[#1191] object/acl: check session token verb

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

pkg/services/object/acl/v2/errors.go

@@ -13,6 +13,8 @@ var (
 	ErrUnknownRole = errors.New("can't classify request sender")
 	// ErrUnknownContainer is returned when container fetching errors appeared.
 	ErrUnknownContainer = errors.New("can't fetch container info")
+	// ErrInvalidVerb is returned when session token verb doesn't include necessary operation.
+	ErrInvalidVerb = errors.New("session token verb is invalid")
 )
 
 type accessErr struct {

pkg/services/object/acl/v2/service.go

@@ -425,7 +425,10 @@ func (b Service) findRequestInfo(
 	}
 
 	// find verb from token if it is present
-	verb := sourceVerbOfRequest(req, op)
+	verb, isUnknown := sourceVerbOfRequest(req.token, op)
+	if !isUnknown && verb != op && !isVerbCompatible(verb, op) {
+		return info, ErrInvalidVerb
+	}
 
 	info.basicACL = cnr.BasicACL()
 	info.requestRole = res.role

pkg/services/object/acl/v2/util.go

@@ -102,18 +102,17 @@ func getObjectOwnerFromMessage(req interface{}) (id *owner.ID, err error) {
 }
 
 // sourceVerbOfRequest looks for verb in session token and if it is not found,
-// returns reqVerb.
-func sourceVerbOfRequest(req MetaWithToken, reqVerb eaclSDK.Operation) eaclSDK.Operation {
-	if req.token != nil {
-		switch v := req.token.Context().(type) {
-		case *sessionSDK.ObjectContext:
-			return tokenVerbToOperation(v)
-		default:
-			// do nothing, return request verb
+// returns reqVerb. Second return value is true if operation is unknown.
+func sourceVerbOfRequest(tok *sessionSDK.Token, reqVerb eaclSDK.Operation) (eaclSDK.Operation, bool) {
+	ctx, ok := tok.Context().(*sessionSDK.ObjectContext)
+	if ok {
+		op := tokenVerbToOperation(ctx)
+		if op != eaclSDK.OperationUnknown {
+			return op, false
 		}
 	}
 
-	return reqVerb
+	return reqVerb, true
 }
 
 func useObjectIDFromSession(req *RequestInfo, token *sessionSDK.Token) {
@@ -195,3 +194,18 @@ func isOwnerFromKey(id *owner.ID, key *keys.PublicKey) bool {
 
 	return id.Equal(owner.NewIDFromPublicKey((*ecdsa.PublicKey)(key)))
 }
+
+// isVerbCompatible checks that tokenVerb operation can create auxiliary op operation.
+func isVerbCompatible(tokenVerb, op eaclSDK.Operation) bool {
+	switch tokenVerb {
+	case eaclSDK.OperationGet:
+		return op == eaclSDK.OperationGet || op == eaclSDK.OperationHead
+	case eaclSDK.OperationDelete:
+		return op == eaclSDK.OperationPut || op == eaclSDK.OperationHead ||
+			op == eaclSDK.OperationSearch
+	case eaclSDK.OperationRange, eaclSDK.OperationRangeHash:
+		return op == eaclSDK.OperationRange || op == eaclSDK.OperationHead
+	default:
+		return tokenVerb == op
+	}
+}

pkg/services/object/acl/v2/util_test.go

@@ -7,6 +7,7 @@ import (
 	acltest "github.com/nspcc-dev/neofs-api-go/v2/acl/test"
 	"github.com/nspcc-dev/neofs-api-go/v2/session"
 	sessiontest "github.com/nspcc-dev/neofs-api-go/v2/session/test"
+	"github.com/nspcc-dev/neofs-sdk-go/eacl"
 	sessionSDK "github.com/nspcc-dev/neofs-sdk-go/session"
 	bearerSDK "github.com/nspcc-dev/neofs-sdk-go/token"
 	"github.com/stretchr/testify/require"
@@ -36,3 +37,41 @@ func testGenerateMetaHeader(depth uint32, b *acl.BearerToken, s *session.Session
 
 	return metaHeader
 }
+
+func TestIsVerbCompatible(t *testing.T) {
+	// Source: https://nspcc.ru/upload/neofs-spec-latest.pdf#page=28
+	table := map[eacl.Operation][]eacl.Operation{
+		eacl.OperationPut:       {eacl.OperationPut},
+		eacl.OperationDelete:    {eacl.OperationPut, eacl.OperationHead, eacl.OperationSearch},
+		eacl.OperationHead:      {eacl.OperationHead},
+		eacl.OperationRange:     {eacl.OperationRange, eacl.OperationHead},
+		eacl.OperationRangeHash: {eacl.OperationRange, eacl.OperationHead},
+		eacl.OperationGet:       {eacl.OperationGet, eacl.OperationHead},
+		eacl.OperationSearch:    {eacl.OperationSearch},
+	}
+
+	ops := []eacl.Operation{
+		eacl.OperationPut,
+		eacl.OperationDelete,
+		eacl.OperationHead,
+		eacl.OperationRange,
+		eacl.OperationRangeHash,
+		eacl.OperationGet,
+		eacl.OperationSearch,
+	}
+
+	for _, opToken := range ops {
+		for _, op := range ops {
+			var contains bool
+			for _, o := range table[opToken] {
+				if o == op {
+					contains = true
+					break
+				}
+			}
+
+			require.Equal(t, contains, isVerbCompatible(opToken, op),
+				"%s in token, %s executing", opToken, op)
+		}
+	}
+}