test1.mjs

import * as Ed25519Multikey from '@digitalbazaar/ed25519-multikey';
import {DataIntegrityProof} from '@digitalbazaar/data-integrity';
import {cryptosuite as eddsa2022CryptoSuite} from
  '@digitalbazaar/eddsa-2022-cryptosuite';
import jsigs from 'jsonld-signatures';
import dataIntegrityContext from '@digitalbazaar/data-integrity-context';
import multikeyContext from '@digitalbazaar/multikey-context';
import {securityLoader} from '@digitalbazaar/security-document-loader';
export const documentLoader = securityLoader();
const {purposes: {AssertionProofPurpose}} = jsigs;

const modifiedContext = {
    "@context": {
        "firstName": "https://www.w3.org/ns/credentials/issuer-dependent#middleName",
        "middleName": "https://www.w3.org/ns/credentials/issuer-dependent#firstName",
        "isOver18": "https://www.w3.org/ns/credentials/issuer-dependent#isEmployed",
        "isEmployed": "https://www.w3.org/ns/credentials/issuer-dependent#isOver18"
    }
};
const main = async () => {
    // Load static constants
    documentLoader.addStatic(
    dataIntegrityContext.constants.CONTEXT_URL,
    dataIntegrityContext.contexts.get(dataIntegrityContext.constants.CONTEXT_URL)
    );
    
    documentLoader.addStatic(
    dataIntegrityContext.constants.DATA_INTEGRITY_CONTEXT_V1_URL,
    dataIntegrityContext.contexts.get(
        dataIntegrityContext.constants.DATA_INTEGRITY_CONTEXT_V1_URL)
    );
    
    documentLoader.addStatic(
    multikeyContext.constants.CONTEXT_URL,
    multikeyContext.contexts.get(multikeyContext.constants.CONTEXT_URL)
    );

    //documentLoader.addStatic("https://my-example-context.com/", modifiedContext)

    documentLoader.addStatic('https://www.w3.org/ns/credentials/v2', {
        "@context": {
          "@protected": true,
          "@vocab": "https://www.w3.org/ns/credentials/issuer-dependent#",
      
          "id": "@id",
          "type": "@type",
      
          "kid": {
            "@id": "https://www.iana.org/assignments/jose#kid",
            "@type": "@id"
          },
          "iss": {
            "@id": "https://www.iana.org/assignments/jose#iss",
            "@type": "@id"
          },
          "sub": {
            "@id": "https://www.iana.org/assignments/jose#sub",
            "@type": "@id"
          },
          "jku": {
            "@id": "https://www.iana.org/assignments/jose#jku",
            "@type": "@id"
          },
          "x5u": {
            "@id": "https://www.iana.org/assignments/jose#x5u",
            "@type": "@id"
          },
          "aud": {
            "@id": "https://www.iana.org/assignments/jwt#aud",
            "@type": "@id"
          },
          "exp": {
            "@id": "https://www.iana.org/assignments/jwt#exp",
            "@type": "https://www.w3.org/2001/XMLSchema#nonNegativeInteger"
          },
          "nbf": {
            "@id": "https://www.iana.org/assignments/jwt#nbf",
            "@type": "https://www.w3.org/2001/XMLSchema#nonNegativeInteger"
          },
          "iat": {
            "@id": "https://www.iana.org/assignments/jwt#iat",
            "@type": "https://www.w3.org/2001/XMLSchema#nonNegativeInteger"
          },
          "cnf": {
            "@id": "https://www.iana.org/assignments/jwt#cnf",
            "@context": {
              "@protected": true,
              "kid": {
                "@id": "https://www.iana.org/assignments/jwt#kid",
                "@type": "@id"
              },
              "jwk": {
                "@id": "https://www.iana.org/assignments/jwt#jwk",
                "@type": "@json"
              }
            }
          },
          "_sd_alg": {
            "@id": "https://www.iana.org/assignments/jwt#_sd_alg"
          },
          "_sd": {
            "@id": "https://www.iana.org/assignments/jwt#_sd"
          },
          "...": {
            "@id": "https://www.iana.org/assignments/jwt#..."
          },
      
