使用RSA私钥错误OSStatus -50 Swift解密

Question

我使用模数和分量生成私钥，但是当我将其转换为SecKey类型时，会得到nil值。

这是我的代码：

 let pubKey = instanceOfCustomObject.generateRSAPrivateKey(withModulus: modData! as Data, exponent: expData! as Data)
print(pubKey! as NSData)

let keyDict:[NSObject:NSObject] = [
    kSecAttrKeyType: kSecAttrKeyTypeRSA,
    kSecAttrKeyClass: kSecAttrKeyClassPrivate,
    kSecAttrKeySizeInBits: NSNumber(value: 128),
    kSecReturnPersistentRef: true as NSObject
]


let privateSecKey = SecKeyCreateWithData(pubKey! as Data as CFData, keyDict as CFDictionary, nil)


let blockSize = SecKeyGetBlockSize(pubSecKey!)
var encrypted = [UInt8](repeating: 0, count: blockSize)
var encSize = blockSize

let status = SecKeyDecrypt(privateSecKey!,
                           SecPadding.PKCS1, textToEncrypt,
                          textToEncrypt.count, &encrypted,
                           &encSize)

当我将kSecAttrKeyClassPrivate设置为kSecAttrKeyClassPublic并使用函数SecKeyDecrypt时，状态值为-50。