Guard against empty signon entry confusion by refusing to add new entries with empty user and empty password, fixing removal of these entries, and attempting to discard these entries as they are read in. Bug 231042.

toolkit/components/passwordmgr/base/nsPasswordManager.cpp

@@ -348,7 +348,12 @@ nsPasswordManager::AddUser(const nsACString& aHost,
                            const nsAString& aUser,
                            const nsAString& aPassword)
 {
-  // First check for an existing entry for this host + user
+  // Silently ignore an empty username/password entry.
+  // There's no point in taking up space in the signon file with this.
+  if (aUser.IsEmpty() && aPassword.IsEmpty())
+    return NS_OK;
+
+  // Check for an existing entry for this host + user
   if (!aHost.IsEmpty()) {
     SignonHashEntry *hashEnt;
     if (mSignonTable.Get(aHost, &hashEnt)) {
@@ -387,7 +392,8 @@ nsPasswordManager::RemoveUser(const nsACString& aHost, const nsAString& aUser)
   for (entry = hashEnt->head; entry; prevEntry = entry, entry = entry->next) {
 
     nsAutoString ptUser;
-    if (NS_FAILED(DecryptData(entry->userValue, ptUser)))
+    if (!entry->userValue.IsEmpty() &&
+        NS_FAILED(DecryptData(entry->userValue, ptUser)))
       break;
 
     if (ptUser.Equals(aUser)) {
@@ -581,7 +587,12 @@ nsPasswordManager::AddUserFull(const nsACString& aHost,
                                const nsAString& aUserFieldName,
                                const nsAString& aPassFieldName)
 {
-  // First check for an existing entry for this host + user
+  // Silently ignore an empty username/password entry.
+  // There's no point in taking up space in the signon file with this.
+  if (aUser.IsEmpty() && aPassword.IsEmpty())
+    return NS_OK;
+
+  // Check for an existing entry for this host + user
   if (!aHost.IsEmpty()) {
     SignonHashEntry *hashEnt;
     if (mSignonTable.Get(aHost, &hashEnt)) {
@@ -644,6 +655,7 @@ nsPasswordManager::ReadPasswords(nsIFile* aPasswordFile)
 
   nsCAutoString realm;
   SignonDataEntry* entry = nsnull;
+  PRBool writeOnFinish = PR_FALSE;
 
   do {
     rv = lineStream->ReadLine(buffer, &moreData);
@@ -667,8 +679,16 @@ nsPasswordManager::ReadPasswords(nsIFile* aPasswordFile)
     case STATE_USERFIELD:
 
       // Commit any completed entry
-      if (entry)
+      if (entry) {
+        // Weed out empty username+password entries from corrupted signon files
+        if (entry->userValue.IsEmpty() && entry->passValue.IsEmpty()) {
+          NS_WARNING("Discarding empty password entry");
+          writeOnFinish = PR_TRUE; // so we won't get this on the next startup
+          delete entry;
+        } else {
           AddSignonData(realm, entry);
+        }
+      }
 
       // If the line is a ., we've reached the end of this realm's entries.
       if (buffer.Equals(NS_LITERAL_STRING("."))) {
@@ -712,6 +732,11 @@ nsPasswordManager::ReadPasswords(nsIFile* aPasswordFile)
   // Don't leak if the file ended unexpectedly
   delete entry;
 
+  if (writeOnFinish) {
+    fileStream->Close();
+    WriteSignonFile();
+  }
+
   return NS_OK;
 }