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c++hashc++builderindysha

C++ Builder - Using TIdHashSHA256 with OpenSSL

As I understand Indy does not directly implement SHA256 and above and I must use OpenSSL.If I use the following I don't get any result:

#include <IdHashSHA.hpp>
...
TIdHashSHA256 *x = new TIdHashSHA256;
ShowMessage(BoolToStr(x->IsAvailable(), true));

i get false. I read somewhere I need to use IdSSLOpenSSLHeaders and load SSL library but I don't know how. Can anyone give an example how to use SHA256 in C++ Builder?

Solution

  • You need to call LoadOpenSSLLibrary() to initialize the OpenSSL functions that TIdHashSHA256 uses internally.

    Also, IsAvailable() is a class method (similar to a static method but with an extra metaclass parameter), so you do not need an object instance to call it:

    #include <IdSSLOpenSSLHeaders.hpp>
#include <IdHashSHA.hpp>
...
LoadOpenSSLLibrary(); // <-- add this

// if using CB2007 or earlier:
ShowMessage(BoolToStr(TIdHashSHA256::IsAvailable(__classid(TIdHashSHA256)), true)); 

// if using CB2009 or later:
ShowMessage(BoolToStr(TIdHashSHA256::IsAvailable(), true));