从钥匙串中检索 SecKey

我正在尝试升级我从中获得的代码这个答案用于生成 CSR，从 Swift 2 到 Swift 3。

我已升级大部分代码，但原始答案的实用程序块中的以下代码失败并出现错误：

“init”不可用：使用“withMemoryRebound(to:capacity:_)”暂时将内存视为另一种布局兼容类型。

错误发生在以下行：

let status: OSStatus = withUnsafeMutablePointer(to: &dataTypeRef) { SecItemCopyMatching(query as NSDictionary, UnsafeMutablePointer($0)) }

func loadKeySecKeyFromKeyChain(key: String) -> SecKey{
    let query: Dictionary<String, AnyObject> = [
        String(kSecAttrKeyType): kSecAttrKeyTypeRSA,
        String(kSecAttrKeySizeInBits): KEY_SIZE as AnyObject,
        String(kSecClass): kSecClassKey,
        String(kSecAttrApplicationTag): key as AnyObject,
        kSecReturnRef as String : kCFBooleanTrue ]

    var dataTypeRef: Unmanaged<AnyObject>? = nil
    var resultData: SecKey? = nil

    let status: OSStatus = withUnsafeMutablePointer(to: &dataTypeRef) { SecItemCopyMatching(query as NSDictionary, UnsafeMutablePointer($0)) }
    NSLog("SecItemCopyMatching: " + status.description)

    if status == errSecSuccess {
        NSLog("private or public debug description is: " + dataTypeRef.debugDescription)
        resultData = (dataTypeRef!.takeRetainedValue() as! SecKey)
        NSLog("SecItemCopyMatching returns SecKey: " + resultData.debugDescription)
        return resultData!
    } else {
        return resultData!
    }
}

我已经被这个问题困扰了一整天，有什么建议可以解决这个错误吗？

只需使用SecItemCopyMatching。我能够将其转换为 Swift 3 并成功生成 CSR。

// Finds the SecKeyRef corresponding to the parameter key and returns it
func loadKeySecKeyFromKeyChain(key: String) -> SecKey {
    let query: Dictionary<String, AnyObject> = [
        String(kSecAttrKeyType): kSecAttrKeyTypeRSA,
        String(kSecAttrKeySizeInBits): KEY_SIZE as AnyObject,
        String(kSecClass): kSecClassKey,
        String(kSecAttrApplicationTag): key as AnyObject,
        kSecReturnRef as String : kCFBooleanTrue ]

    var dataTypeRef: Unmanaged<AnyObject>? = nil
    var resultData: SecKey? = nil
    var result: AnyObject?
    let status = SecItemCopyMatching(query as CFDictionary, &result)

    if status == errSecSuccess {
        resultData = result as! SecKey
        return resultData!
    } else {
        return resultData!
    }
}