RE: OCSP response pre-production

["Florian Oelmaier" <oelmaier@xxxxxxxxxxx>]

> [Florian]
> 
> > Client Type I) Given you have a client with the following behaviour:
> > A) always includes a nonce into his request
> > B) accepts responses without nonce
>
> If a client Type I "accepts responses without nonce" (i.e. "B 
> condition") 
> then a nonce generated by the server is ignored by the client 
> and thus does 
> not help, and "do NOT allow Client Type I operate securely".

Why should the client *ignore* the nonce? The client will check the
nonce when it is included in the response while simultaneous accepting
responses without nonce. Although I have not tested it, I dont think any
client out there that accepts nonce-less responses to his nonce-requests
IGNORES the nonce. After all a mismatching nonce definitely indicates a
replay attack while a response without nonce just indicates no
protection against replay attacks.

This way the responder can decide wether to protect the client against
replay attacks (through server-generated nonces).

So allow me to define the behaviour of "Client Type I" more clearly:
A) always includes a nonce into his request
B) checks if the nonces match if the response included a nonce
C) accepts responses without nonce

-- 
Florian Oelmaier
SyTrust

PS: -> James: To allow replay protection, a pre-defined nonce would not
help. So in my scenario it should be the usual non-predictable random
string.