ACME timestamp parser: do not choke on nanoseconds.

plugins/module_utils/acme/backends.py

@@ -40,8 +40,31 @@
 )
 
 
+_FRACTIONAL_MATCHER = re.compile(r'^(\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2})(|\.\d+)(Z|[+-]\d{2}:?\d{2}.*)$')
+
+
+def _reduce_fractional_digits(timestamp_str):
+ """
+ Given a RFC 3339 timestamp that includes too many digits for the fractional seconds part, reduces these to at most 6.
+ """
+ # RFC 3339 (https://www.rfc-editor.org/info/rfc3339)
+ m = _FRACTIONAL_MATCHER.match(timestamp_str)
+ if not m:
+ raise BackendException('Cannot parse ISO 8601 timestamp {0!r}'.format(timestamp_str))
+ timestamp, fractional, timezone = m.groups()
+ if len(fractional) > 7:
+ # Python does not support anything smaller than microseconds
+ # (Golang supports nanoseconds, Boulder often emits more fractional digits, which Python chokes on)
+ fractional = fractional[:7]
+ return '%s%s%s' % (timestamp, fractional, timezone)
+
+
 def _parse_acme_timestamp(timestamp_str, with_timezone):
+ """
+ Parses a RFC 3339 timestamp.
+ """
  # RFC 3339 (https://www.rfc-editor.org/info/rfc3339)
+ timestamp_str = _reduce_fractional_digits(timestamp_str)
  for format in ('%Y-%m-%dT%H:%M:%SZ', '%Y-%m-%dT%H:%M:%S.%fZ', '%Y-%m-%dT%H:%M:%S%z', '%Y-%m-%dT%H:%M:%S.%f%z'):
  # Note that %z won't work with Python 2... https://stackoverflow.com/a/27829491
  try:

tests/unit/plugins/module_utils/acme/backend_data.py

@@ -117,6 +117,10 @@ def load_fixture(name):
  '2024-01-01T00:11:22.123Z',
  dict(year=2024, month=1, day=1, hour=0, minute=11, second=22, microsecond=123000),
  ),
+ (
+ '2024-04-17T06:54:13.333333334Z',
+ dict(year=2024, month=4, day=17, hour=6, minute=54, second=13, microsecond=333333.334),
+ ),
 ]
 
 if sys.version_info >= (3, 5):