#106 Fix: Adds Secure Cookie flag and tests

src/Microsoft.AspNetCore.Session/SessionMiddleware.cs

@@ -156,6 +156,14 @@ private void SetCookie()
                     HttpOnly = _options.CookieHttpOnly,
                     Path = _options.CookiePath ?? SessionDefaults.CookiePath,
                 };
+                if (_options.CookieSecure == CookieSecurePolicy.SameAsRequest)
+                {
+                    cookieOptions.Secure = _context.Request.IsHttps;
+                }
+                else
+                {
+                    cookieOptions.Secure = _options.CookieSecure == CookieSecurePolicy.Always;
+                }
 
                 _context.Response.Cookies.Append(_options.CookieName, _cookieValue, cookieOptions);
 

src/Microsoft.AspNetCore.Session/SessionOptions.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Session;
 
 namespace Microsoft.AspNetCore.Builder
@@ -35,6 +36,10 @@ public class SessionOptions
         /// </summary>
         public bool CookieHttpOnly { get; set; } = true;
 
+        /// <summary>
+        /// Determines if the cookie should only be transmitted on HTTPS requests. 
+        public CookieSecurePolicy CookieSecure { get; set; } = CookieSecurePolicy.None;
+
         /// <summary>
         /// The IdleTimeout indicates how long the session can be idle before its contents are abandoned. Each session access
         /// resets the timeout. Note this only applies to the content of the session, not the cookie.

test/Microsoft.AspNetCore.Session.Tests/SessionTests.cs

@@ -87,6 +87,59 @@ public async Task SettingAValueCausesTheCookieToBeCreated()
             }
         }
 
+        [Theory]
+        [InlineData(CookieSecurePolicy.Always, "http://example.com/testpath", true)]
+        [InlineData(CookieSecurePolicy.Always, "https://example.com/testpath", true)]
+        [InlineData(CookieSecurePolicy.None, "http://example.com/testpath", false)]
+        [InlineData(CookieSecurePolicy.None, "https://example.com/testpath", false)]
+        [InlineData(CookieSecurePolicy.SameAsRequest, "http://example.com/testpath", false)]
+        [InlineData(CookieSecurePolicy.SameAsRequest, "https://example.com/testpath", true)]
+        public async Task SecureSessionBasedOnHttpsAndSecurePolicy(
+            CookieSecurePolicy cookieSecurePolicy,
+            string requestUri,
+            bool shouldBeSecureOnly)
+        {
+            var builder = new WebHostBuilder()
+               .Configure(app =>
+               {
+                   app.UseSession(new SessionOptions
+                   {
+                       CookieName = "TestCookie",
+                       CookieSecure = cookieSecurePolicy
+                   });
+                   app.Run(context =>
+                   {
+                       Assert.Null(context.Session.GetString("Key"));
+                       context.Session.SetString("Key", "Value");
+                       Assert.Equal("Value", context.Session.GetString("Key"));
+                       return Task.FromResult(0);
+                   });
+               })
+               .ConfigureServices(services =>
+               {
+                   services.AddDistributedMemoryCache();
+                   services.AddSession();
+               });
+
+            using (var server = new TestServer(builder))
+            {
+                var client = server.CreateClient();
+                var response = await client.GetAsync(requestUri);
+                response.EnsureSuccessStatusCode();
+                IEnumerable<string> values;
+                Assert.True(response.Headers.TryGetValues("Set-Cookie", out values));
+                Assert.Equal(1, values.Count());
+                if (shouldBeSecureOnly)
+                {
+                    Assert.Contains("; secure", values.First());
+                }
+                else
+                {
+                    Assert.DoesNotContain("; secure", values.First());
+                }
+            }
+        }
+
         [Fact]
         public async Task SessionCanBeAccessedOnTheNextRequest()
         {