server/ControllerHelpers/MultipartRequestHelper.cs

@@ -0,0 +1,77 @@
+using System;
+using System.IO;
+using Microsoft.Net.Http.Headers;
+
+namespace Sockeye.Api.ControllerHelpers
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public static class MultipartRequestHelper
+    {
+        // Content-Type: multipart/form-data; boundary="----WebKitFormBoundarymx2fSWqWSd0OxQqq"
+        // The spec says 70 characters is a reasonable limit.
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="contentType"></param>
+        /// <param name="lengthLimit"></param>
+        /// <returns></returns>
+        public static string GetBoundary(MediaTypeHeaderValue contentType, int lengthLimit)
+        {
+            var boundary = HeaderUtilities.RemoveQuotes(contentType.Boundary).Value;
+            if (string.IsNullOrWhiteSpace(boundary))
+            {
+                throw new InvalidDataException("Missing content-type boundary.");
+            }
+
+            if (boundary.Length > lengthLimit)
+            {
+                throw new InvalidDataException(
+                    $"Multipart boundary length limit {lengthLimit} exceeded.");
+            }
+
+            return boundary;
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="contentType"></param>
+        /// <returns></returns>
+        public static bool IsMultipartContentType(string contentType)
+        {
+            return !string.IsNullOrEmpty(contentType)
+                   && contentType.IndexOf("multipart/", StringComparison.OrdinalIgnoreCase) >= 0;
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="contentDisposition"></param>
+        /// <returns></returns>
+        public static bool HasFormDataContentDisposition(ContentDispositionHeaderValue contentDisposition)
+        {
+            // Content-Disposition: form-data; name="key";
+            return contentDisposition != null
+                   && contentDisposition.DispositionType.Equals("form-data")
+                   && string.IsNullOrEmpty(contentDisposition.FileName.Value)
+                   && string.IsNullOrEmpty(contentDisposition.FileNameStar.Value);
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="contentDisposition"></param>
+        /// <returns></returns>
+        public static bool HasFileContentDisposition(ContentDispositionHeaderValue contentDisposition)
+        {
+            // Content-Disposition: form-data; name="myfile1"; filename="Misc 002.jpg"
+            return contentDisposition != null
+                   && contentDisposition.DispositionType.Equals("form-data")
+                   && (!string.IsNullOrEmpty(contentDisposition.FileName.Value)
+                       || !string.IsNullOrEmpty(contentDisposition.FileNameStar.Value));
+        }
+    }
+}