docs: WIP Mac codesigning docs

Author: mistydemeo

book/src/SUMMARY.md

@@ -11,6 +11,7 @@
 - [Custom Builds](./custom-builds.md)
 - [Supplychain Security](./supplychain-security/index.md)
   - [Windows Signing](./supplychain-security/signing/windows.md)
+  - [macOS Signing](./supplychain-security/signing/macos.md)
   - [GitHub Attestations](./supplychain-security/attestations/github.md)
 - [Installers](./installers/index.md)
   - [shell](./installers/shell.md)

book/src/reference/config.md

@@ -25,6 +25,7 @@ We're currently in the middle of [a major config migration](https://github.com/a
 * [`extra-artifacts`](#extra-artifacts)
 * [`source-tarball`](#source-tarball)
 * [`ssldotcom-windows-sign`](#ssldotcom-windows-sign)
+* [`macos-sign`](#macos-sign)
 * [archive settings](#artifact-settings)
     * [`auto-includes`](#auto-includes)
     * [`include`](#include)

book/src/supplychain-security/index.md

@@ -9,7 +9,7 @@ If you have an integration you are looking for [file an issue](https://github.co
 ## Signing
 
 * [Windows Codesigning](./signing/windows.md)
-* [🔜 macOS Codesigning](https://github.com/axodotdev/cargo-dist/issues/1121)
+* [macOS Codesigning](./signing/macos.md)
 * [🔜 Linux Codesigning](https://github.com/axodotdev/cargo-dist/issues/120)
 * [🔜 Sigstore Signing](https://github.com/axodotdev/cargo-dist/issues/120)
 * [🔜 Windows Trusted Signing](https://github.com/axodotdev/cargo-dist/issues/1122)

book/src/supplychain-security/signing/macos.md

@@ -0,0 +1,50 @@
+# MacOS Artifact Signing
+
+> since 0.22.0
+
+cargo-dist can automatically codesign Mac executables using Apple's builtin tooling.
+
+## Quickstart
+
+### Part 1: Provision a certificate and set up your repository with it
+
+<!-- TODO: Document the process of obtaining and exporting the signature. -->
+
+3. **Export the certificate to disk**
+
+    Locate your certificate within Keychain, then right-click and select "Export". Ensure that you've selected the "Personal Information Exchange (.p12)" format at the bottom of the export window. Once you've selected a filename, Keychain will prompt you for a password to protect the exported item. Select a secure password, *and ensure remember it* - you'll need this for the next step.
+
+4. **Encode the certificate via base64**
+
+    In order to add the certificate to your GitHub secrets in a future step, we'll need to convert it to a text-based format. To do that, we'll use base64. In your terminal, run the following:
+
+    ```sh
+    base64 < PATH_TO_YOUR_CERT
+    ```
+
+    (Instead of typing the path to your certificate, you can also drag and drop it onto your terminal after typing `base64 <`.)
+
+    Copy *the full text* that was generated; you'll need it in the next step.
+
+5. **Add [GitHub Secrets](https://docs.github.com/en/actions/security-guides/encrypted-secrets) to your repository**
+
+    You'll need the following three secrets:
+
+    - `CODESIGN_IDENTITY`: the identity in the certificate
+    - `CODESIGN_CERTIFICATE_PASSWORD`: this is the base64-encoded certificate from Step 4
+    - `CODESIGN_CERTIFICATE_PASSWORD`: this is the password from Step 3
+
+### Part 2: Enable macOS signing with cargo-dist
+
+1. **Configure cargo-dist to codesign**
+
+    Add the following to your `Cargo.toml` or `dist.toml`:
+
+    ```toml
+    [workspace.metadata.dist]
+    macos-sign = true
+    ```
+
+2. **Run `cargo dist init` on your project**
+
+    You've already fully configured the feature, we're just ensuring your config changes are applied and checked.