Apple SSL安全传输

Question

I have just started to work with os x and have no experience with it at all. But all I want to do now is to replace old OpenSSL code with Apple Security API. I'm using Secure Transport and I'm a bit confused about with these functions: SSLSetIOFuncs , SSLWrite , and SSLRead .

So SSLSetIOFuncs sets callbacks that perform writing/reading operations (which I should implement). And a lot of questions appear at this point:

1. First, I just don't understand why I should implement it (in OpenSSL it is implemented already). But ok, I just have to.
2. Should this implementation be encrypted? I guess no.

Also there are following 2 functions:

OSStatus
SSLWrite                    (SSLContextRef      context,
                             const void *       __nullable data,
                             size_t             dataLength,
                             size_t             *processed);

OSStatus
SSLRead                    (SSLContextRef       context,
                            void *              data,           
                            size_t              dataLength,
                            size_t          *processed);

And they are "Normal application-level read/write." according to code comments. So why do I need to define those 2 callbacks for reading and writing then? And if first twos are callbacks which functions I should call for reading/writing in my code (when I really need to read some data from server)?

There are no good documentation and I got stuck with it all. May be I'm just way too dump but little help would be just perfect anyway. Please help!

Answer 1

SecureTransport is callback-based, unlike OpenSSL's SSL_read() and SSL_write() functions. This could require big changes to your code. If you want a read / write -style API that can use SecureTransport for encryption, look at CFNetwork and specifically CFStream