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How to solve RC4 warning on Qualys SSLLabs Test

In a previous article, I talked about how you can solve the Diffie-Hellman warning on Qualys SSLLabs test, by applying a registry configuration.

Now, we’ll talk about another common warning that most AWS EC2 customer can get.  By default, we got that security issue from SSLLabs:

This server accepts RC4 cipher, but only with older protocols. Grade capped to B.

Solution

Microsoft proposes a solution for disabling the 3 weak RC4 cipher suites in that article.
You need to create 1 new registry entry.  Create an empty text file called rc4fix.reg, and paste that content to it:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\RC4 128/128]
"Enabled"=dword:00000000

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\RC4 40/128]
"Enabled"=dword:00000000

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\RC4 56/128]
"Enabled"=dword:00000000

Then, double-click on it to apply these settings, an reboot.

Finally, run your SSL test again, that warning disappeared.

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