doc: add new doc website

* use mmdoc
* add github pages action to auto publish
* do not edit README for now, will follow up with a commit directs
people to the doc site

.github/workflows/ci.yaml

@@ -11,6 +11,7 @@ jobs:
       with:
         extra_nix_config: "system-features = nixos-test benchmark big-parallel kvm"
     - run: nix build
+    - run: nix build .#doc
     - run: nix fmt . -- --check
     - run: nix flake check
   tests-darwin:
@@ -21,6 +22,7 @@ jobs:
       with:
         extra_nix_config: "system-features = nixos-test benchmark big-parallel kvm"
     - run: nix build
+    - run: nix build .#doc
     - run: nix fmt . -- --check
     - run: nix flake check
     - run: |

.github/workflows/doc.yml

@@ -0,0 +1,36 @@
+name: doc
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: true
+
+jobs:
+  publish:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: cachix/install-nix-action@v20
+      - run: nix build .#doc
+      - name: Setup Pages
+        uses: actions/configure-pages@v3
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v1
+        with:
+          path: 'result/multi'
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v1

doc/acknowledgements.md

@@ -0,0 +1,3 @@
+# Acknowledgements {#acknowledgements}
+
+This project is based off of [sops-nix](https://github.com/Mic92/sops-nix) created Mic92. Thank you to Mic92 for inspiration and advice.

doc/community-and-support.md

@@ -0,0 +1,4 @@
+# Community and Support {#community-and-support}
+
+Support and development discussion is available here on GitHub and
+also through [Matrix](https://matrix.to/#/#agenix:nixos.org).

doc/contributing.md

@@ -0,0 +1,28 @@
+# Contributing {#contributing}
+
+* The main branch is protected against direct pushes
+* All changes must go through GitHub PR review and get at least one approval
+* PR titles and commit messages should be prefixed with at least one of these categories:
+  * contrib - things that make the project development better
+  * doc - documentation
+  * feature - new features
+  * fix - bug fixes
+* Please update or make integration tests for new features
+* Use `nix fmt` to format nix code
+
+
+## Tests
+
+You can run the tests with
+
+```ShellSession
+nix flake check
+```
+
+You can run the integration tests in interactive mode like this:
+
+```ShellSession
+nix run .#checks.x86_64-linux.integration.driverInteractive
+```
+
+After it starts, enter `run_tests()` to run the tests.

doc/features.md

@@ -0,0 +1,8 @@
+# Features {#features}
+
+* Secrets are encrypted with SSH keys
+  * system public keys via `ssh-keyscan`
+  * can use public keys available on GitHub for users (for example, https://github.com/ryantm.keys)
+* No GPG
+* Very little code, so it should be easy for you to audit
+* Encrypted secrets are stored in the Nix store, so a separate distribution mechanism is not necessary

doc/install-via-fetchtarball.md

@@ -0,0 +1,38 @@
+# Install via fetchTarball {#install-via-fetchtarball}
+
+#### Install module via fetchTarball
+
+Add the following to your configuration.nix:
+
+```nix
+{
+  imports = [ "${builtins.fetchTarball "https://github.com/ryantm/agenix/archive/main.tar.gz"}/modules/age.nix" ];
+}
+```
+
+  or with pinning:
+
+```nix
+{
+  imports = let
+    # replace this with an actual commit id or tag
+    commit = "298b235f664f925b433614dc33380f0662adfc3f";
+  in [
+    "${builtins.fetchTarball {
+      url = "https://github.com/ryantm/agenix/archive/${commit}.tar.gz";
+      # update hash from nix build output
+      sha256 = "";
+    }}/modules/age.nix"
+  ];
+}
+```
+
+#### Install CLI via fetchTarball
+
+To install the `agenix` binary:
+
+```nix
+{
+  environment.systemPackages = [ (pkgs.callPackage "${builtins.fetchTarball "https://github.com/ryantm/agenix/archive/main.tar.gz"}/pkgs/agenix.nix" {}) ];
+}
+```

doc/install-via-flakes.md

@@ -0,0 +1,39 @@
+# Install via Flakes {#install-via-flakes}
+
+## Install module via Flakes
+
+```nix
+{
+  inputs.agenix.url = "github:ryantm/agenix";
+  # optional, not necessary for the module
+  #inputs.agenix.inputs.nixpkgs.follows = "nixpkgs";
+
+  outputs = { self, nixpkgs, agenix }: {
+    # change `yourhostname` to your actual hostname
+    nixosConfigurations.yourhostname = nixpkgs.lib.nixosSystem {
+      # change to your system:
+      system = "x86_64-linux";
+      modules = [
+        ./configuration.nix
+        agenix.nixosModules.default
+      ];
+    };
+  };
+}
+```
+
+## Install CLI via Flakes
+
+You don't need to install it,
+
+```ShellSession
+nix run github:ryantm/agenix -- --help
+```
+
+but, if you want to (change the system based on your system):
+
+```nix
+{
+  environment.systemPackages = [ agenix.packages.x86_64-linux.default ];
+}
+```

