Re: Protocol implementation errors

2003-10-07 Thread Markus Friedl
On Sat, Oct 04, 2003 at 05:58:49PM +1200, Peter Gutmann wrote: Bill Frantz [EMAIL PROTECTED] writes: This is the second significant problem I have seen in applications that use ASN.1 data formats. (The first was in a widely deployed implementation of SNMP.) Given that good, security

Re: Protocol implementation errors

2003-10-07 Thread Peter Gutmann
Markus Friedl [EMAIL PROTECTED] writes: On Sat, Oct 04, 2003 at 05:58:49PM +1200, Peter Gutmann wrote: We've already seen half the SSH implementations in existence taken out by the SSH malformed-packet vulnerabilities, I don't think so. According to the CERT advisory, roughly half of all

Re: [e-lang] Re: Protocol implementation errors

2003-10-06 Thread Mark S. Miller
At 02:41 PM 10/5/2003 Sunday, Tyler Close wrote: On Sunday 05 October 2003 11:03, Jonathan S. Shapiro wrote: Peter: I agree that ASN.1 is statically checkable, and that this is an important property. What exactly does it mean for a format to be statically checkable? Peter's statement was:

Re: Protocol implementation errors

2003-10-06 Thread Peter Gutmann
Jerrold Leichter [EMAIL PROTECTED] writes: Both of these are helped by a well-specified low-level syntax. TLV encoding lets you cross-check all sorts of stuff automatically, once, in low-level calls. Ad hoc protocols scatter the validation all over the place - and some of it will inevitably be

Re: Protocol implementation errors

2003-10-05 Thread Jerrold Leichter
| This is the second significant problem I have seen in applications that use | ASN.1 data formats. (The first was in a widely deployed implementation of | SNMP.) Given that good, security conscience programmers have difficultly | getting ASN.1 parsing right, we should favor protocols that use

Re: Protocol implementation errors

2003-10-04 Thread Peter Gutmann
Bill Frantz [EMAIL PROTECTED] writes: This is the second significant problem I have seen in applications that use ASN.1 data formats. (The first was in a widely deployed implementation of SNMP.) Given that good, security conscience programmers have difficultly getting ASN.1 parsing right, we