握手后的 TLS 和警报 21

Question

我们有一个运行 TLS v1.0 的客户端/服务器，并在初始握手后不断从客户端获取加密警报 21。他们正在使用密码块链接，我已经阅读了块密码输入长度与块长度的倍数以外的其他内容不同的地方会导致解密失败警报，但是我如何\在哪里找到这些值以确定这是否是真实的警报的原因？

我在下面附上了握手序列......谢谢......感谢它

安全链路层

TLSv1 Record Layer: Handshake Protocol: Client Hello ##
    Content Type: Handshake (22)###
    Version: TLS 1.0 (0x0301)
    Length: 254
    Handshake Protocol: Client Hello
        Handshake Type: Client Hello (1)
        Length: 250
        Version: TLS 1.2 (0x0303)
        Random
            GMT Unix Time: Jun 25, 1983 13:56:23.000000000 Eastern Daylight Time
            Random Bytes: 2761896c45978dc3868cd4858d7a3d5749f7218e40f5fd3f...
        Session ID Length: 0
        Cipher Suites Length: 100
        Cipher Suites (50 suites)
        Compression Methods Length: 1
        Compression Methods (1 method)
        Extensions Length: 109
        Extension: ec_point_formats
        Extension: elliptic_curves
        Extension: SessionTicket TLS
        Extension: signature_algorithms
        Extension: Heartbeat

安全链路层

TLSv1 Record Layer: Handshake Protocol: Multiple Handshake Messages
    Content Type: Handshake (22)
    Version: TLS 1.0 (0x0301)
    Length: 1449
    Handshake Protocol: Server Hello
        Handshake Type: Server Hello (2)
        Length: 77
        Version: TLS 1.0 (0x0301)
        Random
        Session ID Length: 32
        Session ID: 569d341d4d75bc12b41fa995f22fea93a51d14fa1d612e69...
        Cipher Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA (0x0033)
        Compression Method: null (0)
        Extensions Length: 5
        Extension: renegotiation_info
    Handshake Protocol: Certificate
        Handshake Type: Certificate (11)
        Length: 816
        Certificates Length: 813
        Certificates (813 bytes)
    Handshake Protocol: Server Key Exchange
        Handshake Type: Server Key Exchange (12)
        Length: 540
        Diffie-Hellman Server Params
            p Length: 128
            p: fd7f53811d75122952df4a9c2eece4e7f611b7523cef4400...
            g Length: 20
            g: 9760508f15230bccb292b982a2eb840bf0581cf5
            Pubkey Length: 128
            Pubkey: 73f35da13f584ccb05901f5242f71da41b5f35cc185409a9...
            Signature Length: 256
            Signature: 3b8a31d223c149fb0af62f653be5d61af1297c11c4d6e925...
    Handshake Protocol: Server Hello Done
        Handshake Type: Server Hello Done (14)
        Length: 0

安全链路层

TLSv1 Record Layer: Handshake Protocol: Client Key Exchange
    Content Type: Handshake (22)
    Version: TLS 1.0 (0x0301)
    Length: 134
    Handshake Protocol: Client Key Exchange
        Handshake Type: Client Key Exchange (16)
        Length: 130
        Diffie-Hellman Client Params
            Pubkey Length: 128
            Pubkey: 76ef1851a1202c19b55aebc2cf830cbb023f15f75d7c963a...
TLSv1 Record Layer: Change Cipher Spec Protocol: Change Cipher Spec
    Content Type: Change Cipher Spec (20)
    Version: TLS 1.0 (0x0301)
    Length: 1
    Change Cipher Spec Message
TLSv1 Record Layer: Handshake Protocol: Encrypted Handshake Message
    Content Type: Handshake (22)
    Version: TLS 1.0 (0x0301)
    Length: 48
    Handshake Protocol: Encrypted Handshake Message

安全链路层

TLSv1 Record Layer: Change Cipher Spec Protocol: Change Cipher Spec
    Content Type: Change Cipher Spec (20)
    Version: TLS 1.0 (0x0301)
    Length: 1
    Change Cipher Spec Message

安全链路层

TLSv1 Record Layer: Handshake Protocol: Encrypted Handshake Message
    Content Type: Handshake (22)
    Version: TLS 1.0 (0x0301)
    Length: 48
    Handshake Protocol: Encrypted Handshake Message

安全链路层

客户端->服务器

TLSv1 Record Layer: Application Data Protocol: http
    Content Type: Application Data (23)
    Version: TLS 1.0 (0x0301)
    Length: 32
    Encrypted Application Data: 50c0d7383385d5ea8aa08c9a489904b20fb508a1b53ec017...
TLSv1 Record Layer: Application Data Protocol: http
    Content Type: Application Data (23)
    Version: TLS 1.0 (0x0301)
    Length: 480
    Encrypted Application Data: 18ad9fa298268b2da260c4873075d8116554d3067659a0f6...

