JSON Web Token implementation (symmetric and asymmetric)
An implementation of JSON Web Tokens.
This was developed against
draft-ietf-oauth-json-web-token-08. It makes use of node-jws
$ npm install jsonwebtoken
(Asynchronous) If a callback is supplied, callback is called with the
err or the JWT.
(Synchronous) Returns the JsonWebToken as string
payload could be an object literal, buffer or string. Please note that
exp is only set if the payload is an object literal.
secretOrPrivateKey is a string or buffer containing either the secret for HMAC algorithms, or the PEM
encoded private key for RSA and ECDSA.
expiresIn: expressed in seconds or a string describing a time span zeit/ms. Eg:
notBefore: expressed in seconds or a string describing a time span zeit/ms. Eg:
payload is not a buffer or a string, it will be coerced into a string using
There are no default values for
issuer. These claims can also be provided in the payload directly with
iss respectively, but you can't include in both places.
The header can be customized via the
Generated jwts will include an
iat (issued at) claim by default unless
noTimestamp is specified. If
iat is inserted in the payload, it will be used instead of the real timestamp for calculating other things like
exp given a timespan in
// sign with default (HMAC SHA256)var jwt = ;var token = jwt;//backdate a jwt 30 secondsvar older_token = jwt;// sign with RSA SHA256var cert = fs; // get private keyvar token = jwt;// sign asynchronouslyjwt;
The standard for JWT defines an
exp claim for expiration. The expiration is represented as a NumericDate:
A JSON numeric value representing the number of seconds from 1970-01-01T00:00:00Z UTC until the specified UTC date/time, ignoring leap seconds. This is equivalent to the IEEE Std 1003.1, 2013 Edition [POSIX.1] definition "Seconds Since the Epoch", in which each day is accounted for by exactly 86400 seconds, other than that non-integer values can be represented. See RFC 3339 [RFC3339] for details regarding date/times in general and UTC in particular.
This means that the
exp field should contain the number of seconds since the epoch.
Signing a token with 1 hour of expiration:
Another way to generate a token like this with this library is:
jwt;//or even better:jwt;
(Asynchronous) If a callback is supplied, function acts asynchronously. Callback is passed the decoded payload if the signature and optional expiration, audience, or issuer are valid. If not, it will be passed the error.
(Synchronous) If a callback is not supplied, function acts synchronously. Returns the payload decoded if the signature (and, optionally, expiration, audience, issuer) are valid. If not, it will throw the error.
token is the JsonWebToken string
secretOrPublicKey is a string or buffer containing either the secret for HMAC algorithms, or the PEM
encoded public key for RSA and ECDSA.
algorithms: List of strings with the names of the allowed algorithms. For instance,
audience: if you want to check audience (
aud), provide a value here
issuer(optional): string or array of strings of valid values for the
truedo not validate the expiration of the token.
subject: if you want to check subject (
sub), provide a value here
clockTolerance: number of seconds to tolerate when checking the
expclaims, to deal with small clock differences among different servers
maxAge: the maximum allowed age for tokens to still be valid. Currently it is expressed in milliseconds or a string describing a time span zeit/ms. Eg:
"7d". We advise against using milliseconds precision, though, since JWTs can only contain seconds. The maximum precision might be reduced to seconds in the future.
clockTimestamp: the time in seconds that should be used as the current time for all necessary comparisons (also against
maxAge, so our advise is to avoid using
maxAgein milliseconds together)
// verify a token symmetric - synchronousvar decoded = jwt;console // bar// verify a token symmetricjwt;// invalid token - synchronoustryvar decoded = jwt;catcherr// err// invalid tokenjwt;// verify a token asymmetricvar cert = fs; // get public keyjwt;// verify audiencevar cert = fs; // get public keyjwt;// verify issuervar cert = fs; // get public keyjwt;// verify jwt idvar cert = fs; // get public keyjwt;// verify subjectvar cert = fs; // get public keyjwt;// alg mismatchvar cert = fs; // get public keyjwt;
(Synchronous) Returns the decoded payload without verifying if the signature is valid.
Warning: This will not verify whether the signature is valid. You should not use this for untrusted messages. You most likely want to use
token is the JsonWebToken string
json: force JSON.parse on the payload even if the header doesn't contain
complete: return an object with the decoded payload and header.
// get the decoded payload ignoring signature, no secretOrPrivateKey neededvar decoded = jwt;// get the decoded payload and headervar decoded = jwt;console;console
Possible thrown errors during verification. Error is the first argument of the verification callback.
Thrown error if the token is expired.
Array of supported algorithms. The following algorithms are currently supported.
|alg Parameter Value||Digital Signature or MAC Algorithm|
|HS256||HMAC using SHA-256 hash algorithm|
|HS384||HMAC using SHA-384 hash algorithm|
|HS512||HMAC using SHA-512 hash algorithm|
|RS256||RSASSA using SHA-256 hash algorithm|
|RS384||RSASSA using SHA-384 hash algorithm|
|RS512||RSASSA using SHA-512 hash algorithm|
|ES256||ECDSA using P-256 curve and SHA-256 hash algorithm|
|ES384||ECDSA using P-384 curve and SHA-384 hash algorithm|
|ES512||ECDSA using P-521 curve and SHA-512 hash algorithm|
|none||No digital signature or MAC value included|
If you have found a bug or if you have a feature request, please report them at this repository issues section. Please do not report security vulnerabilities on the public GitHub issue tracker. The Responsible Disclosure Program details the procedure for disclosing security issues.
This project is licensed under the MIT license. See the LICENSE file for more info.