.NET SslStreamハンドシェイクで完全な暗号リストをデコードできません

Question

.NET SslStreamを使用して 'C'ベースのSSL実装からC＃に移行しようとしていますが、.NET SslStreamと私たちが接続しようとしているAS400マシン（以前は動作していました）。

我々はそれが次のように送信されるSslStream.AuthenticateAsClientを呼び出す：

16 03 00 00 37 01 00 00 33 03 00 4D 2C 00 EE 99 4E 0C 5D 83 14 77 78 5C 0F D3 8F 8B D5 E6 B8 CD 61 0F 29 08 AB 75 03 F7 FA（http://www.mozilla.org/projects/security/pki/nss/ssl/draft302.txtに基づく）としてデコード7D 70 00 00 0C 00 05 00 0A 00 13 00 04 00 02 00 FF 01 00

[16] Record Type 
[03 00] SSL Version 
[00 37] Body length 

[01] SSL3_MT_CLIENT_HELLO 
[00 00 33] Length (51 bytes) 

[03 00] Version number = 768 
[4d 2c 00 ee] 4 Bytes unix time 
[… ] 28 Bytes random number 
[00] Session number 
[00 0c] 12 bytes (2 * 6 Cyphers)? 
[00 05, 00 0a, 00 13, 00 04, 00 02, 00 ff] -> [RC4, PBE-MD5-DES, RSA, MD5, PKCS, ???] 
[01 00] Null compression method 

as400サーバーが返信します。

15 03 00 00 02 02 28 

[15] SSL3_RT_ALERT 
[03 00] SSL Version 
[00 02] Body Length (2 Bytes) 

[02 28] 2 = SSL3_RT_FATAL, 40 = SSL3_AD_HANDSHAKE_FAILURE 

私は具体的には、サイファーの最後に「FF」をデコードしようとしています。 正しくデコードしましたか？何があれば、'00 FF 'もデコードされますか？

私は再現/テストするには、次のコードを使用しています：

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
using System.Net.Sockets; 
using System.Net.Security; 
using System.Security.Authentication; 
using System.IO; 
using System.Diagnostics; 
using System.Security.Cryptography.X509Certificates; 

namespace TestSslStreamApp 
{ 
    class DebugStream : 
     Stream 
    { 
     private Stream AggregatedStream { get; set; } 

     public DebugStream(Stream stream) { AggregatedStream = stream; } 

     public override bool CanRead { get { return AggregatedStream.CanRead; } } 
     public override bool CanSeek { get { return AggregatedStream.CanSeek; } } 
     public override bool CanWrite { get { return AggregatedStream.CanWrite; } } 
     public override void Flush() { AggregatedStream.Flush(); } 
     public override long Length { get { return AggregatedStream.Length; } } 

     public override long Position 
     { 
      get { return AggregatedStream.Position; } 
      set { AggregatedStream.Position = value; } 
     } 

     public override int Read(byte[] buffer, int offset, int count) 
     { 
      int bytesRead = AggregatedStream.Read(buffer, offset, count); 

      return bytesRead; 
     } 

     public override long Seek(long offset, SeekOrigin origin) { return AggregatedStream.Seek(offset, origin); } 
     public override void SetLength(long value) { AggregatedStream.SetLength(value); } 

     public override void Write(byte[] buffer, int offset, int count) 
     { 
      AggregatedStream.Write(buffer, offset, count); 
     } 
    } 

    class Program 
    { 
     static void Main(string[] args) 
     { 
      const string HostName = "as400"; 

      TcpClient tcpClient = new TcpClient(HostName, 992); 

      SslStream sslStream = new SslStream(new DebugStream(tcpClient.GetStream()), false, null, null, 
                EncryptionPolicy.AllowNoEncryption); 

      sslStream.AuthenticateAsClient(HostName, null, SslProtocols.Ssl3, false); 
     } 
    } 
} 

Answer 1

出典：RFC 5746 TLS Renegotiation Extension

3.3. Renegotiation Protection Request Signaling Cipher Suite Value 

    Both the SSLv3 and TLS 1.0/TLS 1.1 specifications require 
    implementations to ignore data following the ClientHello (i.e., 
    extensions) if they do not understand it. However, some SSLv3 and 
    TLS 1.0 implementations incorrectly fail the handshake in such a 
    case. This means that clients that offer the "renegotiation_info" 
    extension may encounter handshake failures. In order to enhance 
    compatibility with such servers, this document defines a second 
    signaling mechanism via a special Signaling Cipher Suite Value (SCSV) 
    "TLS_EMPTY_RENEGOTIATION_INFO_SCSV", with code point {0x00, 0xFF}. 
    This SCSV is not a true cipher suite (it does not correspond to any 
    valid set of algorithms) and cannot be negotiated. Instead, it has 
    the same semantics as an empty "renegotiation_info" extension, as 
    described in the following sections. Because SSLv3 and TLS 
    implementations reliably ignore unknown cipher suites, the SCSV may 
    be safely sent to any server. The SCSV can also be included in the 
    SSLv2 backward compatible CLIENT-HELLO (see Appendix E.2 of 
    [RFC5246]).

Answer 2

あなたのCの実装が送信されている情報を確認して、どのSSLを見ることであろう最も簡単な方法それが要求するバージョンと暗号スイート、そして結局どのサーバがSSLバージョンと選択された暗号スイートで応答しているかを調べます。