Lutz Jaenicke wrote: > On Tue, Aug 13, 2002 at 07:45:30PM +0200, Bodo Moeller wrote: > >>On Tue, Aug 13, 2002 at 05:10:34PM +0100, Ben Laurie wrote: >> >>>Yes, and the application will continue as if it were sensible to do so. >> >>In fact it *is* often sensible to do so because such supposedly >>"impossible events" are triggered by certain conditions (such as >>unusual parameters in a certain protocol version) that will not apply >>to all connections. In such cases we cannot continue the one >>connection where a potential buffer overflow was detected, but there's >>no reason to completely kill the application. The internal error >>terminates the single connection for which OpenSSL does not know how >>to continue. There is no reason why this should affect the rest of >>the program. > > > I think we should define our terms clearly. > > For me an "internal error" is an error that must not occur at all and > that can only have appeared due to the library having failed somehow > such that an inconistent state occurs (in M$-notation: "an unexpected > error occured" :-). I consider an error like this to be fatal and think > that it is still sensible to abort(). > By definition we have no explanation on how this could happen and so > we don't know how to continue. > Example: when working through the internal session cache we learn, that > the linked list is corrupted, we have dangling pointers and don't know > what is going on. This would touch all threads using the same SSL_CTX. > Thus: we don't know how to repair it -> abort(). > > If we have protocol errors to catch or errors in using the API (a function, > even an internal one was called with incorrect parameters, maybe a string > is too long), we can oversee the error and its impact, prevent the impact > and return with a corresponding failure message. We do this for a large part > of the public API, so we can also build in additional safety nets that > generate error messages and consequently result in a "normal" handshake > failure.
Precisely. Cheers, Ben. -- http://www.apache-ssl.org/ben.html http://www.thebunker.net/ Available for contract work. "There is no limit to what a man can do or how far he can go if he doesn't mind who gets the credit." - Robert Woodruff ______________________________________________________________________ OpenSSL Project http://www.openssl.org Development Mailing List [EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]
