[security-services] errata on SAML core,section 5.3 Signature Inheritance

[RL 'Bob' Morgan <rlmorgan@washington.edu>]

Sorry if this might have been mentioned before, but section 5.3 of 
cs-sstc-core-00.pdf seems poorly-written enough to be potentially 
problematic.  

Section 5.3.1 supplies rationale.  Lines 1398 and 1399 say:

  In such a case, the SAML sub-message (Assertion, request, response) may 
  be viewed as inheriting a signature from the "super-signature" over the 
  enclosing object, provided certain constraints are met.

Lines 1400-1401 offer only one such constraint, labelled (1).  Lines 
1402-1403 repeat this text, without the label.

Section 5.3.2, called "Rules for SAML Signature Inheritance", as far as I 
can tell says exactly what the previous section says, adding only the 
sentence in line 1408:  'The SAML message inherits the "closest enclosing 
signature."'

It looks to me like there needs to be only a section 5.3, and that the 
lines 1398-1410 could be reduced to three or four lines.  I'd supply the 
text but I'm too tired right now.

 - RL "Bob"