Basic support for minecraft 1.19 (#2084)

* merge commit from milutinke
* chat signature & encrypted login
* Bug fix :EncryptionResponse format error below 1.18.2
* Implemented chat command signature
* Chat message parsing and verification for 1.19
* Add signature settings
* Update Simplified Chinese Translation
* Clear up comments
* Fix wrong variable naming
* Bug fix: SignatureV2 Processing

MinecraftClient/Protocol/ProfileKey/KeyUtils.cs

@@ -0,0 +1,137 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MinecraftClient.Protocol.Keys
+{
+    static class KeyUtils
+    {
+        private static string certificates = "https://api.minecraftservices.com/player/certificates";
+
+        public static PlayerKeyPair? GetKeys(string accessToken)
+        {
+            ProxiedWebRequest.Response? response = null;
+            try
+            {
+                var request = new ProxiedWebRequest(certificates)
+                {
+                    Accept = "application/json"
+                };
+                request.Headers.Add("Authorization", string.Format("Bearer {0}", accessToken));
+
+                response = request.Post("application/json", "");
+
+                if (Settings.DebugMessages)
+                {
+                    ConsoleIO.WriteLine(response.Body.ToString());
+                }
+
+                string jsonString = response.Body;
+                Json.JSONData json = Json.ParseJson(jsonString);
+
+                PublicKey publicKey = new(pemKey: json.Properties["keyPair"].Properties["publicKey"].StringValue,
+                    sig: json.Properties["publicKeySignature"].StringValue,
+                    sigV2: json.Properties["publicKeySignatureV2"].StringValue);
+
+                PrivateKey privateKey = new(pemKey: json.Properties["keyPair"].Properties["privateKey"].StringValue);
+
+                return new PlayerKeyPair(publicKey, privateKey,
+                    expiresAt: json.Properties["expiresAt"].StringValue,
+                    refreshedAfter: json.Properties["refreshedAfter"].StringValue);
+            }
+            catch (Exception e)
+            {
+                int code = (response == null) ? 0 : response.StatusCode;
+                ConsoleIO.WriteLineFormatted("§cFetch profile key failed: HttpCode = " + code + ", Error = " + e.Message);
+                if (Settings.DebugMessages)
+                {
+                    ConsoleIO.WriteLineFormatted("§c" + e.StackTrace);
+                }
+                return null;
+            }
+        }
+
+        public static byte[] DecodePemKey(String key, String prefix, String suffix)
+        {
+            int i = key.IndexOf(prefix);
+            if (i != -1)
+            {
+                i += prefix.Length;
+                int j = key.IndexOf(suffix, i);
+                key = key[i..j];
+            }
+            key = key.Replace("\r", String.Empty);
+            key = key.Replace("\n", String.Empty);
+            return Convert.FromBase64String(key);
+        }
+
+        public static byte[] GetSignatureData(string message, string uuid, DateTimeOffset timestamp, ref byte[] salt)
+        {
+            List<byte> data = new();
+
+            data.AddRange(salt);
+
+            byte[] UUIDLeastSignificantBits = BitConverter.GetBytes(Convert.ToInt64(uuid[..16], 16));
+            Array.Reverse(UUIDLeastSignificantBits);
+            data.AddRange(UUIDLeastSignificantBits);
+
+            byte[] UUIDMostSignificantBits = BitConverter.GetBytes(Convert.ToInt64(uuid.Substring(16, 16), 16));
+            Array.Reverse(UUIDMostSignificantBits);
+            data.AddRange(UUIDMostSignificantBits);
+
+            byte[] timestampByte = BitConverter.GetBytes(timestamp.ToUnixTimeSeconds());
+            Array.Reverse(timestampByte);
+            data.AddRange(timestampByte);
+
+            data.AddRange(Encoding.UTF8.GetBytes(message));
+
+            return data.ToArray();
+        }
+
+        // https://github.com/mono/mono/blob/master/mcs/class/System.Json/System.Json/JsonValue.cs
+        public static string EscapeString(string src)
+        {
+            StringBuilder sb = new();
+
+            int start = 0;
+            for (int i = 0; i < src.Length; i++)
+            {
+                char c = src[i];
+                bool needEscape = c < 32 || c == '"' || c == '\\';
+                // Broken lead surrogate
+                needEscape = needEscape || (c >= '\uD800' && c <= '\uDBFF' &&
+                    (i == src.Length - 1 || src[i + 1] < '\uDC00' || src[i + 1] > '\uDFFF'));
+                // Broken tail surrogate
+                needEscape = needEscape || (c >= '\uDC00' && c <= '\uDFFF' &&
+                    (i == 0 || src[i - 1] < '\uD800' || src[i - 1] > '\uDBFF'));
+                // To produce valid JavaScript
+                needEscape = needEscape || c == '\u2028' || c == '\u2029';
+
+                if (needEscape)
+                {
+                    sb.Append(src, start, i - start);
+                    switch (src[i])
+                    {
+                        case '\b': sb.Append("\\b"); break;
+                        case '\f': sb.Append("\\f"); break;
+                        case '\n': sb.Append("\\n"); break;
+                        case '\r': sb.Append("\\r"); break;
+                        case '\t': sb.Append("\\t"); break;
+                        case '\"': sb.Append("\\\""); break;
+                        case '\\': sb.Append("\\\\"); break;
+                        default:
+                            sb.Append("\\u");
+                            sb.Append(((int)src[i]).ToString("x04"));
+                            break;
+                    }
+                    start = i + 1;
+                }
+
+            }
+            sb.Append(src, start, src.Length - start);
+            return sb.ToString();
+        }
+    }
+}