ox
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56 lines • 2.4 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.parseAsn1Signature = parseAsn1Signature;
exports.parseCredentialPublicKey = parseCredentialPublicKey;
const p256_1 = require("@noble/curves/p256");
const Hex = require("../Hex.js");
const PublicKey = require("../PublicKey.js");
const WebAuthnP256_js_1 = require("../WebAuthnP256.js");
function parseAsn1Signature(bytes) {
const r_start = bytes[4] === 0 ? 5 : 4;
const r_end = r_start + 32;
const s_start = bytes[r_end + 2] === 0 ? r_end + 3 : r_end + 2;
const r = BigInt(Hex.fromBytes(bytes.slice(r_start, r_end)));
const s = BigInt(Hex.fromBytes(bytes.slice(s_start)));
return {
r,
s: s > p256_1.p256.CURVE.n / 2n ? p256_1.p256.CURVE.n - s : s,
};
}
async function parseCredentialPublicKey(response) {
try {
const publicKeyBuffer = response.getPublicKey();
if (!publicKeyBuffer)
throw new WebAuthnP256_js_1.CredentialCreationFailedError();
const publicKeyBytes = new Uint8Array(publicKeyBuffer);
const cryptoKey = await crypto.subtle.importKey('spki', new Uint8Array(publicKeyBytes), {
name: 'ECDSA',
namedCurve: 'P-256',
hash: 'SHA-256',
}, true, ['verify']);
const publicKey = new Uint8Array(await crypto.subtle.exportKey('raw', cryptoKey));
return PublicKey.from(publicKey);
}
catch (error) {
if (error.message !== 'Permission denied to access object')
throw error;
const data = new Uint8Array(response.attestationObject);
const coordinateLength = 0x20;
const cborPrefix = 0x58;
const findStart = (key) => {
const coordinate = new Uint8Array([key, cborPrefix, coordinateLength]);
for (let i = 0; i < data.length - coordinate.length; i++)
if (coordinate.every((byte, j) => data[i + j] === byte))
return i + coordinate.length;
throw new WebAuthnP256_js_1.CredentialCreationFailedError();
};
const xStart = findStart(0x21);
const yStart = findStart(0x22);
return PublicKey.from(new Uint8Array([
0x04,
...data.slice(xStart, xStart + coordinateLength),
...data.slice(yStart, yStart + coordinateLength),
]));
}
}
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