add support for CAA records

[zonemaker.git] / zone.py

diff --git a/zone.py b/zone.py
index 1e1251a5fcd2759a982713b68f908401001a962b..d325915074b943a9ee11aeaddf1aa3fe0417e163 100644 (file)
--- a/zone.py
+++ b/zone.py
@@ -33,7 +33,7 @@ week = 7*day
 
 REGEX_label = r'[a-zA-Z90-9]([a-zA-Z90-9-]{0,61}[a-zA-Z90-9])?' # max. 63 characters; must not start or end with hyphen
 REGEX_ipv4  = r'^\d{1,3}(\.\d{1,3}){3}$'
-REGEX_ipv6  = r'^[a-fA-F0-9]{1,4}(:[a-fA-F0-9]{1,4}){7}$'
+REGEX_ipv6  = r'^[a-fA-F0-9]{1,4}(::?[a-fA-F0-9]{1,4}){1,7}$'
 
 def check_label(label: str) -> str:
     label = str(label)
@@ -101,6 +101,20 @@ def column_widths(datas: 'Sequence', widths: 'Sequence[int]'):
     # last data point
     return result+str(datas[-1])
 
+def concatenate(root, path):
+    if path == '' or root == '':
+        raise Exception("Empty domain name is not valid")
+    if path == '@':
+        return root
+    if root == '@' or path.endswith('.'):
+        return path
+    return path+"."+root
+
+def escape_TXT(text):
+    for c in ('\\', '\"'):
+        text = text.replace(c, '\\'+c)
+    return text
+
 
 ## Enums
 class Protocol:
@@ -131,15 +145,7 @@ class RR:
         return self
     
     def relativize(self, root):
-        def _relativize(path):
-            if path == '' or root == '':
-                raise Exception("Empty domain name is not valid")
-            if path == '@':
-                return root
-            if root == '@' or path.endswith('.'):
-                return path
-            return path+"."+root
-        return self.mapPath(_relativize)
+        return self.mapPath(lambda path: concatenate(root, path))
     
     def mapTTL(self, f):
         '''Run the current TTL and the recordType through f.'''
@@ -181,13 +187,17 @@ class TXT:
         for c in ('\n', '\r', '\t'):
             if c in text:
                 raise Exception("TXT record {0} contains invalid character")
-        # escape text
-        for c in ('\\', '\"'):
-            text = text.replace(c, '\\'+c)
         self._text = text
     
     def generate_rr(self):
-        return RR('@', 'TXT', '"{0}"'.format(self._text))
+        text = escape_TXT(self._text)
+        # split into chunks of max. 255 characters; be careful not to split right after a backslash
+        chunks = re.findall(r'.{0,254}[^\\]', text)
+        assert sum(len(c) for c in chunks) == len (text)
+        chunksep = '"\n' + ' '*20 + '"'
+        chunked = '( "' + chunksep.join(chunks) + '" )'
+        # generate the chunks
+        return RR('@', 'TXT', chunked)
 
 
 class DKIM(TXT): # helper class to treat DKIM more antively
@@ -249,6 +259,19 @@ class TLSA:
     def generate_rr(self):
         return RR('_{}._{}'.format(self._port, self._protocol), 'TLSA', '{} {} {} {}'.format(self._usage, self._selector, self._matching_type, self._data))
 
+class CAA:
+    class Tag:
+        Issue = "issue"
+        IssueWild = "issuewild"
+
+    def __init__(self, flag: int, tag: str, value: str) -> None:
+        self._flag = int(flag)
+        self._tag = str(tag)
+        self._value = str(value)
+
+    def generate_rr(self):
+        return RR('@', 'CAA', '{} {} {}'.format(self._flag, self._tag, self._value))
+
 
 class CNAME:
     def __init__(self, name: str) -> None:
@@ -295,12 +318,12 @@ def CName(name: str) -> Name:
     return Name(CNAME(name))
 
 
-def Delegation(name: str) -> Name:
-    return Name(NS(name))
+def Delegation(*names) -> Name:
+    return Name(list(map(NS, names)))
 
 
-def SecureDelegation(name: str, tag: int, alg: int, digest: int, key: str) -> Name:
-    return Name(NS(name), DS(tag, alg, digest, key))
+def SecureDelegation(tag: int, alg: int, digest: int, key: str, *names) -> Name:
+    return Name(DS(tag, alg, digest, key), list(map(NS, names)))
 
 
 class Zone:
@@ -346,6 +369,20 @@ class Zone:
         # be done
         return cur_serial
     
+    @staticmethod
+    def generate_rrs_from_dict(root, domains):
+        for name in sorted(domains.keys(), key=lambda s: s.split('.')):
+            if name.endswith('.'):
+                raise Exception("You are trying to add a record outside of your zone. This is not supported. Use '@' for the zone root.")
+            domain = domains[name]
+            name = concatenate(root, name)
+            if isinstance(domain, dict):
+                for rr in Zone.generate_rrs_from_dict(name, domain):
+                    yield rr
+            else:
+                for rr in domain.generate_rrs():
+                    yield rr.relativize(name)
+    
     def generate_rrs(self) -> 'Iterator':
         # SOA record
         serial = self.inc_serial()
@@ -360,11 +397,8 @@ class Zone:
         for name in self._NS:
             yield NS(name).generate_rr()
         # all the rest
-        for name in sorted(self._domains.keys(), key=lambda s: list(reversed(s.split('.')))):
-            if name.endswith('.'):
-                raise Exception("You are trying to add a record outside of your zone. This is not supported. Use '@' for the zone root.")
-            for rr in self._domains[name].generate_rrs():
-                yield rr.relativize(name)
+        for rr in Zone.generate_rrs_from_dict('@', self._domains):
+            yield rr
     
     def write(self) -> None:
         print(";; {} zone file, generated by zonemaker <https://www.ralfj.de/projects/zonemaker> on {}".format(self._name, datetime.datetime.now()))