Last active
October 17, 2024 21:56
-
-
Save philholden/50120652bfe0498958fd5926694ba354 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// paste in console of any https site to run (e.g. this page) | |
// sample arguments for registration | |
// https://fidoalliance.org/specs/fido-u2f-v1.1-id-20160915/fido-u2f-raw-message-formats-v1.1-id-20160915.html#authentication-response-message-success | |
var createCredentialDefaultArgs = { | |
publicKey: { | |
// Relying Party (a.k.a. - Service): | |
rp: { | |
name: "Acme" | |
}, | |
// User: | |
user: { | |
id: new Uint8Array(16), | |
name: "john.p.smith@example.com", | |
displayName: "John P. Smith" | |
}, | |
pubKeyCredParams: [{ | |
type: "public-key", | |
alg: -7 | |
}], | |
attestation: "direct", | |
timeout: 60000, | |
challenge: new Uint8Array([ // must be a cryptographically random number sent from a server | |
0x8C, 0x0A, 0x26, 0xFF, 0x22, 0x91, 0xC1, 0xE9, 0xB9, 0x4E, 0x2E, 0x17, 0x1A, 0x98, 0x6A, 0x73, | |
0x71, 0x9D, 0x43, 0x48, 0xD5, 0xA7, 0x6A, 0x15, 0x7E, 0x38, 0x94, 0x52, 0x77, 0x97, 0x0F, 0xEF | |
]).buffer | |
} | |
}; | |
// sample arguments for login | |
var getCredentialDefaultArgs = { | |
publicKey: { | |
timeout: 60000, | |
// allowCredentials: [newCredential] // see below | |
challenge: new Uint8Array([ // must be a cryptographically random number sent from a server | |
0x79, 0x50, 0x68, 0x71, 0xDA, 0xEE, 0xEE, 0xB9, 0x94, 0xC3, 0xC2, 0x15, 0x67, 0x65, 0x26, 0x22, | |
0xE3, 0xF3, 0xAB, 0x3B, 0x78, 0x2E, 0xD5, 0x6F, 0x81, 0x26, 0xE2, 0xA6, 0x01, 0x7D, 0x74, 0x50 | |
]).buffer | |
}, | |
}; | |
// register / create a new credential | |
var cred = await navigator.credentials.create(createCredentialDefaultArgs) | |
console.log("NEW CREDENTIAL", cred); | |
// normally the credential IDs available for an account would come from a server | |
// but we can just copy them from above... | |
var idList = [{ | |
id: cred.rawId, | |
transports: ["usb", "nfc", "ble"], | |
type: "public-key" | |
}]; | |
getCredentialDefaultArgs.publicKey.allowCredentials = idList; | |
var assertation = await navigator.credentials.get(getCredentialDefaultArgs); | |
console.log("ASSERTION", assertation); | |
// verify signature on server | |
var signature = await assertation.response.signature; | |
console.log("SIGNATURE", signature) | |
var clientDataJSON = await assertation.response.clientDataJSON; | |
console.log("clientDataJSON", clientDataJSON) | |
var authenticatorData = new Uint8Array(await assertation.response.authenticatorData); | |
console.log("authenticatorData", authenticatorData) | |
var clientDataHash = new Uint8Array(await crypto.subtle.digest("SHA-256", clientDataJSON)); | |
console.log("clientDataHash", clientDataHash) | |
// concat authenticatorData and clientDataHash | |
var signedData = new Uint8Array(authenticatorData.length + clientDataHash.length); | |
signedData.set(authenticatorData); | |
signedData.set(clientDataHash, authenticatorData.length); | |
console.log("signedData", signedData) | |
// import key | |
var key = await crypto.subtle.importKey( | |
// The getPublicKey() operation thus returns the credential public key as a SubjectPublicKeyInfo. See: | |
// | |
// https://w3c.github.io/webauthn/#sctn-public-key-easy | |
// | |
// crypto.subtle can import the spki format: | |
// | |
// https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/importKey | |
"spki", // "spki" Simple Public Key Infrastructure rfc2692 | |
cred.response.getPublicKey(), | |
{ | |
// these are the algorithm options | |
// await cred.response.getPublicKeyAlgorithm() // returns -7 | |
// -7 is ES256 with P-256 // search -7 in https://w3c.github.io/webauthn | |
// the W3C webcrypto docs: | |
// | |
// https://www.w3.org/TR/WebCryptoAPI/#informative-references (scroll down a bit) | |
// | |
// ES256 corrisponds with the following AlgorithmIdentifier: | |
name: "ECDSA", | |
namedCurve: "P-256", | |
hash: { name: "SHA-256" } | |
}, | |
false, //whether the key is extractable (i.e. can be used in exportKey) | |
["verify"] //"verify" for public key import, "sign" for private key imports | |
); | |
// check signature with public key and signed data | |
var verified = await crypto.subtle.verify( | |
{ name: "ECDSA", namedCurve: "P-256", hash: { name: "SHA-256" } }, | |
key, | |
signature, | |
signedData.buffer | |
); | |
// verified is false I want it to be true | |
console.log('verified', verified) |
Interesting. What's your OS? I'm on MacOS, and can only produce -7
keys, regardless of the flagged support.
Ideally, I could use the output of toJSON
(or similar ponyfill) from both and attestation and an assertion using each algo 😇
I'll then use it as a test fixture for both my ponyfills of toJSON
, related fromJSON
functions, and verify-functions, in a webauthn stand-alone low-level helpers library (to be published).
@tjconcept I'm on windows 11. I'm surprised that OS would change how Chrome's virtual authenticator works, but I suppose it's possible.
In any case, if you'd like to provide a snippet of code (standalone, whatever) that I can run for you, and send you results, I'm happy to help with that.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
@tjconcept
Some of it is raw, some of it was processed by logic in my webauthn-local-client library, including some parsing, and the base64 encoding (for ease of output above).
Sorry for the confusion, no it doesn't come back raw.
It always comes back in SPKI format. My library uses this function for parsing the SPKI format out into the raw public-key and its algo's OID.
I should have included the SPKI, sorry. If you need that, I can re-run a new test to get those values. Or maybe someone clever can just re-pack the key and COSE I provided back into an equivalent SPKI. ;-)
The only "configuration" I did was in setting up the virtual-authenticator like this:
Yeah, the library passes in four requested algorithms, in preference order of -8 (ed25519), -7 (es256), -37 (rsassa-pss), and -257 (rsassa-pkcs1-v1_5). So basically, the
pubKeyCredParams
passed tocreate()
is this array: