This library module contains an OP (OpenID Provider) Authenticator implementation that can be used in React Native projects, it's basically a React Native wrapper around the "Self Issued OpenID Provider v2 (SIOP)" library reducing the implementation effort and troubleshooting involved with getting the SIOP library to work in a React Native environment.

Demo project rn-did-siop-example-app implements this library.

To build

If React Native tools are not installed

yarn global add react-native-cli
yarn global add rn-nodeify

Build

• yarn install
• yarn build

Usage

To use this helper library you need to implement the following: First you create a new instance of OPAuthenticator. There are two static methods with different parameters:

this.opAuthenticator = OPAuthenticator.newInstance(options)

Use this method for simplified instantiation with only the most common parameters.

opDID: string
opKID: string
opPrivateKey: string
expiresIn: number // (optional, default is 6000ms) 
didMethod: string  // optional, IE. "ethr", "eosio". By default it is taken from the authentication requests did_methods_supported

When using typescript these fields are contained in class OPAuthenticatorOptions.

or for more fine-grained control use the OP.builder() from the SIOP library:

    this.opAuthenticator = OPAuthenticator.newInstanceFromOP(OP.builder()
        .withExpiresIn(expiresIn)
        .addDidMethod("ethr")
        .internalSignature(opPrivateKey, opDID, opKID)
        .registrationBy(PassBy.VALUE)
        .response(ResponseMode.POST)
        .build())

see this openid-provider-siop section for details.

The next step is to get an authentication request from the RP (Relying Party) endpoint. Method "getAuthenticationRequestFromRP" will the call the RP endpoint to retrieve the full authentication request based on a state identifier which has to be part of the QR code data, besides the state field state we also need a redirectUrl field to know at which endpoint we can get the authentication request. When using typescript it takes interface QRCodeValues as parameter.
(In case the entire authentication request is encoded in the QR code this step is not necessary.)

this.authRequestURI = await this.opAuthenticator.getAuthenticationRequestFromRP(qrContent as QRCodeValues)

getAuthenticationRequestFromRP will return (when using typescript) and object for interface ParsedAuthenticationRequestURI. This is the input parameter for then next step:

this.verifiedAuthenticationRequest = await this.opAuthenticator.verifyAuthenticationRequestURI(this.authRequestURI)

When verifyAuthenticationRequestURI method, the verification of authenticity of the request send by the RP succeeds, it will return an object for interface VerifiedAuthenticationRequestWithJWT.

Next there a helper method the extract DID information from the request, but this can also be done from within the VerifiedAuthenticationRequestWithJWT interface.

const rpDid = this.opAuthenticator.rpDidFromAuthenticationRequest(this.verifiedAuthenticationRequest)

rpDidFromAuthenticationRequest will return class RPDID containing DID information

export declare class RPDID {
  id: string;
  alsoKnownAs?: string[];
}

At this point the idea is that you present the DID information and ask the user for permission to send your DID back to the RP by using either a button or biometrics dialog. When the user approves you can call the final method "sendAuthResponse" which will send the requested (and signed) OP did information back to the RP callback endpoint:

 try {
  await this.opAuthenticator.sendAuthResponse(this.verifiedAuthenticationRequest as VerifiedAuthenticationRequestWithJWT)
  this.setState({message: "Login successful"})
} catch (e) {
  this.setState({message: "Error: " + e.message})
} finally {
  ...
}

(Except for rpDidFromAuthenticationRequest all methods will return a promise. Errors are raised using Promise.reject())