SSL Error: illegal parameter alert

Question

A customer of us is trying to connect to our helpdesk system using Firefox and SSL. I can not tell if he uses a proxy but it's a probable yes.

When trying to connect to our webplattform using Firefox, he retrieves this error code

ssl_error_illegal_parameter_alert

Since he is the only customer, reporting this issue, i need to know, if i can be sure telling him its an error occured by his network/proxy/etc.

I cant find a clear definition about this error. Can you verify, who failes in this case with just that Error response?

Answer 1

Warning! This will disable some Firefox protection features! This might be risky.

1. In the URL bar, type about:config, accept the warning.
2. Search for "security.tls.version"
3. Change "security.tls.version.min" from 1 to 0
4. Change "security.tls.version.fallback-limit" from 1 to 0

Fixed the issue for me, hope it will help.

Anyways, you might want to consider changing from SSLv3 to TLS certificates I guess. These security features have been introduced after POODLE security flaw.

Answer 2

In my case, I forgot that I had tightened the SSL settings in FireFox: I changed the minimum TLS level acceptable. Resetting to the default, I was able to get to the site I was trying to get to (my older WiFi access point).

In the URL bar, type about:config, accept the warning, search for tls, reset security.tls.version.min to default 0.

In my case, I had that minimum set to 1 (according to http://kb.mozillazine.org/Security.tls.version.*), TLS 1.0, not allowing SSL3 or older. (No restart required, just try to reload the page.)