Version 3 adds several new, frequently requested features. To do so, it introduces a few breaking changes. We've worked to keep these as minimal as possible. This guide explains the breaking changes and how you can quickly update your code.
### `Token.Claims` is now an interface type
The most requested feature from the 2.0 verison of this library was the ability to provide a custom type to the JSON parser for claims. This was implemented by introducing a new interface, `Claims`, to replace `map[string]interface{}`. We also included two concrete implementations of `Claims`: `MapClaims` and `StandardClaims`.
`MapClaims` is an alias for `map[string]interface{}` with built in validation behavior. It is the default claims type when using `Parse`. The usage is unchanged except you must type cast the claims property.
The old example for parsing a token looked like this..
```go
if token, err := jwt.Parse(tokenString, keyLookupFunc); err == nil {
fmt.Printf("Token for user %v expires %v", token.Claims["user"], token.Claims["exp"])
}
```
is now directly mapped to...
```go
if token, err := jwt.Parse(tokenString, keyLookupFunc); err == nil {
claims := token.Claims.(jwt.MapClaims)
fmt.Printf("Token for user %v expires %v", claims["user"], claims["exp"])
}
```
`StandardClaims` is designed to be embedded in your custom type. You can supply a custom claims type with the new `ParseWithClaims` function. Here's an example of using a custom claims type.
fmt.Printf("Token for user %v expires %v", claims.User, claims.StandardClaims.ExpiresAt)
}
```
### `ParseFromRequest` has been moved
To keep this library focused on the tokens without becoming overburdened with complex request processing logic, `ParseFromRequest` and its new companion `ParseFromRequestWithClaims` have been moved to a subpackage, `request`. The method signatues have also been augmented to receive a new argument: `Extractor`.
`Extractors` do the work of picking the token string out of a request. The interface is simple and composable.
fmt.Printf("Token for user %v expires %v", claims["user"], claims["exp"])
}
```
There are several concrete `Extractor` types provided for your convenience:
* `HeaderExtractor` will search a list of headers until one contains content.
* `ArgumentExtractor` will search a list of keys in request query and form arguments until one contains content.
* `MultiExtractor` will try a list of `Extractors` in order until one returns content.
* `AuthorizationHeaderExtractor` will look in the `Authorization` header for a `Bearer` token.
* `OAuth2Extractor` searches the places an OAuth2 token would be specified (per the spec): `Authorization` header and `access_token` argument
* `PostExtractionFilter` wraps an `Extractor`, allowing you to process the content before it's parsed. A simple example is stripping the `Bearer ` text from a header
### RSA signing methods no longer accept `[]byte` keys
Due to a [critical vulnerability](https://auth0.com/blog/2015/03/31/critical-vulnerabilities-in-json-web-token-libraries/), we've decided the convenience of accepting `[]byte` instead of `rsa.PublicKey` or `rsa.PrivateKey` isn't worth the risk of misuse.
To replace this behavior, we've added two helper methods: `ParseRSAPrivateKeyFromPEM(key []byte) (*rsa.PrivateKey, error)` and `ParseRSAPublicKeyFromPEM(key []byte) (*rsa.PublicKey, error)`. These are just simple helpers for unpacking PEM encoded PKCS1 and PKCS8 keys. If your keys are encoded any other way, all you need to do is convert them to the `crypto/rsa` package's types.
```go
func keyLookupFunc(*Token) (interface{}, error) {
// Don't forget to validate the alg is what you expect:
if _, ok := token.Method.(*jwt.SigningMethodRSA); !ok {
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
Starting from [v3.2.1](https://github.com/golang-jwt/jwt/releases/tag/v3.2.1]), the import path has changed from `github.com/dgrijalva/jwt-go` to `github.com/golang-jwt/jwt`. Future releases will be using the `github.com/golang-jwt/jwt` import path and continue the existing versioning scheme of `v3.x.x+incompatible`. Backwards-compatible patches and fixes will be done on the `v3` release branch, where as new build-breaking features will be developed in a `v4` release, possibly including a SIV-style import path.
