[aws|storage] first pass at helper for building forms to post to s3

lib/fog/aws/requests/storage/post_object_hidden_fields.rb

@@ -0,0 +1,49 @@
+module Fog
+  module AWS
+    class Storage
+      class Real
+
+        # Get a hash of hidden fields for form uploading to S3, in the form {:field_name => :field_value}
+        # Form should look like: <form action="http://#{bucket_name}.s3.amazonaws.com/" method="post" enctype="multipart/form-data">
+        # These hidden fields should then appear, followed by a field named 'file' which is either a textarea or file input.
+        #
+        # ==== Parameters
+        # * options<~Hash>:
+        #   * acl<~String> - access control list, in ['private', 'public-read', 'public-read-write', 'authenticated-read', 'bucket-owner-read', 'bucket-owner-full-control']
+        #   * Cache-Control - same as REST header
+        #   * Content-Type - same as REST header
+        #   * Content-Disposition - same as REST header
+        #   * Content-Encoding - same as REST header
+        #   * Expires - same as REST header
+        #   * key - key for object, set to '${filename}' to use filename provided by user
+        #   * policy - security policy for upload
+        #   * success_action_redirect - url to redirct to upon success
+        #   * success_action_status - status code to return on success, in [200, 201, 204]
+        #   * x-amz-security-token - devpay security token
+        #   * x-amz-meta-... - meta data tags
+        #
+        # See also: http://docs.amazonwebservices.com/AmazonS3/latest/dev/HTTPPOSTForms.html
+        #
+        def post_object_hidden_fields(options = {})
+          if options['policy']
+            options['policy'] = options['policy'].to_json
+            options['AWSAccessKeyId'] = @aws_access_key_id
+            string_to_sign = Base64.encode64(options['policy']).chomp!
+            signed_string = @hmac.sign(string_to_sign)
+            options['Signature'] = Base64.encode64(signed_string).chomp!
+          end
+          options
+        end
+
+      end
+
+      class Mock
+
+        def post_object_hidden_fields(options = {})
+          Fog::Mock.not_implemented
+        end
+
+      end
+    end
+  end
+end

lib/fog/aws/storage.rb

@@ -27,6 +27,7 @@ module Fog
       request :get_request_payment
       request :get_service
       request :head_object
+      request :post_object_hidden_fields
       request :put_bucket
       request :put_bucket_acl
       request :put_bucket_logging