Validate TXID in client.py (Issue #30 - thanks to @daniel4x)

paulc · Jan 9, 2022 · 76e8677 · 76e8677
1 parent baef751
commit 76e8677
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diff --git a/README b/README
@@ -357,6 +357,8 @@ Changelog:
                             Add support for all RR types to NSEC type bitmap
                          Merge pull request #17 from sunds/issue_16
                             Issue 16: uncaught exceptions leak open sockets
+ *   0.9.17  2022-01-09  Validate TXID in client.py (Issue #30 - thanks to @daniel4x)
+
 
 License:
 --------

diff --git a/dnslib/__init__.py b/dnslib/__init__.py
@@ -359,6 +359,8 @@
                             Add support for all RR types to NSEC type bitmap
                          Merge pull request #17 from sunds/issue_16
                             Issue 16: uncaught exceptions leak open sockets
+ *   0.9.17  2022-01-09  Validate TXID in client.py (Issue #30 - thanks to @daniel4x)
+                       
 
 License:
 --------
@@ -381,7 +383,7 @@
 
 from dnslib.dns import *
 
-version = "0.9.16"
+version = "0.9.17"
 
 if __name__ == '__main__':
     import doctest,sys,textwrap

diff --git a/dnslib/client.py b/dnslib/client.py
@@ -76,6 +76,9 @@
         a_pkt = q.send(address,port,tcp=args.tcp)
         a = DNSRecord.parse(a_pkt)
 
+        if q.header.id != a.header.id:
+            raise DNSError('Response transaction id does not match query transaction id')
+
         if a.header.tc and args.noretry == False:
             # Truncated - retry in TCP mode
             a_pkt = q.send(address,port,tcp=True)