fixed CER/DER codec for GeneralizedTime/UTCTime

1 files changed, 33 insertions, 28 deletions

diff --git a/pyasn1/codec/cer/encoder.py b/pyasn1/codec/cer/encoder.py
index 17728c6..021fd22 100644
--- a/pyasn1/codec/cer/encoder.py
+++ b/pyasn1/codec/cer/encoder.py
@@ -7,7 +7,7 @@
 from pyasn1.type import univ
 from pyasn1.type import useful
 from pyasn1.codec.ber import encoder
-from pyasn1.compat.octets import int2oct, str2octs, null
+from pyasn1.compat.octets import str2octs, null
 from pyasn1 import error
 
 __all__ = ['encode']
@@ -44,46 +44,51 @@ class RealEncoder(encoder.RealEncoder):
 
 # specialized GeneralStringEncoder here
 
-class GeneralizedTimeEncoder(OctetStringEncoder):
-    zchar = str2octs('Z')
-    pluschar = str2octs('+')
-    minuschar = str2octs('-')
-    zero = str2octs('0')
+class TimeEncoderMixIn(object):
+    zchar, = str2octs('Z')
+    pluschar, = str2octs('+')
+    minuschar, = str2octs('-')
+    commachar, = str2octs(',')
+    minLength = 12
+    maxLength = 19
 
     def encodeValue(self, encodeFun, client, defMode, maxChunkSize):
+        # Encoding constraints:
+        # - minutes are mandatory, seconds are optional
+        # - subseconds must NOT be zero
+        # - no hanging fraction dot
+        # - time in UTC (Z)
+        # - only dot is allowed for fractions
+
         octets = client.asOctets()
-        # This breaks too many existing data items
-        #        if '.' not in octets:
-        #            raise error.PyAsn1Error('Format must include fraction of second: %r' % octets)
-        if len(octets) < 15:
-            raise error.PyAsn1Error('Bad UTC time length: %r' % octets)
+
+        if not self.minLength < len(octets) < self.maxLength:
+            raise error.PyAsn1Error('Length constraint violated: %r' % client)
+
         if self.pluschar in octets or self.minuschar in octets:
             raise error.PyAsn1Error('Must be UTC time: %r' % octets)
-        if octets[-1] != self.zchar[0]:
-            raise error.PyAsn1Error('Missing timezone specifier: %r' % octets)
-        return encoder.OctetStringEncoder.encodeValue(
-            self, encodeFun, client, defMode, 1000
-        )
 
+        if octets[-1] != self.zchar:
+            raise error.PyAsn1Error('Missing "Z" time zone specifier: %r' % octets)
 
-class UTCTimeEncoder(encoder.OctetStringEncoder):
-    zchar = str2octs('Z')
-    pluschar = str2octs('+')
-    minuschar = str2octs('-')
+        if self.commachar in octets:
+            raise error.PyAsn1Error('Comma in fractions disallowed: %r' % client)
 
-    def encodeValue(self, encodeFun, client, defMode, maxChunkSize):
-        octets = client.asOctets()
-        if self.pluschar in octets or self.minuschar in octets:
-            raise error.PyAsn1Error('Must be UTC time: %r' % octets)
-        if octets and octets[-1] != self.zchar[0]:
-            client = client.clone(octets + self.zchar)
-        if len(client) != 13:
-            raise error.PyAsn1Error('Bad UTC time length: %r' % client)
         return encoder.OctetStringEncoder.encodeValue(
             self, encodeFun, client, defMode, 1000
         )
 
 
+class GeneralizedTimeEncoder(TimeEncoderMixIn, OctetStringEncoder):
+    minLength = 12
+    maxLength = 19
+
+
+class UTCTimeEncoder(TimeEncoderMixIn, encoder.OctetStringEncoder):
+    minLength = 10
+    maxLength = 14
+
+
 class SetOfEncoder(encoder.SequenceOfEncoder):
     @staticmethod
     def _sortComponents(components):