X-Git-Url: https://git.distorted.org.uk/~mdw/secnet/blobdiff_plain/3ed1846a624d9428c48528d6464126b7459ad462..1cef26c2d19ca466d617489a65b83346a704f404:/NOTES

diff --git a/NOTES b/NOTES
index f5ebc65..840f06f 100644
--- a/NOTES
+++ b/NOTES
@@ -218,8 +218,18 @@ Capability flag bits must be in one the following two categories:
    applicable.  They may also appear in MSG1, but this is not
    guaranteed.  MSG4 must advertise the same set as MSG2.
 
-No capability flags are currently defined.  Unknown capability flags
-should be treated as late ones.
+Currently, the low 16 bits are allocated for negotiating bulk-crypto
+transforms.  Bits 8 to 15 are used by Secnet as default capability
+numbers for the various kinds of transform closures: bit 8 is for the
+original CBCMAC-based transform, and bit 9 for the new EAX transform;
+bits 10 to 15 are reserved for future expansion.  The the low eight bits
+are reserved for local use, e.g., to allow migration from one set of
+parameters for a particular transform to a different, incompatible set
+of parameters for the same transform.  Bit 31, if advertised by both
+ends, indicates that a mobile end gets priority in case of crossed MSG1.
+The remaining bits have not yet been assigned a purpose.
+
+No early capability bits are currently defined.
 
 
 MTU handling
@@ -263,7 +273,7 @@ negotiated or assumed).
 
 Messages:
 
-1) A->B: *,iA,msg1,A+,B+,nA
+1) A->B: i*,iA,msg1,A+,B+,nA
 
 i* must be encoded as 0.  (However, it is permitted for a site to use
 zero as its "index" for another site.)