[jsonwebtoken] Allow function as secretOrPublicKey argument for async verify

types/jsonwebtoken/index.d.ts

@@ -3,7 +3,8 @@
 // Definitions by: Maxime LUCE <https://github.com/SomaticIT>,
 //                 Daniel Heim <https://github.com/danielheim>,
 //                 Brice BERNARD <https://github.com/brikou>,
-//                 Veli-Pekka Kestilä <https://github.com/vpk>
+//                 Veli-Pekka Kestilä <https://github.com/vpk>,
+//                 Daniel Parker <https://github.com/rlgod>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.2
 
@@ -143,18 +144,18 @@ export declare function verify(
 /**
  * Asynchronously verify given token using a secret or a public key to get a decoded token
  * @param {String} token - JWT string to verify
- * @param {String|Buffer} secretOrPublicKey - Either the secret for HMAC algorithms, or the PEM encoded public key for RSA and ECDSA.
+ * @param {String|Buffer|Function} secretOrPublicKey - A string or buffer containing either the secret for HMAC algorithms, or the PEM encoded public key for RSA and ECDSA. If jwt.verify is called asynchronous, secretOrPublicKey can be a function that should fetch the secret or public key
  * @param {VerifyOptions} [options] - Options for the verification
  * @param {Function} callback - Callback to get the decoded token on
  */
 export declare function verify(
     token: string,
-    secretOrPublicKey: string | Buffer,
+    secretOrPublicKey: string | Buffer | Function,
     callback?: VerifyCallback,
 ): void;
 export declare function verify(
     token: string,
-    secretOrPublicKey: string | Buffer,
+    secretOrPublicKey: string | Buffer | Function,
     options?: VerifyOptions,
     callback?: VerifyCallback,
 ): void;

types/jsonwebtoken/jsonwebtoken-tests.ts

@@ -83,6 +83,19 @@ jwt.verify(token, cert, function(err, decoded) {
     console.log(result.foo); // bar
 });
 
+// verify a token assymetric with async key fetch function
+function getKey(header: Object, callback: Function) {
+    cert = fs.readFileSync("public.pem");
+
+    callback(null, cert);
+}
+
+jwt.verify(token, getKey, function(err, decoded) {
+    const result = decoded as ITestObject;
+
+    console.log(result.foo); // bar
+});
+
 // verify audience
 cert = fs.readFileSync("public.pem"); // get public key
 jwt.verify(token, cert, { audience: "urn:foo" }, function(err, decoded) {