hugo/content/en/about/security-model/index.md
Bjørn Erik Pedersen efa74c5c6e Squashed 'docs/' changes from 9be494de3..ac2c4a487
ac2c4a487 Update documentation for Ugly URLs (#1082)
88bdec17a Change 072.0 to 0.72.0 in release post's description
2aa7d7818 Update rss.md (#1104)
c80677aeb Update quick-start.md (#1076)
d04196bbd Minor spelling and capitalization fixes
837d2feba Fixed spelling mistake
67dc78e12 Update installing.md
ce280c5d6 Update relurl.md
bb4d0e703 Capitalization and Redirecting URL fixes
e1fecada0 Update partials.md
1d99bb182 Typos and whitespacing issues fixed
b20dba125 actually fix index function link this time
f47d6f1e3 Fixing typos, whitespace issues and links
dc82309b9 fix link to the index function
1eab0cbea add missing word (#1130)
9c3ee62ae more fixes
e9bc5880a whitespace, typos and HTTPS fixes
93b806493 Add missing word to Module section
80ced9062 Display image on page bundles page.
727029b0a Update index.md
51fc48e4d Release 0.72.0
1ff68ac3b releaser: Add release notes to /docs for release of 0.72.0
f74a25b92 common/maps: Add Scratch.Values
2fd83db96 Add redirect support to the server
bdfccf9f4 Fix typo in install instructions
e12737ea6 Create SUPPORT.md

git-subtree-dir: docs
git-subtree-split: ac2c4a4871e90ddfb180f23704ce7ec9023529ca
2020-06-16 14:18:51 +02:00

54 lines
3.1 KiB
Markdown

---
title: Hugo's Security Model
description: A summary of Hugo's security model.
date: 2019-10-01
layout: single
keywords: ["Security", "Privacy"]
menu:
docs:
parent: "about"
weight: 4
weight: 5
sections_weight: 5
draft: false
aliases: [/security/]
toc: true
---
## Runtime Security
Hugo produces static output, so once built, the runtime is the browser (assuming the output is HTML) and any server (API) that you integrate with.
But when developing and building your site, the runtime is the `hugo` executable. Securing a runtime can be [a real challenge](https://blog.logrocket.com/how-to-protect-your-node-js-applications-from-malicious-dependencies-5f2e60ea08f9/).
**Hugo's main approach is that of sandboxing:**
* Hugo has a virtual file system and only the main project (not third-party components) is allowed to mount directories or files outside the project root.
* Only the main project can walk symbolic links.
* User-defined components have only read-access to the filesystem.
* We shell out to some external binaries to support [Asciidoctor](/content-management/formats/#list-of-content-formats) and similar, but those binaries and their flags are predefined. General functions to run arbitrary external OS commands have been [discussed](https://github.com/gohugoio/hugo/issues/796), but not implemented because of security concerns.
Hugo will soon introduce a concept of _Content Source Plugins_ (AKA _Pages from Data_), but the above will still hold true.
## Dependency Security
Hugo builds as a static binary using [Go Modules](https://github.com/golang/go/wiki/Modules) to manage its dependencies. Go Modules have several safeguards, one of them being the `go.sum` file. This is a database of the expected cryptographic checksums of all of your dependencies, including any transitive.
[Hugo Modules](/hugo-modules/) is built on top of Go Modules functionality, and a Hugo project using Hugo Modules will have a `go.sum` file. We recommend that you commit this file to your version control system. The Hugo build will fail if there is a checksum mismatch, which would be an indication of [dependency tampering](https://julienrenaux.fr/2019/12/20/github-actions-security-risk/).
## Web Application Security
These are the security threats as defined by [OWASP](https://en.wikipedia.org/wiki/OWASP).
For HTML output, this is the core security model:
https://golang.org/pkg/html/template/#hdr-Security_Model
In short:
Templates authors (you) are trusted, but the data you send in is not.
This is why you sometimes need to use the _safe_ functions, such as `safeHTML`, to avoid escaping of data you know is safe.
There is one exception to the above, as noted in the documentation: If you enable inline shortcodes, you also say that the shortcodes and data handling in content files are trusted, as those macros are treated as pure text.
It may be worth adding that Hugo is a static site generator with no concept of dynamic user input.
For content, the default Markdown renderer is [configured](/getting-started/configuration-markup) to remove or escape potentially unsafe content. This behavior can be reconfigured if you trust your content.