pull in did:peer verification (from endorser-ch)

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Replacement of an existing file
 - Local resolver for did:ethr
+- Validation of did:peer JWANT
 - Testing for file deletion
 ### Fixed
 - Incorrect check for others who recorded same image

package.json

@@ -6,8 +6,12 @@
   "dependencies": {
     "@aws-sdk/client-s3": "^3.614.0",
     "@aws-sdk/lib-storage": "^3.614.0",
+    "@peculiar/asn1-ecc": "^2.3.8",
+    "@peculiar/asn1-schema": "^2.3.8",
+    "base64url": "^3.0.1",
+    "cbor-x": "^1.5.9",
     "cors": "^2.8.5",
-    "did-jwt": "^8.0.4",
+    "did-jwt": "^7.4.7",
     "did-resolver": "^4.1.0",
     "dotenv": "^16.4.5",
     "express": "^4.19.2",

pnpm-lock.yaml

@@ -11,12 +11,24 @@ dependencies:
   '@aws-sdk/lib-storage':
     specifier: ^3.614.0
     version: 3.614.0(@aws-sdk/client-s3@3.614.0)
+  '@peculiar/asn1-ecc':
+    specifier: ^2.3.8
+    version: 2.3.8
+  '@peculiar/asn1-schema':
+    specifier: ^2.3.8
+    version: 2.3.8
+  base64url:
+    specifier: ^3.0.1
+    version: 3.0.1
+  cbor-x:
+    specifier: ^1.5.9
+    version: 1.5.9
   cors:
     specifier: ^2.8.5
     version: 2.8.5
   did-jwt:
-    specifier: ^8.0.4
+    specifier: ^7.4.7
-    version: 8.0.4
+    version: 7.4.7
   did-resolver:
     specifier: ^4.1.0
     version: 4.1.0
@@ -689,6 +701,54 @@ packages:
       tslib: 2.6.3
     dev: false
 
+  /@cbor-extract/cbor-extract-darwin-arm64@2.2.0:
+    resolution: {integrity: sha512-P7swiOAdF7aSi0H+tHtHtr6zrpF3aAq/W9FXx5HektRvLTM2O89xCyXF3pk7pLc7QpaY7AoaE8UowVf9QBdh3w==}
+    cpu: [arm64]
+    os: [darwin]
+    requiresBuild: true
+    dev: false
+    optional: true
+
+  /@cbor-extract/cbor-extract-darwin-x64@2.2.0:
+    resolution: {integrity: sha512-1liF6fgowph0JxBbYnAS7ZlqNYLf000Qnj4KjqPNW4GViKrEql2MgZnAsExhY9LSy8dnvA4C0qHEBgPrll0z0w==}
+    cpu: [x64]
+    os: [darwin]
+    requiresBuild: true
+    dev: false
+    optional: true
+
+  /@cbor-extract/cbor-extract-linux-arm64@2.2.0:
+    resolution: {integrity: sha512-rQvhNmDuhjTVXSPFLolmQ47/ydGOFXtbR7+wgkSY0bdOxCFept1hvg59uiLPT2fVDuJFuEy16EImo5tE2x3RsQ==}
+    cpu: [arm64]
+    os: [linux]
+    requiresBuild: true
+    dev: false
+    optional: true
+
+  /@cbor-extract/cbor-extract-linux-arm@2.2.0:
+    resolution: {integrity: sha512-QeBcBXk964zOytiedMPQNZr7sg0TNavZeuUCD6ON4vEOU/25+pLhNN6EDIKJ9VLTKaZ7K7EaAriyYQ1NQ05s/Q==}
+    cpu: [arm]
+    os: [linux]
+    requiresBuild: true
+    dev: false
+    optional: true
+
+  /@cbor-extract/cbor-extract-linux-x64@2.2.0:
+    resolution: {integrity: sha512-cWLAWtT3kNLHSvP4RKDzSTX9o0wvQEEAj4SKvhWuOVZxiDAeQazr9A+PSiRILK1VYMLeDml89ohxCnUNQNQNCw==}
+    cpu: [x64]
+    os: [linux]
+    requiresBuild: true
+    dev: false
+    optional: true
+
+  /@cbor-extract/cbor-extract-win32-x64@2.2.0:
+    resolution: {integrity: sha512-l2M+Z8DO2vbvADOBNLbbh9y5ST1RY5sqkWOg/58GkUPBYou/cuNZ68SGQ644f1CvZ8kcOxyZtw06+dxWHIoN/w==}
+    cpu: [x64]
+    os: [win32]
+    requiresBuild: true
+    dev: false
+    optional: true
+
   /@cspotcode/source-map-support@0.8.1:
     resolution: {integrity: sha512-IchNf6dN4tHoMFIn/7OE8LWZ19Y6q/67Bmf6vnGREv8RSbBVb9LPJxEcnwrcwX6ixSvaiGoomAUvu4YSxXrVgw==}
     engines: {node: '>=12'}
@@ -722,8 +782,8 @@ packages:
     resolution: {integrity: sha512-eMk0b9ReBbV23xXU693TAIrLyeO5iTgBZGSJfpqriG8UkYvr/hC9u9pyMlAakDNHWmbhMZCDs6KQO0jzKD8OTw==}
     dev: false
 
