feature: add an option to output secrets in armor

README.md

@@ -2,8 +2,8 @@
 
 `agenix` is a small and convenient Nix library for securely managing and deploying secrets using common public-private SSH key pairs:
 You can encrypt a secret (password, access-token, etc.) on a source machine using a number of public SSH keys,
-and deploy that encrypted secret to any another target machine that has the corresponding private SSH key of one of those public keys.  
-This project contains two parts: 
+and deploy that encrypted secret to any another target machine that has the corresponding private SSH key of one of those public keys.
+This project contains two parts:
 1. An `agenix` commandline app (CLI) to encrypt secrets into secured `.age` files that can be copied into the Nix store.
 2. An `agenix` NixOS module to conveniently
     * add those encrypted secrets (`.age` files) into the Nix store so that they can be deployed like any other Nix package using `nixos-rebuild` or similar tools.
@@ -250,7 +250,7 @@ e.g. inside your `flake.nix` file:
    $ cd secrets
    $ touch secrets.nix
    ```
-   This `secrets.nix` file is **not** imported into your NixOS configuration. 
+   This `secrets.nix` file is **not** imported into your NixOS configuration.
    It's only used for the `agenix` CLI tool (example below) to know which public keys to use for encryption.
 3. Add public keys to your `secrets.nix` file:
    ```nix
@@ -266,10 +266,15 @@ e.g. inside your `flake.nix` file:
    {
      "secret1.age".publicKeys = [ user1 system1 ];
      "secret2.age".publicKeys = users ++ systems;
+     "armored-secret.age" = {
+       publicKeys = [ user1 ];
+       armor = true;
+     };
    }
    ```
    These are the users and systems that will be able to decrypt the `.age` files later with their corresponding private keys.
-   You can obtain the public keys from 
+   The armor option may also be supplied here to ensure files are output in Base64 PEM text which is useful for more readable diffs.
+   You can obtain the public keys from
    * your local computer usually in `~/.ssh`, e.g. `~/.ssh/id_ed25519.pub`.
    * from a running target machine with `ssh-keyscan`:
      ```ShellSession
@@ -290,7 +295,7 @@ e.g. inside your `flake.nix` file:
      age.secrets.secret1.file = ../secrets/secret1.age;
    }
    ```
-   When the `age.secrets` attribute set contains a secret, the `agenix` NixOS module will later automatically decrypt and mount that secret under the default path `/run/agenix/secret1`. 
+   When the `age.secrets` attribute set contains a secret, the `agenix` NixOS module will later automatically decrypt and mount that secret under the default path `/run/agenix/secret1`.
    Here the `secret1.age` file becomes part of your NixOS deployment, i.e. moves into the Nix store.
 
 6. Reference the secrets' mount path in your config:
@@ -306,14 +311,14 @@ e.g. inside your `flake.nix` file:
    So `config.age.secrets.secret1.path` will contain the path `/run/agenix/secret1` by default.
 7. Use `nixos-rebuild` or [another deployment tool](https://nixos.wiki/wiki/Applications#Deployment") of choice as usual.
 
-   The `secret1.age` file will be copied over to the target machine like any other Nix package. 
+   The `secret1.age` file will be copied over to the target machine like any other Nix package.
    Then it will be decrypted and mounted as described before.
 8. Edit secret files:
    ```ShellSession
    $ agenix -e secret1.age
    ```
-   It assumes your SSH private key is in `~/.ssh/`. 
-   In order to decrypt and open a `.age` file for editing you need the private key of one of the public keys 
+   It assumes your SSH private key is in `~/.ssh/`.
+   In order to decrypt and open a `.age` file for editing you need the private key of one of the public keys
    it was encrypted with. You can pass the private key you want to use explicitly with `-i`, e.g.
    ```ShellSession
    $ agenix -e secret1.age -i ~/.ssh/id_ed25519

doc/tutorial.md

@@ -25,6 +25,10 @@
    {
      "secret1.age".publicKeys = [ user1 system1 ];
      "secret2.age".publicKeys = users ++ systems;
+     "armored-secret.age" = {
+       publicKeys = [ user1 ];
+       armor = true;
+     };
    }
    ```
 4. Edit secret files (these instructions assume your SSH private key is in ~/.ssh/):

