Allowing whitespace according to RFC7489 (#110)

* Allowing whitespace according to RFC7489

* linter

checkdmarc.py

@@ -55,9 +55,12 @@
 
 __version__ = "4.8.5"
 
-DMARC_VERSION_REGEX_STRING = r"v *= *DMARC1;"
+WSP_REGEX = "[ \t]"
+DMARC_VERSION_REGEX_STRING = fr"v{WSP_REGEX}*={WSP_REGEX}*DMARC1{WSP_REGEX}*;"
 BIMI_VERSION_REGEX_STRING = r"v=BIMI1;"
-DMARC_TAG_VALUE_REGEX_STRING = r"([a-z]{1,5}) *= *([\w.:@/+!,_\- ]+)"
+DMARC_TAG_VALUE_REGEX_STRING = (
+    fr"([a-z]{{1,5}}){WSP_REGEX}*={WSP_REGEX}*([\w.:@/+!,_\- ]+)"
+)
 BIMI_TAG_VALUE_REGEX_STRING = r"([a-z]{1}) *= *(.*)"
 MAILTO_REGEX_STRING = r"^(mailto):" \
                       r"([\w\-!#$%&'*+-/=?^_`{|}~]" \
@@ -327,7 +330,12 @@ class _DMARCGrammar(Grammar):
     """Defines Pyleri grammar for DMARC records"""
     version_tag = Regex(DMARC_VERSION_REGEX_STRING, IGNORECASE)
     tag_value = Regex(DMARC_TAG_VALUE_REGEX_STRING, IGNORECASE)
-    START = Sequence(version_tag, List(tag_value, delimiter=";", opt=True))
+    START = Sequence(
+        version_tag,
+        List(
+            tag_value,
+            delimiter=Regex(f"{WSP_REGEX}*;{WSP_REGEX}*"),
+            opt=True))
 
 
 class _BIMIGrammar(Grammar):
@@ -1399,7 +1407,7 @@ def parse_dmarc_record(
     # Find explicit tags
     for pair in pairs:
         tags[pair[0].lower()] = OrderedDict(
-            [("value", str(pair[1])), ("explicit", True)])
+            [("value", str(pair[1].strip())), ("explicit", True)])
 
     # Include implicit tags and their defaults
     for tag in tag_values.keys():

tests.py

@@ -43,6 +43,8 @@ def testDMARCMixedFormatting(self):
         examples = [
             "v=DMARC1;p=ReJect",
             "v = DMARC1;p=reject;",
+            "v = DMARC1\t;\tp=reject\t;",
+            "v = DMARC1\t;\tp\t\t\t=\t\t\treject\t;",
             "V=DMARC1;p=reject;"
         ]