-  /@noble/ciphers@0.5.3:
+  /@noble/ciphers@0.4.1:
-    resolution: {integrity: sha512-B0+6IIHiqEs3BPMT0hcRmHvEj2QHOLu+uwt+tqDDeVd0oyVzh7BPrDcPjRnV1PV/5LaknXJJQvOuRGR0zQJz+w==}
+    resolution: {integrity: sha512-QCOA9cgf3Rc33owG0AYBB9wszz+Ul2kramWN8tXG44Gyciud/tbkEqvxRF/IpqQaBpRBNi9f4jdNxqB2CQCIXg==}
     dev: false
 
   /@noble/curves@1.4.2:
@@ -757,6 +817,33 @@ packages:
     dev: false
     optional: true
 
+  /@peculiar/asn1-ecc@2.3.8:
+    resolution: {integrity: sha512-Ah/Q15y3A/CtxbPibiLM/LKcMbnLTdUdLHUgdpB5f60sSvGkXzxJCu5ezGTFHogZXWNX3KSmYqilCrfdmBc6pQ==}
+    dependencies:
+      '@peculiar/asn1-schema': 2.3.8
+      '@peculiar/asn1-x509': 2.3.8
+      asn1js: 3.0.5
+      tslib: 2.6.3
+    dev: false
+
+  /@peculiar/asn1-schema@2.3.8:
+    resolution: {integrity: sha512-ULB1XqHKx1WBU/tTFIA+uARuRoBVZ4pNdOA878RDrRbBfBGcSzi5HBkdScC6ZbHn8z7L8gmKCgPC1LHRrP46tA==}
+    dependencies:
+      asn1js: 3.0.5
+      pvtsutils: 1.3.5
+      tslib: 2.6.3
+    dev: false
+
+  /@peculiar/asn1-x509@2.3.8:
+    resolution: {integrity: sha512-voKxGfDU1c6r9mKiN5ZUsZWh3Dy1BABvTM3cimf0tztNwyMJPhiXY94eRTgsMQe6ViLfT6EoXxkWVzcm3mFAFw==}
+    dependencies:
+      '@peculiar/asn1-schema': 2.3.8
+      asn1js: 3.0.5
+      ipaddr.js: 2.2.0
+      pvtsutils: 1.3.5
+      tslib: 2.6.3
+    dev: false
+
   /@scure/base@1.1.7:
     resolution: {integrity: sha512-PPNYBslrLNNUQ/Yad37MHYsNQtK67EhWb6WtSvNLLPo7SdVZgkUjD6Dg+5On7zNwmskf8OX7I7Nx5oN+MIWE0g==}
     dev: false
@@ -1384,6 +1471,15 @@ packages:
       safer-buffer: 2.1.2
     dev: true
 
+  /asn1js@3.0.5:
+    resolution: {integrity: sha512-FVnvrKJwpt9LP2lAMl8qZswRNm3T4q9CON+bxldk2iwk3FFpuwhx2FfinyitizWHsVYyaY+y5JzDR0rCMV5yTQ==}
+    engines: {node: '>=12.0.0'}
+    dependencies:
+      pvtsutils: 1.3.5
+      pvutils: 1.1.3
+      tslib: 2.6.3
+    dev: false
+
   /assert-plus@1.0.0:
     resolution: {integrity: sha512-NfJ4UzBCcQGLDlQq7nHxH+tv3kyZ0hHQqF5BO6J7tNJeP5do1llPr8dZ8zHonfhAu0PHAdMkSo+8o0wxg9lZWw==}
     engines: {node: '>=0.8'}
@@ -1409,6 +1505,11 @@ packages:
     resolution: {integrity: sha512-AKpaYlHn8t4SVbOHCy+b5+KKgvR4vrsD8vbvrbiQJps7fKDTkjkDry6ji0rUJjC0kzbNePLwzxq8iypo41qeWA==}
     dev: false
 
