1 files changed, 110 insertions, 0 deletions
diff --git a/scripts/rpki/sundial.py b/scripts/rpki/sundial.py
new file mode 100644
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+++ b/scripts/rpki/sundial.py
@@ -0,0 +1,110 @@
+# $Id$
+
+"""Unified RPKI date/time handling, based on the standard Python datetime module.
+
+Module name chosen to sidestep a nightmare of import-related errors
+that occur with the more obvious module names.
+"""
+
+import datetime as pydatetime
+
+class datetime(pydatetime.datetime):
+  """RPKI extensions to standard datetime.datetime class.  All work
+  here is in UTC, so we use naive datetime objects.
+  """
+
+  def totimestamp(self):
+    """Convert to seconds from epoch (like time.time()).  Conversion
+    method is a bit silly, but avoids time module timezone whackiness.
+    """
+    return int(self.strftime("%s"))
+
+  @classmethod
+  def fromUTCTime(cls, x):
+    """Convert from ASN.1 UTCTime."""
+    return cls.strptime(x, "%y%m%d%H%M%SZ")
+
+  def toUTCTime(self):
+    """Convert to ASN.1 UTCTime."""
+    return self.strftime("%y%m%d%H%M%SZ")
+
+  @classmethod
+  def fromGeneralizedTime(cls, x):
+    """Convert from ASN.1 GeneralizedTime."""
+    return cls.strptime(x, "%Y%m%d%H%M%SZ")
+
+  def toGeneralizedTime(self):
+    """Convert to ASN.1 GeneralizedTime."""
+    return self.strftime("%Y%m%d%H%M%SZ")
+
+  @classmethod
+  def fromASN1tuple(cls, x):
+    """Convert from ASN.1 tuple representation."""
+    assert isinstance(x, tuple) and len(x) == 2 and x[0] in ("utcTime", "generalTime")
+    if x[0] == "utcTime":
+      return cls.fromUTCTime(x)
+    else:
+      return cls.fromGeneralizedTime(x)
+
+  ## @var PKIX_threshhold
+  # Threshold specified in RFC 3280 for switchover from UTCTime to GeneralizedTime.
+
+  PKIX_threshhold = pydatetime.datetime(2050, 1, 1)
+
+  def toASN1tuple(self):
+    """Convert to ASN.1 tuple representation."""
+    if self < self.PKIX_threshhold:
+      return "utcTime", self.toUTCTime()
+    else:
+      return "generalTime", self.toGeneralizedTime()
+
+  @classmethod
+  def fromXMLtime(cls, x):
+    """Convert from XML time representation."""
+    return cls.strptime(x, "%Y-%m-%dT%H:%M:%SZ")
+
+  def toXMLtime(self):
+    """Convert to XML time representation."""
+    return self.strftime("%Y-%m-%dT%H:%M:%SZ")
+
+  @classmethod
+  def _cast(cls, x):
+    """Convert a datetime.datetime object into this subclass.
+    This is whacky due to the weird constructors for datetime.
+    """
+    return cls.combine(x.date(), x.time())
+
+  def __add__(self, other):
+    """Force correct class for timedelta results."""
+    return self._cast(pydatetime.datetime.__add__(self, other))
+  
+  def __sub__(self, other):
+    """Force correct class for timedelta results."""
+    return self._cast(pydatetime.datetime.__sub__(self, other))
+  
+# Alias to simplify imports for callers
+
+timedelta = pydatetime.timedelta
+
+if __name__ == "__main__":
+
+  now = datetime.utcnow()
+  print now
+  print repr(now)
+  print now.strftime("%s")
+  print now.toUTCTime()
+  print now.toGeneralizedTime()
+  print now.toASN1tuple()
+  print now.toXMLtime()
+
+  print
+
+  then = now
+  then += timedelta(days = 30)
+  print then
+  print repr(then)
+  print then.strftime("%s")
+  print then.toUTCTime()
+  print then.toGeneralizedTime()
+  print then.toASN1tuple()
+  print then.toXMLtime()