How do i create/use an IBuffer?

Question

I want to use functions of the Winapi.Security.Cryptography.Core_IAsymmetricKeyAlgorithmProvider and it has a parameter of type IBuffer . i dont know how to use an IBuffer or how to give data to it.

i tried allocationg memory and giving the function a pwide char but the ide already told me this wont work. I also didnt find anything useful online.

Answer 1

Winapi.Security.Cryptography contains wrappers for Windows.Security.Cryptography.Core (Windows UWP)

Check this page first: https://learn.microsoft.com/en-us/uwp/api/windows.security.cryptography.core.asymmetrickeyalgorithmprovider?view=winrt-22621

There is a C# app example that demonstrates how to use this interface. Details about IBuffer can be found on this page:

https://learn.microsoft.com/en-us/uwp/api/windows.storage.streams.ibuffer?view=winrt-22621

This is probably your first step, if you want encrypt with RSA PKCS1:

uses
  System.Win.WinRT,
  Winapi.WinRT,      
  Winapi.Security.Cryptography,
  Winapi.Storage.Streams;
const
  KeyLength = 512;
var 
  objAlgProv: Core_IAsymmetricKeyAlgorithmProvider;
  data: TBytes;
  cleardata, encrypted: IBuffer;
  key: Core_ICryptographicKey;
  hs: HSTRING;
  EncryptedBase64: string;
begin
  data := TEncoding.UTF8.GetBytes('clear text');
  objAlgProv := TCore_AsymmetricKeyAlgorithmProvider.OpenAlgorithm(TCore_AsymmetricAlgorithmNames.RsaPkcs1);
  key := objAlgProv.CreateKeyPair(KeyLength);
  cleardata := TCryptographicBuffer.CreateFromByteArray(length(data), @data[0]);
  encrypted := TCore_CryptographicEngine.Encrypt(key, cleardata, nil {IV});
  hs := TCryptographicBuffer.EncodeToBase64String(encrypted); 
  EncryptedBase64 := TWindowsString.HStringToString(hs);
end;

If you have further trouble translating the solution into Delphi, show your code an explain the details what you need to know.