From 565ca51ee3ebed90da88c3c3142a6a76f9658290 Mon Sep 17 00:00:00 2001
From: Erik Zhang <erik@vcage.com>
Date: Wed, 26 Oct 2016 16:24:12 +0800
Subject: [PATCH] fix bugs;

---
 .../Cryptography/CertificateQueryService.cs   | 87 +++++++++++++------
 AntSharesUI/UI/MainForm.cs                    | 15 +++-
 2 files changed, 74 insertions(+), 28 deletions(-)

diff --git a/AntSharesUI/Cryptography/CertificateQueryService.cs b/AntSharesUI/Cryptography/CertificateQueryService.cs
index cada1bba4f..31ce3f1878 100644
--- a/AntSharesUI/Cryptography/CertificateQueryService.cs
+++ b/AntSharesUI/Cryptography/CertificateQueryService.cs
@@ -1,6 +1,8 @@
-using AntShares.Core;
-using AntShares.Cryptography.ECC;
+using AntShares.Cryptography.ECC;
 using AntShares.Properties;
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
 using System.IO;
 using System.Net;
 using System.Security.Cryptography;
@@ -10,56 +12,91 @@ namespace AntShares.Cryptography
 {
     internal static class CertificateQueryService
     {
-        public static CertificateQueryResult Query(ECPoint pubkey, string url)
+        private static WebClient web = new WebClient();
+        private static Dictionary<ECPoint, CertificateQueryResult> results = new Dictionary<ECPoint, CertificateQueryResult>();
+
+        static CertificateQueryService()
         {
-            if (pubkey.Equals(Blockchain.AntShare.Issuer) || pubkey.Equals(Blockchain.AntCoin.Issuer))
-                return new CertificateQueryResult { Type = CertificateQueryResultType.System };
             Directory.CreateDirectory(Settings.Default.CertCachePath);
+            web.DownloadFileCompleted += Web_DownloadFileCompleted;
+        }
+
+        private static void Web_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
+        {
+            ECPoint pubkey = (ECPoint)e.UserState;
+            lock (results)
+            {
+                if (e.Cancelled || e.Error != null)
+                    results[pubkey].Type = CertificateQueryResultType.Missing;
+                else
+                    UpdateResultFromFile(pubkey);
+            }
+        }
+
+        public static CertificateQueryResult Query(ECPoint pubkey, string url)
+        {
+            lock (results)
+            {
+                if (results.ContainsKey(pubkey)) return results[pubkey];
+                results[pubkey] = new CertificateQueryResult { Type = CertificateQueryResultType.Querying };
+            }
             string path = Path.Combine(Settings.Default.CertCachePath, $"{pubkey}.cer");
-            if (!File.Exists(path))
+            if (File.Exists(path))
             {
-                if (string.IsNullOrEmpty(url))
-                    url = $"http://cert.onchain.com/antshares/{pubkey}.cer";
-                using (WebClient web = new WebClient())
+                lock (results)
                 {
-                    try
-                    {
-                        web.DownloadFile(url, path);
-                    }
-                    catch (WebException) { }
+                    UpdateResultFromFile(pubkey);
                 }
             }
-            if (!File.Exists(path))
-                return new CertificateQueryResult { Type = CertificateQueryResultType.Missing };
+            else
+            {
+                if (string.IsNullOrEmpty(url))
+                    url = $"http://cert.onchain.com/antshares/{pubkey}.cer";
+                web.DownloadFileAsync(new Uri(url), path, pubkey);
+            }
+            return results[pubkey];
+
+            //if (!File.Exists(path))
+            //    return new CertificateQueryResult { Type = CertificateQueryResultType.Missing };
+        }
+
+        private static void UpdateResultFromFile(ECPoint pubkey)
+        {
             X509Certificate2 cert;
             try
             {
-                cert = new X509Certificate2(path);
+                cert = new X509Certificate2(Path.Combine(Settings.Default.CertCachePath, $"{pubkey}.cer"));
             }
             catch (CryptographicException)
             {
-                return new CertificateQueryResult { Type = CertificateQueryResultType.Missing };
+                results[pubkey].Type = CertificateQueryResultType.Missing;
+                return;
             }
             if (cert.PublicKey.Oid.Value != "1.2.840.10045.2.1")
-                return new CertificateQueryResult { Type = CertificateQueryResultType.Missing };
+            {
+                results[pubkey].Type = CertificateQueryResultType.Missing;
+                return;
+            }
             if (!pubkey.Equals(ECPoint.DecodePoint(cert.PublicKey.EncodedKeyValue.RawData, ECCurve.Secp256r1)))
-                return new CertificateQueryResult { Type = CertificateQueryResultType.Missing };
+            {
+                results[pubkey].Type = CertificateQueryResultType.Missing;
+                return;
+            }
             using (X509Chain chain = new X509Chain())
             {
-                CertificateQueryResult result = new CertificateQueryResult { Certificate = cert };
+                results[pubkey].Certificate = cert;
                 if (chain.Build(cert))
                 {
-                    result.Type = CertificateQueryResultType.Good;
+                    results[pubkey].Type = CertificateQueryResultType.Good;
                 }
                 else if (chain.ChainStatus.Length == 1 && chain.ChainStatus[0].Status == X509ChainStatusFlags.NotTimeValid)
                 {
-                    result.Type = CertificateQueryResultType.Expired;
+                    results[pubkey].Type = CertificateQueryResultType.Expired;
                 }
                 else
                 {
-                    result.Type = CertificateQueryResultType.Invalid;
+                    results[pubkey].Type = CertificateQueryResultType.Invalid;
                 }
-                return result;
             }
         }
     }
diff --git a/AntSharesUI/UI/MainForm.cs b/AntSharesUI/UI/MainForm.cs
index 3473b9c1d9..dfdf4619f9 100644
--- a/AntSharesUI/UI/MainForm.cs
+++ b/AntSharesUI/UI/MainForm.cs
@@ -257,9 +257,18 @@ private void timer1_Tick(object sender, EventArgs e)
             {
                 ListViewItem.ListViewSubItem subitem = item.SubItems["issuer"];
                 RegisterTransaction asset = (RegisterTransaction)item.Tag;
-                byte[] cert_url_data = asset.Attributes.FirstOrDefault(p => p.Usage == TransactionAttributeUsage.CertUrl)?.Data;
-                string cert_url = cert_url_data == null ? null : Encoding.UTF8.GetString(cert_url_data);
-                using (CertificateQueryResult result = CertificateQueryService.Query(asset.Issuer, cert_url))
+                CertificateQueryResult result;
+                if (asset.AssetType == AssetType.AntShare || asset.AssetType == AssetType.AntCoin)
+                {
+                    result = new CertificateQueryResult { Type = CertificateQueryResultType.System };
+                }
+                else
+                {
+                    byte[] cert_url_data = asset.Attributes.FirstOrDefault(p => p.Usage == TransactionAttributeUsage.CertUrl)?.Data;
+                    string cert_url = cert_url_data == null ? null : Encoding.UTF8.GetString(cert_url_data);
+                    result = CertificateQueryService.Query(asset.Issuer, cert_url);
+                }
+                using (result)
                 {
                     switch (result.Type)
                     {