Code Snippet

This section describes how we use the zkPass SDK in our demo code

Generate Proof

import { DvrModuleClient } from "@zkpass/dvr-client-ts";

...

// Step 1: Instantiate DvrModuleClient
const dvrModuleClient = new DvrModuleClient({
      baseUrl: SERVICE_URL,
      apiKey: API_KEY,
      secretApiKey: API_SECRET,
    });

// Step 2: Call the DVR module client's callDvrGenerateZkPassProof
const zkPassProof = dvrModuleClient.callDvrGenerateZkPassProof(
      JSON.stringify(userDataToken),
      dvrToken
    );

This code snippet generates a zkPass proof. It requires 3 parameters:

1. SERVICE_URL : you can use https://playground-zkpass.ssi.id , or use your own endpoint if you deploy zkPass on your own server.

2. API_KEY & API_SECRET: Get yours at https://portal.ssi.id

3. userDataToken : check Generate User Data Token section for more details.

4. dvrToken : check Generate DVR Token section for more details.

Verify Proof

import { DvrModuleClient, extractPayload } from "@zkpass/dvr-client-ts";

const dvrPayload = extractPayload(dvrToken);
...

// Step 1: Instantiate the zkPassClient object.
const dvrModuleClient = new DvrModuleClient({
      baseUrl: ZKPASS_SERVICE_URL,
      apiKey: API_KEY,
      secretApiKey: API_SECRET,
    });

// Step 2: Create the expected metadata
const expectedMetadata = {
      dvr: JSON.stringify(dvrPayload),
      ttl: EXPECTED_DVR_TTL,
      user_data_verifying_keys: userDataVerifyingKeys,
    };

// Step 3: Call zkPassClient.verifyZkPassProof to verify the proof.
const proofOutput = dvrModuleClient.callDvrVerifyZkPassProof(
      ZKPASS_ZKVM,
      zkPassProofToken,
      expectedMetadata
    );

This code snippet verifies a zkPass proof token. Components :

1. zkPassProofToken : check Generate Proof section for more details.

2. expectedMetadata : this is the expected metadata of the dvr.

3. dvrPayload: the dvr payload extracted from Dvr token.

Generate User Data Token

import { DvrModuleClient } from "@zkpass/dvr-client-ts";

...

// Step 1: Instantiate DvrModuleClient
const dvrModuleClient = new DvrModuleClient({
      baseUrl: SERVICE_URL,
      apiKey: API_KEY,
      secretApiKey: API_SECRET,
    });
//
// Step 2: Call the DVR module client's callDvrGenerateUserDataToken
//         This is to digitally-sign the user data.
const userDataToken = dvrModuleClient.callDvrGenerateUserDataToken(
      signingKey,
      JSON.stringify(data),
      verifyingKey
    );

This code snippet generate user data token. Components :

1. signingKey : a private key used to sign user data.

2. data : user data in JSON format.

3. verifyingKey : a public key to verify that user data token.

Generate DVR Token

import { DvrModuleClient } from "@zkpass/dvr-client-ts";

...

// Step 1: Initiate DvrModuleClient
const dvrModuleClient = new DvrModuleClient({
      baseUrl: SERVICE_URL,
      apiKey: API_KEY,
      secretApiKey: API_SECRET,
    });

// Step 2: Generate Dvr query token
const dvrToken = dvrModuleClient.callDvrGenerateQueryToken(
      signingKey,
      dvrData
    );

This code snippet generate DVR token. Components :

1. signingKey : a private key used to sign dvr.

2. dvrData : Dvr data to sign.