First draft of the ballot comments on the new amendment

[Hin-Tak Leung]

Dear Vlad,

Thanks for putting it all together. Whether it is appropriate as a ballot comment now or a more involved revision later, to put in a format closer to your draft, I propose that

under clause 
"5.7.1 DSIG ­ Digital signature table" , 

paragraph
"Format 1: For whole fonts, with either TrueType outlines and/or CFF data", 

item 
"1. If there is an existing DSIG table in the font,",

in the list of 5 steps under item 1, deleting step 
"4. Zero out the file checksum in the head table.", 

and renumbering 
"5. Add the usFlag (reserved, set at 1 for now) to the stream of bytes"
 as 
"4. ....".


The reason of change is to align the algorithm description in the spec with the most widely used implementation of signing and checking from Microsoft. For signing, as noted, there are a few 3rd party implementations e.g. from Fontlab and Dalton Maag; for checking, perhaps the only implementation is Microsoft's (chktrust.exe and the older Font Validator are regarded as the same, as they have a same wintrust mssipotf backend).

Hin-Tak