钥匙串SecItemUpdate返回errSecParam

Question

我可以将物品添加到钥匙串中，甚至可以读出它们。

但是，我正在努力使用SecItemUpdate更新值，并且似乎每次都返回errSecParam。

为此，我正在创建以下查询和属性（在这里很可能是个问题）

let query: [String: Any] = [kSecAttrAccount as String : "MyString",
    kSecValueData as String: "test2".data(using: .utf16)!,
    kSecMatchLimit as String  : kSecMatchLimitOne
]

let attributes: [String: Any] = [kSecAttrAccount as String: "aa",
                                         kSecValueData as String: data]

然后用于更新

SecItemUpdate(query as CFDictionary, attributes as CFDictionary)

Answer 1

应该在查询中指定类而不是数据（用于更新），例如，要在钥匙串中添加/更新密码，应如下所示

// adding item
let addQuery: [CFString: Any] = [
    kSecClass: kSecClassGenericPassword,
    kSecAttrService: service as CFString,        // eg. "www.mysite.com"
    kSecAttrAccount: name as CFString            // eg. "user"
    kSecValueData: password.data(using: .utf8)   // eg. "password"
] as CFDictionary

if errSecSuccess != SecItemAdd(addQuery, nil) { 
    // report error here
}

// updating item (same query is for SecItemDelete)

let updateQuery: [CFString: Any] = [
    kSecClass: kSecClassGenericPassword,
    kSecAttrService: service as CFString,        // eg. "www.mysite.com"
    kSecAttrAccount: name as CFString            // eg. "user"
] as CFDictionary

let newAttributes = [
    kSecAttrAccount: newName as CFString            // eg. "user1"
    kSecValueData: newPassword.data(using: .utf8)   // eg. "password1"
] as CFDictionary

if errSecSuccess != SecItemUpdate(updateQuery, newAttributes) {
   // report error here
}