+  /base64url@3.0.1:
+    resolution: {integrity: sha512-ir1UPr3dkwexU7FdV8qBBbNDRUhMmIekYMFZfi+C/sLNnRESKPl23nB9b2pltqfOQNnGzsDdId90AEtG5tCx4A==}
+    engines: {node: '>=6.0.0'}
+    dev: false
+
   /bcrypt-pbkdf@1.0.2:
     resolution: {integrity: sha512-qeFIXtP4MSoi6NLqO12WfqARWWuCKi2Rn/9hJLEmtB5yTNr9DqFWkJRCf2qShWzPeAMRnOgCrq0sg/KLv5ES9w==}
     dependencies:
@@ -1556,6 +1657,28 @@ packages:
     resolution: {integrity: sha512-4tYFyifaFfGacoiObjJegolkwSU4xQNGbVgUiNYVUxbQ2x2lUsFvY4hVgVzGiIe6WLOPqycWXA40l+PWsxthUw==}
     dev: true
 
+  /cbor-extract@2.2.0:
+    resolution: {integrity: sha512-Ig1zM66BjLfTXpNgKpvBePq271BPOvu8MR0Jl080yG7Jsl+wAZunfrwiwA+9ruzm/WEdIV5QF/bjDZTqyAIVHA==}
+    hasBin: true
+    requiresBuild: true
+    dependencies:
+      node-gyp-build-optional-packages: 5.1.1
+    optionalDependencies:
+      '@cbor-extract/cbor-extract-darwin-arm64': 2.2.0
+      '@cbor-extract/cbor-extract-darwin-x64': 2.2.0
+      '@cbor-extract/cbor-extract-linux-arm': 2.2.0
+      '@cbor-extract/cbor-extract-linux-arm64': 2.2.0
+      '@cbor-extract/cbor-extract-linux-x64': 2.2.0
+      '@cbor-extract/cbor-extract-win32-x64': 2.2.0
+    dev: false
+    optional: true
+
+  /cbor-x@1.5.9:
+    resolution: {integrity: sha512-OEI5rEu3MeR0WWNUXuIGkxmbXVhABP+VtgAXzm48c9ulkrsvxshjjk94XSOGphyAKeNGLPfAxxzEtgQ6rEVpYQ==}
+    optionalDependencies:
+      cbor-extract: 2.2.0
+    dev: false
+
   /chokidar@3.6.0:
     resolution: {integrity: sha512-7VT13fmjotKpGipCW9JEQAusEPE+Ei8nl6/g4FBAmIm0GOOLMua9NDDo/DWp0ZAxCr3cPq5ZpBqmPAQgDda2Pw==}
     engines: {node: '>= 8.10.0'}
@@ -1736,10 +1859,10 @@ packages:
     engines: {node: '>=8'}
     dev: false
 
-  /did-jwt@8.0.4:
+  /did-jwt@7.4.7:
-    resolution: {integrity: sha512-KPtG7H+8GgKGMiDqFvOdNy5BBN3hpA+8xV7VygEnpst5oPIqjvcH3rTtnPF55a8bOxIzE2PudKGIXIQhekv7WA==}
+    resolution: {integrity: sha512-Apz7nIfIHSKWIMaEP5L/K8xkwByvjezjTG0xiqwKdnNj1x8M0+Yasury5Dm/KPltxi2PlGfRPf3IejRKZrT8mQ==}
     dependencies:
-      '@noble/ciphers': 0.5.3
+      '@noble/ciphers': 0.4.1
       '@noble/curves': 1.4.2
       '@noble/hashes': 1.4.0
       '@scure/base': 1.1.7
@@ -2279,6 +2402,11 @@ packages:
     engines: {node: '>= 0.10'}
     dev: false
 