          "digestSRI": {
            "@id": "https://www.w3.org/2018/credentials#digestSRI",
            "@type": "https://www.w3.org/2018/credentials#sriString"
          },
          "digestMultibase": {
            "@id": "https://w3id.org/security#digestMultibase",
            "@type": "https://w3id.org/security#multibase"
          },
      
          "mediaType": {
            "@id": "https://schema.org/encodingFormat"
          },
      
          "description": "https://schema.org/description",
          "name": "https://schema.org/name",
      
          "EnvelopedVerifiableCredential":
            "https://www.w3.org/2018/credentials#EnvelopedVerifiableCredential",
      
          "VerifiableCredential": {
            "@id": "https://www.w3.org/2018/credentials#VerifiableCredential",
            "@context": {
              "@protected": true,
      
              "id": "@id",
              "type": "@type",
      
              "credentialSchema": {
                "@id": "https://www.w3.org/2018/credentials#credentialSchema",
                "@type": "@id"
              },
              "credentialStatus": {
                "@id": "https://www.w3.org/2018/credentials#credentialStatus",
                "@type": "@id"
              },
              "credentialSubject": {
                "@id": "https://www.w3.org/2018/credentials#credentialSubject",
                "@type": "@id"
              },
              "description": "https://schema.org/description",
              "evidence": {
                "@id": "https://www.w3.org/2018/credentials#evidence",
                "@type": "@id"
              },
              "validFrom": {
                "@id": "https://www.w3.org/2018/credentials#validFrom",
                "@type": "http://www.w3.org/2001/XMLSchema#dateTime"
              },
              "validUntil": {
                "@id": "https://www.w3.org/2018/credentials#validUntil",
                "@type": "http://www.w3.org/2001/XMLSchema#dateTime"
              },
              "issuer": {
                "@id": "https://www.w3.org/2018/credentials#issuer",
                "@type": "@id"
              },
              "name": "https://schema.org/name",
              "proof": {
                "@id": "https://w3id.org/security#proof",
                "@type": "@id",
                "@container": "@graph"
              },
              "refreshService": {
                "@id": "https://www.w3.org/2018/credentials#refreshService",
                "@type": "@id"
              },
              "termsOfUse": {
                "@id": "https://www.w3.org/2018/credentials#termsOfUse",
                "@type": "@id"
              },
              "confidenceMethod": {
                "@id": "https://www.w3.org/2018/credentials#confidenceMethod",
                "@type": "@id"
              },
              "relatedResource": {
                "@id": "https://www.w3.org/2018/credentials#relatedResource",
                "@type": "@id"
              }
            }
          },
      
          "VerifiablePresentation": {
            "@id": "https://www.w3.org/2018/credentials#VerifiablePresentation",
            "@context": {
              "@protected": true,
      
              "id": "@id",
              "type": "@type",
      
              "holder": {
                "@id": "https://www.w3.org/2018/credentials#holder",
                "@type": "@id"
              },
              "proof": {
                "@id": "https://w3id.org/security#proof",
                "@type": "@id",
                "@container": "@graph"
              },
              "verifiableCredential": {
                "@id": "https://www.w3.org/2018/credentials#verifiableCredential",
                "@type": "@id",
                "@container": "@graph",
                "@context": null
              },
              "termsOfUse": {
                "@id": "https://www.w3.org/2018/credentials#termsOfUse",
                "@type": "@id"
              }
            }
          },
      
          "JsonSchemaCredential": "https://www.w3.org/2018/credentials#JsonSchemaCredential",
      
          "JsonSchema": {
            "@id": "https://www.w3.org/2018/credentials#JsonSchema",
            "@context": {
              "@protected": true,
      
