From: Peter van Dijk <peter.van.dijk@powerdns.com>
Date: Tue, 25 Jul 2023 09:06:54 +0000 (+0200)
Subject: CAA records: handle empty value more gracefully, fixes #13070
X-Git-Tag: rec-5.0.0-rc1~16^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d97b8188a58ccdcbb17471b9162da9d65005e4f4;p=thirdparty%2Fpdns.git

CAA records: handle empty value more gracefully, fixes #13070
---

diff --git a/pdns/dnsparser.cc b/pdns/dnsparser.cc
index df48d0c984..ea1e6e8bfa 100644
--- a/pdns/dnsparser.cc
+++ b/pdns/dnsparser.cc
@@ -516,6 +516,10 @@ string PacketReader::getText(bool multi, bool lenField)
       break;
   }
 
+  if (ret.empty() && !lenField) {
+    // all lenField == false cases (CAA and URI at the time of this writing) want that emptiness to be explicit
+    return "\"\"";
+  }
   return ret;
 }
 
@@ -536,7 +540,7 @@ string PacketReader::getUnquotedText(bool lenField)
     return "";
 
   d_pos++;
-  string ret(&d_content.at(d_pos), &d_content.at(stop_at));
+  string ret(d_content.substr(d_pos, stop_at-d_pos));
   d_pos = stop_at;
   return ret;
 }
diff --git a/pdns/test-dnsrecords_cc.cc b/pdns/test-dnsrecords_cc.cc
index 3e65d783f7..c790b89a91 100644
--- a/pdns/test-dnsrecords_cc.cc
+++ b/pdns/test-dnsrecords_cc.cc
@@ -276,6 +276,12 @@ BOOST_AUTO_TEST_CASE(test_record_types) {
      (CASE_S(QType::URI, "10000 1 \"ftp://ftp1.example.com/public\"", "\x27\x10\x00\x01\x66\x74\x70\x3a\x2f\x2f\x66\x74\x70\x31\x2e\x65\x78\x61\x6d\x70\x6c\x65\x2e\x63\x6f\x6d\x2f\x70\x75\x62\x6c\x69\x63"))
      (CASE_S(QType::URI, "10 1 \"ftp://ftp1.example.com/public/with/a/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/very/long/url\"", "\x00\x0a\x00\x01\x66\x74\x70\x3a\x2f\x2f\x66\x74\x70\x31\x2e\x65\x78\x61\x6d\x70\x6c\x65\x2e\x63\x6f\x6d\x2f\x70\x75\x62\x6c\x69\x63\x2f\x77\x69\x74\x68\x2f\x61\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x6c\x6f\x6e\x67\x2f\x75\x72\x6c"))
      (CASE_S(QType::CAA, "0 issue \"example.net\"", "\x00\x05\x69\x73\x73\x75\x65\x65\x78\x61\x6d\x70\x6c\x65\x2e\x6e\x65\x74"))
+     (CASE_S(QType::CAA, "0 issue \"\"", "\x00\x05\x69\x73\x73\x75\x65"))
+     (CASE_S(QType::CAA, "0 issue \";\"", "\x00\x05\x69\x73\x73\x75\x65\x3b"))
+     (CASE_S(QType::CAA, "0 issue \"a\"", "\x00\x05\x69\x73\x73\x75\x65\x61"))
+     (CASE_S(QType::CAA, "0 issue \"aa\"", "\x00\x05\x69\x73\x73\x75\x65\x61\x61"))
+     (CASE_S(QType::CAA, "0 issue \"aaaaaaa\"", "\x00\x05\x69\x73\x73\x75\x65\x61\x61\x61\x61\x61\x61\x61"))
+     (CASE_S(QType::CAA, "0 issue \"aaaaaaa.aaa\"", "\x00\x05\x69\x73\x73\x75\x65\x61\x61\x61\x61\x61\x61\x61\x2e\x61\x61\x61"))
      (CASE_S(QType::DLV, "20642 8 2 04443abe7e94c3985196beae5d548c727b044dda5151e60d7cd76a9fd931d00e", "\x50\xa2\x08\x02\x04\x44\x3a\xbe\x7e\x94\xc3\x98\x51\x96\xbe\xae\x5d\x54\x8c\x72\x7b\x04\x4d\xda\x51\x51\xe6\x0d\x7c\xd7\x6a\x9f\xd9\x31\xd0\x0e"))
      (CASE_S((QType::typeenum)65226,"\\# 3 414243","\x41\x42\x43"))