Initial release

Sources/Knotchy/Keychain.swift

@@ -0,0 +1,38 @@
+import Foundation
+import Security
+
+enum Keychain {
+    private static let service = "aculix.knotchy.app"
+
+    static func read(_ account: String) -> String? {
+        let query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrService as String: service,
+            kSecAttrAccount as String: account,
+            kSecReturnData as String: true,
+            kSecMatchLimit as String: kSecMatchLimitOne,
+        ]
+        var result: AnyObject?
+        guard SecItemCopyMatching(query as CFDictionary, &result) == errSecSuccess, let data = result as? Data else { return nil }
+        return String(data: data, encoding: .utf8)
+    }
+
+    static func write(_ value: String, for account: String) {
+        let query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrService as String: service,
+            kSecAttrAccount as String: account,
+        ]
+        guard !value.isEmpty else {
+            SecItemDelete(query as CFDictionary)
+            return
+        }
+        let data = Data(value.utf8)
+        if SecItemUpdate(query as CFDictionary, [kSecValueData as String: data] as CFDictionary) == errSecItemNotFound {
+            var item = query
+            item[kSecValueData as String] = data
+            item[kSecAttrAccessible as String] = kSecAttrAccessibleWhenUnlocked
+            SecItemAdd(item as CFDictionary, nil)
+        }
+    }
+}