On Wed, Oct 18, 2006 at 03:50:02PM -0400, [EMAIL PROTECTED] wrote: > Title : EAP Generalized Pre-Shared Key (EAP-GPSK) > Author(s) : C. Clancy, H. Tschofenig > Filename : draft-ietf-emu-eap-gpsk-00.txt
While updating my implementation to the new draft, I noticed couple of conflicts in how the key derivation is defined. Chapter 4 uses KDF_Zero-String(PL || PSK | ...) to derive MK whereas 6.1.8 and 6.2.8 use GKDF-#(PSK, ...). I would assume that the version in 6.1.8 and 6.2.8 is the correct one and chapter 4 should be updated to match with this. Another difference is in whether CSuite_Sel is to be included in the GKDF data field. Chapter 4 seems to include it (just before inputString), but 6.1.8 and 6.2.8 do not. Should it be there or not? The new draft is trying to fix the GKDF-X n (number of output blocks) calculation, but that seems to have a typo of some sort. Now: n = int( X / size - 1 ) + 1; That doesn't make any sense since -1 and +1 are are cancelling eachother and we are left with n = int( X / size ). I would assume that this was supposed to be taken into account rounding up (ceiling) by using n = int( (X + size - 1) / size ) which could be written as n = int( (X - 1) / size ) + 1. -- Jouni Malinen PGP id EFC895FA _______________________________________________ Emu mailing list [email protected] https://www1.ietf.org/mailman/listinfo/emu
