Accepts aws-sdk-java timestamp format

The aws-sdk-java timestamp format is "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"
which contains millisecond representation. However, the current
implementation does not accept this kind of format.

References:
https://github.com/aws/aws-sdk-java/blob/master/src/main/java/com/amazonaws/auth/QueryStringSigner.java#L173

Adds ability to parse this format in ec2utils.is_ec2_timestamp_expired.

Fixes bug 1156445.

Change-Id: I389ff8b9c6c91b699538b889add264d66dbb8131

2 files changed, 33 insertions, 4 deletions

diff --git a/nova/api/ec2/ec2utils.py b/nova/api/ec2/ec2utils.py
index bb0f7245a..46f45f3f0 100644
--- a/nova/api/ec2/ec2utils.py
+++ b/nova/api/ec2/ec2utils.py
@@ -178,6 +178,9 @@ def ec2_vol_id_to_uuid(ec2_id):
     return get_volume_uuid_from_int_id(ctxt, int_id)
 
 
+_ms_time_regex = re.compile('^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3,6}Z$')
+
+
 def is_ec2_timestamp_expired(request, expires=None):
     """Checks the timestamp or expiry time included in an EC2 request
     and returns true if the request is expired
@@ -185,6 +188,15 @@ def is_ec2_timestamp_expired(request, expires=None):
     query_time = None
     timestamp = request.get('Timestamp')
     expiry_time = request.get('Expires')
+
+    def parse_strtime(strtime):
+        if _ms_time_regex.match(strtime):
+            # NOTE(MotoKen): time format for aws-sdk-java contains millisecond
+            time_format = "%Y-%m-%dT%H:%M:%S.%fZ"
+        else:
+            time_format = "%Y-%m-%dT%H:%M:%SZ"
+        return timeutils.parse_strtime(strtime, time_format)
+
     try:
         if timestamp and expiry_time:
             msg = _("Request must include either Timestamp or Expires,"
@@ -192,12 +204,10 @@ def is_ec2_timestamp_expired(request, expires=None):
             LOG.error(msg)
             raise exception.InvalidRequest(msg)
         elif expiry_time:
-            query_time = timeutils.parse_strtime(expiry_time,
-                                        "%Y-%m-%dT%H:%M:%SZ")
+            query_time = parse_strtime(expiry_time)
             return timeutils.is_older_than(query_time, -1)
         elif timestamp:
-            query_time = timeutils.parse_strtime(timestamp,
-                                        "%Y-%m-%dT%H:%M:%SZ")
+            query_time = parse_strtime(timestamp)
 
             # Check if the difference between the timestamp in the request
             # and the time on our servers is larger than 5 minutes, the
diff --git a/nova/tests/api/ec2/test_ec2_validate.py b/nova/tests/api/ec2/test_ec2_validate.py
index 24d226335..9b67d67a1 100644
--- a/nova/tests/api/ec2/test_ec2_validate.py
+++ b/nova/tests/api/ec2/test_ec2_validate.py
@@ -194,6 +194,25 @@ class EC2TimestampValidationTestCase(test.TestCase):
         expired = ec2utils.is_ec2_timestamp_expired(params)
         self.assertFalse(expired)
 
+    def test_validate_ec2_timestamp_ms_time_regex(self):
+        result = ec2utils._ms_time_regex.match('2011-04-22T11:29:49.123Z')
+        self.assertIsNotNone(result)
+        result = ec2utils._ms_time_regex.match('2011-04-22T11:29:49.123456Z')
+        self.assertIsNotNone(result)
+        result = ec2utils._ms_time_regex.match('2011-04-22T11:29:49.1234567Z')
+        self.assertIsNone(result)
+        result = ec2utils._ms_time_regex.match('2011-04-22T11:29:49.123')
+        self.assertIsNone(result)
+        result = ec2utils._ms_time_regex.match('2011-04-22T11:29:49Z')
+        self.assertIsNone(result)
+
+    def test_validate_ec2_timestamp_aws_sdk_format(self):
+        params = {'Timestamp': '2011-04-22T11:29:49.123Z'}
+        expired = ec2utils.is_ec2_timestamp_expired(params)
+        self.assertFalse(expired)
+        expired = ec2utils.is_ec2_timestamp_expired(params, expires=300)
+        self.assertTrue(expired)
+
     def test_validate_ec2_timestamp_invalid_format(self):
         params = {'Timestamp': '2011-04-22T11:29:49.000P'}
         expired = ec2utils.is_ec2_timestamp_expired(params)