libcloud s3 using authentication version 4 protocol

gistfile1.diff

diff --git a/libcloud/storage/drivers/s3.py b/libcloud/storage/drivers/s3.py
index 9577f98..de15e72 100644
--- a/libcloud/storage/drivers/s3.py
+++ b/libcloud/storage/drivers/s3.py
@@ -13,14 +13,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import time
 import copy
 import base64
 import hmac
 import sys
-
 from hashlib import sha1
 
+from datetime import datetime
+from time import mktime
+from wsgiref.handlers import format_date_time
+
 try:
     from lxml.etree import Element, SubElement
 except ImportError:
@@ -100,16 +102,14 @@ class BaseS3Connection(ConnectionUserAndKey):
     responseCls = S3Response
     rawResponseCls = S3RawResponse
 
-    def add_default_params(self, params):
-        expires = str(int(time.time()) + EXPIRATION_SECONDS)
-        params['AWSAccessKeyId'] = self.user_id
-        params['Expires'] = expires
-        return params
-
     def pre_connect_hook(self, params, headers):
-        params['Signature'] = self._get_aws_auth_param(
+        stamp = mktime(datetime.now().timetuple())
+        date = format_date_time(stamp)
+        headers['date'] = date
+        signature = self._get_aws_auth_param(
             method=self.method, headers=headers, params=params,
-            expires=params['Expires'], secret_key=self.key, path=self.action)
+            expires=date, secret_key=self.key, path=self.action)
+        headers['Authorization'] = "AWS %s:%s" % (self.user_id, signature)
         return params, headers
 
     def _get_aws_auth_param(self, method, headers, params, expires,
@@ -170,6 +170,7 @@ class BaseS3Connection(ConnectionUserAndKey):
                 values_to_sign.append(value)
 
         string_to_sign = '\n'.join(values_to_sign)
+
         b64_hmac = base64.b64encode(
             hmac.new(b(secret_key), b(string_to_sign), digestmod=sha1).digest()
         )