package grpc_auth

import "github.com/grpc-ecosystem/go-grpc-middleware/auth"

`grpc_auth` a generic server-side auth middleware for gRPC.

Server Side Auth Middleware

It allows for easy assertion of `:authorization` headers in gRPC calls, be it HTTP Basic auth, or OAuth2 Bearer tokens.

The middleware takes a user-customizable `AuthFunc`, which can be customized to verify and extract auth information from the request. The extracted information can be put in the `context.Context` of handlers downstream for retrieval.

It also allows for per-service implementation overrides of `AuthFunc`. See `ServiceAuthFuncOverride`.

Please see examples for simple examples of use.

package main

import (
	"github.com/grpc-ecosystem/go-grpc-middleware/auth"
	"github.com/grpc-ecosystem/go-grpc-middleware/tags"
	"golang.org/x/net/context"
	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"
)

var (
	cc *grpc.ClientConn
)

func parseToken(token string) (struct{}, error) {
	return struct{}{}, nil
}

func userClaimFromToken(struct{}) string {
	return "foobar"
}

// Simple example of server initialization code.
func main() {
	exampleAuthFunc := func(ctx context.Context) (context.Context, error) {
		token, err := grpc_auth.AuthFromMD(ctx, "bearer")
		if err != nil {
			return nil, err
		}
		tokenInfo, err := parseToken(token)
		if err != nil {
			return nil, grpc.Errorf(codes.Unauthenticated, "invalid auth token: %v", err)
		}
		grpc_ctxtags.Extract(ctx).Set("auth.sub", userClaimFromToken(tokenInfo))
		newCtx := context.WithValue(ctx, "tokenInfo", tokenInfo)
		return newCtx, nil
	}

	_ = grpc.NewServer(
		grpc.StreamInterceptor(grpc_auth.StreamServerInterceptor(exampleAuthFunc)),
		grpc.UnaryInterceptor(grpc_auth.UnaryServerInterceptor(exampleAuthFunc)),
	)
}

Index ¶

• func AuthFromMD(ctx context.Context, expectedScheme string) (string, error)
• func StreamServerInterceptor(authFunc AuthFunc) grpc.StreamServerInterceptor
• func UnaryServerInterceptor(authFunc AuthFunc) grpc.UnaryServerInterceptor
• type AuthFunc
• type ServiceAuthFuncOverride

Examples ¶

• package (ServerConfig)

Functions ¶

func AuthFromMD ¶

func AuthFromMD(ctx context.Context, expectedScheme string) (string, error)

AuthFromMD is a helper function for extracting the :authorization header from the gRPC metadata of the request.

It expects the `:authorization` header to be of a certain scheme (e.g. `basic`, `bearer`), in a case-insensitive format (see rfc2617, sec 1.2). If no such authorization is found, or the token is of wrong scheme, an error with gRPC status `Unauthenticated` is returned.

func StreamServerInterceptor ¶

func StreamServerInterceptor(authFunc AuthFunc) grpc.StreamServerInterceptor

StreamServerInterceptor returns a new unary server interceptors that performs per-request auth.

func UnaryServerInterceptor ¶

func UnaryServerInterceptor(authFunc AuthFunc) grpc.UnaryServerInterceptor

UnaryServerInterceptor returns a new unary server interceptors that performs per-request auth.

Types ¶

type AuthFunc ¶

type AuthFunc func(ctx context.Context) (context.Context, error)

AuthFunc is the pluggable function that performs authentication.

The passed in `Context` will contain the gRPC metadata.MD object (for header-based authentication) and the peer.Peer information that can contain transport-based credentials (e.g. `credentials.AuthInfo`).

The returned context will be propagated to handlers, allowing user changes to `Context`. However, please make sure that the `Context` returned is a child `Context` of the one passed in.

If error is returned, its `grpc.Code()` will be returned to the user as well as the verbatim message. Please make sure you use `codes.Unauthenticated` (lacking auth) and `codes.PermissionDenied` (authed, but lacking perms) appropriately.

type ServiceAuthFuncOverride ¶

type ServiceAuthFuncOverride interface {
	AuthFuncOverride(ctx context.Context, fullMethodName string) (context.Context, error)
}

ServiceAuthFuncOverride allows a given gRPC service implementation to override the global `AuthFunc`.

If a service implements the AuthFuncOverride method, it takes precedence over the `AuthFunc` method, and will be called instead of AuthFunc for all method invocations within that service.

Source Files ¶

auth.go doc.go metadata.go