We would like tu use Confluence v5.5.3 and v5.5.6 with 256 bit SSL certificate. When try to connect to Confluence https://localhost:8443 with firefox we get the error message: Code ssl_error_no_cypher_overlap
Asked by Alfa Beta:

Hello

We would like tu use Confluence with 256 bit SSL certificate.  
When try to connect to Confluence <https://localhost:8443> with firefox we get this error message.

|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------|
| A secure connection failed An error occurred during a connection to localhost: 8443. You can not communicate securely with peer: no common encryption algorithm. (Code ssl_error_no_cypher_overlap) The page you are trying not shown because the authenticity of the received data could not be verified. You may contact the operator of the site and notify of the problem. Could you help me how can we use Confluence with 256 bit SSL certificate Best regards Ferenc Jordanics mail: [Jordanics.Ferenc@gmail.com](mailto:Jordanics.Ferenc@gmail.com) |
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| Affects Version/s                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 5.5.3, 5.6.5     |
| Customer Timezone                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | GMT+1            |
| Phone Number                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | + 36 30 261 5378 |


Answers:
author: rrudnicki
body: Hi Alfa Beta,

I answered a question related to this topic yesterday. You can check it [on this link](https://answers.atlassian.com/questions/11971240/answers/11971335) to see the Willian's suggestion as well.

If the problem is related to Firefox, you can try the steps below:

Enable support for 40-bit RSA encryption in the Firefox Browser:  
1: enter 'about:config' in Browser Address bar  
2: find/select "security.ssl3.rsa_rc4_40_md5"  
3: set boolean to TRUE  

Once this is done, when the Welcome screen is manually refreshed, a screen requiring the user  
to register the Certificate Exception will come up, where the Error message had been before.   
Once the Exception is registered, the Welcome screen, and other Report screens will display

<br />

Regards,

Renato Rudnicki

comments: author: rrudnicki
body: Hi Alpha, Now I realize you opened the same question twice. Is there a reason for it?


author: Nic Brough -Adaptavist-
body: The error you are seeing happens when the browser is unable to agree on a way of talking to the server. Sometimes this is because people have turned off some levels of ssl support in the browser (often for security - it's usually the less secure protocols that they turn off), but sometimes it's genuinely because a server certificate does not support the methods the browser has.

To fix this, you'll need to

1. Make sure Confluence is running over SSL. This is not a function of Confluence directly, it's done by the container or web server if you're using one, but the basics are that you'll need a certificate (the 256 bit one you suggest) installed in the server. See <https://confluence.atlassian.com/display/DOC/Running+Confluence+Over+SSL+or+HTTPS>
2. You'll need the browser to support it

I actually suspect the problem is the browser support though. 256 bits is WAY too low and my guess is that your browser has rightly dropped support for it. You should really be looking at 2048 bits as a minimum nowadays.