurityEvents.Delivery 'Abblix\.SecurityEvents\.Delivery') ## PushDeliveryHandler Class The host\-agnostic core of a push delivery endpoint \(RFC 8935\): one method from the raw transmission \- content type and body \- to the [PushDeliveryResult](https://www.abblix.com/en/docs/api/abblix-securityevents/Abblix.SecurityEvents.Delivery.PushDeliveryResult 'Abblix\.SecurityEvents\.Delivery\.PushDeliveryResult') the transport renders\. A host adapter owns routing and transmitter authentication; this type owns everything the specifications say about the SET itself\. ```csharp public sealed class PushDeliveryHandler ``` Inheritance [System\.Object](https://learn.microsoft.com/en-us/dotnet/api/system.object 'System\.Object') → PushDeliveryHandler ### Remarks The order inside is the security order. Validation decides first, so an attacker cannot burn replay identifiers with forgeries; the sink then consumes what validation let through; and only a token the sink accepted is written to the replay cache. Nothing on this path READS that cache, so a redelivery reaches the sink again - RFC 8935 Section 2 lets a transmitter redeliver regardless of earlier responses, and [ISecurityEventSink](https://www.abblix.com/en/docs/api/abblix-securityevents/Abblix.SecurityEvents.Delivery.ISecurityEventSink 'Abblix\.SecurityEvents\.Delivery\.ISecurityEventSink') answers for it by requiring idempotent processing. Why the write cannot come earlier, and why that is the only correct order available here, is on `RecordAsync`. Nothing here knows which profile of SET it carries. RFC 8935 is a delivery specification and the kinds it delivers are somebody else's business, so the three things that differ between consumers - the validation profile, what that profile expects, and where events land - arrive as parameters. The consumer's own registration binds them, which is also why the profile cannot be named by a keyed-service attribute here: an attribute takes a compile-time constant, and the key belongs to whoever registers this. ### Constructors ## PushDeliveryHandler\(ISecurityEventTokenValidator, SecurityEventTokenValidationOptions, ISecurityEventSink, IReplayCache\) Constructor {#Abblix.SecurityEvents.Delivery.PushDeliveryHandler.PushDeliveryHandler(Abblix.SecurityEvents.Validation.ISecurityEventTokenValidator,Abblix.SecurityEvents.Validation.SecurityEventTokenValidationOptions,Abblix.SecurityEvents.Delivery.ISecurityEventSink,Abblix.Jwt.ReplayPrevention.IReplayCache)} The host\-agnostic core of a push delivery endpoint \(RFC 8935\): one method from the raw transmission \- content type and body \- to the [PushDeliveryResult](https://www.abblix.com/en/docs/api/abblix-securityevents/Abblix.SecurityEvents.Delivery.PushDeliveryResult 'Abblix\.SecurityEvents\.Delivery\.PushDeliveryResult') the transport renders\. A host adapter owns routing and transmitter authentication; this type owns everything the specifications say about the SET itself\. ```csharp public PushDeliveryHandler(Abblix.SecurityEvents.Validation.ISecurityEventTokenValidator validator, Abblix.SecurityEvents.Validation.SecurityEventTokenValidationOptions options, Abblix.SecurityEvents.Delivery.ISecurityEventSink sink, Abblix.Jwt.ReplayPrevention.IReplayCache? replayCache=null); ``` #### Parameters ###### `validator` [ISecurityEventTokenValidator](https://www.abblix.com/en/docs/api/abblix-securityevents/Abblix.SecurityEvents.Validation.ISecurityEventTokenValidator 'Abblix\.SecurityEvents\.Validation\.ISecurityEventTokenValidator') {#Abblix.SecurityEvents.Delivery.PushDeliveryHandler.PushDeliveryHandler(Abblix.SecurityEvents.Validation.ISecurityEventTokenValidator,Abblix.SecurityEvents.Validation.SecurityEventTokenValidationOptions,Abblix.SecurityEvents.Delivery.ISecurityEventSink,Abblix.Jwt.ReplayPrevention.IReplayCache).validator} The validation pipeline, which the registering consumer resolves from its OWN named profile \- never the host's plain family, which another consumer of security event tokens may have shaped to refuse every SET of this kind\. ###### `options` [SecurityEventTokenValidationOptions](https://www.abblix.com/en/docs/api/abblix-securityevents/Abblix.SecurityEvents.Validation.SecurityEventTokenValidationOptions 