doc/install-via-niv.md

@@ -0,0 +1,27 @@
+# Install via [niv](https://github.com/nmattia/niv) {#install-via-niv}
+
+First add it to niv:
+
+```ShellSession
+$ niv add ryantm/agenix
+```
+
+## Install module via niv
+
+Then add the following to your `configuration.nix` in the `imports` list:
+
+```nix
+{
+  imports = [ "${(import ./nix/sources.nix).agenix}/modules/age.nix" ];
+}
+```
+
+## Install CLI via niv
+
+To install the `agenix` binary:
+
+```nix
+{
+  environment.systemPackages = [ (pkgs.callPackage "${(import ./nix/sources.nix).agenix}/pkgs/agenix.nix" {}) ];
+}
+```

doc/install-via-nix-channel.md

@@ -0,0 +1,28 @@
+# Install via nix-channel {#install-via-nix-channel}
+
+As root run:
+
+```ShellSession
+$ sudo nix-channel --add https://github.com/ryantm/agenix/archive/main.tar.gz agenix
+$ sudo nix-channel --update
+```
+
+## Install module via nix-channel
+
+Then add the following to your `configuration.nix` in the `imports` list:
+
+```nix
+{
+  imports = [ <agenix/modules/age.nix> ];
+}
+```
+
+## Install CLI via nix-channel
+
+To install the `agenix` binary:
+
+```nix
+{
+  environment.systemPackages = [ (pkgs.callPackage <agenix/pkgs/agenix.nix> {}) ];
+}
+```

doc/introduction.md

@@ -0,0 +1,3 @@
+# agenix - [age](https://github.com/FiloSottile/age)-encrypted secrets for NixOS {#introduction}
+
+`agenix` is a commandline tool for managing secrets encrypted with your existing SSH keys. This project also includes the NixOS module `age` for adding encrypted secrets into the Nix store and decrypting them.

doc/notices.md

@@ -0,0 +1,3 @@
+# Notices {#notices}
+
+* Password-protected ssh keys: since the underlying tool age/rage do not support ssh-agent, password-protected ssh keys do not work well. For example, if you need to rekey 20 secrets you will have to enter your password 20 times.

doc/overriding-age-binary.md

@@ -0,0 +1,12 @@
+# Overriding age binary {#overriding-age-binary}
+
+The agenix CLI uses `rage` by default as its age implemenation, you
+can use the reference implementation `age` with Flakes like this:
+
+```nix
+{pkgs,agenix,...}:{
+  environment.systemPackages = [
+    (agenix.packages.x86_64-linux.default.override { ageBin = "${pkgs.age}/bin/age"; })
+  ];
+}
+```

doc/problem-and-solution.md

@@ -0,0 +1,5 @@
+# Problem and solution {#problem-and-solution}
+
+All files in the Nix store are readable by any system user, so it is not a suitable place for including cleartext secrets. Many existing tools (like NixOps deployment.keys) deploy secrets separately from `nixos-rebuild`, making deployment, caching, and auditing more difficult. Out-of-band secret management is also less reproducible.
+
+`agenix` solves these issues by using your pre-existing SSH key infrastructure and `age` to encrypt secrets into the Nix store. Secrets are decrypted using an SSH host private key during NixOS system activation.

