unique_ptr 和 OpenSSL 的 STACK_OF(X509)*

2022-01-07 00:00:00 openssl c++ c++11 unique-ptr smart-pointers

我使用一些 using 语句和 unique_ptr 来处理 OpenSSL，如 在另一个问题中建议.否则，代码会变得非常丑陋，而且我不太喜欢 goto 语句.

I use some using statements and unique_ptr to work with OpenSSL, as suggested in another question. Without, code becomes really ugly and I am not so much a fan of goto statements.

到目前为止，我已经尽可能地更改了我的代码.以下是我使用的示例:

So far I have changed my code as far as possible. Here are examples, what I use:

using BIO_ptr = std::unique_ptr<BIO, decltype(&::BIO_free)>;
using X509_ptr = std::unique_ptr<X509, decltype(&::X509_free)>;
using EVP_PKEY_ptr = std::unique_ptr<EVP_PKEY, decltype(&::EVP_PKEY_free)>;
using PKCS7_ptr = std::unique_ptr<PKCS7, decltype(&::PKCS7_free)>;
...

BIO_ptr tbio(BIO_new_file(some_filename, "r"), ::BIO_free);

现在我需要 STACK_OF(X509)，但我不知道，unique_ptr 是否也可以.我正在寻找类似于下面的内容，但这不起作用.

Now I have the need of a STACK_OF(X509) and I do not know, if this is also possible with unique_ptr. I am looking for something similar to below, but this is not working.

using STACK_OF_X509_ptr = std::unique_ptr<STACK_OF(X509), decltype(&::sk_X509_free)>;

我也尝试过 Functor:

I also tried the Functor:

struct StackX509Deleter {
    void operator()(STACK_OF(X509) *ptr) {
        sk_X509_free(ptr);
    }
};

using STACK_OF_X509_ptr = std::unique_ptr<STACK_OF(X509), StackX509Deleter>;

STACK_OF_X509_ptr chain(loadIntermediate(cert.string()));

编译器接受这个并且应用程序运行.只是一个问题:在上面显示的其他 unique_ptrs 中，我总是指定了第二个参数，所以我打赌我遗漏了一些东西:

The compiler accepts this and the application runs. Just one question: In other unique_ptrs as shown above, I always had specified a second argument, so I bet I am missing something:

STACK_OF_X509_ptr chain(loadIntermediate(cert.string()),  ??????);

我如何使用 C++ unique_ptr 和 OpenSSL 的 STACK_OF(X509)*?

How do I use C++ unique_ptr and OpenSSL's STACK_OF(X509)*?

推荐答案

我定义了一个正则函数:

I defined a regular function:

void stackOfX509Deleter(STACK_OF(X509) *ptr) {
    sk_X509_free(ptr);
}

然后我在我的代码中使用它:

Then I use it in my code:

using STACK_OF_X509_ptr = std::unique_ptr<STACK_OF(X509),
    decltype(&stackOfX509Deleter)>;

STACK_OF_X509_ptr chain(loadIntermediate(cert.string()),
                    stackOfX509Deleter);

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