1. Early capability flags must be advertised in MSG1 or MSG2, as
applicable. If MSG3 or MSG4 advertise any "early" capability bits,
- MSG1 or MSG3 (as applicable) must have advertised them too. Sadly,
- advertising an early capability flag will produce MSG1s which are
- not understood by versions of secnet which predate the capability
- mechanism.
-
-2. Late capability flags are advertised in MSG2 or MSG3, as
- applicable. They may also appear in MSG1, but this is not
- guaranteed. MSG4 must advertise the same set as MSG2.
+ MSG1 or MSG3 (as applicable) must have advertised them too.
+
+2. Late capability flags may be advertised only in MSG2 or MSG3, as
+ applicable. They are only in MSG1 with newer secnets; older
+ versions omit them. MSG4 must advertise the same set as MSG2.
Currently, the low 16 bits are allocated for negotiating bulk-crypto
transforms. Bits 8 to 15 are used by Secnet as default capability