jsonwebtoken

JsonWebToken implementation for node.js

Authentication / Authorization
auth0/node-jsonwebtokenjsonwebtoken

README

jsonwebtoken


**Build****Dependency**
|-----------|---------------|
[![Build[![Dependency

An implementation of JSON Web Tokens.

This was developed against draft-ietf-oauth-json-web-token-08. It makes use of node-jws

Install


  1. ``` sh
  2. $ npm install jsonwebtoken
  3. ```

Migration notes


From v7 to v8

Usage


jwt.sign(payload, secretOrPrivateKey, [options, callback])


(Asynchronous) If a callback is supplied, the callback is called with the err or the JWT.

(Synchronous) Returns the JsonWebToken as string

payload could be an object literal, buffer or string representing valid JSON.

Please _note_ that exp or any other claim is only set if the payload is an object literal. Buffer or string payloads are not checked for JSON validity.


If payload is not a buffer or a string, it will be coerced into a string using JSON.stringify.


secretOrPrivateKey is a string, buffer, or object containing either the secret for HMAC algorithms or the PEM
encoded private key for RSA and ECDSA. In case of a private key with passphrase an object { key, passphrase } can be used (based on crypto documentation), in this case be sure you pass thealgorithm option.

options:

algorithm (default: HS256)
expiresIn: expressed in seconds or a string describing a time span vercel/ms.
  > Eg: 60, "2 days", "10h", "7d". A numeric value is interpreted as a seconds count. If you use a string be sure you provide the time units (days, hours, etc), otherwise milliseconds unit is used by default ("120" is equal to "120ms").
notBefore: expressed in seconds or a string describing a time span vercel/ms.
  > Eg: 60, "2 days", "10h", "7d". A numeric value is interpreted as a seconds count. If you use a string be sure you provide the time units (days, hours, etc), otherwise milliseconds unit is used by default ("120" is equal to "120ms").
audience
issuer
jwtid
subject
noTimestamp
header
keyid
mutatePayload: if true, the sign function will modify the payload object directly. This is useful if you need a raw reference to the payload after claims have been applied to it but before it has been encoded into a token.

There are no default values for expiresIn, notBefore, audience, subject, issuer. These claims can also be provided in the payload directly with exp, nbf, aud, sub and iss respectively, but you _can't_ include in both places.


Remember that exp, nbf and iat are NumericDate, see related Token Expiration (exp claim)

The header can be customized via the options.header object.

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 options.expiresIn.

Synchronous Sign with default (HMAC SHA256)

  1. ``` js
  2. var jwt = require('jsonwebtoken');
  3. var token = jwt.sign({ foo: 'bar' }, 'shhhhh');
  4. ```

Synchronous Sign with RSA SHA256
  1. ``` js
  2. // sign with RSA SHA256
  3. var privateKey = fs.readFileSync('private.key');
  4. var token = jwt.sign({ foo: 'bar' }, privateKey, { algorithm: 'RS256' });
  5. ```

Sign asynchronously
  1. ``` js
  2. jwt.sign({ foo: 'bar' }, privateKey, { algorithm: 'RS256' }, function(err, token) {
  3.   console.log(token);
  4. });
  5. ```

Backdate a jwt 30 seconds
  1. ``` js
  2. var older_token = jwt.sign({ foo: 'bar', iat: Math.floor(Date.now() / 1000) - 30 }, 'shhhhh');
  3. ```

Token Expiration (exp claim)


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:

  1. ``` js
  2. jwt.sign({
  3.   exp: Math.floor(Date.now() / 1000) + (60 * 60),
  4.   data: 'foobar'
  5. }, 'secret');
  6. ```

Another way to generate a token like this with this library is:

  1. ``` js
  2. jwt.sign({
  3.   data: 'foobar'
  4. }, 'secret', { expiresIn: 60 * 60 });

  6. //or even better:

  8. jwt.sign({
  9.   data: 'foobar'
  10. }, 'secret', { expiresIn: '1h' });
  11. ```

jwt.verify(token, secretOrPublicKey, [options, callback])


(Asynchronous) If a callback is supplied, function acts asynchronously. The callback is called with the decoded payload if the signature is valid and optional expiration, audience, or issuer are valid. If not, it will be called with the error.

(Synchronous) If a callback is not supplied, function acts synchronously. Returns the payload decoded if the signature is valid and optional expiration, audience, or issuer are valid. If not, it will throw the error.

