OF-1278 Do not be such an idiot while recursing (#751)

* OF-1278 Recurse more sensibly in SCRAM code

Previously, we called setPassword if (and only if) there was a plaintext password present AND the configuration was for SCRAM hashed passwords only.

However, we would then retest to see if there was a salt present, and then recurse, if there was a plaintext password present.

This meant that if there were pre-existing users (with only plaintext or encrypted passwords) but with no SCRAM information, and the userInfo.salt was unset, recursion would continue indefinitely.

* OF-1278 Recurse more sensibly in SCRAM code

This patch further proofs against infinite recursion, and is more aggressive about SCRAMming pre-existing users.

Recursion is now prevented from being more than one deep, as designed.

src/java/org/jivesoftware/openfire/auth/DefaultAuthProvider.java

@@ -78,6 +78,9 @@ public class DefaultAuthProvider implements AuthProvider {
     }
 
     private UserInfo getUserInfo(String username) throws UnsupportedOperationException, UserNotFoundException {
+        return getUserInfo(username, false);
+    }
+    private UserInfo getUserInfo(String username, boolean recurse) throws UnsupportedOperationException, UserNotFoundException {
         if (!isScramSupported()) {
             // Reject the operation since the provider  does not support SCRAM
             throw new UnsupportedOperationException();
@@ -108,15 +111,15 @@ public class DefaultAuthProvider implements AuthProvider {
                     // Ignore and return plain password instead.
                 }
             }
+            if (!recurse) {
                 if (userInfo.plainText != null) {
                     boolean scramOnly = JiveGlobals.getBooleanProperty("user.scramHashedPasswordOnly");
-                if (scramOnly) {
+                    if (scramOnly || userInfo.salt == null) {
                         // If we have a password here, but we're meant to be scramOnly, we should reset it.
                         setPassword(username, userInfo.plainText);
-                }
-                if (userInfo.salt == null) {
                         // RECURSE
-                    return getUserInfo(username);
+                        return getUserInfo(username, true);
+                    }
                 }
             }
             // Good to go.