doc/reference.md

@@ -0,0 +1,250 @@
+# Reference {#reference}
+
+## `age` module reference {#age-module-reference}
+
+### `age.secrets`
+
+`age.secrets` attrset of secrets. You always need to use this
+configuration option. Defaults to `{}`.
+
+### `age.secrets.<name>.file`
+
+`age.secrets.<name>.file` is the path to the encrypted `.age` for this
+secret. This is the only required secret option.
+
+Example:
+
+```nix
+{
+  age.secrets.monitrc.file = ../secrets/monitrc.age;
+}
+```
+
+### `age.secrets.<name>.path`
+
+`age.secrets.<name>.path` is the path where the secret is decrypted
+to. Defaults to `/run/agenix/<name>` (`config.age.secretsDir/<name>`).
+
+Example defining a different path:
+
+```nix
+{
+  age.secrets.monitrc = {
+    file = ../secrets/monitrc.age;
+    path = "/etc/monitrc";
+  };
+}
+```
+
+For many services, you do not need to set this. Instead, refer to the
+decryption path in your configuration with
+`config.age.secrets.<name>.path`.
+
+Example referring to path:
+
+```nix
+{
+  users.users.ryantm = {
+    isNormalUser = true;
+    passwordFile = config.age.secrets.passwordfile-ryantm.path;
+  };
+}
+```
+
+#### builtins.readFile anti-pattern
+
+```nix
+{
+  # Do not do this!
+  config.password = builtins.readFile config.age.secrets.secret1.path;
+}
+```
+
+This can cause the cleartext to be placed into the world-readable Nix
+store. Instead, have your services read the cleartext path at runtime.
+
+### `age.secrets.<name>.mode`
+
+`age.secrets.<name>.mode` is permissions mode of the decrypted secret
+in a format understood by chmod. Usually, you only need to use this in
+combination with `age.secrets.<name>.owner` and
+`age.secrets.<name>.group`
+
+Example:
+
+```nix
+{
+  age.secrets.nginx-htpasswd = {
+    file = ../secrets/nginx.htpasswd.age;
+    mode = "770";
+    owner = "nginx";
+    group = "nginx";
+  };
+}
+```
+
+### `age.secrets.<name>.owner`
+
+`age.secrets.<name>.owner` is the username of the decrypted file's
+owner. Usually, you only need to use this in combination with
+`age.secrets.<name>.mode` and `age.secrets.<name>.group`
+
+Example:
+
+```nix
+{
+  age.secrets.nginx-htpasswd = {
+    file = ../secrets/nginx.htpasswd.age;
+    mode = "770";
+    owner = "nginx";
+    group = "nginx";
+  };
+}
+```
+
+### `age.secrets.<name>.group`
+
+`age.secrets.<name>.group` is the name of the decrypted file's
+group. Usually, you only need to use this in combination with
+`age.secrets.<name>.owner` and `age.secrets.<name>.mode`
+
+Example:
+
+```nix
+{
+  age.secrets.nginx-htpasswd = {
+    file = ../secrets/nginx.htpasswd.age;
+    mode = "770";
+    owner = "nginx";
+    group = "nginx";
+  };
+}
+```
+
+### `age.secrets.<name>.symlink`
+
+`age.secrets.<name>.symlink` is a boolean. If true (the default),
+secrets are symlinked to `age.secrets.<name>.path`. If false, secerts
+are copied to `age.secrets.<name>.path`. Usually, you want to keep
+this as true, because it secure cleanup of secrets no longer
+used. (The symlink will still be there, but it will be broken.) If
+false, you are responsible for cleaning up your own secrets after you
+stop using them.
+
+Some programs do not like following symlinks (for example Java
+programs like Elasticsearch).
+
+Example:
+
+```nix
+{
+  age.secrets."elasticsearch.conf" = {
+    file = ../secrets/elasticsearch.conf.age;
+    symlink = false;
+  };
+}
+```
+
+### `age.secrets.<name>.name`
+
+`age.secrets.<name>.name` is the string of the name of the file after
+it is decrypted. Defaults to the `<name>` in the attrpath, but can be
+set separately if you want the file name to be different from the
+attribute name part.
+
+Example of a secret with a name different from its attrpath:
+
+```nix
+{
+  age.secrets.monit = {
+    name = "monitrc";
+    file = ../secrets/monitrc.age;
+  };
+}
+```
+
+### `age.ageBin`
+
+`age.ageBin` the string of the path to the `age` binary. Usually, you
+don't need to change this. Defaults to `rage/bin/rage`.
+
+Overriding `age.ageBin` example:
+
+```nix
+{pkgs, ...}:{
+    age.ageBin = "${pkgs.age}/bin/age";
+}
+```
+
+### `age.identityPaths`
+
+`age.identityPaths` is a list of paths to recipient keys to try to use to
+decrypt the secrets. By default, it is the `rsa` and `ed25519` keys in
+`config.services.openssh.hostKeys`, and on NixOS you usually don't need to
+change this. The list items should be strings (`"/path/to/id_rsa"`), not
+nix paths (`../path/to/id_rsa`), as the latter would copy your private key to
+the nix store, which is the exact situation `agenix` is designed to avoid. At
+least one of the file paths must be present at runtime and able to decrypt the
+secret in question. Overriding `age.identityPaths` example:
+
+```nix
+{
+    age.identityPaths = [ "/var/lib/persistent/ssh_host_ed25519_key" ];
+}
+```
+
+### `age.secretsDir`
+
+`age.secretsDir` is the directory where secrets are symlinked to by
+default.Usually, you don't need to change this. Defaults to
+`/run/agenix`.
+
+Overriding `age.secretsDir` example:
+
+```nix
+{
+    age.secretsDir = "/run/keys";
+}
+```
+
+### `age.secretsMountPoint`
+
+`age.secretsMountPoint` is the directory where the secret generations
+are created before they are symlinked. Usually, you don't need to
+change this. Defaults to `/run/agenix.d`.
+
+
+Overriding `age.secretsMountPoint` example:
+
+```nix
+{
+    age.secretsMountPoint = "/run/secret-generations";
+}
+```
+
+## agenix CLI reference {#agenix-cli-reference}
+
+```
+agenix - edit and rekey age secret files
+
+agenix -e FILE [-i PRIVATE_KEY]
+agenix -r [-i PRIVATE_KEY]
+
+options:
+-h, --help                show help
+-e, --edit FILE           edits FILE using $EDITOR
+-r, --rekey               re-encrypts all secrets with specified recipients
+-d, --decrypt FILE        decrypts FILE to STDOUT
+-i, --identity            identity to use when decrypting
+-v, --verbose             verbose output
+
+FILE an age-encrypted file
+
+PRIVATE_KEY a path to a private SSH key used to decrypt file
+
+EDITOR environment variable of editor to use when editing FILE
+
+If STDIN is not interactive, EDITOR will be set to "cp /dev/stdin"
+
+RULES environment variable with path to Nix file specifying recipient public keys.
+Defaults to './secrets.nix'

