Files
flux2/internal/flags/safe_relative_path.go
Hidde Beydals 5ea4e814f5 Add safe guards for relative paths
This commit adds multiple safe guards for relative paths, ensuring they
never traverse outside the working directory.

The `SafeRelativePath` flag calculates the safe relative path based on a
relative base dir, which results in a flattened path.

The write methods of `manifestgen` make use of the `SecureJoin` as well,
to ensure writes are never outside of the given directory when used as
a lib outside of the CLI.

Signed-off-by: Hidde Beydals <hello@hidde.co>
2020-12-14 15:14:49 +01:00

51 lines
1.4 KiB
Go

/*
Copyright 2020 The Flux authors
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package flags
import (
"fmt"
"strings"
securejoin "github.com/cyphar/filepath-securejoin"
)
type SafeRelativePath string
func (p *SafeRelativePath) String() string {
return string(*p)
}
func (p *SafeRelativePath) Set(str string) error {
// The result of secure joining on a relative base dir is a flattened relative path.
cleanP, err := securejoin.SecureJoin("./", strings.TrimSpace(str))
if err != nil {
return fmt.Errorf("invalid relative path '%s': %w", cleanP, err)
}
// NB: required, as a secure join of "./" will result in "."
cleanP = fmt.Sprintf("./%s", strings.TrimPrefix(cleanP, "."))
*p = SafeRelativePath(cleanP)
return nil
}
func (p *SafeRelativePath) Type() string {
return "safeRelativePath"
}
func (p *SafeRelativePath) Description() string {
return fmt.Sprintf("secure relative path")
}