mirror of
https://github.com/Ylianst/MeshCentral.git
synced 2024-11-29 18:14:14 +03:00
264 lines
12 KiB
JavaScript
264 lines
12 KiB
JavaScript
/**
|
||
* @description MeshCentral WebAuthn module
|
||
* @version v0.0.1
|
||
*/
|
||
|
||
// This code is based on a portion of the webauthn module at: https://www.npmjs.com/package/webauthn
|
||
|
||
"use strict"
|
||
|
||
const crypto = require('crypto');
|
||
const cbor = require('cbor');
|
||
//const iso_3166_1 = require('iso-3166-1')
|
||
//const Certificate = null; //require('@fidm/x509')
|
||
|
||
module.exports.CreateWebAuthnModule = function () {
|
||
var obj = {};
|
||
|
||
obj.generateRegistrationChallenge = function (rpName, user) {
|
||
return {
|
||
rp: { name: rpName },
|
||
user: user,
|
||
challenge: crypto.randomBytes(64).toString('base64'),
|
||
pubKeyCredParams: [{ type: 'public-key', alg: -7 }],
|
||
timeout: 60000,
|
||
attestation: 'none'
|
||
};
|
||
}
|
||
|
||
obj.verifyAuthenticatorAttestationResponse = function (webauthnResponse) {
|
||
const attestationBuffer = Buffer.from(webauthnResponse.attestationObject, 'base64');
|
||
const ctapMakeCredResp = cbor.decodeAllSync(attestationBuffer)[0];
|
||
const authrDataStruct = parseMakeCredAuthData(ctapMakeCredResp.authData);
|
||
//console.log('***CTAP_RESPONSE', ctapMakeCredResp)
|
||
//console.log('***AUTHR_DATA_STRUCT', authrDataStruct)
|
||
|
||
const response = { 'verified': false };
|
||
|
||
if ((ctapMakeCredResp.fmt === 'none') || (ctapMakeCredResp.fmt === 'fido-u2f')) {
|
||
if (!(authrDataStruct.flags & 0x01)) { throw new Error('User was NOT presented during authentication!'); } // U2F_USER_PRESENTED
|
||
|
||
const publicKey = COSEECDHAtoPKCS(authrDataStruct.COSEPublicKey);
|
||
response.verified = true;
|
||
|
||
if (response.verified) {
|
||
response.authrInfo = {
|
||
fmt: 'none',
|
||
publicKey: ASN1toPEM(publicKey),
|
||
counter: authrDataStruct.counter,
|
||
keyId: authrDataStruct.credID.toString('base64')
|
||
};
|
||
}
|
||
}
|
||
/*
|
||
else if (ctapMakeCredResp.fmt === 'fido-u2f') {
|
||
if (!(authrDataStruct.flags & 0x01)) // U2F_USER_PRESENTED
|
||
throw new Error('User was NOT presented during authentication!');
|
||
|
||
const clientDataHash = hash(webauthnResponse.clientDataJSON)
|
||
const reservedByte = Buffer.from([0x00]);
|
||
const publicKey = COSEECDHAtoPKCS(authrDataStruct.COSEPublicKey)
|
||
const signatureBase = Buffer.concat([reservedByte, authrDataStruct.rpIdHash, clientDataHash, authrDataStruct.credID, publicKey]);
|
||
|
||
const PEMCertificate = ASN1toPEM(ctapMakeCredResp.attStmt.x5c[0]);
|
||
const signature = ctapMakeCredResp.attStmt.sig;
|
||
|
||
response.verified = verifySignature(signature, signatureBase, PEMCertificate)
|
||
|
||
if (response.verified) {
|
||
response.authrInfo = {
|
||
fmt: 'fido-u2f',
|
||
publicKey: ASN1toPEM(publicKey),
|
||
counter: authrDataStruct.counter,
|
||
keyId: authrDataStruct.credID.toString('base64')
|
||
}
|
||
}
|
||
} else if (ctapMakeCredResp.fmt === 'packed' && ctapMakeCredResp.attStmt.hasOwnProperty('x5c')) {
|
||
if (!(authrDataStruct.flags & 0x01)) // U2F_USER_PRESENTED
|
||
throw new Error('User was NOT presented durring authentication!');
|
||
|
||
const clientDataHash = hash(webauthnResponse.clientDataJSON)
|
||
const publicKey = COSEECDHAtoPKCS(authrDataStruct.COSEPublicKey)
|
||
const signatureBase = Buffer.concat([ctapMakeCredResp.authData, clientDataHash]);
|
||
|
||
const PEMCertificate = ASN1toPEM(ctapMakeCredResp.attStmt.x5c[0]);
|
||
const signature = ctapMakeCredResp.attStmt.sig;
|
||
|
||
const pem = Certificate.fromPEM(PEMCertificate);
|
||
|
||
// Getting requirements from https://www.w3.org/TR/webauthn/#packed-attestation
|
||
const aaguid_ext = pem.getExtension('1.3.6.1.4.1.45724.1.1.4')
|
||
|
||
response.verified = // Verify that sig is a valid signature over the concatenation of authenticatorData
|
||
// and clientDataHash using the attestation public key in attestnCert with the algorithm specified in alg.
