To call the CryptoSys API functions
from a classic Visual Basic project or VBA application,
just add the module basCryptoSys.bas to your project
(VBA users should delete the first line Attribute VB_Name = "basCryptoSys").
The VB6/VBA functions work in the same way as you would call the Win32 API functions from VB6. You must use the correct variable types and must pre-dimension strings and byte arrays that are to receive output or you will suffer the wrath of the great god Gee-pee-eff.
For examples, see the test code provided in the distribution.
The module basCryptoSys.bas and distribution test code will be found in the VB6 sub-directory of the installation folder, typically
C:\Program Files (x86)\CryptoSys\VB6 (or C:\Program Files\CryptoSys\VB6 on a 32-bit machine).
To find the installation folder, use Start > All Programs > CryptoSysAPI > CryptoSys API Example Files.