chore: updates samples to also show how to use multiple proofs

This additional sample is used to show how the deriveProof API can be used to derive proofs from
multiple signatures.

re #79

sample/README.md

@@ -2,9 +2,16 @@
 
 A simple runnable sample demoing how to use the API.
 
-Run the following and observe the console output
+Run the following and observe the console output for a JSON-LD document with a single proof
 
 ```
 yarn install --frozen-lockfile
 yarn demo
 ```
+
+Run the following and observe the console output for a JSON-LD document with multiple proofs
+
+```
+yarn install --frozen-lockfile
+yarn demo:multi
+```

sample/package.json

@@ -8,7 +8,8 @@
   "license": "Apache 2.0",
   "private": false,
   "scripts": {
-    "demo": "ts-node --files src/index.ts"
+    "demo": "ts-node --files src/demo_single.ts",
+    "demo:multi": "ts-node --files src/demo_multi.ts"
   },
   "devDependencies": {
     "@types/node": "12.7.2",

sample/src/demo_multi.ts

@@ -0,0 +1,113 @@
+/*
+ * Copyright 2020 - MATTR Limited
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {
+  Bls12381G2KeyPair,
+  BbsBlsSignature2020,
+  BbsBlsSignatureProof2020,
+  deriveProof
+} from "@mattrglobal/jsonld-signatures-bbs";
+import { extendContextLoader, sign, verify, purposes } from "jsonld-signatures";
+import { documentLoaders } from "jsonld";
+
+import inputDocument from "./data/inputDocument.json";
+import keyPairOptions from "./data/keyPair.json";
+import exampleControllerDoc from "./data/controllerDocument.json";
+import bbsContext from "./data/lds-bbsbls2020-v0.0.json";
+import revealDocument from "./data/deriveProofFrame.json";
+import citizenVocab from "./data/citizenVocab.json";
+
+/* eslint-disable-next-line @typescript-eslint/no-explicit-any */
+const documents: any = {
+  "did:example:489398593#test": keyPairOptions,
+  "did:example:489398593": exampleControllerDoc,
+  "https://w3c-ccg.github.io/ldp-bbs2020/context/v1": bbsContext,
+  "https://w3id.org/citizenship/v1": citizenVocab
+};
+
+/* eslint-disable-next-line @typescript-eslint/no-explicit-any */
+const customDocLoader = (url: string): any => {
+  const context = documents[url];
+
+  if (context) {
+    return {
+      contextUrl: null, // this is for a context via a link header
+      document: context, // this is the actual document that was loaded
+      documentUrl: url // this is the actual context URL after redirects
+    };
+  }
+
+  return documentLoaders.node()(url);
+};
+
+//Extended document load that uses local contexts
+/* eslint-disable-next-line @typescript-eslint/no-explicit-any */
+const documentLoader: any = extendContextLoader(customDocLoader);
+
+const main = async (): Promise<void> => {
+  //Import the example key pair
+  const keyPair = await new Bls12381G2KeyPair(keyPairOptions);
+
+  console.log("Input document");
+  console.log(JSON.stringify(inputDocument, null, 2));
+
+  //Sign the input document
+  const signedDocument = await sign(inputDocument, {
+    suite: new BbsBlsSignature2020({ key: keyPair }),
+    purpose: new purposes.AssertionProofPurpose(),
+    documentLoader
+  });
+
+  console.log("Input document with proof");
+  console.log(JSON.stringify(signedDocument, null, 2));
+
+  const multiSignedDocument = await sign(signedDocument, {
+    suite: new BbsBlsSignature2020({ key: keyPair }),
+    purpose: new purposes.AssertionProofPurpose(),
+    documentLoader
+  });
+
+  console.log("Input document with multiple proofs");
+  console.log(JSON.stringify(multiSignedDocument, null, 2));
+
+  //Verify the proof
+  const verified = await verify(multiSignedDocument, {
+    suite: new BbsBlsSignature2020(),
+    purpose: new purposes.AssertionProofPurpose(),
+    documentLoader
+  });
+
+  console.log("Verify the signed proof");
+  console.log(JSON.stringify(verified, null, 2));
+
+  //Derive a proof
+  const derivedProof = await deriveProof(multiSignedDocument, revealDocument, {
+    suite: new BbsBlsSignatureProof2020(),
+    documentLoader
+  });
+
+  console.log("Derived Proof Result");
+  console.log(JSON.stringify(derivedProof, null, 2));
+
+  //Verify the derived proof
+  const derivedProofVerified = await verify(derivedProof, {
+    suite: new BbsBlsSignatureProof2020(),
+    purpose: new purposes.AssertionProofPurpose(),
+    documentLoader
+  });
+
+  console.log("Derived Proof Verification result");
+  console.log(JSON.stringify(derivedProofVerified, null, 2));
+};
+
+main();

sample/src/index.ts → sample/src/demo_single.ts

@@ -72,7 +72,7 @@ const main = async (): Promise<void> => {
   console.log(JSON.stringify(inputDocument, null, 2));
 
   //Verify the proof
-  let verified = await verify(inputDocument, {
+  let verified = await verify(signedDocument, {
     suite: new BbsBlsSignature2020(),
     purpose: new purposes.AssertionProofPurpose(),
     documentLoader
@@ -82,7 +82,7 @@ const main = async (): Promise<void> => {
   console.log(JSON.stringify(verified, null, 2));
 
   //Derive a proof
-  const derivedProof = await deriveProof(inputDocument, revealDocument, {
+  const derivedProof = await deriveProof(signedDocument, revealDocument, {
     suite: new BbsBlsSignatureProof2020(),
     documentLoader
   });