|
||
verifySignature(signature, signatureBase, PEMCertificate) &&
|
||
// version must be 3 (which is indicated by an ASN.1 INTEGER with value 2)
|
||
pem.version == 3 &&
|
||
// ISO 3166 valid country
|
||
typeof iso_3166_1.whereAlpha2(pem.subject.countryName) !== 'undefined' &&
|
||
// Legal name of the Authenticator vendor (UTF8String)
|
||
pem.subject.organizationName &&
|
||
// Literal string “Authenticator Attestation” (UTF8String)
|
||
pem.subject.organizationalUnitName === 'Authenticator Attestation' &&
|
||
// A UTF8String of the vendor’s choosing
|
||
pem.subject.commonName &&
|
||
// The Basic Constraints extension MUST have the CA component set to false
|
||
!pem.extensions.isCA &&
|
||
// If attestnCert contains an extension with OID 1.3.6.1.4.1.45724.1.1.4 (id-fido-gen-ce-aaguid)
|
||
// verify that the value of this extension matches the aaguid in authenticatorData.
|
||
// The extension MUST NOT be marked as critical.
|
||
(aaguid_ext != null ?
|
||
(authrDataStruct.hasOwnProperty('aaguid') ?
|
||
!aaguid_ext.critical && aaguid_ext.value.slice(2).equals(authrDataStruct.aaguid) : false)
|
||
: true);
|
||
|
||
if (response.verified) {
|
||
response.authrInfo = {
|
||
fmt: 'fido-u2f',
|
||
publicKey: publicKey,
|
||
counter: authrDataStruct.counter,
|
||
keyId: authrDataStruct.credID.toString('base64')
|
||
}
|
||
}
|
||
|
||
// Self signed
|
||
} else if (ctapMakeCredResp.fmt === 'packed') {
|
||
if (!(authrDataStruct.flags & 0x01)) // U2F_USER_PRESENTED
|
||
throw new Error('User was NOT presented durring authentication!');
|
||
|
||
const clientDataHash = hash(webauthnResponse.clientDataJSON)
|
||
const publicKey = COSEECDHAtoPKCS(authrDataStruct.COSEPublicKey)
|
||
const signatureBase = Buffer.concat([ctapMakeCredResp.authData, clientDataHash]);
|
||
const PEMCertificate = ASN1toPEM(publicKey);
|
||
|
||
const { attStmt: { sig: signature, alg } } = ctapMakeCredResp
|
||
|
||
response.verified = // Verify that sig is a valid signature over the concatenation of authenticatorData
|
||
// and clientDataHash using the attestation public key in attestnCert with the algorithm specified in alg.
|
||
verifySignature(signature, signatureBase, PEMCertificate) && alg === -7
|
||
|
||
if (response.verified) {
|
||
response.authrInfo = {
|
||
fmt: 'fido-u2f',
|
||
publicKey: ASN1toPEM(publicKey),
|
||
counter: authrDataStruct.counter,
|
||
keyId: authrDataStruct.credID.toString('base64')
|
||
}
|
||
}
|
||
|
||
} else if (ctapMakeCredResp.fmt === 'android-safetynet') {
|
||
console.log("Android safetynet request\n")
|
||
console.log(ctapMakeCredResp)
|
||
|
||
const authrDataStruct = parseMakeCredAuthData(ctapMakeCredResp.authData);
|
||
console.log('AUTH_DATA', authrDataStruct)
|
||
//console.log('CLIENT_DATA_JSON ', webauthnResponse.clientDataJSON)
|
||
|
||
const publicKey = COSEECDHAtoPKCS(authrDataStruct.COSEPublicKey)
|
||
|
||
let [header, payload, signature] = ctapMakeCredResp.attStmt.response.toString('utf8').split('.')
|
||
const signatureBase = Buffer.from([header, payload].join('.'))
|
||
|
||
header = JSON.parse(header)
|
||
payload = JSON.parse(payload)
|
||
|
||
console.log('JWS HEADER', header)
|
||
console.log('JWS PAYLOAD', payload)
|
||
console.log('JWS SIGNATURE', signature)
|
||
|
||
const PEMCertificate = ASN1toPEM(Buffer.from(header.x5c[0], 'base64'))
|
||
|
||
const pem = Certificate.fromPEM(PEMCertificate)
|
||
|
||
console.log('PEM', pem)
|
||
|
||
response.verified = // Verify that sig is a valid signature over the concatenation of authenticatorData
|
||
// and clientDataHash using the attestation public key in attestnCert with the algorithm specified in alg.
