From 66fe3fee7b83ebc53e5c1f3dd75343f248cf2590 Mon Sep 17 00:00:00 2001
From: Alex Vanin <alexey@nspcc.ru>
Date: Thu, 21 Jul 2022 12:55:33 +0300
Subject: [PATCH] [#574] Produce deny records for private objects

Signed-off-by: Alex Vanin <alexey@nspcc.ru>
---
 api/handler/acl.go      | 24 ++++++++++++++++++++++++
 api/handler/acl_test.go | 18 ++++++++++++++----
 2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/api/handler/acl.go b/api/handler/acl.go
index 1ea6d5e93..7befb2986 100644
--- a/api/handler/acl.go
+++ b/api/handler/acl.go
@@ -1190,6 +1190,13 @@ func aclToPolicy(acl *AccessControlPolicy, resInfo *resourceInfo) (*bucketPolicy
 		getAllowStatement(resInfo, acl.Owner.ID, aclFullControl),
 	}
 
+	// Expect to have at least 1 full control grant for owner which is set in
+	// parseACLHeaders(). If there is no other grants, then user sets private
+	// canned ACL, which is processed in this branch.
+	if len(acl.AccessControlList) < 2 {
+		results = append([]statement{getDenyStatement(resInfo, allUsersWildcard, aclFullControl)}, results...)
+	}
+
 	for _, grant := range acl.AccessControlList {
 		if grant.Grantee.Type == acpAmazonCustomerByEmail || (grant.Grantee.Type == acpGroup && grant.Grantee.URI != allUsersGroup) {
 			return nil, stderrors.New("unsupported grantee type")
@@ -1227,6 +1234,23 @@ func getAllowStatement(resInfo *resourceInfo, id string, permission AWSACL) stat
 	return state
 }
 
+func getDenyStatement(resInfo *resourceInfo, id string, permission AWSACL) statement {
+	state := statement{
+		Effect: "Deny",
+		Principal: principal{
+			CanonicalUser: id,
+		},
+		Action:   getActions(permission, resInfo.IsBucket()),
+		Resource: []string{arnAwsPrefix + resInfo.Name()},
+	}
+
+	if id == allUsersWildcard {
+		state.Principal = principal{AWS: allUsersWildcard}
+	}
+
+	return state
+}
+
 func getActions(permission AWSACL, isBucket bool) []string {
 	var res []string
 	switch permission {
diff --git a/api/handler/acl_test.go b/api/handler/acl_test.go
index f9580c6e3..84b2df35e 100644
--- a/api/handler/acl_test.go
+++ b/api/handler/acl_test.go
@@ -862,7 +862,7 @@ func TestObjectWithVersionAclToTable(t *testing.T) {
 		Bucket: "bucketName",
 		Object: "object",
 	}
-	expectedTable := allowedTableForObject(t, key, resInfoObject)
+	expectedTable := allowedTableForPrivateObject(t, key, resInfoObject)
 	actualTable := tableFromACL(t, acl, resInfoObject)
 	checkTables(t, expectedTable, actualTable)
 
@@ -871,12 +871,12 @@ func TestObjectWithVersionAclToTable(t *testing.T) {
 		Object:  "objectVersion",
 		Version: "Gfrct4Afhio8pCGCCKVNTf1kyexQjMBeaUfvDtQCkAvg",
 	}
-	expectedTable = allowedTableForObject(t, key, resInfoObjectVersion)
+	expectedTable = allowedTableForPrivateObject(t, key, resInfoObjectVersion)
 	actualTable = tableFromACL(t, acl, resInfoObjectVersion)
 	checkTables(t, expectedTable, actualTable)
 }
 
-func allowedTableForObject(t *testing.T, key *keys.PrivateKey, resInfo *resourceInfo) *eacl.Table {
+func allowedTableForPrivateObject(t *testing.T, key *keys.PrivateKey, resInfo *resourceInfo) *eacl.Table {
 	var isVersion bool
 	var objID oid.ID
 	if resInfo.Version != "" {
@@ -886,7 +886,7 @@ func allowedTableForObject(t *testing.T, key *keys.PrivateKey, resInfo *resource
 	}
 
 	expectedTable := eacl.NewTable()
-	serviceRec := &ServiceRecord{Resource: resInfo.Name(), GroupRecordsLength: len(readOps)}
+	serviceRec := &ServiceRecord{Resource: resInfo.Name(), GroupRecordsLength: len(readOps) * 2}
 	expectedTable.AddRecord(serviceRec.ToEACLRecord())
 
 	for i := len(readOps) - 1; i >= 0; i-- {
@@ -899,6 +899,16 @@ func allowedTableForObject(t *testing.T, key *keys.PrivateKey, resInfo *resource
 		}
 		expectedTable.AddRecord(record)
 	}
+	for i := len(readOps) - 1; i >= 0; i-- {
+		op := readOps[i]
+		record := getOthersRecord(op, eacl.ActionDeny)
+		if isVersion {
+			record.AddObjectIDFilter(eacl.MatchStringEqual, objID)
+		} else {
+			record.AddObjectAttributeFilter(eacl.MatchStringEqual, object.AttributeFileName, resInfo.Object)
+		}
+		expectedTable.AddRecord(record)
+	}
 
 	return expectedTable
 }