trust_box.py

   1 import gtk
   2 from zeroinstall.injector.model import SafeException
   3 from zeroinstall.injector import gpg, trust
   4 from zeroinstall.injector.iface_cache import iface_cache
   5
   6 import gui
   7 import dialog, help_box
   8
   9 def fingerprint(sig):
  10         try:
  11                 return sig.fingerprint
  12         except:
  13                 # Work around a bug in injector-0.9
  14                 return sig.status[sig.FINGERPRINT]
  15
  16 def pretty_fp(fp):
  17         s = fp[0:4]
  18         for x in range(4, len(fp), 4):
  19                 s += ' ' + fp[x:x + 4]
  20         return s
  21
  22 class TrustBox(dialog.Dialog):
  23         model = None
  24         tree_view = None
  25
  26         interface = None
  27         sigs = None
  28         iface_xml = None
  29
  30         def __init__(self, interface, sigs, iface_xml):
  31                 dialog.Dialog.__init__(self)
  32                 self.connect('destroy', lambda a: _pop_queue())
  33
  34                 self.interface = interface
  35                 self.sigs = sigs
  36                 self.iface_xml = iface_xml
  37
  38                 self.set_title('Confirm trust')
  39
  40                 label = gtk.Label('Please confirm that you trust '
  41                                   'these keys to sign software updates:')
  42                 label.set_padding(8, 8)
  43                 self.vbox.pack_start(label, False, True, 0)
  44
  45                 swin = gtk.ScrolledWindow()
  46                 self.vbox.pack_start(swin, True, True, 0)
  47                 swin.set_policy(gtk.POLICY_NEVER, gtk.POLICY_AUTOMATIC)
  48                 swin.set_shadow_type(gtk.SHADOW_IN)
  49                 swin.set_border_width(8)
  50
  51                 self.model = gtk.ListStore(str, object)
  52                 self.tree_view = gtk.TreeView(self.model)
  53                 self.tree_view.get_selection().set_mode(gtk.SELECTION_NONE)
  54                 swin.add(self.tree_view)
  55
  56                 self.tree_view.set_size_request(-1, 100)
  57
  58                 text = gtk.CellRendererText()
  59
  60                 for column in [gtk.TreeViewColumn('Key fingerprint', text, text = 0)]:
  61                         self.tree_view.append_column(column)
  62
  63                 self.vbox.show_all()
  64
  65                 self.add_button(gtk.STOCK_HELP, gtk.RESPONSE_HELP)
  66                 self.add_button(gtk.STOCK_CANCEL, gtk.RESPONSE_CANCEL)
  67                 self.add_button(gtk.STOCK_ADD, gtk.RESPONSE_OK)
  68                 self.set_default_response(gtk.RESPONSE_OK)
  69
  70                 def response(box, resp):
  71                         if resp == gtk.RESPONSE_HELP:
  72                                 trust_help.display()
  73                                 return
  74                         if resp == gtk.RESPONSE_OK:
  75                                 self.trust_keys()
  76                         self.destroy()
  77                 self.connect('response', response)
  78
  79                 valid_sigs = [s for s in sigs if isinstance(s, gpg.ValidSig)]
  80                 if not valid_sigs:
  81                         raise SafeException('No valid signatures found')
  82
  83                 for sig in sigs:
  84                         titer = self.model.append()
  85                         self.model[titer][0] = pretty_fp(fingerprint(sig))
  86                         self.model[titer][1] = sig
  87
  88                 self.tree_view.expand_all()
  89                 self.present()
  90
  91         def trust_keys(self):
  92                 try:
  93                         for row in self.model:
  94                                 sig = row[1]
  95                                 trust.trust_db.trust_key(fingerprint(sig))
  96
  97                         if not iface_cache.update_interface_if_trusted(self.interface, self.sigs,
  98                                                                       self.iface_xml):
  99                                 raise Exception('Bug: still not trusted!!')
 100                 except Exception, ex:
 101                         dialog.alert(None, ex)
 102
 103 _queue = []
 104 def _pop_queue():
 105         if _queue:
 106                 a = _queue.pop()
 107                 a.show()
 108
 109 def confirm_trust(interface, sigs, iface_xml):
 110         _queue.append(TrustBox(interface, sigs, iface_xml))
 111         if len(_queue) == 1:
 112                 _pop_queue()
 113
 114 trust_help = help_box.HelpBox("Trust Help",
 115 ('Overview', """
 116 When you run a program, it typically has access to all your files and can generally do \
 117 anything that you're allowed to do (delete files, send emails, etc). So it's important \
 118 to make sure that you don't run anything malicious."""),
 119
 120 ('Digital signatures', """
 121 Each software author creates a 'key-pair'; a 'public key' and a 'private key'. Without going \
 122 into the maths, only something encrypted with the private key will decrypt with the public key.
 123
 124 So, when a programmer releases some software, they encrypt it with their private key (which no-one \
 125 else has). When you download it, the injector checks that it decrypts using their public key, thus \
 126 proving that it came from them and hasn't been tampered with."""),
 127
 128 ('Trust', """
 129 After the injector has checked that the software hasn't been modified since it was signed with \
 130 the private key, you still have the following problems:
 131
 132 1. Does the public key you have really belong to the author?
 133 2. Even if the software really did come from that person, do you trust them?"""),
 134
 135 ('Key fingerprints', """
 136 To confirm (1), you should compare the public key you have with the genuine one. To make this \
 137 easier, the injector displays a 'fingerprint' for the key. Look in mailing list postings or some \
 138 other source to check that the fingerprint is right (a different key will have a different \
 139 fingerprint).
 140
 141 You're trying to protect against the situation where an attacker breaks into a web site \
 142 and puts up malicious software, signed with the attacker's private key, and puts up the \
 143 attacker's public key too. If you've downloaded this software before, you \
 144 should be suspicious that you're being asked to confirm another key!"""),
 145
 146 ('Reputation', """
 147 In general, most problems seem to come from malicous and otherwise-unknown people \
 148 replacing software with modified versions, or creating new programs intended only to \
 149 cause damage. So, check your programs are signed by a key with a good reputation!"""))