minio/internal/config/dns/dns_path.go
Klaus Post 8d42f37e4b
Fix msgUnPath crash (#20614)
These are needed checks for the functions to be un-crashable with any input 
given to `msgUnPath` (tested with fuzzing).

Both conditions would result in a crash, which prevents that. Some 
additional upstream checks are needed.

Fixes #20610
2024-11-05 04:37:59 -08:00

65 lines
1.9 KiB
Go

// Copyright (c) 2015-2024 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package dns
import (
"path"
"strings"
"github.com/miekg/dns"
)
// msgPath converts a domainname to an etcd path. If s looks like service.staging.skydns.local.,
// the resulting key will be /skydns/local/skydns/staging/service .
func msgPath(s, prefix string) string {
l := dns.SplitDomainName(s)
for i, j := 0, len(l)-1; i < j; i, j = i+1, j-1 {
l[i], l[j] = l[j], l[i]
}
return path.Join(append([]string{etcdPathSeparator + prefix + etcdPathSeparator}, l...)...)
}
// dnsJoin joins labels to form a fully qualified domain name. If the last label is
// the root label it is ignored. Not other syntax checks are performed.
func dnsJoin(labels ...string) string {
if len(labels) == 0 {
return ""
}
ll := len(labels)
if labels[ll-1] == "." {
return strings.Join(labels[:ll-1], ".") + "."
}
return dns.Fqdn(strings.Join(labels, "."))
}
// msgUnPath converts a etcd path to domainName.
func msgUnPath(s string) string {
l := strings.Split(s, etcdPathSeparator)
if l[len(l)-1] == "" {
l = l[:len(l)-1]
}
if len(l) < 2 {
return s
}
// start with 1, to strip /skydns
for i, j := 1, len(l)-1; i < j; i, j = i+1, j-1 {
l[i], l[j] = l[j], l[i]
}
return dnsJoin(l[1 : len(l)-1]...)
}