Encryption/Decription using the windows CryptoAPI

This class provides encryption/decryption through the CryptoAPI. This is the standard API you can use regardless of the underlying dll used to do the encryption. These dlls are called Cryptographic Service Providers (CSPs) and you get one as standard from Microsoft called "Microsoft Base Cryptographic Provider v1.0" This class uses the standard CSP, but this can be changed by changing the constant SERVICE_PROVIDER There is additional code in this class to ensure that the encrypted values do not contain CR or LF characters so that the result can be written to a file A word of warning: If you are going to use WritePrivateProfileString to write the encrypted value to an ini file, you must write a NULL first to delete the existing entry as it does not clear previous entries when writing binary data. This is a problem if you are overwriting a value with a smaller one.