add QR scanner for adding a contact

src/libs/crypto/index.ts

@@ -1,5 +1,4 @@
 import { IIdentifier } from "@veramo/core";
-import { DEFAULT_DID_PROVIDER_NAME } from "../veramo/setup";
 import { getRandomBytesSync } from "ethereum-cryptography/random";
 import { entropyToMnemonic } from "ethereum-cryptography/bip39";
 import { wordlist } from "ethereum-cryptography/bip39/wordlists/english";
@@ -7,6 +6,9 @@ import { HDNode } from "@ethersproject/hdnode";
 import * as didJwt from "did-jwt";
 import * as u8a from "uint8arrays";
 
+import { ENDORSER_JWT_URL_LOCATION } from "@/libs/endorserServer";
+import { DEFAULT_DID_PROVIDER_NAME } from "../veramo/setup";
+
 export const DEFAULT_ROOT_DERIVATION_PATH = "m/76798669'/0'/0'/0'";
 
 /**
@@ -150,3 +152,24 @@ export function fromJose(signature: string): {
 export function bytesToHex(b: Uint8Array): string {
   return u8a.toString(b, "base16");
 }
+
+/**
+ @return results of uportJwtPayload:
+ { iat: number, iss: string (DID), own: { name, publicEncKey (base64-encoded key) } }
+
+ Note that similar code is also contained in time-safari
+ */
+export const getContactPayloadFromJwtUrl = (jwtUrlText: string) => {
+  let jwtText = jwtUrlText;
+  const endorserContextLoc = jwtText.indexOf(ENDORSER_JWT_URL_LOCATION);
+  if (endorserContextLoc > -1) {
+    jwtText = jwtText.substring(
+      endorserContextLoc + ENDORSER_JWT_URL_LOCATION.length,
+    );
+  }
+
+  // JWT format: { header, payload, signature, data }
+  const jwt = didJwt.decodeJWT(jwtText);
+
+  return jwt.payload;
+};