doc/rekeying.md

@@ -0,0 +1,13 @@
+# Rekeying {#rekeying}
+
+If you change the public keys in `secrets.nix`, you should rekey your
+secrets:
+
+```ShellSession
+$ agenix --rekey
+```
+
+To rekey a secret, you have to be able to decrypt it. Because of
+randomness in `age`'s encryption algorithms, the files always change
+when rekeyed, even if the identities do not. (This eventually could be
+improved upon by reading the identities from the age file.)

doc/threat-model-warnings.md

@@ -0,0 +1,14 @@
+# Threat model/Warnings {#threat-model-warnings}
+
+This project has not been audited by a security professional.
+
+People unfamiliar with `age` might be surprised that secrets are not
+authenticated. This means that every attacker that has write access to
+the secret files can modify secrets because public keys are exposed.
+This seems like not a problem on the first glance because changing the
+configuration itself could expose secrets easily. However, reviewing
+configuration changes is easier than reviewing random secrets (for
+example, 4096-bit rsa keys). This would be solved by having a message
+authentication code (MAC) like other implementations like GPG or
+[sops](https://github.com/Mic92/sops-nix) have, however this was left
+out for simplicity in `age`.

doc/toc.md

@@ -0,0 +1,18 @@
+# agenix
+
+* [Introduction](#introduction)
+* [Problem and solution](#problem-and-solution)
+* [Features](#features)
+* Installation
+  * [flakes](#install-via-flakes)
+  * [niv](#install-via-niv)
+  * [fetchTarball](#install-via-fetchtarball)
+  * [nix-channel](#install-via-nix-channel)
+* [Tutorial](#tutorial)
+* [Reference](#reference)
+  * [`age` module reference](#age-module-reference)
+  * [agenix CLI reference](#agenix-cli-reference)
+* [Community and Support](#community-and-support)
+* [Threat model/Warnings](#threat-model-warnings)
+* [Contributing](#contributing)
+* [Acknowledgements](#acknowledgements)