### go.mod replacement
In a first step, the easiest way is to use `go mod edit` to issue a replacement.
```
go mod edit -replace github.com/dgrijalva/jwt-go=github.com/golang-jwt/jwt@v3.2.1+incompatible
go mod tidy
```
This will still keep the old import path in your code but replace it with the new package and also introduce a new indirect dependency to `github.com/golang-jwt/jwt`. Try to compile your project; it should still work.
### Cleanup
If your code still consistently builds, you can replace all occurences of `github.com/dgrijalva/jwt-go` with `github.com/golang-jwt/jwt`, either manually or by using tools such as `sed`. Finally, the `replace` directive in the `go.mod` file can be removed.
## Older releases (before v3.2.0)
The original migration guide for older releases can be found at https://github.com/dgrijalva/jwt-go/blob/master/MIGRATION_GUIDE.md.
A [go](http://www.golang.org) (or 'golang' for search engine friendliness) implementation of [JSON Web Tokens](http://self-issued.info/docs/draft-ietf-oauth-json-web-token.html)
A [go](http://www.golang.org) (or 'golang' for search engine friendliness) implementation of [JSON Web Tokens](https://datatracker.ietf.org/doc/html/rfc7519).
**NEW VERSION COMING:** There have been a lot of improvements suggested since the version 3.0.0 released in 2016. I'm working now on cutting two different releases: 3.2.0 will contain any non-breaking changes or enhancements. 4.0.0 will follow shortly which will include breaking changes. See the 4.0.0 milestone to get an idea of what's coming. If you have other ideas, or would like to participate in 4.0.0, now's the time. If you depend on this library and don't want to be interrupted, I recommend you use your dependency mangement tool to pin to version 3.
**IMPORT PATH CHANGE:** Starting from [v3.2.1](https://github.com/golang-jwt/jwt/releases/tag/v3.2.1), the import path has changed from `github.com/dgrijalva/jwt-go` to `github.com/golang-jwt/jwt`. After the original author of the library suggested migrating the maintenance of `jwt-go`, a dedicated team of open source maintainers decided to clone the existing library into this repository. See [dgrijalva/jwt-go#462](https://github.com/dgrijalva/jwt-go/issues/462) for a detailed discussion on this topic.
**SECURITY NOTICE:** Some older versions of Go have a security issue in the cryotp/elliptic. Recommendation is to upgrade to at least 1.8.3. See issue #216 for more detail.
Future releases will be using the `github.com/golang-jwt/jwt` import path and continue the existing versioning scheme of `v3.x.x+incompatible`. Backwards-compatible patches and fixes will be done on the `v3` release branch, where as new build-breaking features will be developed in a `v4` release, possibly including a SIV-style import path.
**SECURITY NOTICE:** It's important that you [validate the `alg` presented is what you expect](https://auth0.com/blog/2015/03/31/critical-vulnerabilities-in-json-web-token-libraries/). This library attempts to make it easy to do the right thing by requiring key types match the expected alg, but you should take the extra step to verify it in your usage. See the examples provided.
**SECURITY NOTICE:** Some older versions of Go have a security issue in the crypto/elliptic. Recommendation is to upgrade to at least 1.8.3. See issue [dgrijalva/jwt-go#216](https://github.com/dgrijalva/jwt-go/issues/216) for more detail.
**SECURITY NOTICE:** It's important that you [validate the `alg` presented is what you expect](https://auth0.com/blog/critical-vulnerabilities-in-json-web-token-libraries/). This library attempts to make it easy to do the right thing by requiring key types match the expected alg, but you should take the extra step to verify it in your usage. See the examples provided.
## What the heck is a JWT?
JWT.io has [a great introduction](https://jwt.io/introduction) to JSON Web Tokens.
In short, it's a signed JSON object that does something useful (for example, authentication). It's commonly used for `Bearer` tokens in Oauth 2. A token is made of three parts, separated by `.`'s. The first two parts are JSON objects, that have been [base64url](http://tools.ietf.org/html/rfc4648) encoded. The last part is the signature, encoded the same way.