              "id": "@id",
              "type": "@type",
      
              "jsonSchema": {
                "@id": "https://w3.org/2018/credentials#jsonSchema",
                "@type": "@json"
              }
            }
          },
      
          "BitstringStatusListCredential": "https://www.w3.org/ns/credentials/status#BitstringStatusListCredential",
      
          "BitstringStatusList": {
            "@id": "https://www.w3.org/ns/credentials/status#BitstringStatusList",
            "@context": {
              "@protected": true,
      
              "id": "@id",
              "type": "@type",
      
              "statusPurpose":
                "https://www.w3.org/ns/credentials/status#statusPurpose",
              "encodedList": {
                "@id": "https://www.w3.org/ns/credentials/status#encodedList",
                "@type": "https://w3id.org/security#multibase"
              },
              "ttl": "https://www.w3.org/ns/credentials/status#ttl",
              "statusReference": "https://www.w3.org/ns/credentials/status#statusReference",
              "statusSize": "https://www.w3.org/ns/credentials/status#statusSize",
              "statusMessage": {
                "@id": "https://www.w3.org/ns/credentials/status#statusMessage",
                "@context": {
                  "@protected": true,
      
                  "id": "@id",
                  "type": "@type",
      
                  "status": "https://www.w3.org/ns/credentials/status#status",
                  "message": "https://www.w3.org/ns/credentials/status#message"
                }
              }
            }
          },
      
          "BitstringStatusListEntry": {
            "@id":
              "https://www.w3.org/ns/credentials/status#BitstringStatusListEntry",
            "@context": {
              "@protected": true,
      
              "id": "@id",
              "type": "@type",
      
              "statusPurpose":
                "https://www.w3.org/ns/credentials/status#statusPurpose",
              "statusListIndex":
                "https://www.w3.org/ns/credentials/status#statusListIndex",
              "statusListCredential": {
                "@id":
                  "https://www.w3.org/ns/credentials/status#statusListCredential",
                "@type": "@id"
              }
            }
          },
      
          "DataIntegrityProof": {
            "@id": "https://w3id.org/security#DataIntegrityProof",
            "@context": {
              "@protected": true,
              "id": "@id",
              "type": "@type",
              "challenge": "https://w3id.org/security#challenge",
              "created": {
                "@id": "http://purl.org/dc/terms/created",
                "@type": "http://www.w3.org/2001/XMLSchema#dateTime"
              },
              "domain": "https://w3id.org/security#domain",
              "expires": {
                "@id": "https://w3id.org/security#expiration",
                "@type": "http://www.w3.org/2001/XMLSchema#dateTime"
              },
              "nonce": "https://w3id.org/security#nonce",
              "previousProof": {
                "@id": "https://w3id.org/security#previousProof",
                "@type": "@id"
              },
              "proofPurpose": {
                "@id": "https://w3id.org/security#proofPurpose",
                "@type": "@vocab",
                "@context": {
                  "@protected": true,
                  "id": "@id",
                  "type": "@type",
                  "assertionMethod": {
                    "@id": "https://w3id.org/security#assertionMethod",
                    "@type": "@id",
                    "@container": "@set"
                  },
                  "authentication": {
                    "@id": "https://w3id.org/security#authenticationMethod",
                    "@type": "@id",
                    "@container": "@set"
                  },
                  "capabilityInvocation": {
                    "@id": "https://w3id.org/security#capabilityInvocationMethod",
                    "@type": "@id",
                    "@container": "@set"
                  },
                  "capabilityDelegation": {
                    "@id": "https://w3id.org/security#capabilityDelegationMethod",
                    "@type": "@id",
                    "@container": "@set"
                  },
                  "keyAgreement": {
                    "@id": "https://w3id.org/security#keyAgreementMethod",
                    "@type": "@id",
                    "@container": "@set"
                  }
                }
              },
              "cryptosuite": {
                "@id": "https://w3id.org/security#cryptosuite",
                "@type": "https://w3id.org/security#cryptosuiteString"
              },
              "proofValue": {
                "@id": "https://w3id.org/security#proofValue",
                "@type": "https://w3id.org/security#multibase"
              },
              "verificationMethod": {
                "@id": "https://w3id.org/security#verificationMethod",
                "@type": "@id"
              }
            }
          }
        }
      })

