unsafeParseJWT function

README.md

@@ -72,6 +72,13 @@ const data = await validateJWT(jwt, cryptoKey);
 const data = await validateJWT(jwt, false);
 ```
 
+- **`unsafeParseJWT(jwt: string): Promise<JWTPayload>`**
+
+```javascript
+// "unsafely" parse a JWT without cryptokey, will return the payload.
+const unsafeData = unsafeParseJWT(jwt);
+```
+
 **Helper Functions**
 
 - **`generateKey(keyStr: string, optionsOrAlgorithm?: SupportedKeyAlgorithms | Options): Promise<CryptoKey>`**

deno.jsonc

@@ -1,6 +1,6 @@
 {
  "name": "@cross/jwt",
- "version": "0.4.2",
+ "version": "0.4.3",
  "exports": "./mod.ts",
 
  "tasks": {

mod.ts

@@ -1,6 +1,6 @@
 // mod.ts
 export { signJWT } from "./src/sign.ts";
-export { validateJWT } from "./src/validate.ts";
+export { unsafeParseJWT, validateJWT } from "./src/validate.ts";
 export { exportPEMKey, generateKey, generateKeyPair, importPEMKey } from "./src/cryptokeys.ts";
 export type {
  GenerateKeyOptions,

src/error.ts

@@ -97,3 +97,16 @@ export class JWTRequiredOptionMissingError extends JWTFormatError {
  this.name = "JWTRequiredOptionMissingError";
  }
 }
+
+/**
+ * Represents a parsing error that occurred during JWT parsing.
+ */
+export class JWTParseError extends Error {
+ /**
+ * @param {string} message - A descriptive message about the parsing failure.
+ */
+ constructor(message: string) {
+ super(message);
+ this.name = "JWTParseError";
+ }
+}

src/validate.ts

@@ -5,6 +5,7 @@ import {
  JWTExpiredError,
  JWTFormatError,
  JWTNotYetValidError,
+ JWTParseError,
  JWTRequiredClaimMissingError,
  JWTUnsupportedAlgorithmError,
  JWTValidationError,
@@ -237,3 +238,20 @@ export async function verify(key: CryptoKey, data: string, signature: string, op
  throw new Error("Unsupported algorithm");
  }
 }
+
+/**
+ * Validates and parses a JWT, verifying it with the given key.
+ *
+ * @param {string} jwt - The encoded JWT string.
+ * @returns {Promise<JWTPayload>} A promise resolving to the decoded JWT payload.
+ * @throws {JWTParseError} If the jwt string is not parsable.
+ */
+export function unsafeParseJWT(jwt: string): Promise<JWTPayload> {
+ try {
+ const jwtParts = validateParts(jwt);
+ const payload = JSON.parse(textDecode(decodeBase64Url(jwtParts[1])));
+ return payload;
+ } catch (error) {
+ throw new JWTParseError(error);
+ }
+}