pkcs11 — archive

[Michael StJohns]

On 5/20/2013 5:46 PM, Chris Zimman wrote: I think the right thing to do here is for me to withdraw this comment (unless someone comes up with an actual problem encountered). I don't think withdrawing it is necessary -- it's just something that might be better left until 3.0. Having non-exact specified types is bad, and it can lead to a wide variety of problematic situations. The most simple example is where a token and interface disagree on the size of a CK_ULONG. For example, a token that's internally 64 bit and can support 64 and 32 bit clients: If the 64 bit client creates an object that contains an item with a 64 bit CK_ULONG value inside of it for whatever reason, there's no way for the 32 bit client to understand it since it may contain a value greater than 32 bits. Both things have been operating legally. Also, what is a 64 bit client supposed to do if it tries to submit a value to a 32 bit token in a CK_ULONG that exceeds 32 bits? The token will have to reject it, but there aren't even error codes to handle all the cases. Granted, most values fit into a 32 bit size, but that's more coincidence vs. good design. Hmm... Actually, I don't think this is quite right. There is the program to pkcs11 driver stuff on the using system. There is the on-the-wire protocol between the driver and the server on the HSM system. There is the server to underlying HSM implementation - which may or may not be PKCS11. The program to PKCS11 stuff is covered as discussed. Mapping the on-the-wire protocol can be tricky, but people do it every day. You just need to ensure that you do the translation from the using system representation of CK_ULONG to an on-the-wire representation to a server representation. And let's not even talk about how you deal with pointers in a network encoding! I think that the network representation is out of the purview of this group mostly. How about: "Although the internal representation for a CK_ULONG may be 32 bits or longer, by convention, only the least significant 32 bits shall be used to represent PKCS11 data values (with the one exception of the ~0UL value *sigh*). This permits a loss-less conversion from a CK_ULONG 32 bit value to a CK_ULONG 64 bit value and vice versa." This wouldn't be a change to the headers or anything else, just a description of the convention used for assigning values so that reasonable choices can be made to do network protocol design (or even VM to VM type calls). Mike