Stuart McLachlan
stuart at lexacorp.com.pg
Sun Mar 7 16:23:39 CST 2010
If you are going to the extent of a separate file, I'd just create a DLL in PowerBasic containing the crypto functions and call it when required. Much more secure, smaller, faster and doesn't need referencing. :-) -- Stuart On 7 Mar 2010 at 21:50, Max Wanadoo wrote: > What I would do is create the encrypt/decrypt code in a separate mdb, make > it an mde and encrypt that itself. > Rename it to something like, Mylibrary.lib > > The in the main mdb, go to references and set a reference to it. The code > gets called to do its work but the user never gets to see the "inner > workings". > > Max > > > -----Original Message----- > From: accessd-bounces at databaseadvisors.com > [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Stuart McLachlan > Sent: Sunday, March 07, 2010 9:19 PM > To: Access Developers discussion and problem solving > Subject: Re: [AccessD] How to set up a license key for an AccessFE/BE > system? > > But you can't "hide" the decryption/validation code in an MDB. There's no > need to hide dates/licence details at all if they are encypted. It's the > code that has to be hidden. > > -- > Stuart > > On 7 Mar 2010 at 20:06, Max Wanadoo wrote: > > > Umm, not so. > > > > You can hide as much stuff as you want by creating user properties in > > the BE mdb. Put your license details there plus all the expirary > > dates encoded, etc. > > > > All lateral stuff > > > > Max > > > > > > -----Original Message----- > > From: accessd-bounces at databaseadvisors.com > > [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Rocky > > Smolin > > Sent: Sunday, March 07, 2010 7:31 PM > > To: 'Access Developers discussion and problem solving' > > Subject: Re: [AccessD] How to set up a license key for an AccessFE/BE > > system? > > > > Well, you've got to hide it somehow, and there's no hiding in an mdb. > > Use vb and make a dll? Assuming that mde is not an option. > > > > R > > > > -----Original Message----- > > From: accessd-bounces at databaseadvisors.com > > [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Dan Waters > > Sent: Sunday, March 07, 2010 11:17 AM > > To: 'Access Developers discussion and problem solving' > > Subject: Re: [AccessD] How to set up a license key for an AccessFE/BE > > system? > > > > This sounds like you have the key creator routine and key reader > > routine written in VBA. But I think that your system is an mde? Is this > correct? > > > > Mine is an mdb, so for me that method would be easily readable. > > > > Thanks! > > Dan > > > > -----Original Message----- > > From: accessd-bounces at databaseadvisors.com > > [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Rocky > > Smolin > > Sent: Sunday, March 07, 2010 12:09 PM > > To: 'Access Developers discussion and problem solving' > > Subject: Re: [AccessD] How to set up a license key for an Access FE/BE > > system? > > > > Dan: > > > > I did this for my manufacturing system. I have several pieces of > > information stored in it and it's fifteen characters. I group them > > three at a time for the user to input into the program to renew the > > license, so it looks kind of like a Microsoft registration key. > > > > What I did for the expiration date was fairly simple - OK real simple > > - I took the month of expiration and converted it to a letter, took > > the day of expiration and converted it to two letters because it could > > go up to 31, and converted the year of expiration to a letter as well, > > selecting a base year far enough back so that the expiration year > > would not always be A or B but would start further down the alphabet. > > And added constants to a couple of these number to make decryption even > harder - but that is probably overkill. > > > > I then scattered these three values in the key. I have a routine in > > the key maker that creates a key, and a routine in the product which > > decodes the key. > > > > Simple but effective enough for my purposes. There are several 'garbage' > > characters in the key and those are generated randomly. So comparing > > keys over a period of years (assuming anyone had that interest) would > > be difficult. > > > > Finally, one of the characters is a checksum. > > > > > > HTH > > > > Rocky > > > > P.S. Often wondered what scheme Microsoft was using and what > > information they had encrypted in their key. > > > > -----Original Message----- > > From: accessd-bounces at databaseadvisors.com > > [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Dan Waters > > Sent: Sunday, March 07, 2010 9:09 AM > > To: 'Access Developers discussion and problem solving' > > Subject: [AccessD] How to set up a license key for an Access FE/BE system? > > > > I'd like to learn how to set up an encrypted license key mechanism for > > a customer using a split configuration system. The key would allow > > the system to work until a specified date. > > > > What could I look at to learn how to do this? > > > > Thanks! > > Dan > > > > > > -- > > AccessD mailing list > > AccessD at databaseadvisors.com > > http://databaseadvisors.com/mailman/listinfo/accessd > > Website: http://www.databaseadvisors.com > > > > -- > > AccessD mailing list > > AccessD at databaseadvisors.com > > http://databaseadvisors.com/mailman/listinfo/accessd > > Website: http://www.databaseadvisors.com > > > > -- > > AccessD mailing list > > AccessD at databaseadvisors.com > > http://databaseadvisors.com/mailman/listinfo/accessd > > Website: http://www.databaseadvisors.com > > > > -- > > AccessD mailing list > > AccessD at databaseadvisors.com > > http://databaseadvisors.com/mailman/listinfo/accessd > > Website: http://www.databaseadvisors.com > > > > -- > > AccessD mailing list > > AccessD at databaseadvisors.com > > http://databaseadvisors.com/mailman/listinfo/accessd > > Website: http://www.databaseadvisors.com > > > -- > AccessD mailing list > AccessD at databaseadvisors.com > http://databaseadvisors.com/mailman/listinfo/accessd > Website: http://www.databaseadvisors.com > > -- > AccessD mailing list > AccessD at databaseadvisors.com > http://databaseadvisors.com/mailman/listinfo/accessd > Website: http://www.databaseadvisors.com