On 29 August 2010 18:24, tedd <t...@sperling.com> wrote: > Hi gangl: > > I realize that the problem stated herein has been solved by others, so I'm > not claiming I've done anything new -- it's only new to me. It was a > learning experience for *me* and my solution may help others. > > In any event, I've finished creating a method for establishing what I think > is secure communication between two servers. I've written two scripts that > run on different servers, which confirm communication between them via > hard-wired urls and creating/writing/reading a url-confirmation file. > > The purpose of this exercise was to simply to keep database-access data > (i.e., user_name, password, key to decryption) secret. However, the secret > could be anything you want to keep secret -- secret being defined as no data > residing on the server of concern while allowing that server access to the > data when needed and under authorization. > > Here's what I've done -- I have two domains, namely webbytedd.com (the > Master) and php1.net (the Slave) -- both domains reside on different > servers. The domain names really don't matter, it's just that this method > currently works between those two domains. > > Statement of Requirements: > > 1. The Master requires "access" to it's database. > > 2. The Slave keeps "access" to Master's database in it's own database. > > 3. It's required that "access" remain secret in the event that the Master is > hacked. > > *The term "access" above is defined as database-access data, such as > user_name, password, and key to decryption. > > Description of Method: > > 1. When the Master wants access to it's database, it first creates a > url-confirmation file and writes a token to that file, which resides on the > Master. I've used time() as the token, but the token could be any variable > -- it really doesn't make much difference other than the value should be > different each time. > > 2. The Master then sends a cURL request to the Slave via a POST where the > POST variable contains the token. > > 3. The Slave when receiving the POST request from Master reads the token > from the newly created url-confirmation file residing on the Master and then > compares that token with the token provided by the POST -- if the tokens > match, then the Slave returns "the access" to the Master. If not, the > process fails. > > 4. After receiving "access" the Master deletes the url-confirmation file and > continues with it operation. If the Master does not receive "access" then it > deletes the url-confirmation file and exits. > > This method sounds simple enough and does several things. > > 1. There is no "access" stored on the Master. > > 2. While the Slave has "access" for the Master stored in its database, the > access to the Slave's database is kept in an out-of-root (not open to the > web) file. Note, in this case, this was not possible on the Master because > the host did not allow out-of-root files -- but that is only tangential to > the problem addressed here. > > 3. If a hacker did obtain access to the Slave database, then the hacker > would discover the contents have been encrypted and only the Master has the > decryption key kept in it's database. > > 4. If a hacker did obtain access to the code residing on the Master, then > the hacker could not access the Master's database because the "access" data > is recorded on another server (i.e., Slave). Furthermore, the hacker could > not get the code to run anywhere else because the Slave's "look-up URL" for > the url-confirmation file is hardwired to the Master address. > > 5. And lastly, all communication between both domains is done via https. > > Now, for the exception of both server's being hacked at the same time, what > could go wrong?
A) I wouldn't want to reinvent the wheel but would use SSL/certificates/something to that effect (it's a whole lot more secure than your setup), and B) there's nothing in this setup that secures you from someone hacking Master and just sucking out data from that machine. Regards Peter -- <hype> WWW: http://plphp.dk / http://plind.dk LinkedIn: http://www.linkedin.com/in/plind BeWelcome/Couchsurfing: Fake51 Twitter: http://twitter.com/kafe15 </hype> -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
