[EC2 Query API] AttachVolume fails with 'Permission Denied: Invalid Signature' error.

https://reviews.apache.org/r/8480/

In AWSAPI while forming the signature to validate an API, url-encode every parameter name with UTF-8 encoding scheme.

awsapi/src/com/cloud/bridge/service/EC2RestServlet.java

diff --git a/awsapi/src/com/cloud/bridge/service/EC2RestServlet.java b/awsapi/src/com/cloud/bridge/service/EC2RestServlet.java
index 91e08be..78e736f 100644
--- a/awsapi/src/com/cloud/bridge/service/EC2RestServlet.java
+++ b/awsapi/src/com/cloud/bridge/service/EC2RestServlet.java
@@ -1770,8 +1770,8 @@
                     String paramName = (String) params.nextElement();
                     // exclude the signature string obviously. ;)
                     if (paramName.equalsIgnoreCase("Signature")) continue;
-                    if (queryString == null) 
-                        queryString = paramName + "=" + request.getParameter(paramName);
+                    if (queryString == null)
+                        queryString = paramName + "=" + URLEncoder.encode(request.getParameter(paramName), "UTF-8"); 
                     else 
                         queryString = queryString + "&" + paramName + "=" + URLEncoder.encode(request.getParameter(paramName), "UTF-8"); 
                 }