短縮URL展開時にHTTPSが使用できるドメインは強制的にHTTPSを使用する

[opentween/open-tween.git] / OpenTween / ShortUrl.cs

diff --git a/OpenTween/ShortUrl.cs b/OpenTween/ShortUrl.cs
index 1a8255c..2edf8c5 100644 (file)
--- a/OpenTween/ShortUrl.cs
+++ b/OpenTween/ShortUrl.cs
@@ -117,6 +117,23 @@ namespace OpenTween
             "youtu.be",
         };
 
+        /// <summary>
+        /// HTTPS非対応の短縮URLサービス
+        /// </summary>
+        private static readonly HashSet<string> InsecureDomains = new HashSet<string>
+        {
+            "budurl.com",
+            "ff.im",
+            "ht.ly",
+            "htn.to",
+            "moi.st",
+            "ow.ly",
+            "tinami.jp",
+            "tl.gd",
+            "twme.jp",
+            "urx2.nu",
+        };
+
         static ShortUrl()
             => _instance = new Lazy<ShortUrl>(() => new ShortUrl(), true);
 
@@ -443,6 +460,8 @@ namespace OpenTween
 
         private async Task<Uri> GetRedirectTo(Uri url)
         {
+            url = this.UpgradeToHttpsIfAvailable(url);
+
             var request = new HttpRequestMessage(HttpMethod.Head, url);
 
             using (var response = await this.http.SendAsync(request).ConfigureAwait(false))
@@ -472,6 +491,24 @@ namespace OpenTween
             }
         }
 
+        /// <summary>
+        /// 指定されたURLのスキームを https:// に書き換える
+        /// </summary>
+        private Uri UpgradeToHttpsIfAvailable(Uri original)
+        {
+            if (original.Scheme != "http")
+                return original;
+
+            if (InsecureDomains.Contains(original.Host))
+                return original;
+
+            var builder = new UriBuilder(original);
+            builder.Scheme = "https";
+            builder.Port = 443;
+
+            return builder.Uri;
+        }
+
         [SuppressMessage("Microsoft.Reliability", "CA2000:DisposeObjectsBeforeLosingScope")]
         private static HttpClient CreateDefaultHttpClient()
         {