__Warning:__ When the token comes from an untrusted source (e.g. user input or external requests), the returned decoded payload should be treated like any other user input; please make sure to sanitize and only work with properties that are expected


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.
If jwt.verify is called asynchronous, secretOrPublicKey can be a function that should fetch the secret or public key. See below for a detailed example

As mentioned in this comment, there are other libraries that expect base64 encoded secrets (random bytes encoded using base64), if that is your case you can passBuffer.from(secret, 'base64'), by doing this the secret will be decoded using base64 and the token verification will use the original random bytes.

options

algorithms: List of strings with the names of the allowed algorithms. For instance, ["HS256", "HS384"].
audience: if you want to check audience (aud), provide a value here. The audience can be checked against a string, a regular expression or a list of strings and/or regular expressions.
  > Eg: "urn:foo", /urn:f[o]{2}/, [/urn:f[o]{2}/, "urn:bar"]
complete: return an object with the decoded { payload, header, signature } instead of only the usual content of the payload.
issuer (optional): string or array of strings of valid values for the iss field.
jwtid (optional): if you want to check JWT ID (jti), provide a string value here.
ignoreExpiration: if true do not validate the expiration of the token.
ignoreNotBefore...
subject: if you want to check subject (sub), provide a value here
clockTolerance: number of seconds to tolerate when checking the nbf and exp claims, to deal with small clock differences among different servers
maxAge: the maximum allowed age for tokens to still be valid. It is expressed in seconds or a string describing a time span vercel/ms.
  > Eg: 1000, "2 days", "10h", "7d". A numeric value is interpreted as a seconds count. If you use a string be sure you provide the time units (days, hours, etc), otherwise milliseconds unit is used by default ("120" is equal to "120ms").
clockTimestamp: the time in seconds that should be used as the current time for all necessary comparisons.
nonce: if you want to check nonce claim, provide a string value here. It is used on Open ID for the ID Tokens. (Open ID implementation notes)

  1. ``` js
  2. // verify a token symmetric - synchronous
  3. var decoded = jwt.verify(token, 'shhhhh');
  4. console.log(decoded.foo) // bar

  6. // verify a token symmetric
  7. jwt.verify(token, 'shhhhh', function(err, decoded) {
  8.   console.log(decoded.foo) // bar
  9. });

  11. // invalid token - synchronous
  12. try {
  13.   var decoded = jwt.verify(token, 'wrong-secret');
  14. } catch(err) {
  15.   // err
  16. }

  18. // invalid token
  19. jwt.verify(token, 'wrong-secret', function(err, decoded) {
  20.   // err
  21.   // decoded undefined
  22. });

  24. // verify a token asymmetric
  25. var cert = fs.readFileSync('public.pem');  // get public key
  26. jwt.verify(token, cert, function(err, decoded) {
  27.   console.log(decoded.foo) // bar
  28. });

  30. // verify audience
  31. var cert = fs.readFileSync('public.pem');  // get public key
  32. jwt.verify(token, cert, { audience: 'urn:foo' }, function(err, decoded) {
  33.   // if audience mismatch, err == invalid audience
  34. });

  36. // verify issuer
  37. var cert = fs.readFileSync('public.pem');  // get public key
  38. jwt.verify(token, cert, { audience: 'urn:foo', issuer: 'urn:issuer' }, function(err, decoded) {
  39.   // if issuer mismatch, err == invalid issuer
  40. });

  42. // verify jwt id
  43. var cert = fs.readFileSync('public.pem');  // get public key
  44. jwt.verify(token, cert, { audience: 'urn:foo', issuer: 'urn:issuer', jwtid: 'jwtid' }, function(err, decoded) {
  45.   // if jwt id mismatch, err == invalid jwt id
  46. });

  48. // verify subject
  49. var cert = fs.readFileSync('public.pem');  // get public key
  50. jwt.verify(token, cert, { audience: 'urn:foo', issuer: 'urn:issuer', jwtid: 'jwtid', subject: 'subject' }, function(err, decoded) {
  51.   // if subject mismatch, err == invalid subject
  52. });

  54. // alg mismatch
  55. var cert = fs.readFileSync('public.pem'); // get public key
  56. jwt.verify(token, cert, { algorithms: ['RS256'] }, function (err, payload) {
  57.   // if token alg != RS256,  err == invalid signature
  58. });

  60. // Verify using getKey callback
  61. // Example uses https://github.com/auth0/node-jwks-rsa as a way to fetch the keys.
  62. var jwksClient = require('jwks-rsa');
  63. var client = jwksClient({
  64.   jwksUri: 'https://sandrino.auth0.com/.well-known/jwks.json'
  65. });
  66. function getKey(header, callback){
  67.   client.getSigningKey(header.kid, function(err, key) {
  68.     var signingKey = key.publicKey || key.rsaPublicKey;
  69.     callback(null, signingKey);
  70.   });
  71. }

  73. jwt.verify(token, getKey, options, function(err, decoded) {
  74.   console.log(decoded.foo) // bar
  75. });

  77. ```

Need to peek into a JWT without verifying it? (Click to expand)

jwt.decode(token [, options])


(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 jwt.verify instead.