In short, it's a signed JSON object that does something useful (for example, authentication). It's commonly used for `Bearer` tokens in Oauth 2. A token is made of three parts, separated by `.`'s. The first two parts are JSON objects, that have been [base64url](https://datatracker.ietf.org/doc/html/rfc4648) encoded. The last part is the signature, encoded the same way.
The first part is called the header. It contains the necessary information for verifying the last part, the signature. For example, which encryption method was used for signing and what key was used.
The part in the middle is the interesting bit. It's called the Claims and contains the actual stuff you care about. Refer to [the RFC](http://self-issued.info/docs/draft-jones-json-web-token.html) for information about reserved keys and the proper way to add your own.
The part in the middle is the interesting bit. It's called the Claims and contains the actual stuff you care about. Refer to [RFC 7519](https://datatracker.ietf.org/doc/html/rfc7519) for information about reserved keys and the proper way to add your own.
## What's in the box?
@ -27,31 +29,31 @@ This library supports the parsing and verification as well as the generation and
## Examples
See [the project documentation](https://godoc.org/github.com/dgrijalva/jwt-go) for examples of usage:
See [the project documentation](https://pkg.go.dev/github.com/golang-jwt/jwt) for examples of usage:
* [Simple example of parsing and validating a token](https://godoc.org/github.com/dgrijalva/jwt-go#example-Parse--Hmac)
* [Simple example of building and signing a token](https://godoc.org/github.com/dgrijalva/jwt-go#example-New--Hmac)
* [Directory of Examples](https://godoc.org/github.com/dgrijalva/jwt-go#pkg-examples)
* [Simple example of parsing and validating a token](https://pkg.go.dev/github.com/golang-jwt/jwt#example-Parse-Hmac)
* [Simple example of building and signing a token](https://pkg.go.dev/github.com/golang-jwt/jwt#example-New-Hmac)
* [Directory of Examples](https://pkg.go.dev/github.com/golang-jwt/jwt#pkg-examples)
## Extensions
This library publishes all the necessary components for adding your own signing methods. Simply implement the `SigningMethod` interface and register a factory method using `RegisterSigningMethod`.
Here's an example of an extension that integrates with the Google App Engine signing tools: https://github.com/someone1/gcp-jwt-go
Here's an example of an extension that integrates with multiple Google Cloud Platform signing tools (AppEngine, IAM API, Cloud KMS): https://github.com/someone1/gcp-jwt-go
## Compliance
This library was last reviewed to comply with [RTF 7519](http://www.rfc-editor.org/info/rfc7519) dated May 2015 with a few notable differences:
This library was last reviewed to comply with [RTF 7519](https://datatracker.ietf.org/doc/html/rfc7519) dated May 2015 with a few notable differences:
* In order to protect against accidental use of [Unsecured JWTs](http://self-issued.info/docs/draft-ietf-oauth-json-web-token.html#UnsecuredJWT), tokens using `alg=none` will only be accepted if the constant `jwt.UnsafeAllowNoneSignatureType` is provided as the key.
* In order to protect against accidental use of [Unsecured JWTs](https://datatracker.ietf.org/doc/html/rfc7519#section-6), tokens using `alg=none` will only be accepted if the constant `jwt.UnsafeAllowNoneSignatureType` is provided as the key.
## Project Status & Versioning
This library is considered production ready. Feedback and feature requests are appreciated. The API should be considered stable. There should be very few backwards-incompatible changes outside of major version updates (and only with good reason).
This project uses [Semantic Versioning 2.0.0](http://semver.org). Accepted pull requests will land on `master`. Periodically, versions will be tagged from `master`. You can find all the releases on [the project releases page](https://github.com/dgrijalva/jwt-go/releases).
This project uses [Semantic Versioning 2.0.0](http://semver.org). Accepted pull requests will land on `main`. Periodically, versions will be tagged from `main`. You can find all the releases on [the project releases page](https://github.com/golang-jwt/jwt/releases).
