hugo/resources/resource_transformers
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
..
babel Add some basic security policies with sensible defaults 2021-12-16 09:40:22 +01:00
htesting Add some basic security policies with sensible defaults 2021-12-16 09:40:22 +01:00
integrity all: Format code with gofumpt 2020-12-03 13:12:58 +01:00
js js: Fix import order for ./foo when both ./foo.js and ./foo/index.js exists 2021-09-01 10:47:41 +02:00
minifier Pass minification errors to the user 2021-09-22 20:54:40 +02:00
postcss Add some basic security policies with sensible defaults 2021-12-16 09:40:22 +01:00
templates Revert "resources: Add data context to the key in ExecuteAsTemplate" 2020-03-21 18:38:19 +01:00
tocss Add some basic security policies with sensible defaults 2021-12-16 09:40:22 +01:00