refine "vc" functions further, separating passkey-specific items from did-peer file

src/libs/crypto/vc/didPeer.ts

@@ -0,0 +1,96 @@
+import {Buffer} from "buffer/";
+import {decode as cborDecode} from "cbor-x";
+import {bytesToMultibase, multibaseToBytes} from "did-jwt";
+
+import {getWebCrypto} from "@/libs/crypto/vc/passkeyHelpers";
+
+const PEER_DID_PREFIX = "did:peer:";
+const PEER_DID_MULTIBASE_PREFIX = PEER_DID_PREFIX + "0";
+
+/**
+ *
+ *
+ * similar code is in crowd-funder-for-time-pwa libs/crypto/vc/passkeyDidPeer.ts verifyJwtWebCrypto
+ *
+ * @returns {Promise<boolean>}
+ */
+export async function verifyPeerSignature(
+  payloadBytes: Buffer,
+  issuerDid: string,
+  signatureBytes: Uint8Array,
+): Promise<boolean> {
+  const publicKeyBytes = peerDidToPublicKeyBytes(issuerDid);
+
+  const WebCrypto = await getWebCrypto();
+  const verifyAlgorithm = {
+    name: "ECDSA",
+    hash: { name: "SHA-256" },
+  };
+  const publicKeyJwk = cborToKeys(publicKeyBytes).publicKeyJwk;
+  const keyAlgorithm = {
+    name: "ECDSA",
+    namedCurve: publicKeyJwk.crv,
+  };
+  const publicKeyCryptoKey = await WebCrypto.subtle.importKey(
+    "jwk",
+    publicKeyJwk,
+    keyAlgorithm,
+    false,
+    ["verify"],
+  );
+  const verified = await WebCrypto.subtle.verify(
+    verifyAlgorithm,
+    publicKeyCryptoKey,
+    signatureBytes,
+    payloadBytes,
+  );
+  return verified;
+}
+
+export 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 };
+}
+
+export function toBase64Url(anythingB64: string) {
+  return anythingB64.replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
+}
+
+export function arrayToBase64Url(anything: Uint8Array) {
+  return toBase64Url(Buffer.from(anything).toString("base64"));
+}
+
+export function peerDidToPublicKeyBytes(did: string) {
+  return multibaseToBytes(did.substring(PEER_DID_MULTIBASE_PREFIX.length));
+}
+
+export function createPeerDid(publicKeyBytes: Uint8Array) {
+  // https://github.com/decentralized-identity/veramo/blob/next/packages/did-provider-peer/src/peer-did-provider.ts#L67
+  //const provider = new PeerDIDProvider({ defaultKms: LOCAL_KMS_NAME });
+  const methodSpecificId = bytesToMultibase(
+    publicKeyBytes,
+    "base58btc",
+    "p256-pub",
+  );
+  return PEER_DID_MULTIBASE_PREFIX + methodSpecificId;
+}

src/libs/crypto/vc/index.ts

@@ -1,13 +1,17 @@
 /**
  * Verifiable Credential & DID functions, specifically for EndorserSearch.org tools
+ *
+ * The goal is to make this folder similar across projects, then move it to a library.
+ * Other projects: endorser-ch, image-api
+ *
  */
 
 import * as didJwt from "did-jwt";
+import { JWTDecoded } from "did-jwt/lib/JWT";
 import { IIdentifier } from "@veramo/core";
 import * as u8a from "uint8arrays";
 
 import { createDidPeerJwt } from "@/libs/crypto/vc/passkeyDidPeer";
-import {JWTDecoded} from "did-jwt/lib/JWT";
 
 /**
  * Meta info about a key
@@ -93,7 +97,7 @@ function fromJose(signature: string): {
   const s = bytesToHex(signatureBytes.slice(32, 64));
   const recoveryParam =
     signatureBytes.length === 65 ? signatureBytes[64] : undefined;
-  return {r, s, recoveryParam};
+  return { r, s, recoveryParam };
 }
 
 // from did-jwt/util; see SimpleSigner above

src/libs/crypto/vc/passkeyDidPeer.ts

@@ -1,6 +1,5 @@
 import { Buffer } from "buffer/";
-import { decode as cborDecode } from "cbor-x";
-import { bytesToMultibase, JWTPayload, multibaseToBytes } from "did-jwt";
+import { JWTPayload } from "did-jwt";
 import { DIDResolutionResult } from "did-resolver";
 import { sha256 } from "ethereum-cryptography/sha256.js";
 import {
@@ -21,13 +20,14 @@ import {
 } from "@simplewebauthn/types";
 
 import { AppString } from "@/constants/app";
+import { unwrapEC2Signature } from "@/libs/crypto/vc/passkeyHelpers";
 import {
-  getWebCrypto,
-  unwrapEC2Signature,
-} from "@/libs/crypto/vc/passkeyHelpers";
+  arrayToBase64Url,
+  cborToKeys,
+  peerDidToPublicKeyBytes,
+  verifyPeerSignature,
+} from "@/libs/crypto/vc/didPeer";
 
