#### [Abblix\.Oidc\.Server](https://www.abblix.com/docs/api/abblix-oidc-server 'index')
### [Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication')

## BackChannelRequestStorage Class

Implements the storage of backchannel authentication requests, allowing for persistence
and retrieval of authentication request data in the context of Client\-Initiated Backchannel Authentication \(CIBA\)\.

```csharp
public class BackChannelRequestStorage : Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IBackChannelRequestStorage
```

Inheritance [System\.Object](https://learn.microsoft.com/en-us/dotnet/api/system.object 'System\.Object') → BackChannelRequestStorage

Implements [IBackChannelRequestStorage](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IBackChannelRequestStorage 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.Interfaces\.IBackChannelRequestStorage')
### Constructors

## BackChannelRequestStorage\(IEntityStorage, IAuthenticationRequestIdGenerator, IEntityStorageKeyFactory\) Constructor {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.BackChannelRequestStorage(Abblix.Oidc.Server.Features.Storages.IEntityStorage,Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IAuthenticationRequestIdGenerator,Abblix.Oidc.Server.Features.Storages.IEntityStorageKeyFactory)}

Implements the storage of backchannel authentication requests, allowing for persistence
and retrieval of authentication request data in the context of Client\-Initiated Backchannel Authentication \(CIBA\)\.

```csharp
public BackChannelRequestStorage(Abblix.Oidc.Server.Features.Storages.IEntityStorage storage, Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IAuthenticationRequestIdGenerator authenticationRequestIdGenerator, Abblix.Oidc.Server.Features.Storages.IEntityStorageKeyFactory keyFactory);
```
#### Parameters

###### `storage` [IEntityStorage](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.Storages.IEntityStorage 'Abblix\.Oidc\.Server\.Features\.Storages\.IEntityStorage') {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.BackChannelRequestStorage(Abblix.Oidc.Server.Features.Storages.IEntityStorage,Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IAuthenticationRequestIdGenerator,Abblix.Oidc.Server.Features.Storages.IEntityStorageKeyFactory).storage}

The storage system used for persisting authentication requests\.

###### `authenticationRequestIdGenerator` [IAuthenticationRequestIdGenerator](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IAuthenticationRequestIdGenerator 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.Interfaces\.IAuthenticationRequestIdGenerator') {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.BackChannelRequestStorage(Abblix.Oidc.Server.Features.Storages.IEntityStorage,Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IAuthenticationRequestIdGenerator,Abblix.Oidc.Server.Features.Storages.IEntityStorageKeyFactory).authenticationRequestIdGenerator}

Generator for creating unique authentication request IDs\.

###### `keyFactory` [IEntityStorageKeyFactory](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.Storages.IEntityStorageKeyFactory 'Abblix\.Oidc\.Server\.Features\.Storages\.IEntityStorageKeyFactory') {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.BackChannelRequestStorage(Abblix.Oidc.Server.Features.Storages.IEntityStorage,Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IAuthenticationRequestIdGenerator,Abblix.Oidc.Server.Features.Storages.IEntityStorageKeyFactory).keyFactory}

The factory for generating standardized storage keys\.
### Methods

## BackChannelRequestStorage\.StoreAsync\(BackChannelAuthenticationRequest, TimeSpan\) Method {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.StoreAsync(Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest,System.TimeSpan)}

Asynchronously stores a backchannel authentication request and generates a unique identifier for it\.
This method also sets an expiration duration for the stored request\.

```csharp
public System.Threading.Tasks.Task<string> StoreAsync(Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest authenticationRequest, System.TimeSpan expiresIn);
```
#### Parameters

###### `authenticationRequest` [BackChannelAuthenticationRequest](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.BackChannelAuthenticationRequest') {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.StoreAsync(Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest,System.TimeSpan).authenticationRequest}

The backchannel authentication request to store\.

###### `expiresIn` [System\.TimeSpan](https://learn.microsoft.com/en-us/dotnet/api/system.timespan 'System\.TimeSpan') {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.StoreAsync(Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest,System.TimeSpan).expiresIn}

The duration after which the stored request will expire\.

Implements [StoreAsync\(BackChannelAuthenticationRequest, TimeSpan\)](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IBackChannelRequestStorage#Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IBackChannelRequestStorage.StoreAsync(Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest,System.TimeSpan) 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.Interfaces\.IBackChannelRequestStorage\.StoreAsync\(Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.BackChannelAuthenticationRequest, System\.TimeSpan\)')

#### Returns
[System\.Threading\.Tasks\.Task&lt;](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')[System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String')[&gt;](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')  
A task that returns the unique ID of the stored authentication request\.

## BackChannelRequestStorage\.TryGetAsync\(string\) Method {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.TryGetAsync(string)}

Tries to retrieve a backchannel authentication request by its unique identifier\.

```csharp
public System.Threading.Tasks.Task<Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest?> TryGetAsync(string authenticationRequestId);
```
#### Parameters

###### `authenticationRequestId` [System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String') {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.TryGetAsync(string).authenticationRequestId}

The unique identifier of the authentication request to retrieve\.

