grpc-jwt

This is a simple Go package that provides a gRPC server interceptor for JWT authentication. The package currently only supports asymmetric keys, and can be used with any gRPC server. Symmetric keys are not supported, but can be added if there is a need for it.

The package uses the github.com/golang-jwt/jwt/v4 package for JWT validation, and the github.com/MicahParks/keyfunc package for key fetching and parsing jwks key sets.

Todos

Installation

go get -u github.com/mscno/grpc-jwt

Usage

Basic usage with the built in UnaryServerInterceptor

import (
    "github.com/mscno/grpc-jwt"
)

func main() {
    validator := grpc_jwt.NewJWTValidator(Config{
        JwksUrl:   "http://localhost:9999/.well-known/jwks.json",
        Algorithm: jwt.SigningMethodRS256,
        CacheTTL:  60 * time.Minute,
        Audience:  "my-audience",
        Issuer:    "my-issuer",
    })
	
    myServer := grpc.NewServer(
        grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(
            grpc_jwt.UnaryServerInterceptor(validator),
            grpc_recovery.UnaryServerInterceptor(),
        )),
    )

The validator can also be used with the grpc_auth package. In which case it is recommended that you use the SetMethodNameInContext interceptor to set the method name in the context. This is useful for the AuthFunc function to determine which method is being called, and it, and it is a requirement for the skipFn logic to work correctly.

import (
    "github.com/mscno/grpc-jwt"
)

func main() {
    validator := grpc_jwt.NewJWTValidator(Config{
        JwksUrl:   "http://localhost:9999/.well-known/jwks.json",
        Algorithm: jwt.SigningMethodRS256,
        CacheTTL:  60 * time.Minute,
        Audience:  "my-audience",
        Issuer:    "my-issuer",
    })

    myServer := grpc.NewServer(
        grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(
            grpc_jwt.SetMethodNameInContext(),
            grpc_auth.UnaryServerInterceptor(validator.AuthFunc),
            grpc_recovery.UnaryServerInterceptor(),
        )),
    )

Coverage

Test coverage is currently 99%.

$ go test -cover -race
PASS
coverage: 99.3% of statements
ok      github.com/mscno/grpc-jwt       0.395s