From 3e2ad444bdcf16466352818997205efca0dd69e7 Mon Sep 17 00:00:00 2001
From: Markus Thielker <mail.markus.thielker@gmail.com>
Date: Thu, 16 Jan 2025 00:20:36 +0100
Subject: [PATCH] Add password repository to interact with keychain

---
 .../data/repository/PasswordRepository.swift  | 121 ++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 password/data/repository/PasswordRepository.swift

diff --git a/password/data/repository/PasswordRepository.swift b/password/data/repository/PasswordRepository.swift
new file mode 100644
index 0000000..4af2e63
--- /dev/null
+++ b/password/data/repository/PasswordRepository.swift
@@ -0,0 +1,121 @@
+//
+//  PasswordRepository.swift
+//  password
+//
+//  Created by Markus Thielker on 16.01.25.
+//
+
+import Foundation
+import Security
+
+enum KeychainError: Error {
+    case unknown
+    case duplicateItem
+    case itemNotFound
+    case unexpectedPasswordData
+}
+
+protocol PasswordRepository {
+    func getAllPasswords() -> [Password]
+    func getPassword(withID id: UUID) -> Password?
+    func savePassword(_ password: Password) throws
+    func deletePassword(withID id: UUID) throws
+}
+
+class KeychainPasswordRepository: PasswordRepository {
+    
+    private let serviceName = "dev.thielker.password"
+
+    func getAllPasswords() -> [Password] {
+        
+        // TODO: fix query to work with 'kSecMatchLimit as String: kSecMatchLimitAll'
+        let query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrService as String: serviceName,
+            kSecMatchLimit as String: 100,
+            kSecReturnAttributes as String: true,
+            kSecReturnData as String: true,
+        ]
+
+        var result: AnyObject?
+        let status = SecItemCopyMatching(query as CFDictionary, &result)
+
+        if status != errSecSuccess {
+            print("Error retrieving passwords: \(SecCopyErrorMessageString(status, nil) ?? "Unknown error" as CFString)")
+            return []
+        }
+
+        guard let items = result as? [[String: Any]] else {
+            print("No passwords found.")
+            return []
+        }
+        
+        var passwords: [Password] = []
+        for item in items {
+            if let data = item[kSecValueData as String] as? Data,
+               let password = try? JSONDecoder().decode(Password.self, from: data) {
+                passwords.append(password)
+            }
+        }
+        return passwords
+    }
+    
+    func getPassword(withID id: UUID) -> Password? {
+        
+        let query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrService as String: serviceName,
+            kSecAttrAccount as String: id.uuidString,
+            kSecReturnData as String: true
+        ]
+
+        var result: AnyObject?
+        SecItemCopyMatching(query as CFDictionary, &result)
+
+        guard let data = result as? Data,
+              let password = try? JSONDecoder().decode(Password.self, from: data) else {
+            return nil
+        }
+        
+        return password
+    }
+    
+    func savePassword(_ password: Password) throws {
+
+        let query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword, // Generic password item
+            kSecAttrService as String: serviceName, // Service name for your app
+            kSecAttrAccount as String: password.id.uuidString, // Unique identifier
+            kSecValueData as String: try JSONEncoder().encode(password) // Encode password data
+        ]
+
+        let status = SecItemAdd(query as CFDictionary, nil)
+
+        guard status == errSecSuccess else {
+            if status == errSecDuplicateItem {
+                throw KeychainError.duplicateItem
+            } else {
+                throw KeychainError.unknown
+            }
+        }
+    }
+    
+    func deletePassword(withID id: UUID) throws {
+        
+        let query: [String: Any] = [
+            kSecClass as String: kSecClassGenericPassword,
+            kSecAttrService as String: serviceName,
+            kSecAttrAccount as String: id.uuidString
+        ]
+
+        let status = SecItemDelete(query as CFDictionary)
+
+        guard status == errSecSuccess else {
+            if status == errSecItemNotFound {
+                throw KeychainError.itemNotFound
+            } else {
+                throw KeychainError.unknown
+            }
+        }
+    }
+}