Implement client configuration delivery and reissue lifecycle

src/persistence.rs

@@ -515,6 +515,54 @@ impl SavedStore {
             self.vault_path(),
         ]
     }
+
+    /// Paths which client plaintext delivery must not replace. This is a
+    /// read-only view of the resolved installation mapping; source candidates
+    /// are protected individually so a safe, newly selected sibling output
+    /// remains available.
+    pub(crate) fn delivery_output_protection(
+        &self,
+    ) -> Result<crate::delivery::files::OutputProtection, crate::delivery::files::FileOutputError>
+    {
+        let mut protected_files = self.targets().into_iter().collect::<Vec<_>>();
+        let source_directory = &self.settings.client_source_directory;
+        match fs::symlink_metadata(source_directory) {
+            Ok(metadata) if metadata.file_type().is_dir() => {}
+            Ok(_) => return Err(crate::delivery::files::FileOutputError::UnsafePath),
+            Err(error) if error.kind() == io::ErrorKind::NotFound => {
+                return Ok(crate::delivery::files::OutputProtection::new(
+                    protected_files,
+                    vec![
+                        self.settings.data_directory.clone(),
+                        self.settings.archives_directory.clone(),
+                    ],
+                ));
+            }
+            Err(_) => return Err(crate::delivery::files::FileOutputError::UnsafePath),
+        }
+        match fs::read_dir(source_directory) {
+            Ok(entries) => {
+                let mut count = 0usize;
+                for entry in entries {
+                    let entry = entry.map_err(|_| crate::delivery::files::FileOutputError::Io)?;
+                    count += 1;
+                    if count > crate::vault::source::MAX_DIRECTORY_ENTRIES {
+                        return Err(crate::delivery::files::FileOutputError::UnsafePath);
+                    }
+                    protected_files.push(entry.path());
+                }
+            }
+            Err(error) if error.kind() == io::ErrorKind::NotFound => {}
+            Err(_) => return Err(crate::delivery::files::FileOutputError::UnsafePath),
+        }
+        Ok(crate::delivery::files::OutputProtection::new(
+            protected_files,
+            vec![
+                self.settings.data_directory.clone(),
+                self.settings.archives_directory.clone(),
+            ],
+        ))
+    }
 }
 
 #[derive(Deserialize, Serialize)]