+  /ipaddr.js@2.2.0:
+    resolution: {integrity: sha512-Ag3wB2o37wslZS19hZqorUnrnzSkpOVy+IiiDEiTqNubEYpYuHWIf6K4psgN2ZWKExS4xhVCrRVfb/wfW8fWJA==}
+    engines: {node: '>= 10'}
+    dev: false
+
   /is-binary-path@2.1.0:
     resolution: {integrity: sha512-ZMERYes6pDydyuGidse7OsHxtbI7WVeUEozgR/g7rd0xUimYNlvZRE/K2MgZTjWy725IfelLeVcEM97mmtRGXw==}
     engines: {node: '>=8'}
@@ -2605,6 +2733,15 @@ packages:
     resolution: {integrity: sha512-5m3bsyrjFWE1xf7nz7YXdN4udnVtXK6/Yfgn5qnahL6bCkf2yKt4k3nuTKAtT4r3IG8JNR2ncsIMdZuAzJjHQQ==}
     dev: false
 
+  /node-gyp-build-optional-packages@5.1.1:
+    resolution: {integrity: sha512-+P72GAjVAbTxjjwUmwjVrqrdZROD4nf8KgpBoDxqXXTiYZZt/ud60dE5yvCSr9lRO8e8yv6kgJIC0K0PfZFVQw==}
+    hasBin: true
+    requiresBuild: true
+    dependencies:
+      detect-libc: 2.0.3
+    dev: false
+    optional: true
+
   /node-gyp@8.4.1:
     resolution: {integrity: sha512-olTJRgUtAb/hOXG0E93wZDs5YiJlgbXxTwQAFHyNlRsXQnYzUaF2aGgujZbw+hR8aF4ZG/rST57bWMWD16jr9w==}
     engines: {node: '>= 10.12.0'}
@@ -2810,6 +2947,17 @@ packages:
     engines: {node: '>=6'}
     dev: true
 
+  /pvtsutils@1.3.5:
+    resolution: {integrity: sha512-ARvb14YB9Nm2Xi6nBq1ZX6dAM0FsJnuk+31aUp4TrcZEdKUlSqOqsxJHUPJDNE3qiIp+iUPEIeR6Je/tgV7zsA==}
+    dependencies:
+      tslib: 2.6.3
+    dev: false
+
+  /pvutils@1.1.3:
+    resolution: {integrity: sha512-pMpnA0qRdFp32b1sJl1wOJNxZLQ2cbQx+k6tjNtZ8CpvVhNqEPRgivZ2WOUev2YMajecdH7ctUPDvEe87nariQ==}
+    engines: {node: '>=6.0.0'}
+    dev: false
+
   /qs@6.11.0:
     resolution: {integrity: sha512-MvjoMCJwEarSbUYk5O+nmoSzSutSsTwF85zcHPQ9OrlFoZOYIjaqBAJIqIXjptyD5vThxGq52Xu/MaJzRkIk4Q==}
     engines: {node: '>=0.6'}

src/server.ts

@@ -1,4 +1,5 @@
 //@ts-nocheck
+
 const { DeleteObjectCommand, PutObjectCommand, S3Client } = require('@aws-sdk/client-s3');
 const cors = require('cors');
 const crypto = require('crypto');
@@ -11,7 +12,7 @@ const multer = require('multer');
 const path = require('path');
 const sqlite3 = require('sqlite3').verbose();
 
-const { didEthLocalResolver } = require("./vc/did-eth-local-resolver");
+import { decodeAndVerifyJwt } from "./vc";
 
 require('dotenv').config()
 
@@ -24,8 +25,6 @@ const dbFile = process.env.SQLITE_FILE || './image-db.sqlite';
 const bucketName = process.env.S3_BUCKET_NAME || 'gifts-image-test';
 const imageServer = process.env.DOWNLOAD_IMAGE_SERVER || 'test-image.timesafari.app';
 
