depp / safepath

Go library which checks that file paths are safe to use

SafePath: Path Sanitizing

SafePath checks that pathnames are safe for use.

Installation

SafePath can be installed with the go get command.

go get github.com/depp/safepath

Usage

import "github.com/depp/safepath"

To check if a filename, choose a combination of Rules flags and call the CheckPathSegment() function. For example, the URLUnescaped rule rejects any path which would require percent-encoding when used in a URL.

rules := safepath.URLUnescaped
filename := "my_file.txt"
if err := rules.CheckPathSegment(filename); err != nil {
    return err
}

Relative paths can be checked with the CheckPath() function. Note that this function only recognizes the path separator /, it does not recognize \.

rules := safepath.URLUnescaped
filepath := "directory/my_file.txt"
if err := rules.CheckPathSegment(filepath); err != nil {
    return err
}

Error messages from this library are descriptive. Some examples:

Error: invalid path "/": path is absolute
Error: invalid path segment "NUL.TXT": uses reserved Windows filename "nul"

Unicode

The notion of “safe” in Unicode is a bit difficult to define. This library does not have a comprehensive notion of safety for non-ASCII characters. Currently, there are only two rules that affect non-ASCII characters: ValidUTF8 and ASCIIOnly.

License

SafePath is provided under the MIT license. See LICENSE.txt for details.