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檢測弱加密和過時的協議

tag-icon • tag-icon networking ssl network-monitoring tls
檢測弱加密和過時的協議

我正在尋找能夠幫助檢測在中心位置使用弱加密或過時協議的應用程式的軟體。抱歉，如果這聽起來很模糊。也許一個例子會有所幫助。

讓我們使用一個透過 https 連接到某個網站的瀏覽器。但由於某些原因，協商的密碼很弱，低於某個閾值，比如說 56 位元密碼。或協定是 SSL 2.0 或任何「低於」TLS 1.0 的協定。有沒有什麼軟體可以監控網路流量在伺服器或路由器上如果發生類似情況，並顯示警告或採取其他措施？它不必是完美的，它可以是啟發式的；每一點資訊都有幫助。

我不想在每個執行技術上中間人攻擊的客戶端上安裝軟體。

編輯：我不是在尋找探測特定伺服器的工具，而是在尋找在我們的伺服器/路由器上運行並在“另一個客戶端”與互聯網上的“某個伺服器”建立不安全連接時發出某種警告的工具。是的，我知道這不太可能……但希望是最後消失的東西。

答案1

我不相信一旦伺服器和客戶端之間的 SSL 握手完成，您就可以窺探流量。您可能需要掃描伺服器以查看它是否提供弱密碼。也許“sslscan”？

http://sourceforge.net/projects/sslscan/

https://www.titania-security.com/labs/sslscan

我知道有一個 Ubuntu 軟體包可用於此。

這將顯示伺服器提供的密碼套件。

因此，使用 sslscan 掃描 GMail，我得到：

$ sslscan --no-failed mail.google.com:443
                   _
           ___ ___| |___  ___ __ _ _ __
          / __/ __| / __|/ __/ _` | '_ \
          \__ \__ \ \__ \ (_| (_| | | | |
          |___/___/_|___/\___\__,_|_| |_|

                  Version 1.8.2
             http://www.titania.co.uk
        Copyright Ian Ventura-Whiting 2009

Testing SSL server mail.google.com on port 443

  Supported Server Cipher(s):
    Accepted  SSLv3  256 bits  AES256-SHA
    Accepted  SSLv3  128 bits  AES128-SHA
    Accepted  SSLv3  168 bits  DES-CBC3-SHA
    Accepted  SSLv3  128 bits  RC4-SHA
    Accepted  SSLv3  128 bits  RC4-MD5
    Accepted  TLSv1  256 bits  AES256-SHA
    Accepted  TLSv1  128 bits  AES128-SHA
    Accepted  TLSv1  168 bits  DES-CBC3-SHA
    Accepted  TLSv1  128 bits  RC4-SHA
    Accepted  TLSv1  128 bits  RC4-MD5

  Prefered Server Cipher(s):
    SSLv3  128 bits  RC4-SHA
    TLSv1  128 bits  RC4-SHA

  SSL Certificate:
    Version: 2
    Serial Number: 4294967295
    Signature Algorithm: sha1WithRSAEncryption
    Issuer: /C=ZA/O=Thawte Consulting (Pty) Ltd./CN=Thawte SGC CA
    Not valid before: Oct 26 00:00:00 2011 GMT
    Not valid after: Sep 30 23:59:59 2013 GMT
    Subject: /C=US/ST=California/L=Mountain View/O=Google Inc/CN=mail.google.com
    Public Key Algorithm: rsaEncryption
    RSA Public Key: (1024 bit)
      Modulus (1024 bit):
          00:af:39:15:98:68:e4:92:fe:4f:4f:f1:bb:ff:0d:
          2e:b0:fe:25:aa:bd:68:04:67:27:ea:6c:43:4c:a7:
          6d:cb:c8:8f:7e:81:ee:87:26:25:10:12:54:33:9e:
          aa:3d:9b:8f:8e:92:b3:4b:01:e3:f9:4a:29:c3:0f:
          fd:ac:b7:d3:4c:97:29:3f:69:55:cf:70:83:04:af:
          2e:04:6e:74:d6:0f:17:09:fe:9e:20:24:24:e3:c7:
          68:9c:ac:11:bd:92:e4:b2:1b:09:f2:02:32:bb:55:
          1b:2d:16:5f:30:12:23:e2:4c:4a:8d:c2:da:3f:e1:
          b8:bf:f7:3a:b1:86:be:f0:c5
      Exponent: 65537 (0x10001)
    X509v3 Extensions:
      X509v3 Basic Constraints: critical
        CA:FALSE
      X509v3 CRL Distribution Points: 
        URI:http://crl.thawte.com/ThawteSGCCA.crl

      X509v3 Extended Key Usage: 
        TLS Web Server Authentication, TLS Web Client Authentication, Netscape Server Gated Crypto
      Authority Information Access: 
        OCSP - URI:http://ocsp.thawte.com
        CA Issuers - URI:http://www.thawte.com/repository/Thawte_SGC_CA.crt

  Verify Certificate:
    unable to get local issuer certificate

編輯:

啊，看看這個頁面：http://prefetch.net/articles/debuggingssl.html

因此，您可以使用該工具來查看握手以及商定的密碼是什麼。

答案2

您可以使用ssl 枚舉密碼腳本來自地圖以獲得密碼充足性的估計。

一個例子：

$ nmap --script ssl-enum-ciphers.nse mail.google.com

Starting Nmap 5.61TEST2 ( http://nmap.org ) at 2011-11-22 14:09 CET
Nmap scan report for mail.google.com (173.194.34.245)
Host is up (0.0050s latency).
Other addresses for mail.google.com (not scanned): 173.194.34.246 173.194.34.247
rDNS record for 173.194.34.245: mad01s09-in-f21.1e100.net
Not shown: 998 filtered ports
PORT    STATE SERVICE
80/tcp  open  http
443/tcp open  https
| ssl-enum-ciphers:
|   SSLv3
|     Ciphers (9)
|       TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA - strong
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - strong
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - unknown strength
|       TLS_ECDHE_RSA_WITH_RC4_128_SHA - strong
|       TLS_RSA_WITH_3DES_EDE_CBC_SHA - strong
|       TLS_RSA_WITH_AES_128_CBC_SHA - strong
|       TLS_RSA_WITH_AES_256_CBC_SHA - unknown strength
|       TLS_RSA_WITH_RC4_128_MD5 - unknown strength
|       TLS_RSA_WITH_RC4_128_SHA - strong
|     Compressors (1)
|       NULL
|   TLSv1.0
|     Ciphers (9)
|       TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA - strong
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - strong
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - unknown strength
|       TLS_ECDHE_RSA_WITH_RC4_128_SHA - strong
|       TLS_RSA_WITH_3DES_EDE_CBC_SHA - strong
|       TLS_RSA_WITH_AES_128_CBC_SHA - strong
|       TLS_RSA_WITH_AES_256_CBC_SHA - unknown strength
|       TLS_RSA_WITH_RC4_128_MD5 - unknown strength
|       TLS_RSA_WITH_RC4_128_SHA - strong
|     Compressors (1)
|       NULL
|_  Least strength = unknown strength

Nmap done: 1 IP address (1 host up) scanned in 16.38 seconds

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