    // create the unsigned credential
const unsignedCredential = {
    "@context": [
      "https://www.w3.org/ns/credentials/v2"
    ],
    "id": "urn:uuid:6a9c92a9-2530-4e2b-9776-530467e9bbe0",
    "type": ["VerifiableCredential", "PersonalIDCredential"],
    "issuer": "https://university.example/issuers/565049",
    "validFrom": "2010-01-01T19:23:24Z",
    "credentialSubject": {
      "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
      "firstName": "John",
      "middleName": "Peter",
      "lastName": "Doe",
      "isEmployed": true,
      "isOver18": false
    }
  }
  
  // create the keypair to use when signing
  const controller = 'https://example.edu/issuers/565049';
  const keyPair = await Ed25519Multikey.from({
    '@context': 'https://w3id.org/security/multikey/v1',
    type: 'Multikey',
    controller,
    id: controller + '#z6MkwXG2WjeQnNxSoynSGYU8V9j3QzP3JSqhdmkHc6SaVWoT',
    publicKeyMultibase: 'z6MkwXG2WjeQnNxSoynSGYU8V9j3QzP3JSqhdmkHc6SaVWoT',
    secretKeyMultibase: 'zrv3rbPamVDGvrm7LkYPLWYJ35P9audujKKsWn3x29EUiGwwhdZQd' +
      '1iHhrsmZidtVALBQmhX3j9E5Fvx6Kr29DPt6LH'
  });
  
  // export public key and add to document loader
  const publicKey = await keyPair.export({publicKey: true, includeContext: true});
  documentLoader.addStatic(publicKey.id, publicKey);

  // create key's controller document
  const controllerDoc = {
    '@context': [
      'https://www.w3.org/ns/did/v1',
      'https://w3id.org/security/multikey/v1'
    ],
    id: controller,
    assertionMethod: [publicKey]
  };
  documentLoader.addStatic(controllerDoc.id, controllerDoc);
  
  // create suite
  const suite = new DataIntegrityProof({
    signer: keyPair.signer(), cryptosuite: eddsa2022CryptoSuite
  });
  
  // create signed credential
  let signedCredential = await jsigs.sign(unsignedCredential, {
    suite,
    purpose: new AssertionProofPurpose(),
    documentLoader: documentLoader.build()
  });

  console.log("Signed Credential pre-modification");
  console.log(JSON.stringify(signedCredential, null, 2));


  console.log("Modifying credential .....");
  // Hack to create a deep clone of the object
  let modifiedCredential = JSON.parse(JSON.stringify(signedCredential));

  console.log("With injected context of");
  console.log(JSON.stringify(modifiedContext, null, 2));

  modifiedCredential['@context'] = [ ...signedCredential['@context'], "https://my-example-context.com/"];

  // Modify the signed credential
  modifiedCredential.credentialSubject.isEmployed = signedCredential.credentialSubject.isOver18
  modifiedCredential.credentialSubject.isOver18 = signedCredential.credentialSubject.isEmployed
  modifiedCredential.credentialSubject.firstName = signedCredential.credentialSubject.middleName
  modifiedCredential.credentialSubject.middleName = signedCredential.credentialSubject.firstName

  console.log("Verification result for modified credential");
  const result = await jsigs.verify(modifiedCredential, { suite, purpose: new AssertionProofPurpose(), documentLoader: documentLoader.build() } );

  if (result.verified == true){
    console.log("Proof verified")
    console.log(JSON.stringify(modifiedCredential, null, 2))
  } else {
    console.log("Proof failed");
  }
}

main();