[PATCH] Pygrub exception trap when import fails

[Michal Novotny <minovotn@redhat.com>]

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Hi all,
this is the patch that fixes the issue when importing 'crypt' module or 
crypt.crypt fails in pygrub. The exception is written on the same line 
like "Failed!" message but only if there is an exception. If there is no 
exception, we don't bother users with details (probably the password 
they entered was wrong) so we just display "Failed!" message. Also, the 
code for hasPassword() was rewritten not to have try/except block here.

Michal

Signed-off-by: Michal Novotny <minovotn@redhat.com>

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diff -r ead107bc25cb tools/pygrub/src/GrubConf.py
--- a/tools/pygrub/src/GrubConf.py	Fri Sep 04 08:43:05 2009 +0100
+++ b/tools/pygrub/src/GrubConf.py	Mon Sep 07 10:36:09 2009 +0200
@@ -158,6 +158,7 @@ class GrubConfigFile(object):
         self.timeout = -1
         self._default = 0
         self.passwordAccess = True
+        self.passExc = None
 
         if fn is not None:
             self.parse()
@@ -197,7 +198,6 @@ class GrubConfigFile(object):
             if self.commands.has_key(com):
                 if self.commands[com] is not None:
                     setattr(self, self.commands[com], arg.strip())
-                    #print "%s = %s => %s" % (com, self.commands[com], arg.strip() )
                 else:
                     logging.info("Ignored directive %s" %(com,))
             else:
@@ -216,25 +216,28 @@ class GrubConfigFile(object):
         self.passwordAccess = val
 
     def hasPassword(self):
-        try:
-            getattr(self, self.commands['password'])
+        return hasattr(self, 'password')
+
+    def checkPassword(self, password):
+        # Always allow if no password defined in grub.conf
+        if not self.hasPassword:
             return True
-        except:
-            return False
-
-    def checkPassword(self, password):
-        try:
-            pwd = getattr(self, self.commands['password']).split()
-            if pwd[0] == '--md5':
+
+        # If we're here, we're having 'password' attribute set
+        pwd = getattr(self, 'password').split()
+
+        # We check whether password is in MD5 hash for comparison
+        if pwd[0] == '--md5':
+            try:
                 import crypt
                 if crypt.crypt(password, pwd[1]) == pwd[1]:
                     return True
-
-            if pwd[0] == password:
-                return True
-
-            return False
-        except:
+            except Exception, e:
+                self.passExc = "Can't verify password: %s" % str(e)
+                return False
+
+        # ... and if not, we compare it as a plain text
+        if pwd[0] == password:
             return True
 
     def set(self, line):
diff -r ead107bc25cb tools/pygrub/src/pygrub
--- a/tools/pygrub/src/pygrub	Fri Sep 04 08:43:05 2009 +0100
+++ b/tools/pygrub/src/pygrub	Mon Sep 07 10:36:09 2009 +0200
@@ -483,7 +483,11 @@ class Grub:
                 pwd = self.text_win.getstr(6, 8)
                 if not self.cf.checkPassword(pwd):
                     self.text_win.addstr(6, 1, "Password: ")
-                    self.text_win.addstr(7, 0, "Failed!")
+                    if self.cf.passExc is not None:
+                        self.text_win.addstr(7, 0, "Exception: %s"
+                                                  % self.cf.passExc)
+                    else:
+                        self.text_win.addstr(7, 0, "Failed!")
                     self.cf.setPasswordAccess( False )
                 else:
                     self.cf.setPasswordAccess( True )

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