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Connectionless Presentation

Description​

A Connectionless PresentationRequest is an Out of Band Invitation with a PresentationRequest Attachment. This should be a URI with a single query parameter _oob, which is an encoded JSON. It should look similar to:

https://my.domain.com/path?_oob=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

The Verifier creates a PresentationRequest and shares it with the Holder as an out-of-band URL. The Holder can then decode the PresentationRequest and use the SDK to either approve or reject it.

If the Holder accepts the PresentationRequest, a credential Presentation is sent to the Verifier. The Verifier will then resolve the DIDs onChain and verify that the Presentation is valid. All communications are performed using DIDComm v2.

For Issuers​

Using the Cloud Agent​

Creating a Credential Offer OOB Url through the Cloud Agent is pretty straight forward, do POST request to /present-proof/presentations/invitation:

curl --location 'http:///cloud-agent/present-proof/presentations/invitation' \
--header 'Content-Type: application/json' \
--data '.......'

A successful response will contain (string) invitation.invitationUrl.

Using TS SDK​

The SDK provides everything that is needed by Verifiers, creating and publishing prism:dids, resolving those onChain, creating OOB Presentation requests...

Add the required imports

import SDK from "@hyperledger/identus-sdk";

Here's the types we are going to be using

async function createRequestPresentationMessage<T extends SDK.Domain.CredentialType>(
  agent: SDK.Agent,
  type: T,
  claims: SDK.Domain.PresentationClaims<T>,
  toDID?: SDK.Domain.DID,
): Promise<SDK.Domain.Message>  {
  if (!agent) {
    throw new Error("No agent found");
  }

  const peerDID = await createPeerDID();
  let task: SDK.Utils.Task<any>;

  const task = new SDK.Tasks.CreatePresentationRequest({ 
    type, 
    toDID: toDID ?? peerDID, 
    claims:claims
  })

  const requestPresentation = await agent.runTask<SDK.RequestPresentation>(task);
  const requestPresentationMessage = requestPresentation.makeMessage();
  if (!toDID) {
    delete (requestPresentationMessage as any).to;
  }
  return requestPresentationMessage;
}

That function will return a SDK.Domain.Message that we can easily send with agent.send(requestPresentationMessage)

For Holders​

Holders will scan the qrcode, and extract the PresentationRequest from the OutOfBandInvitation Message.

Parsing the OOB Url is very easy in the SDK:

import SDK from "@hyperledger/identus-sdk";
async function parseOOB(agent: SDK.Agent, url: string): Promise<SDK.InvitationType> {
    return agent.parseInvitation(url)
}

We would then build the complete Presentation message, holder at this point should have accepted or rejected already:

import SDK from "@hyperledger/identus-sdk";
const selfPeerDID = await agent.createPeerDID([], true)
const oobMessage = await parseOOB(agent, oobURL);
const presentationRequestMessage = SDK.Domain.Message.fromJson(
  oobMessage.attachments.at(0)?.payload
)
const request = SDK.RequestPresentation.fromMessage(message);
const credential:SDK.Domain.Credential = //The credential tha the user accepted the PresentaionRequest with
const task = new SDK.Tasks.CreatePresentation({ request, credential })
const presentationMessage = await agent.runTask(task);

Once the user has accepted the PresentationRequest, it will choose one SDK.Domain.Credential and reply to the SDK.RequestPresentation Message with a SDK.Presentation Message.

await agent.send(presentationMessage);