WebAuthn (#633)

src/connectors/common-webauthn.ts

@@ -0,0 +1,62 @@
+export function buildDataString(assertedCredential: PublicKeyCredential) {
+    const response = assertedCredential.response as AuthenticatorAssertionResponse;
+
+    const authData = new Uint8Array(response.authenticatorData);
+    const clientDataJSON = new Uint8Array(response.clientDataJSON);
+    const rawId = new Uint8Array(assertedCredential.rawId);
+    const sig = new Uint8Array(response.signature);
+
+    const data = {
+        id: assertedCredential.id,
+        rawId: coerceToBase64Url(rawId),
+        type: assertedCredential.type,
+        extensions: assertedCredential.getClientExtensionResults(),
+        response: {
+            authenticatorData: coerceToBase64Url(authData),
+            clientDataJson: coerceToBase64Url(clientDataJSON),
+            signature: coerceToBase64Url(sig),
+        },
+    };
+
+    return JSON.stringify(data);
+}
+
+export function b64Decode(str: string) {
+    return decodeURIComponent(Array.prototype.map.call(atob(str), (c: string) => {
+        return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2);
+    }).join(''));
+}
+
+// From https://github.com/abergs/fido2-net-lib/blob/b487a1d47373ea18cd752b4988f7262035b7b54e/Demo/wwwroot/js/helpers.js#L34
+// License: https://github.com/abergs/fido2-net-lib/blob/master/LICENSE.txt
+function coerceToBase64Url(thing: any) {
+    // Array or ArrayBuffer to Uint8Array
+    if (Array.isArray(thing)) {
+        thing = Uint8Array.from(thing);
+    }
+
+    if (thing instanceof ArrayBuffer) {
+        thing = new Uint8Array(thing);
+    }
+
+    // Uint8Array to base64
+    if (thing instanceof Uint8Array) {
+        let str = '';
+        const len = thing.byteLength;
+
+        for (let i = 0; i < len; i++) {
+            str += String.fromCharCode(thing[i]);
+        }
+        thing = window.btoa(str);
+    }
+
+    if (typeof thing !== 'string') {
+        throw new Error('could not coerce to string');
+    }
+
+    // base64 to base64url
+    // NOTE: "=" at the end of challenge is optional, strip it off here
+    thing = thing.replace(/\+/g, '-').replace(/\//g, '_').replace(/=*$/g, '');
+
+    return thing;
+}