introducing signed aliases

client/gui.py

@@ -588,7 +588,7 @@ class BitcoinGUI:
                     r = r.strip()
                     if re.match('^(|([\w\-\.]+)@)((\w[\w\-]+\.)+[\w\-]+)$', r):
                         try:
-                            to_address = self.wallet.get_alias(r)
+                            to_address = self.wallet.read_alias(r)[0]
                         except:
                             continue
                         if to_address:
@@ -807,22 +807,43 @@ class BitcoinGUI:
             entry.set_text('')
 
 
+    def question(self,msg):
+        dialog = gtk.MessageDialog( self.window, gtk.DIALOG_MODAL | gtk.DIALOG_DESTROY_WITH_PARENT, gtk.MESSAGE_QUESTION, gtk.BUTTONS_OK_CANCEL, msg)
+        dialog.show()
+        result = dialog.run()
+        dialog.destroy()
+        return result == gtk.RESPONSE_OK
+
     def get_alias(self, r):
         try:
-            to_address = self.wallet.get_alias(r)
+            target, signing_address, auth_name = self.wallet.read_alias(r)
         except BaseException, e:
-            to_address = None
-            msg = "Warning: the key corresponding to %s does not match its previously known value.\nDo you wish to accept the new key?"%r
-            dialog = gtk.MessageDialog( self.window, gtk.DIALOG_MODAL | gtk.DIALOG_DESTROY_WITH_PARENT, gtk.MESSAGE_QUESTION, gtk.BUTTONS_OK_CANCEL, msg)
-            dialog.show()
-            result = dialog.run()
-            dialog.destroy()
-            if result != gtk.RESPONSE_CANCEL:
-                print e.message
-                to_address = e.message
-                self.wallet.aliases[r] = to_address
+            # raise exception if verify fails (verify the chain)
+            self.show_message("Alias error: " + e.message)
+            return
 
-        return to_address
+        if auth_name is None:
+            a = self.wallet.aliases.get(r)
+            if not a:
+                if self.question( "Warning: the alias is self-signed. Do you want to trust address %s ?"%to_address ):
+                    self.wallet.aliases[r] = signing_address
+                else:
+                    target = None
+            else:
+                if signing_address != a:
+                    if self.question( "Warning: the signing key of %s does not match its previously known value! It is possible that someone is trying to do something nasty!!!\nDo you wish to accept the new key?"%r ):
+                        self.wallet.aliases[r] = signing_address
+                    else:
+                        target = None
+        else:
+            if signing_address not in self.wallet.authorities.keys():
+                if self.question( "Warning: the alias '%s' was signed by %s [%s].\n\nDo you want to add this key to your list of trusted keys?"\
+                                  %(r,auth_name,signing_address)):
+                    self.wallet.authorities[signing_address] = auth_name
+                else:
+                    target = None
+            
+        return target
             
 
 

client/wallet.py

@@ -248,6 +248,8 @@ class Wallet:
         self.history = {}
         self.labels = {}             # labels for addresses and transactions
         self.aliases = {}            # aliases for addresses
+        self.authorities = {}        # trusted addresses
+        
         self.receipts = {}           # signed URIs
         self.receipt = None          # next receipt
         self.addressbook = []        # outgoing addresses, for payments
@@ -383,7 +385,7 @@ class Wallet:
         order = G.order()
         # extract r,s from signature
         sig = base64.b64decode(signature)
-        if len(sig) != 65: raise BaseException("error")
+        if len(sig) != 65: raise BaseException("Wrong encoding")
         r,s = util.sigdecode_string(sig[1:], order)
         recid = ord(sig[0]) - 27
         # 1.1
@@ -407,7 +409,10 @@ class Wallet:
         # check that we get the original signing address
         addr = public_key_to_bc_address( '04'.decode('hex') + public_key.to_string() )
         # print addr
-        assert address == addr
+        try:
+            assert address == addr
+        except:
+            raise BaseException("Bad signature")
     
 
     def create_new_address2(self, for_change):
@@ -489,6 +494,7 @@ class Wallet:
             'contacts':self.addressbook,
             'imported_keys':self.imported_keys,
             'aliases':self.aliases,
+            'authorities':self.authorities,
             'receipts':self.receipts,
             }
         f = open(self.path,"w")
@@ -521,6 +527,7 @@ class Wallet:
             self.addressbook = d.get('contacts')
             self.imported_keys = d.get('imported_keys',{})
             self.aliases = d.get('aliases',{})
+            self.authorities = d.get('authorities',{})
             self.receipts = d.get('receipts',{})
         except:
             raise BaseException(upgrade_msg)
@@ -724,34 +731,47 @@ class Wallet:
             self.receipt = None
         return True, out
 
-    def get_alias(self, x):
+
+    def read_alias(self, alias):
         # this might not be the right place for this function.
         import urllib
-        if self.is_valid(x):
-            return x
+        if self.is_valid(alias):
+            return alias
         else:
-            m1 = re.match('([\w\-\.]+)@((\w[\w\-]+\.)+[\w\-]+)', x)
-            m2 = re.match('((\w[\w\-]+\.)+[\w\-]+)', x)
+            m1 = re.match('([\w\-\.]+)@((\w[\w\-]+\.)+[\w\-]+)', alias)
+            m2 = re.match('((\w[\w\-]+\.)+[\w\-]+)', alias)
             if m1:
                 url = 'http://' + m1.group(2) + '/bitcoin.id/' + m1.group(1) 
             elif m2:
-                url = 'http://' + x + '/bitcoin.id'
+                url = 'http://' + alias + '/bitcoin.id'
             else:
                 return ''
             try:
-                print url
-                xx = urllib.urlopen(url).read().strip()
+                lines = urllib.urlopen(url).readlines()
             except:
                 return ''
-            if not self.is_valid(xx):
-                return ''
-            self.labels[xx] = x
 
-            s = self.aliases.get(x)
-            if s:
-                if s != xx:
-                    raise BaseException( xx )
+            # line 0
+            line = lines[0].strip().split(':')
+            if len(line) == 1:
+                auth_name = None
+                target = signing_addr = line[0]
             else:
-                self.aliases[x] = xx
-            
-            return xx
+                target, auth_name, signing_addr, signature = line
+                msg = "alias:%s:%s:%s"%(alias,target,auth_name)
+                print msg, signature
+                self.verify_message(signing_addr, signature, msg)
+
+            # other lines are signed updates
+            for line in lines[1:]:
+                line = line.strip()
+                if not line: continue
+                line = line.split(':')
+                previous = target
+                print repr(line)
+                target, signature = line
+                self.verify_message(previous, signature, "alias:%s:%s"%(alias,target))
+
+            assert self.is_valid(target)
+
+            return target, signing_addr, auth_name