Question on Encryption and decryption in AES-GCM mode

Question

I follow the code in the link below to learn the encryption API.
https://learn.microsoft.com/en-us/windows/win32/seccng/encrypting-data-with-cng

And I found four questions that confused me.

Q1: If I execute the link code in application A three times, each time I save the key generated by BcryptExportkey as a static variable, I can decrypt the newly encrypted data with any of the three keys, is that right?

Q2: If I execute the link code in application A and B respectively, and pass the key generated by A to B, B can also use the key to decrypt, is that right?

Q3: Will the key generated by BcryptExportkey API be different in different Windows' versions?

Q4: The key generated by BcryptExportkey are the same, so what parameters do AES-GCM mode use to complete the decryption?

Sorry, I'm still a rookie. so many questions here. I hope you can guide me.

Answer 1

Q4: The algorithm described by AES is a symmetric-key algorithm, meaning the same key is used for both encrypting and decrypting the data.
CipherText + Key ==> PlainText.
PlainText + Key ==> CipherText.
Searching for more details about AES Algorithm.

Q1 Yes
Q2 Yes
The Sample uses same key and same algorithm(AES) to export. So the exported key can be used exchanged.
Q3: According to BCryptGenerateSymmetricKey function, The BCryptGenerateSymmetricKey function creates a key object for use with a symmetrical key encryption algorithm from a supplied key. There is no other information involved.