doc/tutorial.md

@@ -0,0 +1,51 @@
+# Tutorial {#tutorial}
+
+1. The system you want to deploy secrets to should already exist and
+   have `sshd` running on it so that it has generated SSH host keys in
+   `/etc/ssh/`.
+
+2. Make a directory to store secrets and `secrets.nix` file for listing secrets and their public keys (This file is **not** imported into your NixOS configuration. It is only used for the `agenix` CLI.):
+
+   ```ShellSession
+   $ mkdir secrets
+   $ cd secrets
+   $ touch secrets.nix
+   ```
+3. Add public keys to `secrets.nix` file (hint: use `ssh-keyscan` or GitHub (for example, https://github.com/ryantm.keys)):
+   ```nix
+   let
+     user1 = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIL0idNvgGiucWgup/mP78zyC23uFjYq0evcWdjGQUaBH";
+     user2 = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILI6jSq53F/3hEmSs+oq9L4TwOo1PrDMAgcA1uo1CCV/";
+     users = [ user1 user2 ];
+
+     system1 = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPJDyIr/FSz1cJdcoW69R+NrWzwGK/+3gJpqD1t8L2zE";
+     system2 = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKzxQgondgEYcLpcPdJLrTdNgZ2gznOHCAxMdaceTUT1";
+     systems = [ system1 system2 ];
+   in
+   {
+     "secret1.age".publicKeys = [ user1 system1 ];
+     "secret2.age".publicKeys = users ++ systems;
+   }
+   ```
+4. Edit secret files (these instructions assume your SSH private key is in ~/.ssh/):
+   ```ShellSession
+   $ agenix -e secret1.age
+   ```
+5. Add secret to a NixOS module config:
+   ```nix
+   {
+     age.secrets.secret1.file = ../secrets/secret1.age;
+   }
+   ```
+6. Use the secret in your config:
+   ```nix
+   {
+     users.users.user1 = {
+       isNormalUser = true;
+       passwordFile = config.age.secrets.secret1.path;
+     };
+   }
+   ```
+7. NixOS rebuild or use your deployment tool like usual.
+
+   The secret will be decrypted to the value of `config.age.secrets.secret1.path` (`/run/agenix/secret1` by default).

flake.lock

@@ -23,11 +23,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1674641431,
-        "narHash": "sha256-qfo19qVZBP4qn5M5gXc/h1MDgAtPA5VxJm9s8RUAkVk=",
+        "lastModified": 1677676435,
+        "narHash": "sha256-6FxdcmQr5JeZqsQvfinIMr0XcTyTuR7EXX0H3ANShpQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "9b97ad7b4330aacda9b2343396eb3df8a853b4fc",
+        "rev": "a08d6979dd7c82c4cef0dcc6ac45ab16051c1169",
         "type": "github"
       },
       "original": {

flake.nix

@@ -15,6 +15,7 @@
     darwin,
   }: let
     agenix = system: nixpkgs.legacyPackages.${system}.callPackage ./pkgs/agenix.nix {};
+    doc = system: nixpkgs.legacyPackages.${system}.callPackage ./pkgs/doc.nix {};
   in {
     nixosModules.age = import ./modules/age.nix;
     nixosModules.default = self.nixosModules.age;
@@ -26,23 +27,28 @@
 
     formatter.x86_64-darwin = nixpkgs.legacyPackages.x86_64-darwin.alejandra;
     packages.x86_64-darwin.agenix = agenix "x86_64-darwin";
+    packages.x86_64-darwin.doc = doc "x86_64-darwin";
     packages.x86_64-darwin.default = self.packages.x86_64-darwin.agenix;
 
     formatter.aarch64-darwin = nixpkgs.legacyPackages.aarch64-darwin.alejandra;
     packages.aarch64-darwin.agenix = agenix "aarch64-darwin";
+    packages.aarch64-darwin.doc = doc "aarch64-darwin";
     packages.aarch64-darwin.default = self.packages.aarch64-darwin.agenix;
 
     formatter.aarch64-linux = nixpkgs.legacyPackages.aarch64-linux.alejandra;
     packages.aarch64-linux.agenix = agenix "aarch64-linux";
+    packages.aarch64-linux.doc = doc "aarch64-linux";
     packages.aarch64-linux.default = self.packages.aarch64-linux.agenix;
 
     formatter.i686-linux = nixpkgs.legacyPackages.i686-linux.alejandra;
     packages.i686-linux.agenix = agenix "i686-linux";
+    packages.i686-linux.doc = doc "i686-linux";
     packages.i686-linux.default = self.packages.i686-linux.agenix;
 
     formatter.x86_64-linux = nixpkgs.legacyPackages.x86_64-linux.alejandra;
     packages.x86_64-linux.agenix = agenix "x86_64-linux";
     packages.x86_64-linux.default = self.packages.x86_64-linux.agenix;
+    packages.x86_64-linux.doc = doc "x86_64-linux";
     checks.x86_64-linux.integration = import ./test/integration.nix {
       inherit nixpkgs;
       pkgs = nixpkgs.legacyPackages.x86_64-linux;

pkgs/doc.nix

@@ -0,0 +1,11 @@
+{
+  stdenvNoCC,
+  mmdoc,
+  self,
+}:
+stdenvNoCC.mkDerivation rec {
+  name = "agenix-doc";
+  src = ../doc;
+  phases = ["mmdocPhase"];
+  mmdocPhase = "${mmdoc}/bin/mmdoc agenix $src $out";
+}