POST / HTTP/1.1
Host: us-east-1.ec2.amazonaws.com
Connection: close
Accept-encoding: gzip, deflate
User-Agent: Zend_Http_Client
Content-Type: application/x-www-form-urlencoded
Content-Length: 233

Action=DescribeAvailabilityZones&AWSAccessKeyId=0123456789&SignatureVersion=2&Timestamp=2011-10-04T10%3A20%3A49Z&Version=2009-04-04&SignatureMethod=HmacSHA256&Signature=LVze4BB8t%2FDxjV%2FHBaMAwihBGSfJOACF75dEg1%2Ff%2BrQ%3D