Separate getting key and checking signature in a thread

Review the logic of checking

2 files changed, 36 insertions, 17 deletions

diff --git a/backend/magiback b/backend/magiback
index 7c56253..904afcf 100755
--- a/backend/magiback
+++ b/backend/magiback
@@ -36,6 +36,9 @@ class Isodumper(raw_write.Dumper):
 					<arg type='s' name='target' direction='in'/>
 					<arg type='s' name='source' direction='in'/>
 				</method>
+				<method name='get_sum'>
+					<arg type='s' name='source' direction='in'/>
+				</method>
 				<method name='end'>
 					<arg type='b' name='success' direction='out'/>
 					<arg type='s' name='message' direction='out'/>
@@ -61,6 +64,9 @@ class Isodumper(raw_write.Dumper):
         self.return_message = ""
         self.authorized_sender_read = set()
         self.authorized_sender_write = set()
+        self.sum_check = ""
+        self.sum_check_searched = False
+        self.signature_checked = False
 
     def do_write(self,source, target, size, dbus_context):
         self.finished.clear()
@@ -99,6 +105,10 @@ class Isodumper(raw_write.Dumper):
         print("Unmounting")
         return self._do_unmount([device])
 
+    def get_sum(self, source):
+        key_thread = threading.Thread(target=self._get_sum, args=(source,))
+        key_thread.start()
+        
     def check_write(self,target, source):
         self.thread = threading.Thread(target=self._check_write, args=(target, source,))
         self.thread.start()
diff --git a/backend/raw_write.py b/backend/raw_write.py
index 40dc99b..d9a5a19 100755
--- a/backend/raw_write.py
+++ b/backend/raw_write.py
@@ -146,35 +146,42 @@ class Dumper(object):
         print(message)
         return not bool(retcode), message
 
-    def _check_write(self, target, source):
+    def _get_sum(self, source):
         self.return_state = False
         self.return_message = ""
-        b = os.path.getsize(source)
         #       Check if the sum file has a valid signature
-        signature_checked = False
         gpg = gnupg.GPG()
         gpg.encoding = 'utf-8'
         # Use Mageia public key
         sig_file = source +'.sha512.gpg'
-        sumcheck = ""
         try:
             gpg.recv_keys('pgp.mit.edu', 'EDCA7A90')
+            self.sum_check_searched = True
             with open(sig_file, 'rb') as g:
+                self.signature_found = True
                 verified = gpg.verify_file(g)
                 if verified.valid: 
-                    signature_checked = True
-                    # Look for sum files in the same directory as source
-                    fs=open(source+'.sha512','r')
-                    # Read the sum in the file
-                    sumcheck=(fs.readline()).split()[0]
+                    self.signature_checked = True
+                    logging.debug("signature checked")
                 else:
-                    self.return_message = _('Invalid signature for %s.sha512')%source
-                    self.return_state = True
-                    self.finished.set()
-                    return 
+                    self.signature_checked = False
         except:
+            self.signature_found = False
             self.return_message = _("Signature file {} not found\n").format(sig_file)
-        
+        try:
+            # Look for sum files in the same directory as source
+            with open(source+'.sha512','r') as fs:
+                # Read the sum in the file
+                self.sum_check=(fs.readline()).split()[0]
+            self.sum_file = True
+        except:
+            self.return_message = _("Sum SHA512 file {} not found\n").format(source+'.sha512')
+            self.sum_file = False
+
+    def _check_write(self, target, source):
+        self.return_state = False
+        self.return_message = ""
+        b = os.path.getsize(source)
         # Compute the sum from the written device
         steps=list(range(0, b+1, int(b/100)))
         steps.append(b)
@@ -195,11 +202,13 @@ class Dumper(object):
             sha512func.update(block)
             sha512sumcalc=sha512func.hexdigest()
         f.close()
-        if (sumcheck == "") :
+        if self.signature_found and not self.signature_checked:
+            self.return_message = _('Invalid signature for %s.sha512')%source
+        if (self.sum_check == "") :
                 self.return_message += _('SHA512 sum: {}').format(sha512sumcalc)
         #  compare the sums
-        elif (sha512sumcalc == sumcheck) :
-            if signature_checked:
+        elif (sha512sumcalc == self.sum_check) :
+            if self.signature_checked:
                 self.return_message += _("The sha512 sum check is OK and the sum is signed")
             else :
                 self.return_message += _("The sha512 sum check is OK but the signature can't be found")