-const PEER_DID_PREFIX = "did:peer:";
-const PEER_DID_MULTIBASE_PREFIX = PEER_DID_PREFIX + "0";
 export interface JWK {
   kty: string;
   crv: string;
@@ -35,14 +35,6 @@ export interface JWK {
   y: string;
 }
 
-function toBase64Url(anythingB64: string) {
-  return anythingB64.replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
-}
-
-function arrayToBase64Url(anything: Uint8Array) {
-  return toBase64Url(Buffer.from(anything).toString("base64"));
-}
-
 export async function registerCredential(passkeyName?: string) {
   const options: PublicKeyCredentialCreationOptionsJSON =
     await generateRegistrationOptions({
@@ -95,21 +87,6 @@ export async function registerCredential(passkeyName?: string) {
   };
 }
 
-export function createPeerDid(publicKeyBytes: Uint8Array) {
-  // https://github.com/decentralized-identity/veramo/blob/next/packages/did-provider-peer/src/peer-did-provider.ts#L67
-  //const provider = new PeerDIDProvider({ defaultKms: LOCAL_KMS_NAME });
-  const methodSpecificId = bytesToMultibase(
-    publicKeyBytes,
-    "base58btc",
-    "p256-pub",
-  );
-  return PEER_DID_MULTIBASE_PREFIX + methodSpecificId;
-}
-
-function peerDidToPublicKeyBytes(did: string) {
-  return multibaseToBytes(did.substring(PEER_DID_MULTIBASE_PREFIX.length));
-}
-
 export class PeerSetup {
   public authenticatorData?: ArrayBuffer;
   public challenge?: Uint8Array;
@@ -422,33 +399,7 @@ export async function verifyJwtWebCrypto(
 
   // Construct the preimage
   const preimage = Buffer.concat([authDataFromBase, hash]);
-
-  const publicKeyBytes = peerDidToPublicKeyBytes(issuerDid);
-
-  const WebCrypto = await getWebCrypto();
-  const verifyAlgorithm = {
-    name: "ECDSA",
-    hash: { name: "SHA-256" },
-  };
-  const publicKeyJwk = cborToKeys(publicKeyBytes).publicKeyJwk;
-  const keyAlgorithm = {
-    name: "ECDSA",
-    namedCurve: publicKeyJwk.crv,
-  };
-  const publicKeyCryptoKey = await WebCrypto.subtle.importKey(
-    "jwk",
-    publicKeyJwk,
-    keyAlgorithm,
-    false,
-    ["verify"],
-  );
-  const verified = await WebCrypto.subtle.verify(
-    verifyAlgorithm,
-    publicKeyCryptoKey,
-    finalSigBuffer,
-    preimage,
-  );
-  return verified;
+  return verifyPeerSignature(preimage, issuerDid, finalSigBuffer);
 }
 
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -554,31 +505,6 @@ function base64URLStringToArrayBuffer(base64URLString: string) {
   return buffer;
 }
 
-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 };
-}
-
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
 async function pemToCryptoKey(pem: string) {
   const binaryDerString = atob(

src/libs/util.ts

@@ -11,10 +11,11 @@ import { MASTER_SETTINGS_KEY } from "@/db/tables/settings";
 import { deriveAddress, generateSeed, newIdentifier } from "@/libs/crypto";
 import { GenericCredWrapper, containsHiddenDid } from "@/libs/endorserServer";
 import * as serverUtil from "@/libs/endorserServer";
-import { createPeerDid, registerCredential } from "@/libs/crypto/vc/passkeyDidPeer";
+import { registerCredential } from "@/libs/crypto/vc/passkeyDidPeer";
 
 import { Buffer } from "buffer";
 import {KeyMeta} from "@/libs/crypto/vc";
+import {createPeerDid} from "@/libs/crypto/vc/didPeer";
 
 export const PRIVACY_MESSAGE =
   "The data you send will be visible to the world -- except: your IDs and the IDs of anyone you tag will stay private, only visible to them and others you explicitly allow.";