8 changed files with 496 additions and 12 deletions
@ -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; |
||||
|
} |
||||
@ -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; |
||||
|
} |
||||
@ -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 } |
||||
|
|
||||
|
} |
||||
Loading…
Reference in new issue