我如何存储加密数据

时间:2020-05-19 14:32:38

标签: ios swift apple-cryptokit

我正在尝试在UserDefaults中存储和检索我的加密文本数据,但是检索时出现问题。我使用CryptoKit加密和解密数据。

错误消息是:“无法将类型'Foundation .__ NSSwiftData'(0x7fff89d1ee50)的值强制转换为'CryptoKit.ChaChaPoly.SealedBox'(0x7fff8085abc8)。”

是否有更好的方法将SymmetricKey存储在钥匙串中,而不用UnsafeBytes将其转换为String?我使用SwiftKeychainWrapper。

func encrypt(text: String) {
    let key = SymmetricKey(size: .bits256)
    let message = text.data(using: .utf8)!
    let sealedBox = try! ChaChaPoly.seal(message, using: key)

    let defaults = UserDefaults.standard
    defaults.set(sealedBox.combined, forKey: "sealedBox")

    let savedKey = key.withUnsafeBytes {Data(Array($0)).base64EncodedString()}
    Services.saveKey(key: savedKey)
}

func decrypt() {
    let savedKey = Services.getKey()

    if let keyData = Data(base64Encoded: savedKey) {
        let retrievedKey = SymmetricKey(data: keyData)

        let defaults = UserDefaults.standard
        let sealedBox = (defaults.object(forKey: "sealedBox") as? ChaChaPoly.SealedBox)!

        let decryptedMessage = try! ChaChaPoly.open(sealedBox, using: retrievedKey)
        textView.text = String(data: decryptedMessage, encoding: .utf8)!
    }
}

1 个答案:

答案 0 :(得分:1)

您将Data存储在UserDefaults中,因此必须再次提取该内容。然后从中创建一个SealedBox,如下所示:

let defaults = UserDefaults.standard
let data = defaults.object(forKey: "sealedBox") as? Data

let sealedBox = try! ChaChaPoly.SealedBox(combined: data!)
let decryptedMessage = try! ChaChaPoly.open(sealedBox, using: retrievedKey)

(当然,您要避免在实际的生产代码中用力解包)