Allow using a separate key file when setting up 'Sign in with Apple'

crates/cli/src/sync.rs

@@ -189,10 +189,18 @@ pub async fn config_sync(
             let encrypted_client_secret =
                 if let Some(client_secret) = provider.client_secret.as_deref() {
                     Some(encrypter.encrypt_to_string(client_secret.as_bytes())?)
-                } else if let Some(siwa) = provider.sign_in_with_apple.as_ref() {
-                    // For SIWA, we JSON-encode the config and encrypt it, reusing the client_secret
-                    // field in the database
-                    let encoded = serde_json::to_vec(siwa)?;
+                } else if let Some(mut siwa) = provider.sign_in_with_apple.clone() {
+                    // if private key file is defined and not private key (raw), we populate the
+                    // private key to hold the content of the private key file.
+                    // private key (raw) takes precedence so both can be defined
+                    // without issues
+                    if siwa.private_key.is_none() {
+                        if let Some(private_key_file) = siwa.private_key_file.take() {
+                            let key = tokio::fs::read_to_string(private_key_file).await?;
+                            siwa.private_key = Some(key);
+                        }
+                    }
+                    let encoded = serde_json::to_vec(&siwa)?;
                     Some(encrypter.encrypt_to_string(&encoded)?)
                 } else {
                     None

crates/config/src/sections/upstream_oauth2.rs

@@ -6,6 +6,7 @@
 
 use std::collections::BTreeMap;
 
+use camino::Utf8PathBuf;
 use mas_iana::jose::JsonWebSignatureAlg;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize, de::Error};
@@ -383,8 +384,14 @@ fn signed_response_alg_default() -> JsonWebSignatureAlg {
 
 #[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
 pub struct SignInWithApple {
+    /// The private key file used to sign the `id_token`
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[schemars(with = "Option<String>")]
+    pub private_key_file: Option<Utf8PathBuf>,
+
     /// The private key used to sign the `id_token`
-    pub private_key: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub private_key: Option<String>,
 
     /// The Team ID of the Apple Developer Portal
     pub team_id: String,

docs/config.schema.json

@@ -2158,10 +2158,13 @@
       "type": "object",
       "required": [
         "key_id",
-        "private_key",
         "team_id"
       ],
       "properties": {
+        "private_key_file": {
+          "description": "The private key file used to sign the `id_token`",
+          "type": "string"
+        },
         "private_key": {
           "description": "The private key used to sign the `id_token`",
           "type": "string"

docs/setup/sso.md

@@ -84,18 +84,23 @@ Sign-in with Apple uses special non-standard for authenticating clients, which r
 ```yaml
 upstream_oauth2:
   providers:
-    - client_id: 01JAYS74TCG3BTWKADN5Q4518C
-      client_name: "<Service ID>" # TO BE FILLED
+    - id: 01JAYS74TCG3BTWKADN5Q4518C
+      issuer: "https://appleid.apple.com"
+      human_name: "Apple"
+      brand_name: "apple"
+      client_id: "<Service ID>" # TO BE FILLED
       scope: "openid name email"
       response_mode: "form_post"
-
       token_endpoint_auth_method: "sign_in_with_apple"
       sign_in_with_apple:
-        private_key: |
-          # Content of the PEM-encoded private key file, TO BE FILLED
+
+        # Only one of the below should be filled for the private key
+        private_key_file: "<Location of the PEM-encoded private key file>" # TO BE FILLED
+        private_key: | # TO BE FILLED
+          # <Contents of the private key>
+
         team_id: "<Team ID>" # TO BE FILLED
         key_id: "<Key ID>" # TO BE FILLED
-
       claims_imports:
         localpart:
           action: ignore
@@ -549,4 +554,4 @@ To use a Rauthy-supported [Ephemeral Client](https://sebadob.github.io/rauthy/wo
   "access_token_signed_response_alg": "RS256",
   "id_token_signed_response_alg": "RS256"
 }
-```
+```