Skip to content

Instantly share code, notes, and snippets.

@clyang

clyang/gist:1a11fc914467a29240d9

Last active October 17, 2015 01:49
Show Gist options
  • Save clyang/1a11fc914467a29240d9 to your computer and use it in GitHub Desktop.
Save clyang/1a11fc914467a29240d9 to your computer and use it in GitHub Desktop.
Download ZIP
貼心小提醒, 強化ssh設定來避開Logjam攻擊
Raw
gistfile1.txt
*** Nginx / Apache / IIS / Tomcat / Postfix / Sendmail / Dovecot / HAProxy使用者請參考 https://weakdh.org/sysadmin.html ***
*** 這邊有現成的tool可以掃 .. https://github.com/GDSSecurity/SSH-Weak-DH ***
這兩天很紅的weak DH的Logjam攻擊也是會影響到ssh key exchange的, 最簡單的解法就是強迫自己的client不用prime-field Diffie-Hellman的key exchange algorithm.
在 .ssh/config 中加上下面設定即可:
Host *
KexAlgorithms [email protected],ecdh-sha2-nistp256 # 如果你要連到很古老的機器, 那可以多加一個 diffie-hellman-group14-sha1
自己有server也可以在 /etc/ssh/config中加上 `KexAlgorithms [email protected],ecdh-sha2-nistp256` 然後restart ssh server
Windows user使用putty的話, 請把 `Diffie-Hellman group exchange` 跟 `Diffie-Hellman group 1` 移到 `— warn below here —` 下方, Make sure `group 14` 是在最上方! http://marc.terrier.free.fr/docputty/PuTTY-Configuration-XP-Kex.png
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment