$CALG_USERKEY what exactly is this for?

[Morthawt]

When you are encrypting data, I am used to setting the algorithm. But I saw $CALG_USERKEY in the documentation but I have no context as to what algorithm that is. The documentation says it is value 0.

I would appreciate a heads up on what $CALG_USERKEY is for?

Thanks.

[TheXman]

If you look at the help file for both the _Crypt_EncryptData and _CryptEncryptFile functions, then you will see that it says that the $vCryptKey parameter can be either a password or a handle.  If you are using a handle, then you must use $CALG_USERKEY for the $iAlgID parameter for the _Crypt_EncryptData and _CryptEncryptFile functions.  The _Crypt_DeriveKey function lets you create a key using the specified encryption method (and hashing method if supplied).  The return value from the _Crypt_DeriveKey function is the handle that you would supply to the _Crypt_EncryptData and _CryptEncryptFile functions.

_Crypt_EncryptData
_Crypt_EncryptFile
_Crypt_DeriveKey

 

Edited April 23, 2018 by TheXman
Added references to the commands which can be clicked to go to the help file.