add auth interceptors

interceptors/auth/interceptors.go

@@ -0,0 +1,94 @@
+package auth
+
+import (
+	"context"
+	"strings"
+
+	grpc_auth "github.com/grpc-ecosystem/go-grpc-middleware/auth"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	"go.linka.cloud/grpc/interceptors"
+)
+
+func ChainedAuthFuncs(fn ...grpc_auth.AuthFunc) grpc_auth.AuthFunc {
+	return func(ctx context.Context) (context.Context, error) {
+		code := codes.Unauthenticated
+		for _, v := range fn {
+			ctx2, err := v(ctx)
+			if err == nil {
+				return ctx2, nil
+			}
+			s, ok := status.FromError(err)
+			if !ok {
+				return ctx2, err
+			}
+			if s.Code() == codes.PermissionDenied {
+				code = codes.PermissionDenied
+			}
+		}
+		return ctx, status.Error(code, code.String())
+	}
+}
+
+func NewServerInterceptors(opts ...Option) interceptors.ServerInterceptors {
+	o := options{}
+	for _, v := range opts {
+		v(&o)
+	}
+	return &interceptor{o: o, authFn: ChainedAuthFuncs(o.authFns...)}
+}
+
+type interceptor struct{
+	o options
+	authFn grpc_auth.AuthFunc
+}
+
+func (i *interceptor) UnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	a := grpc_auth.UnaryServerInterceptor(i.authFn)
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+		if i.isNotProtected(info.FullMethod) {
+			return handler(ctx, req)
+		}
+		return a(ctx, req, info, handler)
+	}
+}
+
+func (i *interceptor) StreamServerInterceptor() grpc.StreamServerInterceptor {
+	a := grpc_auth.StreamServerInterceptor(i.authFn)
+	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		if i.isNotProtected(info.FullMethod) {
+			return handler(srv, ss)
+		}
+		return a(srv, ss, info, handler)
+	}
+}
+
+func (i *interceptor) isNotProtected(endpoint string) bool {
+	// default to not ignored
+	if len(i.o.ignoredMethods) == 0 && len(i.o.methods) == 0 {
+		return false
+	}
+	// endpoint is like /helloworld.Greeter/SayHello
+	parts := strings.Split(strings.TrimPrefix(endpoint, "/"), "/")
+	// invalid endpoint format
+	if len(parts) != 2 {
+		return false
+	}
+	method := parts[1]
+	for _, v := range i.o.ignoredMethods {
+		if v == method {
+			return true
+		}
+	}
+	if len(i.o.methods) == 0 {
+		return false
+	}
+	for _, v := range i.o.methods {
+		if v == method {
+			return false
+		}
+	}
+	return true
+}