Implements [TryGetAsync\(string\)](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IBackChannelRequestStorage#Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IBackChannelRequestStorage.TryGetAsync(string) 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.Interfaces\.IBackChannelRequestStorage\.TryGetAsync\(string\)')

#### Returns
[System\.Threading\.Tasks\.Task&lt;](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')[BackChannelAuthenticationRequest](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.BackChannelAuthenticationRequest')[&gt;](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')  
A task that returns the authentication request if found;
otherwise, null\.

## BackChannelRequestStorage\.TryRemoveAsync\(string\) Method {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.TryRemoveAsync(string)}

Retrieves and removes a backchannel authentication request from storage, through the store's claim
protocol\. The claim is what keeps two polls from both being told they took the same request; the
per\-key gate around the removal is what keeps a contended key from ending with NEITHER of them
told\. The value is read under that same hold, so a poll is handed the bytes the removal took rather
than the ones it read on its way in\.

That is the whole of what the hold buys, and it is narrower than "no write is lost". Only the read
and the removal are inside it: [UpdateAsync\(string, BackChannelAuthenticationRequest, TimeSpan\)](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.UpdateAsync(string,Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest,System.TimeSpan) 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.BackChannelRequestStorage\.UpdateAsync\(string, Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.BackChannelAuthenticationRequest, System\.TimeSpan\)') is a plain set on this key and takes no
gate, so a write from the CIBA grant handler's next-poll bump can still land after the in-gate read
and be destroyed by the removal without ever being seen - which that handler's own remarks already
treat as an ordinary race. Closing THAT needs the writers to take the gate too, not a wider claim
here.

```csharp
public System.Threading.Tasks.Task<Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest?> TryRemoveAsync(string authenticationRequestId);
```
#### Parameters

###### `authenticationRequestId` [System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String') {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.TryRemoveAsync(string).authenticationRequestId}

The unique identifier of the authentication request to remove\.

Implements [TryRemoveAsync\(string\)](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IBackChannelRequestStorage#Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IBackChannelRequestStorage.TryRemoveAsync(string) 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.Interfaces\.IBackChannelRequestStorage\.TryRemoveAsync\(string\)')

#### Returns
[System\.Threading\.Tasks\.Task&lt;](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')[BackChannelAuthenticationRequest](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.BackChannelAuthenticationRequest')[&gt;](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task-1 'System\.Threading\.Tasks\.Task\`1')  
A task that returns the authentication request when this caller removed it and still held its own
claim afterwards\. Null otherwise, and that covers more than a competitor: the request not being
there, and a claim that expired while a store call was in flight \- the second on one caller with
nobody to lose to, its outcome being the request gone with nobody able to be told they took it\. A
store call that fails after the removal raises instead of answering\.

## BackChannelRequestStorage\.UpdateAsync\(string, BackChannelAuthenticationRequest, TimeSpan\) Method {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.UpdateAsync(string,Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest,System.TimeSpan)}

Updates an existing backchannel authentication request in storage\.
Used in ping mode to update request status when user completes authentication\.

```csharp
public System.Threading.Tasks.Task UpdateAsync(string requestId, Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest request, System.TimeSpan expiresIn);
```
#### Parameters

###### `requestId` [System\.String](https://learn.microsoft.com/en-us/dotnet/api/system.string 'System\.String') {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.UpdateAsync(string,Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest,System.TimeSpan).requestId}

The unique identifier of the authentication request to update\.

###### `request` [BackChannelAuthenticationRequest](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.BackChannelAuthenticationRequest') {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.UpdateAsync(string,Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest,System.TimeSpan).request}

The updated authentication request data\.

###### `expiresIn` [System\.TimeSpan](https://learn.microsoft.com/en-us/dotnet/api/system.timespan 'System\.TimeSpan') {#Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelRequestStorage.UpdateAsync(string,Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest,System.TimeSpan).expiresIn}

The duration after which the request expires\.

Implements [UpdateAsync\(string, BackChannelAuthenticationRequest, TimeSpan\)](https://www.abblix.com/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IBackChannelRequestStorage#Abblix.Oidc.Server.Features.BackChannelAuthentication.Interfaces.IBackChannelRequestStorage.UpdateAsync(string,Abblix.Oidc.Server.Features.BackChannelAuthentication.BackChannelAuthenticationRequest,System.TimeSpan) 'Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.Interfaces\.IBackChannelRequestStorage\.UpdateAsync\(string, Abblix\.Oidc\.Server\.Features\.BackChannelAuthentication\.BackChannelAuthenticationRequest, System\.TimeSpan\)')

#### Returns
[System\.Threading\.Tasks\.Task](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task 'System\.Threading\.Tasks\.Task')  
A task that completes when the request is updated in storage\.