Fix CAA from_wire()

2 files changed, 13 insertions, 1 deletions

diff --git a/dns/rdtypes/ANY/CAA.py b/dns/rdtypes/ANY/CAA.py
index 7425606..2381ea6 100644
--- a/dns/rdtypes/ANY/CAA.py
+++ b/dns/rdtypes/ANY/CAA.py
@@ -69,5 +69,5 @@ class CAA(dns.rdata.Rdata):
         (flags, l) = struct.unpack('!BB', wire[current : current + 2])
         current += 2
         tag = wire[current : current + l].decode('latin_1')
-        value = wire[current + l:].decode('latin_1')
+        value = wire[current + l:current + rdlen - 2].decode('latin_1')
         return cls(rdclass, rdtype, flags, tag, value)
diff --git a/tests/test_bugs.py b/tests/test_bugs.py
index 906e0fd..5aae6a4 100644
--- a/tests/test_bugs.py
+++ b/tests/test_bugs.py
@@ -14,6 +14,7 @@
 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 import binascii
+import io
 import unittest
 
 import dns.rdata
@@ -59,6 +60,17 @@ class BugsTestCase(unittest.TestCase):
                                      b"", 0, 0)
         self.assertTrue(rdata == rdata2)
 
+    def test_CAA_from_wire(self):
+        rdata = dns.rdata.from_text(dns.rdataclass.IN, dns.rdatatype.CAA,
+                                    '0 issue "ca.example.net"');
+        f = io.BytesIO()
+        rdata.to_wire(f)
+        wire = f.getvalue()
+        rdlen = len(wire)
+        wire += b"trailing garbage"
+        rdata2 = dns.rdata.from_wire(dns.rdataclass.IN, dns.rdatatype.CAA,
+                                     wire, 0, rdlen)
+        self.failUnless(rdata == rdata2)
 
 if __name__ == '__main__':
     unittest.main()