hugo/common/collections/slice.go
Bjørn Erik Pedersen f4389e48ce
Add some basic security policies with sensible defaults
This ommmit contains some security hardening measures for the Hugo build runtime.

There are some rarely used features in Hugo that would be good to have disabled by default. One example would be the "external helpers".

For `asciidoctor` and some others we use Go's `os/exec` package to start a new process.

These are a predefined set of binary names, all loaded from `PATH` and with a predefined set of arguments. Still, if you don't use `asciidoctor` in your project, you might as well have it turned off.

You can configure your own in the new `security` configuration section, but the defaults are configured to create a minimal amount of site breakage. And if that do happen, you will get clear instructions in the loa about what to do.

The default configuration is listed below. Note that almost all of these options are regular expression _whitelists_ (a string or a slice); the value `none` will block all.

```toml
[security]
  enableInlineShortcodes = false
  [security.exec]
    allow = ['^dart-sass-embedded$', '^go$', '^npx$', '^postcss$']
    osEnv = ['(?i)^(PATH|PATHEXT|APPDATA|TMP|TEMP|TERM)$']

  [security.funcs]
    getenv = ['^HUGO_']

  [security.http]
    methods = ['(?i)GET|POST']
    urls = ['.*']
```
2021-12-16 09:40:22 +01:00

77 lines
1.9 KiB
Go

// Copyright 2018 The Hugo Authors. All rights reserved.
//
// 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 collections
import (
"reflect"
)
// Slicer defines a very generic way to create a typed slice. This is used
// in collections.Slice template func to get types such as Pages, PageGroups etc.
// instead of the less useful []interface{}.
type Slicer interface {
Slice(items interface{}) (interface{}, error)
}
// Slice returns a slice of all passed arguments.
func Slice(args ...interface{}) interface{} {
if len(args) == 0 {
return args
}
first := args[0]
firstType := reflect.TypeOf(first)
if firstType == nil {
return args
}
if g, ok := first.(Slicer); ok {
v, err := g.Slice(args)
if err == nil {
return v
}
// If Slice fails, the items are not of the same type and
// []interface{} is the best we can do.
return args
}
if len(args) > 1 {
// This can be a mix of types.
for i := 1; i < len(args); i++ {
if firstType != reflect.TypeOf(args[i]) {
// []interface{} is the best we can do
return args
}
}
}
slice := reflect.MakeSlice(reflect.SliceOf(firstType), len(args), len(args))
for i, arg := range args {
slice.Index(i).Set(reflect.ValueOf(arg))
}
return slice.Interface()
}
// StringSliceToInterfaceSlice converts ss to []interface{}.
func StringSliceToInterfaceSlice(ss []string) []interface{} {
result := make([]interface{}, len(ss))
for i, s := range ss {
result[i] = s
}
return result
}