Permify / permify

import (

	"context"

	"google.golang.org/grpc/codes"

	"google.golang.org/grpc/status"

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

	"github.com/pkg/errors"

	"github.com/Permify/permify/internal/config"

	base "github.com/Permify/permify/pkg/pb/base/v1"

)

// KeyAuthenticator - Interface for key authenticator

type KeyAuthenticator interface {

	Authenticate(ctx context.Context) error

}

// KeyAuthn - Authentication Keys Structure

type KeyAuthn struct {

	keys map[string]struct{}

}

// NewKeyAuthn - Create New Authenticated Keys

func NewKeyAuthn(_ context.Context, cfg config.Preshared) (*KeyAuthn, error) {

	if len(cfg.Keys) < 1 {

		return nil, errors.New("pre shared key authn must have at least one key")

	}

	mapKeys := make(map[string]struct{})

	for _, k := range cfg.Keys {

		mapKeys[k] = struct{}{}

	}

	return &KeyAuthn{

		keys: mapKeys,

	}, nil

}

// Authenticate - Checking whether any API request contain keys

func (a *KeyAuthn) Authenticate(ctx context.Context) error {

	key, err := grpcAuth.AuthFromMD(ctx, "Bearer")

	if err != nil {

		return errors.New(base.ErrorCode_ERROR_CODE_MISSING_BEARER_TOKEN.String())

	}

	if _, found := a.keys[key]; found {

		return nil

	}

	return status.Error(codes.Unauthenticated, base.ErrorCode_ERROR_CODE_INVALID_KEY.String())

}