-const resolver = new Resolver({ 'ethr': didEthLocalResolver });
-
 // Open a connection to the SQLite database
 const db = new sqlite3.Database(dbFile, (err) => {
   if (err) {
@@ -502,7 +501,7 @@ async function decodeJwt(req, res) {
     };
   }
   const jwt = auth.substring('Bearer '.length);
-  const verified = await didJwt.verifyJWT(jwt, { resolver });
+  const verified = await decodeAndVerifyJwt(jwt);
   if (!verified.verified) {
     const errorTime = new Date().toISOString();
     console.error(errorTime, 'Got invalid JWT in Authorization header:', verified);

src/vc/did-eth-local-resolver.ts

@@ -0,0 +1,8 @@
+import {DIDResolutionResult} from "did-resolver";
+
+declare module './did-eth-local-resolver.js' {
+  const value: {
+    didEthLocalResolver: (jwt: string) => Promise<DIDResolutionResult>;
+  };
+  export default value;
+}

src/vc/didPeer.ts

@@ -0,0 +1,139 @@
+import { AsnParser } from "@peculiar/asn1-schema";
+import { ECDSASigValue } from "@peculiar/asn1-ecc";
+import crypto from "crypto";
+import { decode as cborDecode } from "cbor-x";
+
+/**
+ *
+ *
+ * similar code is in crowd-funder-for-time-pwa libs/crypto/vc/passkeyDidPeer.ts verifyJwtWebCrypto
+ *
+ * @returns {Promise<boolean>}
+ */
+export async function verifyPeerSignature(
+  payloadBytes: Uint8Array,
+  publicKeyBytes: Uint8Array,
+  signatureBytes: Uint8Array
+) {
+  // this simple approach doesn't work
+  //const verify = crypto.createVerify('sha256')
+  //verify.update(preimage)
+  //const result = verify.verify(publicKey, signature)
+
+  const finalSignatureBuffer = unwrapEC2Signature(signatureBytes);
+  const verifyAlgorithm = {
+    name: "ECDSA",
+    hash: { name: "SHA-256" },
+  };
+  const publicKeyJwk = cborToKeys(publicKeyBytes).publicKeyJwk;
+  const keyAlgorithm = {
+    name: "ECDSA",
+    namedCurve: publicKeyJwk.crv,
+  };
+  const publicKeyCryptoKey = await crypto.subtle.importKey(
+    "jwk",
+    publicKeyJwk,
+    keyAlgorithm,
+    false,
+    ["verify"],
+  );
+  const verified = await crypto.subtle.verify(
+    verifyAlgorithm,
+    publicKeyCryptoKey,
+    finalSignatureBuffer,
+    payloadBytes,
+  );
+  return verified;
+}
+
+function cborToKeys(publicKeyBytes: Uint8Array) {
+  const jwkObj = cborDecode(publicKeyBytes);
+  if (
+    jwkObj[1] != 2 || // kty "EC"
+    jwkObj[3] != -7 || // alg "ES256"
+    jwkObj[-1] != 1 || // crv "P-256"
+    jwkObj[-2].length != 32 || // x
+    jwkObj[-3].length != 32 // y
+  ) {
+    throw new Error("Unable to extract key.");
+  }
+  const publicKeyJwk = {
+    alg: "ES256",
+    crv: "P-256",
+    kty: "EC",
+    x: arrayToBase64Url(jwkObj[-2]),
+    y: arrayToBase64Url(jwkObj[-3]),
+  };
+  const publicKeyBuffer = Buffer.concat([
+    Buffer.from(jwkObj[-2]),
+    Buffer.from(jwkObj[-3]),
+  ]);
+  return { publicKeyJwk, publicKeyBuffer };
+}
+
+function toBase64Url(anythingB64: string) {
+  return anythingB64.replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
+}
+
+function arrayToBase64Url(anything: Uint8Array) {
+  return toBase64Url(Buffer.from(anything).toString("base64"));
+}
+
+/**
+ * In WebAuthn, EC2 signatures are wrapped in ASN.1 structure so we need to peel r and s apart.
+ *
+ * See https://www.w3.org/TR/webauthn-2/#sctn-signature-attestation-types
+ *
+ * @return Uint8Array of the signature inside
+ */
+function unwrapEC2Signature(signature: Uint8Array) {
+  const parsedSignature = AsnParser.parse(signature, ECDSASigValue);
+  let rBytes = new Uint8Array(parsedSignature.r);
+  let sBytes = new Uint8Array(parsedSignature.s);
+
+  if (shouldRemoveLeadingZero(rBytes)) {
+    rBytes = rBytes.slice(1);
+  }
+
+  if (shouldRemoveLeadingZero(sBytes)) {
+    sBytes = sBytes.slice(1);
+  }
+
+  const finalSignature = isoUint8ArrayConcat([rBytes, sBytes]);
+
+  return finalSignature;
+}
+
+/**
+ * Determine if the DER-specific `00` byte at the start of an ECDSA signature byte sequence
+ * should be removed based on the following logic:
+ *
+ * "If the leading byte is 0x0, and the high order bit on the second byte is not set to 0,
+ * then remove the leading 0x0 byte"
+ *
+ * @return true if leading zero should be removed
+ */
+function shouldRemoveLeadingZero(bytes: Uint8Array) {
+  return bytes[0] === 0x0 && (bytes[1] & (1 << 7)) !== 0;
+}
+
+// from https://github.com/MasterKale/SimpleWebAuthn/blob/master/packages/server/src/helpers/iso/isoUint8Array.ts#L49
+/**
+ * Combine multiple Uint8Arrays into a single Uint8Array
+ *
+ * @param arrays - Uint8Array[]
+ * @return Uint8Array
+ */
+function isoUint8ArrayConcat(arrays: Uint8Array[]) {
+  let pointer = 0;
+  const totalLength = arrays.reduce((prev, curr) => prev + curr.length, 0);
+
+  const toReturn = new Uint8Array(totalLength);
+
+  arrays.forEach((arr) => {
+    toReturn.set(arr, pointer);
+    pointer += arr.length;
+  });
+
+  return toReturn;
+}

