From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Fri, 19 Apr 2019 11:54:57 +0000 (+0200)
Subject: dnsdist: Fix the addition of omitted padding in DOH
X-Git-Tag: dnsdist-1.4.0-alpha2~6^2~9
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=53e47857593498ceff6622e1fd22fec2ca09c00e;p=pdns

dnsdist: Fix the addition of omitted padding in DOH
---

diff --git a/pdns/dnsdistdist/doh.cc b/pdns/dnsdistdist/doh.cc
index e6f436c41..c933b9f2b 100644
--- a/pdns/dnsdistdist/doh.cc
+++ b/pdns/dnsdistdist/doh.cc
@@ -357,7 +357,15 @@ try
       string sdns(path.substr(pos+5));
       boost::replace_all(sdns,"-", "+");
       boost::replace_all(sdns,"_", "/");
-      sdns.append(sdns.size() % 4, '='); // re-add padding that may have been missing
+      // re-add padding that may have been missing
+      switch (sdns.size() % 4) {
+      case 2:
+        sdns.append(2, '=');
+        break;
+      case 3:
+        sdns.append(1, '=');
+        break;
+      }
 
       string decoded;
       /* rough estimate so we hopefully don't need a need allocation later */