From 80def6b0cbf34e60102576f19a975ff54108e59d Mon Sep 17 00:00:00 2001
From: Pieter Lexis <pieter.lexis@powerdns.com>
Date: Thu, 9 Nov 2017 11:24:36 +0100
Subject: [PATCH] Check return of getTSIGKey and B64Decode in the TCPReceiver

(cherry picked from commit 53ace5d500563c3a5156b496898e5e2b1d6cbcfb)
---
 pdns/tcpreceiver.cc | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/pdns/tcpreceiver.cc b/pdns/tcpreceiver.cc
index ec8a4aac3..cf8e29dfb 100644
--- a/pdns/tcpreceiver.cc
+++ b/pdns/tcpreceiver.cc
@@ -626,8 +626,14 @@ int TCPNameserver::doAXFR(const DNSName &target, shared_ptr<DNSPacket> q, int ou
       algorithm = DNSName("hmac-md5");
     if (algorithm != DNSName("gss-tsig")) {
       Lock l(&s_plock);
-      s_P->getBackend()->getTSIGKey(tsigkeyname, &algorithm, &tsig64);
-      B64Decode(tsig64, tsigsecret);
+      if(!s_P->getBackend()->getTSIGKey(tsigkeyname, &algorithm, &tsig64)) {
+        L<<Logger::Error<<"TSIG key '"<<tsigkeyname<<"' for domain '"<<target<<"' not found"<<endl;
+        return 0;
+      }
+      if (B64Decode(tsig64, tsigsecret) == -1) {
+        L<<Logger::Error<<"Unable to Base-64 decode TSIG key '"<<tsigkeyname<<"' for domain '"<<target<<"'"<<endl;
+        return 0;
+      }
     }
   }
   
@@ -1142,8 +1148,14 @@ int TCPNameserver::doIXFR(shared_ptr<DNSPacket> q, int outsock)
       if (algorithm == DNSName("hmac-md5.sig-alg.reg.int"))
         algorithm = DNSName("hmac-md5");
       Lock l(&s_plock);
-      s_P->getBackend()->getTSIGKey(tsigkeyname, &algorithm, &tsig64);
-      B64Decode(tsig64, tsigsecret);
+      if(!s_P->getBackend()->getTSIGKey(tsigkeyname, &algorithm, &tsig64)) {
+        L<<Logger::Error<<"TSIG key '"<<tsigkeyname<<"' for domain '"<<target<<"' not found"<<endl;
+        return 0;
+      }
+      if (B64Decode(tsig64, tsigsecret) == -1) {
+        L<<Logger::Error<<"Unable to Base-64 decode TSIG key '"<<tsigkeyname<<"' for domain '"<<target<<"'"<<endl;
+        return 0;
+      }
     }
 
     UeberBackend signatureDB;
-- 
2.40.0