src/vc/index.ts

@@ -5,3 +5,84 @@
  * Other projects: endorser-ch, crowd-funder-for-time-pwa
  *
  */
+
+import base64url from "base64url";
+import didJwt from "did-jwt";
+import {Resolver} from "did-resolver";
+
+import ethResolver from "./did-eth-local-resolver";
+import {verifyJwt as peerVerifyJwt} from "./passkeyDidPeer";
+
+
+export const TEST_BYPASS_ENV_VALUE = "test-local";
+export const ETHR_DID_PREFIX = 'did:ethr:'
+export const PEER_DID_PREFIX = 'did:peer:'
+export const JWT_VERIFY_FAILED_CODE = "JWT_VERIFY_FAILED_CODE"
+export const UNSUPPORTED_DID_METHOD_CODE = "UNSUPPORTED_DID_METHOD"
+
+const resolver = new Resolver({
+  'ethr': ethResolver.didEthLocalResolver
+});
+
+// return Promise of at least { issuer, payload, verified boolean }
+// ... and also if successfully verified by did-jwt (not JWANT): data, doc, signature, signer
+export async function decodeAndVerifyJwt(jwt: string) {
+  const pieces = jwt.split('.')
+  const header = JSON.parse(base64url.decode(pieces[0]))
+  const payload = JSON.parse(base64url.decode(pieces[1]))
+  const issuerDid = payload.iss
+  if (!issuerDid) {
+    return Promise.reject({
+      clientError: {
+        message: `Missing "iss" field in JWT.`,
+      }
+    })
+  }
+  if (issuerDid && issuerDid.startsWith(ETHR_DID_PREFIX) && process.env.NODE_ENV === TEST_BYPASS_ENV_VALUE) {
+    // Error of "Cannot read property 'toString' of undefined" usually means the JWT is malformed
+    // eg. no "." separators.
+    let nowEpoch =  Math.floor(new Date().getTime() / 1000)
+    if (payload.exp < nowEpoch) {
+      console.log("JWT with exp " + payload.exp
+        + " has expired but we're in test mode so we'll use a new time."
+      )
+      payload.exp = nowEpoch + 100
+    }
+    return { issuer: issuerDid, payload, verified: true } // other elements will = undefined
+  }
+
+  if (issuerDid.startsWith(ETHR_DID_PREFIX)) {
+    try {
+      let verified = await didJwt.verifyJWT(jwt, {resolver})
+      return verified
+
+    } catch (e) {
+      return Promise.reject({
+        clientError: {
+          message: `JWT failed verification: ` + e,
+          code: JWT_VERIFY_FAILED_CODE
+        }
+      })
+    }
+  }
+
+  if (issuerDid.startsWith(PEER_DID_PREFIX) && header.typ === "JWANT") {
+    const { claimPayload, verified } = await peerVerifyJwt(payload, issuerDid, pieces[2])
+    return { issuer: issuerDid, payload: claimPayload, verified: verified }
+  }
+
+  if (issuerDid.startsWith(PEER_DID_PREFIX)) {
+    return Promise.reject({
+      clientError: {
+        message: `JWT with a PEER DID currently only supported with typ == JWANT. Contact us us for JWT suport since it should be straightforward.`
+      }
+    })
+  }
+
+  return Promise.reject({
+    clientError: {
+      message: `Unsupported DID method ${issuerDid}`,
+      code: UNSUPPORTED_DID_METHOD_CODE
+    }
+  })
+}