While we try to make it obvious when we make breaking changes, there isn't a great mechanism for pushing announcements out to users. You may want to use this alternative package include: `gopkg.in/dgrijalva/jwt-go.v3`. It will do the right thing WRT semantic versioning.
While we try to make it obvious when we make breaking changes, there isn't a great mechanism for pushing announcements out to users. You may want to use this alternative package include: `gopkg.in/golang-jwt/jwt.v3`. It will do the right thing WRT semantic versioning.
**BREAKING CHANGES:***
* Version 3.0.0 includes _a lot_ of changes from the 2.x line, including a few that break the API. We've tried to break as few things as possible, so there should just be a few type signature changes. A full list of breaking changes is available in `VERSION_HISTORY.md`. See `MIGRATION_GUIDE.md` for more information on updating your code.
@ -79,9 +81,9 @@ Asymmetric signing methods, such as RSA, use different keys for signing and veri
Each signing method expects a different object type for its signing keys. See the package documentation for details. Here are the most common ones:
* The [HMAC signing method](https://godoc.org/github.com/dgrijalva/jwt-go#SigningMethodHMAC) (`HS256`,`HS384`,`HS512`) expect `[]byte` values for signing and validation
* The [RSA signing method](https://godoc.org/github.com/dgrijalva/jwt-go#SigningMethodRSA) (`RS256`,`RS384`,`RS512`) expect `*rsa.PrivateKey` for signing and `*rsa.PublicKey` for validation
* The [ECDSA signing method](https://godoc.org/github.com/dgrijalva/jwt-go#SigningMethodECDSA) (`ES256`,`ES384`,`ES512`) expect `*ecdsa.PrivateKey` for signing and `*ecdsa.PublicKey` for validation
* The [HMAC signing method](https://pkg.go.dev/github.com/golang-jwt/jwt#SigningMethodHMAC) (`HS256`,`HS384`,`HS512`) expect `[]byte` values for signing and validation
* The [RSA signing method](https://pkg.go.dev/github.com/golang-jwt/jwt#SigningMethodRSA) (`RS256`,`RS384`,`RS512`) expect `*rsa.PrivateKey` for signing and `*rsa.PublicKey` for validation
* The [ECDSA signing method](https://pkg.go.dev/github.com/golang-jwt/jwt#SigningMethodECDSA) (`ES256`,`ES384`,`ES512`) expect `*ecdsa.PrivateKey` for signing and `*ecdsa.PublicKey` for validation
### JWT and OAuth
@ -93,8 +95,12 @@ Without going too far down the rabbit hole, here's a description of the interact
* OAuth defines several options for passing around authentication data. One popular method is called a "bearer token". A bearer token is simply a string that _should_ only be held by an authenticated user. Thus, simply presenting this token proves your identity. You can probably derive from here why a JWT might make a good bearer token.
* Because bearer tokens are used for authentication, it's important they're kept secret. This is why transactions that use bearer tokens typically happen over SSL.
### Troubleshooting
This library uses descriptive error messages whenever possible. If you are not getting the expected result, have a look at the errors. The most common place people get stuck is providing the correct type of key to the parser. See the above section on signing methods and key types.
## More
Documentation can be found [on godoc.org](http://godoc.org/github.com/dgrijalva/jwt-go).
Documentation can be found [on pkg.go.dev](https://pkg.go.dev/github.com/golang-jwt/jwt).
The command line utility included in this project (cmd/jwt) provides a straightforward example of token creation and parsing as well as a useful tool for debugging your own integration. You'll also find several implementation examples in the documentation.
* **Import Path Change**: See MIGRATION_GUIDE.md for tips on updating your code
* Changed the import path from `github.com/dgrijalva/jwt-go` to `github.com/golang-jwt/jwt`
* Fixed type confusing issue between `string` and `[]string` in `VerifyAudience` ([#12](https://github.com/golang-jwt/jwt/pull/12)). This fixes CVE-2020-26160
#### 3.2.0
* Added method `ParseUnverified` to allow users to split up the tasks of parsing and validation