macaroons: remove temporary macaroon creation and verification logic

auth/authenticator.go

@@ -4,11 +4,11 @@ import (
 	"context"
 	"encoding/base64"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"net/http"
 	"regexp"
 
-	"github.com/lightninglabs/kirin/macaroons"
 	"github.com/lightninglabs/kirin/mint"
 	"github.com/lightninglabs/loop/lsat"
 	"github.com/lightningnetwork/lnd/lntypes"
@@ -187,10 +187,10 @@ func FromHeader(header *http.Header) (*macaroon.Macaroon, lntypes.Preimage, erro
 		return nil, lntypes.Preimage{}, fmt.Errorf("unable to "+
 			"unmarshal macaroon: %v", err)
 	}
-	preimageHex, err := macaroons.ExtractCaveat(mac, macaroons.CondPreimage)
-	if err != nil {
-		return nil, lntypes.Preimage{}, fmt.Errorf("unable to extract "+
-			"preimage from macaroon: %v", err)
+	preimageHex, ok := lsat.HasCaveat(mac, lsat.PreimageKey)
+	if !ok {
+		return nil, lntypes.Preimage{}, errors.New("preimage caveat " +
+			"not found")
 	}
 	preimage, err := lntypes.MakePreimageFromStr(preimageHex)
 	if err != nil {

auth/authenticator_test.go

@@ -7,7 +7,7 @@ import (
 	"testing"
 
 	"github.com/lightninglabs/kirin/auth"
-	"github.com/lightninglabs/kirin/macaroons"
+	"github.com/lightninglabs/loop/lsat"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"gopkg.in/macaroon.v2"
 )
@@ -27,9 +27,8 @@ func createDummyMacHex(preimage string) string {
 	if err != nil {
 		panic(err)
 	}
-	err = dummyMac.AddFirstPartyCaveat(
-		[]byte(macaroons.CondPreimage + " " + preimage),
-	)
+	preimageCaveat := lsat.Caveat{Condition: lsat.PreimageKey, Value: preimage}
+	err = lsat.AddFirstPartyCaveats(dummyMac, preimageCaveat)
 	if err != nil {
 		panic(err)
 	}

go.mod

@@ -29,7 +29,7 @@ require (
 	golang.org/x/sys v0.0.0-20191112214154-59a1497f0cea // indirect
 	google.golang.org/genproto v0.0.0-20191108220845-16a3f7862a1a // indirect
 	google.golang.org/grpc v1.25.1
-	gopkg.in/macaroon-bakery.v2 v2.1.0
+	gopkg.in/macaroon-bakery.v2 v2.1.0 // indirect
 	gopkg.in/macaroon.v2 v2.1.0
 	gopkg.in/yaml.v2 v2.2.2
 	sigs.k8s.io/yaml v1.1.0 // indirect

macaroons/service.go

@@ -1,151 +0,0 @@
-package macaroons
-
-import (
-	"context"
-	"encoding/hex"
-	"fmt"
-
-	"github.com/lightningnetwork/lnd/macaroons"
-	"gopkg.in/macaroon-bakery.v2/bakery"
-	"gopkg.in/macaroon-bakery.v2/bakery/checkers"
-	"gopkg.in/macaroon.v2"
-)
-
-const (
-	// CondRHash is the macaroon caveat condition for a payment hash.
-	CondRHash = "r-hash"
-
-	// CondPreimage is the macaroon caveat condition for a payment preimage.
-	CondPreimage = "preimage"
-)
-
-var (
-	rootKey   = "aabbccddeeff00112233445566778899"
-	rootKeyId = []byte("0")
-)
-
-type rootKeyStore struct{}
-
-// A compile time flag to ensure the rootKeyStore satisfies the
-// bakery.RootKeyStore interface.
-var _ bakery.RootKeyStore = (*rootKeyStore)(nil)
-
-func (r *rootKeyStore) Get(_ context.Context, id []byte) ([]byte, error) {
-	return hex.DecodeString(rootKey)
-}
-
-func (r *rootKeyStore) RootKey(_ context.Context) (rootKey, id []byte,
-	err error) {
-
-	key, err := r.Get(nil, rootKeyId)
-	if err != nil {
-		return nil, nil, err
-	}
-	return key, rootKeyId, nil
-}
-
-// Service can bake and validate macaroons.
-type Service struct {
-	bakery.Bakery
-}
-
-// NewService creates a new macaroon service with the given checker functions
-// that should be supported when validating a macaroon.
-func NewService(checks ...macaroons.Checker) (*Service, error) {
-	macaroonParams := bakery.BakeryParams{
-		Location:     "kirin",
-		RootKeyStore: &rootKeyStore{},
-		Locator:      nil,
-		Key:          nil,
-	}
-
-	svc := bakery.New(macaroonParams)
-
-	// Register all custom caveat checkers with the bakery's checker.
-	checker := svc.Checker.FirstPartyCaveatChecker.(*checkers.Checker)
-	for _, check := range checks {
-		cond, fun := check()
-		if !isRegistered(checker, cond) {
-			checker.Register(cond, "std", fun)
-		}
-	}
-
-	return &Service{*svc}, nil
-}
-
-// NewMacaroon bakes a new macaroon with the given allowed operations and
-// optional first-party caveats.
-func (s *Service) NewMacaroon(operations []bakery.Op, caveats []string) (
-	[]byte, error) {
-
-	ctx := context.Background()
-	mac, err := s.Oven.NewMacaroon(
-		ctx, bakery.LatestVersion, nil, operations...,
-	)
-	if err != nil {
-		return nil, err
-	}
-
-	// Add all first party caveats before serializing the macaroon.
-	for _, caveat := range caveats {
-		err := mac.M().AddFirstPartyCaveat([]byte(caveat))
-		if err != nil {
-			return nil, err
-		}
-	}
-	macBytes, err := mac.M().MarshalBinary()
-	if err != nil {
-		return nil, err
-	}
-	return macBytes, nil
-}
-
-// ValidateMacaroon verifies the signature chain of a macaroon and then
-// checks that none of the applied restrictions are violated.
-func (s *Service) ValidateMacaroon(mac *macaroon.Macaroon,
-	perms []bakery.Op) error {
-
-	// Check the method being called against the permitted operation and
-	// the expiration time and IP address and return the result.
-	authChecker := s.Checker.Auth(macaroon.Slice{mac})
-	_, err := authChecker.Allow(context.Background(), perms...)
-	return err
-}
-
-// ExtractCaveat extracts the value of a given caveat condition or returns an
-// empty string if that caveat does not exist.
-func ExtractCaveat(mac *macaroon.Macaroon, cond string) (string, error) {
-	if mac == nil {
-		return "", fmt.Errorf("macaroon cannot be nil")
-	}
-	for _, caveat := range mac.Caveats() {
-		cavStr := string(caveat.Id)
-		cavCond, cavArg, err := checkers.ParseCaveat(cavStr)
-		if err != nil {
-			continue
-		}
-		if cavCond == cond {
-			return cavArg, nil
-		}
-	}
-
-	return "", nil
-}
-
-// isRegistered checks to see if the required checker has already been
-// registered in order to avoid a panic caused by double registration.
-func isRegistered(c *checkers.Checker, name string) bool {
-	if c == nil {
-		return false
-	}
-
-	for _, info := range c.Info() {
-		if info.Name == name &&
-			info.Prefix == "" &&
-			info.Namespace == "std" {
-			return true
-		}
-	}
-
-	return false
-}