src/vc/passkeyDidPeer.ts

@@ -0,0 +1,104 @@
+import crypto from "crypto";
+import didJwt from "did-jwt";
+
+import {PEER_DID_PREFIX, TEST_BYPASS_ENV_VALUE} from "./index";
+import {verifyPeerSignature} from "./didPeer";
+
+/**
+ *
+ * @param payload
+ * @param issuerDid
+ * @param signatureString
+ * @returns {Promise<{claimPayload: string, verified: boolean}>}
+ */
+export async function verifyJwt(payload: any, issuerDid: any, signatureString: any) {
+  if (!payload.iss) {
+    return Promise.reject({
+      clientError: {
+        message: `JWT is missing an "iss" field.`,
+      }
+    })
+  }
+  let nowEpoch =  Math.floor(new Date().getTime() / 1000)
+  if (!payload.exp) {
+    return Promise.reject({
+      clientError: {
+        message: `JWT with is missing an "exp" field.`,
+      }
+    })
+  }
+  if (payload.exp < nowEpoch && process.env.NODE_ENV !== TEST_BYPASS_ENV_VALUE) {
+    return Promise.reject({
+      clientError: {
+        message: `JWT with exp ${payload.exp} has expired.`,
+      }
+    });
+  }
+
+  const authData: string = payload.AuthenticationDataB64URL
+  const clientData: string = payload.ClientDataJSONB64URL
+  if (!authData || !clientData) {
+    return Promise.reject({
+      clientError: {
+        message: `JWT with typ == JWANT requires AuthenticationData and ClientDataJSON.`
+      }
+    })
+  }
+
+  const decodedAuthDataBuff = Buffer.from(authData, 'base64url')
+  const decodedClientData = Buffer.from(clientData, 'base64url')
+
+  let claimPayload = JSON.parse(decodedClientData.toString())
+  if (claimPayload.challenge) {
+    claimPayload = JSON.parse(Buffer.from(claimPayload.challenge, "base64url").toString())
+    if (!claimPayload.exp) {
+      claimPayload.exp = payload.exp
+    }
+    if (!claimPayload.iat) {
+      claimPayload.iat = payload.iat
+    }
+    if (!claimPayload.iss) {
+      claimPayload.iss = payload.iss
+    }
+  }
+  if (!claimPayload.exp) {
+    return Promise.reject({
+      clientError: {
+        message: `JWT client data challenge is missing an "exp" field.`,
+      }
+    })
+  }
+  if (claimPayload.exp < nowEpoch && process.env.NODE_ENV !== TEST_BYPASS_ENV_VALUE) {
+    return Promise.reject({
+      clientError: {
+        message: `JWT client data challenge exp time is past.`,
+      }
+    })
+  }
+  if (claimPayload.exp !== payload.exp) {
+    return Promise.reject({
+      clientError: {
+        message: `JWT client data challenge "exp" field doesn't match the outside payload "exp".`,
+      }
+    })
+  }
+  if (claimPayload.iss !== payload.iss) {
+    return Promise.reject({
+      clientError: {
+        message: `JWT client data challenge "iss" field doesn't match the outside payload "iss".`,
+      }
+    })
+  }
+
+  const hashedClientDataBuff = crypto.createHash("sha256")
+  .update(decodedClientData)
+  .digest()
+  const preimage = new Uint8Array(Buffer.concat([decodedAuthDataBuff, hashedClientDataBuff]))
+  const PEER_DID_MULTIBASE_PREFIX = PEER_DID_PREFIX + "0"
+  // Uint8Array
+  const publicKey = didJwt.multibaseToBytes(issuerDid.substring(PEER_DID_MULTIBASE_PREFIX.length));
+  const signature = new Uint8Array(Buffer.from(signatureString, 'base64url'))
+  const verified = await verifyPeerSignature(preimage, publicKey, signature)
+  return { claimPayload, verified }
+
+}