Ventriloquist: insert a dummy dsig table (with serials)

Ventriloquist.py

# Ventriloquist - Build 0.1
# insert a dummy dsig table with unique numbers into .otf fonts
# the idea is to kill two birds with one stone
# this idea needs lots of testing
# to do: add SerialDump[] to a txt file for record keeping
# 
# [email protected]

from fontTools.ttLib import TTFont
from mojo.compile import *
from robofab.interface.all.dialogs import GetFolder
import os
import datetime
from time import sleep
from os.path import exists

# number of serials to generate
packageNos=1

# notification center, so you can get coffee
def notify(title, subtitle, message):
    from os import system
    t = '-title {!r}'.format(title)
    s = '-subtitle {!r}'.format(subtitle)
    m = '-message {!r}'.format(message)
    a = '-sender {!r}'.format("com.typemytype.robofont")
    system('terminal-notifier {}'.format(' '.join([m, t, s, a])))
    
if exists("/usr/bin/terminal-notifier"):
    use_notifications = True
else:
    use_notifications = False
    print "In order to use notifications, install the command line program with:"
    print "$ sudo gem install terminal-notifier"

# make up the serials, based on the time
SerialDump=[]
for x in range(0, packageNos):
    b = "1"+datetime.datetime.now().strftime("%m%d%H%M%S%f")
    b = b[:-1]
    sleep(0.01)
    SerialDump.append(b)
    
# cull list to just .otf files
def collectSources(root):
    files = []
    ext = ['.otf']
    names = os.listdir(root)
    for n in names:
        if os.path.splitext(n)[1] in ext:
            files.append(os.path.join(root, n))
    return files

# set target folder
def makeDestination(root, z):
    macPath = os.path.join(root, 'Serialized', z)
    if not os.path.exists(macPath):
        os.makedirs(macPath)
    return macPath

# insert table into temp xml file
def seriaLize(savetemp, q):
    xbefor = '</ttFont>'
    xafter = '  <DSIG>\n    <tableHeader flag="0x1" numSigs="1" version="1"/>\n    <SignatureRecord format="1">\n'+q+'\n    </SignatureRecord>\n  </DSIG>\n\n</ttFont>'
    ttxf = open(savetemp, 'r')
    ttxfread = ttxf.read()
    ttxf.close()
    ttxfreplaced = ttxfread.replace(xbefor, xafter)
    ttxf = open(savetemp, 'w')
    ttxf.write(ttxfreplaced)
    ttxf.close()

# iterate through selected files
def doStuff(f):
    if f is not None:        
        # cut f to just .otf files
        paths = collectSources(f)

        for x in range(0, len(SerialDump)):
            currentNo = str(SerialDump[x])
            makeDestination(f, currentNo)
            
            for i in paths:
                
                instanceFolder, instanceName = os.path.split(i)    
                q = TTFont(i)
                
                serialfolder = instanceFolder + "/Serialized/" + currentNo + "/"
                savetemp =  serialfolder + instanceName + "-" + currentNo + ".ttx"
                savetemp = savetemp.replace(".otf", "")
                newfile = serialfolder + instanceName.replace(".otf", ".ttx")
                q.saveXML(savetemp)

                seriaLize(savetemp, currentNo)

                os.rename(savetemp, newfile)
                stderr, stdout = executeCommand(['ttx', newfile])
                os.remove(newfile)

                #print i, "finished serializing as", currentNo

# select fonts
f = GetFolder("Select Folder")

# run shit
doStuff(f)

notify("Ventriloquist is Done", "", "Check your output folders")

Worth mentioning that I'm not sure if the dummy DSIG tables will actually work in applications 
that enforce DSIG.

Hah, those being? I've never run across one. Plus the process for obtaining a legal DSIG is a nightmare... have you ever tried?

What are the "two birds" you refer to killing in the comments? Tracking down font pirates and...?

MS Office 2010 Windows doesn't implement OpenType features in TTF fonts without a DSIG table, real or dummied.

The usefulness of unique font numbers is questionable though. It would help tracking where rogue files came from but that doesn't necessarily translate into license enforcement IRL.

I knew about the Office thing, which is puzzling (are OT features that dangerous that you need to verify the font?) but I meant I've only come across programs (Office) that checks for the presence of the DSIG table, but never a program that actually needs a real signature.