|
||
verifySignature(signature, signatureBase, PEMCertificate) &&
|
||
// version must be 3 (which is indicated by an ASN.1 INTEGER with value 2)
|
||
pem.version == 3 &&
|
||
pem.subject.commonName === 'attest.android.com'
|
||
|
||
if (response.verified) {
|
||
response.authrInfo = {
|
||
fmt: 'fido-u2f',
|
||
publicKey: ASN1toPEM(publicKey),
|
||
counter: authrDataStruct.counter,
|
||
keyId: authrDataStruct.credID.toString('base64')
|
||
}
|
||
}
|
||
|
||
console.log('RESPONSE', response)
|
||
} */
|
||
else {
|
||
throw new Error(`Unsupported attestation format: ${ctapMakeCredResp.fmt}`);
|
||
}
|
||
|
||
return response;
|
||
}
|
||
|
||
obj.verifyAuthenticatorAssertionResponse = function (webauthnResponse, authr) {
|
||
const response = { 'verified': false }
|
||
if (['fido-u2f'].includes(authr.fmt)) {
|
||
const authrDataStruct = parseGetAssertAuthData(webauthnResponse.authenticatorData);
|
||
if (!(authrDataStruct.flags & 0x01)) { throw new Error('User was not presented durring authentication!'); } // U2F_USER_PRESENTED
|
||
response.counter = authrDataStruct.counter;
|
||
response.verified = verifySignature(webauthnResponse.signature, Buffer.concat([authrDataStruct.rpIdHash, authrDataStruct.flagsBuf, authrDataStruct.counterBuf, hash(webauthnResponse.clientDataJSON)]), authr.publicKey);
|
||
}
|
||
return response;
|
||
}
|
||
|
||
function hash(data) { return crypto.createHash('sha256').update(data).digest() }
|
||
function verifySignature(signature, data, publicKey) { return crypto.createVerify('SHA256').update(data).verify(publicKey, signature); }
|
||
|
||
function parseGetAssertAuthData(buffer) {
|
||
const rpIdHash = buffer.slice(0, 32);
|
||
buffer = buffer.slice(32);
|
||
const flagsBuf = buffer.slice(0, 1);
|
||
buffer = buffer.slice(1);
|
||
const flags = flagsBuf[0];
|
||
const counterBuf = buffer.slice(0, 4);
|
||
buffer = buffer.slice(4);
|
||
const counter = counterBuf.readUInt32BE(0);
|
||
return { rpIdHash, flagsBuf, flags, counter, counterBuf };
|
||
}
|
||
|
||
function parseMakeCredAuthData(buffer) {
|
||
const rpIdHash = buffer.slice(0, 32);
|
||
buffer = buffer.slice(32);
|
||
const flagsBuf = buffer.slice(0, 1);
|
||
buffer = buffer.slice(1);
|
||
const flags = flagsBuf[0];
|
||
const counterBuf = buffer.slice(0, 4);
|
||
buffer = buffer.slice(4);
|
||
const counter = counterBuf.readUInt32BE(0);
|
||
const aaguid = buffer.slice(0, 16);
|
||
buffer = buffer.slice(16);
|
||
const credIDLenBuf = buffer.slice(0, 2);
|
||
buffer = buffer.slice(2);
|
||
const credIDLen = credIDLenBuf.readUInt16BE(0);
|
||
const credID = buffer.slice(0, credIDLen);
|
||
buffer = buffer.slice(credIDLen);
|
||
const COSEPublicKey = buffer;
|
||
return { rpIdHash, flagsBuf, flags, counter, counterBuf, aaguid, credID, COSEPublicKey };
|
||
}
|
||
|
||
function COSEECDHAtoPKCS(COSEPublicKey) {
|
||
const coseStruct = cbor.decodeAllSync(COSEPublicKey)[0];
|
||
return Buffer.concat([Buffer.from([0x04]), coseStruct.get(-2), coseStruct.get(-3)]);
|
||
}
|
||
|
||
function ASN1toPEM(pkBuffer) {
|
||
if (!Buffer.isBuffer(pkBuffer)) { throw new Error("ASN1toPEM: pkBuffer must be Buffer."); }
|
||
let type;
|
||
if (pkBuffer.length == 65 && pkBuffer[0] == 0x04) { pkBuffer = Buffer.concat([Buffer.from("3059301306072a8648ce3d020106082a8648ce3d030107034200", "hex"), pkBuffer]); type = 'PUBLIC KEY'; } else { type = 'CERTIFICATE'; }
|
||
const b64cert = pkBuffer.toString('base64');
|
||
let PEMKey = '';
|
||
for (let i = 0; i < Math.ceil(b64cert.length / 64); i++) { const start = 64 * i; PEMKey += b64cert.substr(start, 64) + '\n'; }
|
||
PEMKey = `-----BEGIN ${type}-----\n` + PEMKey + `-----END ${type}-----\n`;
|
||
return PEMKey;
|
||
}
|
||
|
||
return obj;
|
||
}
|