__Warning:__ When the token comes from an untrusted source (e.g. user input or external request), the returned decoded payload should be treated like any other user input; please make sure to sanitize and only work with properties that are expected


token is the JsonWebToken string

options:

json: force JSON.parse on the payload even if the header doesn't contain "typ":"JWT".
complete: return an object with the decoded payload and header.

Example

  1. ``` js
  2. // get the decoded payload ignoring signature, no secretOrPrivateKey needed
  3. var decoded = jwt.decode(token);

  5. // get the decoded payload and header
  6. var decoded = jwt.decode(token, {complete: true});
  7. console.log(decoded.header);
  8. console.log(decoded.payload)
  9. ```


Errors & Codes

Possible thrown errors during verification.
Error is the first argument of the verification callback.

TokenExpiredError


Thrown error if the token is expired.

Error object:

name: 'TokenExpiredError'
message: 'jwt expired'
expiredAt: [ExpDate]

  1. ``` js
  2. jwt.verify(token, 'shhhhh', function(err, decoded) {
  3.   if (err) {
  4.     /*
  5.       err = {
  6.         name: 'TokenExpiredError',
  7.         message: 'jwt expired',
  8.         expiredAt: 1408621000
  9.       }
  10.     */
  11.   }
  12. });
  13. ```

JsonWebTokenError

Error object:

name: 'JsonWebTokenError'
message:
  'invalid token' - the header or payload could not be parsed
  'jwt malformed' - the token does not have three components (delimited by a .)
  'jwt signature is required'
  'invalid signature'
  'jwt audience invalid. expected: [OPTIONS AUDIENCE]'
  'jwt issuer invalid. expected: [OPTIONS ISSUER]'
  'jwt id invalid. expected: [OPTIONS JWT ID]'
  'jwt subject invalid. expected: [OPTIONS SUBJECT]'

  1. ``` js
  2. jwt.verify(token, 'shhhhh', function(err, decoded) {
  3.   if (err) {
  4.     /*
  5.       err = {
  6.         name: 'JsonWebTokenError',
  7.         message: 'jwt malformed'
  8.       }
  9.     */
  10.   }
  11. });
  12. ```

NotBeforeError

Thrown if current time is before the nbf claim.

Error object:

name: 'NotBeforeError'
message: 'jwt not active'
date: 2018-10-04T16:10:44.000Z

  1. ``` js
  2. jwt.verify(token, 'shhhhh', function(err, decoded) {
  3.   if (err) {
  4.     /*
  5.       err = {
  6.         name: 'NotBeforeError',
  7.         message: 'jwt not active',
  8.         date: 2018-10-04T16:10:44.000Z
  9.       }
  10.     */
  11.   }
  12. });
  13. ```

Algorithms supported


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-PKCS1-v1_5 using SHA-256 hash algorithm
RS384 | RSASSA-PKCS1-v1_5 using SHA-384 hash algorithm
RS512 | RSASSA-PKCS1-v1_5 using SHA-512 hash algorithm
PS256 | RSASSA-PSS using SHA-256 hash algorithm (only node ^6.12.0 OR >=8.0.0)
PS384 | RSASSA-PSS using SHA-384 hash algorithm (only node ^6.12.0 OR >=8.0.0)
PS512 | RSASSA-PSS using SHA-512 hash algorithm (only node ^6.12.0 OR >=8.0.0)
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

Refreshing JWTs


First of all, we recommend you to think carefully if auto-refreshing a JWT will not introduce any vulnerability in your system.

We are not comfortable including this as part of the library, however, you can take a look at this example to show how this could be accomplished.
Apart from that example there are an issue and a pull request to get more knowledge about this topic.

TODO


X.509 certificate chain is not checked

Issue Reporting


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.

Author


Auth0

License


This project is licensed under the MIT license. See the LICENSE file for more info.