example/armored-secret.age

@@ -0,0 +1,7 @@
+-----BEGIN AGE ENCRYPTED FILE-----
+YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IHNzaC1lZDI1NTE5IFYzWG1FQSBpZkZW
+aFpLNnJxc0VUMHRmZ2dZS0pjMGVENnR3OHd5K0RiT1RjRUhibFZBCnN5UG5vUjA3
+SXpsNGtiVUw4T0tIVFo5Wkk5QS9NQlBndzVvektiQ0ozc0kKLS0tIGxyY1Q4dEZ1
+VGZEanJyTFNta2JNRmpZb2FnK2JyS1hSVml1UGdMNWZKQXMKYla+wTXcRedyZoEb
+LVWaSx49WoUTU0KBPJg9RArxaeC23GoCDzR/aM/1DvYU
+-----END AGE ENCRYPTED FILE-----

example/secrets.nix

@@ -5,4 +5,8 @@ in {
   "secret1.age".publicKeys = [user1 system1];
   "secret2.age".publicKeys = [user1];
   "passwordfile-user1.age".publicKeys = [user1 system1];
+  "armored-secret.age" = {
+    publicKeys = [user1];
+    armor = true;
+  };
 }

pkgs/agenix.sh

@@ -118,6 +118,10 @@ function keys {
     (@nixInstantiate@ --json --eval --strict -E "(let rules = import $RULES; in rules.\"$1\".publicKeys)" | @jqBin@ -r .[]) || exit 1
 }
 
+function armor {
+    (@nixInstantiate@ --json --eval --strict -E "(let rules = import $RULES; in (builtins.hasAttr \"armor\" rules.\"$1\" && rules.\"$1\".armor))") || exit 1
+}
+
 function decrypt {
     FILE=$1
     KEYS=$2
@@ -148,6 +152,7 @@ function decrypt {
 function edit {
     FILE=$1
     KEYS=$(keys "$FILE") || exit 1
+    ARMOR=$(armor "$FILE") || exit 1
 
     CLEARTEXT_DIR=$(@mktempBin@ -d)
     CLEARTEXT_FILE="$CLEARTEXT_DIR/$(basename "$FILE")"
@@ -169,6 +174,9 @@ function edit {
     [ -f "$FILE" ] && [ "$EDITOR" != ":" ] && @diffBin@ -q "$CLEARTEXT_FILE.before" "$CLEARTEXT_FILE" && warn "$FILE wasn't changed, skipping re-encryption." && return
 
     ENCRYPT=()
+    if [[ "$ARMOR" == "true" ]]; then
+        ENCRYPT+=(--armor)
+    fi
     while IFS= read -r key
     do
         if [ -n "$key" ]; then

test/integration.nix

@@ -63,6 +63,9 @@ pkgs.nixosTest {
           file = ../example/secret2.age;
           path = "/home/user1/secret2";
         };
+        secrets.armored-secret = {
+          file = ../example/armored-secret.age;
+        };
       };
     };
   };
@@ -71,6 +74,7 @@ pkgs.nixosTest {
     user = "user1";
     password = "password1234";
     secret2 = "world!";
+    armored-secret = "Hello World!";
   in ''
     system1.wait_for_unit("multi-user.target")
     system1.wait_until_succeeds("pgrep -f 'agetty.*tty1'")
@@ -91,6 +95,9 @@ pkgs.nixosTest {
     system1.send_chars("cat /run/user/$(id -u)/agenix/secret2 > /tmp/2\n")
     system1.wait_for_file("/tmp/2")
     assert "${secret2}" in system1.succeed("cat /tmp/2")
+    system1.send_chars("cat /run/user/$(id -u)/agenix/armored-secret > /tmp/3\n")
+    system1.wait_for_file("/tmp/3")
+    assert "${armored-secret}" in system1.succeed("cat /tmp/3")
 
     userDo = lambda input : f"sudo -u user1 -- bash -c 'set -eou pipefail; cd /tmp/secrets; {input}'"