'Abblix\.SecurityEvents\.Validation\.SecurityEventTokenValidationOptions') {#Abblix.SecurityEvents.Delivery.PushDeliveryHandler.PushDeliveryHandler(Abblix.SecurityEvents.Validation.ISecurityEventTokenValidator,Abblix.SecurityEvents.Validation.SecurityEventTokenValidationOptions,Abblix.SecurityEvents.Delivery.ISecurityEventSink,Abblix.Jwt.ReplayPrevention.IReplayCache).options} What that consumer expects of every token it accepts\. ###### `sink` [ISecurityEventSink](https://www.abblix.com/en/docs/api/abblix-securityevents/Abblix.SecurityEvents.Delivery.ISecurityEventSink 'Abblix\.SecurityEvents\.Delivery\.ISecurityEventSink') {#Abblix.SecurityEvents.Delivery.PushDeliveryHandler.PushDeliveryHandler(Abblix.SecurityEvents.Validation.ISecurityEventTokenValidator,Abblix.SecurityEvents.Validation.SecurityEventTokenValidationOptions,Abblix.SecurityEvents.Delivery.ISecurityEventSink,Abblix.Jwt.ReplayPrevention.IReplayCache).sink} Where validated events land\. ###### `replayCache` [IReplayCache](https://www.abblix.com/en/docs/api/abblix-jwt/Abblix.Jwt.ReplayPrevention.IReplayCache 'Abblix\.Jwt\.ReplayPrevention\.IReplayCache') {#Abblix.SecurityEvents.Delivery.PushDeliveryHandler.PushDeliveryHandler(Abblix.SecurityEvents.Validation.ISecurityEventTokenValidator,Abblix.SecurityEvents.Validation.SecurityEventTokenValidationOptions,Abblix.SecurityEvents.Delivery.ISecurityEventSink,Abblix.Jwt.ReplayPrevention.IReplayCache).replayCache} Tells first deliveries from repeats; null runs without replay tracking, leaving idempotency entirely to the sink's contract\. ### Remarks The order inside is the security order. Validation decides first, so an attacker cannot burn replay identifiers with forgeries; the sink then consumes what validation let through; and only a token the sink accepted is written to the replay cache. Nothing on this path READS that cache, so a redelivery reaches the sink again - RFC 8935 Section 2 lets a transmitter redeliver regardless of earlier responses, and [ISecurityEventSink](https://www.abblix.com/en/docs/api/abblix-securityevents/Abblix.SecurityEvents.Delivery.ISecurityEventSink 'Abblix\.SecurityEvents\.Delivery\.ISecurityEventSink') answers for it by requiring idempotent processing. Why the write cannot come earlier, and why that is the only correct order available here, is on `RecordAsync`. Nothing here knows which profile of SET it carries. RFC 8935 is a delivery specification and the kinds it delivers are somebody else's business, so the three things that differ between consumers - the validation profile, what that profile expects, and where events land - arrive as parameters. The consumer's own registration binds them, which is also why the profile cannot be named by a keyed-service attribute here: an attribute takes a compile-time constant, and the key belongs to whoever registers this. ### Methods ## PushDeliveryHandler\.HandleAsync\(string, string, CancellationToken\) Method {#Abblix.SecurityEvents.Delivery.PushDeliveryHandler.HandleAsync(string,string,System.Threading.CancellationToken)} Handles one push transmission\. ```csharp public System.Threading.Tasks.Task HandleAsync(string? contentType, string? body, System.Threading.CancellationToken cancellationToken=default(System.Threading.CancellationToken)); ``` #### Parameters ###### `contentType` [System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String') {#Abblix.SecurityEvents.Delivery.PushDeliveryHandler.HandleAsync(string,string,System.Threading.CancellationToken).contentType} The request's Content\-Type header, as received\. ###### `body` [System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String') {#Abblix.SecurityEvents.Delivery.PushDeliveryHandler.HandleAsync(string,string,System.Threading.CancellationToken).body} The request body: one SET in compact serialization\. ###### `cancellationToken` [System\.Threading\.CancellationToken](https://learn.microsoft.com/en-us/dotnet/api/system.threading.cancellationtoken 'System\.Threading\.CancellationToken') {#Abblix.SecurityEvents.Delivery.PushDeliveryHandler.HandleAsync(string,string,System.Threading.CancellationToken).cancellationToken} Cancels validation I/O and processing\. #### Returns [System\.Threading\.Tasks\.Task<](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')[PushDeliveryResult](https://www.abblix.com/en/docs/api/abblix-securityevents/Abblix.SecurityEvents.Delivery.PushDeliveryResult 'Abblix\.SecurityEvents\.Delivery\.PushDeliveryResult')[>](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')