安全链路层

服务器->客户端

TLSv1 Record Layer: Application Data Protocol: http
    Content Type: Application Data (23)
    Version: TLS 1.0 (0x0301)
    Length: 352
    Encrypted Application Data: a425edb24ceb1fab0516b7cf64e18d571db0f222e606d1a7...

安全链路层

客户端->服务器

TLSv1 Record Layer: Application Data Protocol: http
    Content Type: Application Data (23)
    Version: TLS 1.0 (0x0301)
    Length: 32
    Encrypted Application Data: 4952a32d5ca081870f74397b4b45d8af9017938b92db648a...
TLSv1 Record Layer: Application Data Protocol: http
    Content Type: Application Data (23)
    Version: TLS 1.0 (0x0301)
    Length: 480
    Encrypted Application Data: 3a97d944ddabc997a965cc75ed946aa0dd4b13e525f44aff...

安全链路层

服务器->客户端

TLSv1 Record Layer: Application Data Protocol: http
    Content Type: Application Data (23)
    Version: TLS 1.0 (0x0301)
    Length: 32
    Encrypted Application Data: 47f3838b409d33cfd039f51e432e7675095f6f724ba7c728...
TLSv1 Record Layer: Application Data Protocol: http
    Content Type: Application Data (23)
    Version: TLS 1.0 (0x0301)
    Length: 352
    Encrypted Application Data: 8bd4f772427b1bf25901b3cc59cff003d83b02bd11421e62...

安全链路层

客户端->服务器

TLSv1 Record Layer: Application Data Protocol: http
    Content Type: Application Data (23)
    Version: TLS 1.0 (0x0301)
    Length: 32
    Encrypted Application Data: 1a0750299f160c207a88d6d6b2bc794373b7d45ae845129f...
TLSv1 Record Layer: Application Data Protocol: http
    Content Type: Application Data (23)
    Version: TLS 1.0 (0x0301)
    Length: 480
    Encrypted Application Data: 094956aa5f580d500d9402bc84696748f6c008d8f75bcafc...

安全链路层

客户端->服务器

TLSv1 Record Layer: Encrypted Alert
    Content Type: Alert (21)
    Version: TLS 1.0 (0x0301)
    Length: 32
    Alert Message: Encrypted Alert

Answer 1

这是一个混搭

这不是AlertDescription21。

相反，这是ContentType21。

  enum {
      change_cipher_spec(20), alert(21), handshake(22),
      application_data(23), (255)
  } ContentType;

现在怎么办？所以我们知道这是一个警报，但是，好吗？一个AlertDescription字段是一个字节宽。那么这是哪一款呢？而且，可悲的是，答案是......

Alert Message: Encrypted Alert

……我们只是不知道。它是加密的。

问：但是如果我们使用证书的私钥，我们就不能解密这个数据包转储吗？
A:不可以。这个连接使用了一个临时密码套件（即Cipher Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA (0x0033)），所以它是前向安全的，会话批量加密密钥不能从证书的私钥重建。

进行新的跟踪。

进行另一次跟踪，但这次确保您可以在之后解密它。为此，要么准备好私钥并强制使用非前向安全套件（DHE名称中没有或 ECDHE 的任何东西），要么让您的软件将会话密钥转储到某处。（Chrome 和 Firefox 可以做到这一点。）

Answer 2

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...我们有一个运行 TLS v1.0 的客户端/服务器，并在初始握手后不断从客户端获取加密警报 21...

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看来客户端的级别较低，需要升级。

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根据RFC 5246，传输层安全 (TLS) 协议版本 1.2，警报 21 为解密_失败_保留。以及警报的含义：

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解密_failed_RESERVED
\n\xc2\xa0\xc2\xa0\xc2\xa0此警报用于某些早期版本的 TLS，并且可能
\n\xc2\xa0\xc2\xa0\xc2\xa0 允许针对 CBC 模式的某些攻击 [CBCATT ]。它必须
\n\xc2\xa0\xc2\xa0\xc2\xa0NOT 由兼容的实现发送。

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