example ruby on rails backend

mule-uploader.js

@@ -344,6 +344,7 @@
             XHR({
                 url: u.settings.ajax_base + "/signing_key/",
                 extra_params: args,
+                headers: u.settings.headers, //allow headers to be passed in from settings
                 load_callback: function(e) {
                     var json = JSON.parse(e.target.responseText);
                     json.date = new Date(json.date);

rails_backend/mule_controller.rb

@@ -0,0 +1,129 @@
+class MuleController < ApplicationController
+
+
+    AWS_ACCESS_KEY = 'AWS_ACCESS_KEY'
+    AWS_SECRET = 'AWS_SECRET_KEY'
+    BUCKET = 'YOUR_BUCKET'
+
+    AWS_REGION = 'us-east-1'
+    MIME_TYPE = 'application/octet-stream'
+    CHUNK_SIZE = 6 * 1024 * 1024  # 6MB
+
+
+    def signing_key 
+
+        date = Time.now
+
+        key = get_signature(date)
+
+
+        data = {
+            date: date.utc.iso8601,
+            signature: key,
+            access_key: AWS_ACCESS_KEY,
+            region: AWS_REGION,
+            bucket: BUCKET,
+            backup_key: 1000,
+            content_type: MIME_TYPE,
+        }
+
+        render json: data
+
+    end
+
+
+
+
+    def chunk_loaded
+
+        key = params[:key]
+        upload_id = params[:upload_id]
+        chunk = params[:chunk]
+
+
+        filename = params[:filename]
+        filesize = params[:filesize].to_i
+        last_modified = params[:last_modified]
+        chunk = params[:chunk].to_i
+
+        if filesize > CHUNK_SIZE
+
+
+               upload = Upload.where(filename: filename)
+                                .and(filesize: filesize)
+                                .and(last_modified: last_modified).first
+
+
+
+               if upload
+
+                   upload.chunks_uploaded << chunk
+                   upload.chunks_uploaded = upload.chunks_uploaded.uniq
+                   upload.save
+
+               else
+
+
+
+                  upload = Upload.create( filename: filename,
+                                          filesize: filesize,
+                                          last_modified: last_modified, 
+                                          chunks_uploaded: [chunk], 
+                                          key: key, 
+                                          upload_id: upload_id)
+
+               end
+
+          end
+
+
+         render json: {}
+
+    end
+
+
+
+
+
+
+private
+
+
+
+     def bin_to_hex(s)
+
+       s.unpack('H*')[0]
+
+     end
+
+
+     def sign(key, msg)
+
+         sha256 = OpenSSL::Digest::Digest.new('sha256')
+         hmac =  OpenSSL::HMAC.digest(sha256, key, msg.encode("utf-8"))
+         hmac
+
+     end
+
+
+     def get_signature_key(key, date_stamp, region_name, service_name)
+         k_date = sign(("AWS4" + key).encode("utf-8"), date_stamp)
+         k_region = sign(k_date, region_name)
+         k_service = sign(k_region, service_name)
+         k_signing = sign(k_service, "aws4_request")
+         k_signing
+
+     end
+
+
+     def get_signature(date)
+
+         sig_key = get_signature_key(AWS_SECRET, date.utc.strftime("%Y%m%d"), AWS_REGION, "s3")
+         result = bin_to_hex(sig_key)
+         result
+
+     end
+
+
+
+end