Raising for unrelated DMARC records is configurable (#99)

checkdmarc.py

@@ -828,7 +828,7 @@ def _get_txt_records(domain, nameservers=None, resolver=None, timeout=2.0):
     return records
 
 
-def _query_dmarc_record(domain, nameservers=None, resolver=None, timeout=2.0):
+def _query_dmarc_record(domain, nameservers=None, resolver=None, timeout=2.0, raise_for_unrelated_records=True):
     """
     Queries DNS for a DMARC record
 
@@ -846,12 +846,13 @@ def _query_dmarc_record(domain, nameservers=None, resolver=None, timeout=2.0):
     dmarc_record = None
     dmarc_record_count = 0
     unrelated_records = []
+    dmarc_prefix = "v=DMARC1"
 
     try:
         records = _query_dns(target, "TXT", nameservers=nameservers,
                              resolver=resolver, timeout=timeout)
         for record in records:
-            if record.startswith("v=DMARC1"):
+            if record.startswith(dmarc_prefix):
                 dmarc_record_count += 1
             elif record.strip().startswith("v=DMARC1"):
                 raise DMARCRecordStartsWithWhitespace(
@@ -867,12 +868,13 @@ def _query_dmarc_record(domain, nameservers=None, resolver=None, timeout=2.0):
                 "Multiple DMARC policy records are not permitted - "
                 "https://tools.ietf.org/html/rfc7489#section-6.6.3")
         if len(unrelated_records) > 0:
-            raise UnrelatedTXTRecordFoundAtDMARC(
-                "Unrelated TXT records were discovered. These should be "
-                "removed, as some receivers may not expect to find "
-                "unrelated TXT records "
-                "at {0}\n\n{1}".format(target, "\n\n".join(unrelated_records)))
-        dmarc_record = records[0]
+            if raise_for_unrelated_records:
+                raise UnrelatedTXTRecordFoundAtDMARC(
+                    "Unrelated TXT records were discovered. These should be "
+                    "removed, as some receivers may not expect to find "
+                    "unrelated TXT records "
+                    "at {0}\n\n{1}".format(target, "\n\n".join(unrelated_records)))
+        dmarc_record = [record for record in records if record.startswith(dmarc_prefix)][0]
 
     except dns.resolver.NoAnswer:
         try:
@@ -969,7 +971,7 @@ def _query_bmi_record(domain, selector="default", nameservers=None,
     return bimi_record
 
 
-def query_dmarc_record(domain, nameservers=None, resolver=None, timeout=2.0):
+def query_dmarc_record(domain, nameservers=None, resolver=None, timeout=2.0, raise_for_unrelated_records=True):
     """
     Queries DNS for a DMARC record
 
@@ -998,7 +1000,7 @@ def query_dmarc_record(domain, nameservers=None, resolver=None, timeout=2.0):
     base_domain = get_base_domain(domain)
     location = domain.lower()
     record = _query_dmarc_record(domain, nameservers=nameservers,
-                                 resolver=resolver, timeout=timeout)
+                                 resolver=resolver, timeout=timeout, raise_for_unrelated_records=raise_for_unrelated_records)
     try:
         root_records = _query_dns(domain.lower(), "TXT",
                                   nameservers=nameservers, resolver=resolver,