Re: [TLS] draft-rescorla-tls-subcerts

2016-07-15 Thread Ilari Liusvaara
On Fri, Jul 15, 2016 at 12:28:18AM +, Andrei Popov wrote: > Naïve question: why not simply get a constrained CA certificate and > issue short-validity end entity certs? Unless I’m missing something, > this would work with existing TLS implementations, no extensions > required. The I-D actually

[TLS] Why is resumption_context hashed?

2016-07-15 Thread David Benjamin
Every time resumption_context is used, it's fed into the PRF hash. Handshake Context gets hashed since that actually expands to the full concatenation and we want to be able to maintain a rolling hash. But resumption_context is always a short value and is already the size of the PRF hash. (If not r

Re: [TLS] Why is resumption_context hashed?

2016-07-15 Thread Eric Rescorla
On Fri, Jul 15, 2016 at 11:39 AM, David Benjamin wrote: > Every time resumption_context is used, it's fed into the PRF hash. > Handshake Context gets hashed since that actually expands to the full > concatenation and we want to be able to maintain a rolling hash. > But resumption_context is alway

Re: [TLS] draft-rescorla-tls-subcerts

2016-07-15 Thread Andrei Popov
> The I-D actually covers this. Understood; the I-D lists a few cons, but arguably none of them are blocking issues. It seems unnecessary to create a new TLS-specific mechanism that duplicates existing PKI semantics. > Those two serve different purposes. Sometimes you really need the ES/KS > sp

Re: [TLS] draft-rescorla-tls-subcerts

2016-07-15 Thread Benjamin Kaduk
On 07/15/2016 12:34 PM, Andrei Popov wrote: >> The I-D actually covers this. > Understood; the I-D lists a few cons, but arguably none of them are blocking > issues. It seems unnecessary to create a new TLS-specific mechanism that > duplicates existing PKI semantics. > I think the main justifica