Ssl – What’s causing the SSL Protocol Error

errorsssltls

My site: https://www.notfriendly.xyz/ (disabled CloudFlare) (See CloudFlare enabled at https://host.notfriendly.xyz) is failing to connect claiming a protocol error after enabling CloudFlare. Could someone tell me what is causing this? For the time being I disabeld their reverse proxy and the protectons.

My nginx ssl config is:

    https://50.16.136.91
 #ssl_protocols       TLSv1 TLSv1.1 TLSv1.2;
    ssl_protocols TLSv1.2;
    ssl_prefer_server_ciphers on;
    #ssl_ciphers        "ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA25$
    ssl_ciphers AES256+EECDH:AES256+EDH:!aNULL;
    ssl_dhparam ssl/dhparam.pem;
    ssl_stapling on;
    ssl_stapling_verify on;
    ssl_session_timeout 10m;
    add_header Strict-Transport-Security "max-age=31536000; includeSubdomains; $
    add_header X-Frame-Options DENY;
    add_header X-Content-Type-Options nosniff;

I'm unsure what's causing the error.

CloudFlare is also stuck on "authorizing certificate".

It's disabled so hopefully site will be back soon.

What can I do to make CloudFlare work with my site?

EDIT: I showed a working URL and added a test to demonstate the error.

Best Answer

If there is an SSL error between your origin and CloudFlare has failed, you'd see either a 525 Handshake Failed or a 526 Invalid Certificate error.

In your case there is evidently an issue between CloudFlare and the browser. An SSL protocol error can indicate that CloudFlare hasn't issued the SSL certificates. SSL certificates are instant when using a Pro plan but can take up to 24 hours for Free users. Your domain name may be flagged for additional review before our vendors will issue a certificate if it's suspicious; you will need to contact CloudFlare Support to complete the manual review.

Related Solutions

SSL Certificate – How to Download SSL Certificate from a Website

In order to download the certificate, you need to use the client built into openssl like so:

echo -n | openssl s_client -connect $HOST:$PORTNUMBER -servername $SERVERNAME \
    | openssl x509 > /tmp/$SERVERNAME.cert

That will save the certificate to /tmp/$SERVERNAME.cert.

The -servername is used to select the correct certificate when multiple are presented, in the case of SNI.

You can use -showcerts if you want to download all the certificates in the chain. But if you just want to download the server certificate, there is no need to specify -showcerts. The x509 at the end will strip out the intermediate certs, you will need to use sed -n '/-----BEGIN/,/-----END/p' instead of the x509 at the end.

echo -n gives a response to the server, so that the connection is released

openssl x509 removes information about the certificate chain and connection details. This is the preferred format to import the certificate into other keystores.

Security – Exact Protocol Level Differences Between SSL and TLS

SSLv2 and SSLv3 are completely different (and both are now considered insecure). SSLv3 and TLSv1.0 are very similar, but have a few differences.

You could consider TLSv1.0 as SSLv3.1 (in fact that's what happens within the records exchanged). It's just easier to compare the TLSv1.0 with TLSv1.1 and TLSv1.2 because they've all been edited within IETF and follow more or less the same structure. SSLv3 being edited by a different institution (Netscape), it makes it a bit more difficult to spot the differences.

Here are a few differences, but I doubt I can list them all:

In the ClientHello message (first message sent by the client, to initiate the handshake), the version is {3,0} for SSLv3, {3,1} for TLSv1.0 and {3,2} for TLSv1.1.
The ClientKeyExchange differs.
The MAC/HMAC differs (TLS uses HMAC whereas SSL uses an earlier version of HMAC).
The key derivation differs.
The client application data can be sent straight after sending the SSL/TLS Finished message in SSLv3. In TLSv1, it must wait for the server's Finished message.
The list of cipher suites differ (and some of them have been renamed from SSL_* to TLS_*, keeping the same id number).
There are also differences regarding the new re-negotiation extension.

I would strongly recommend Eric Rescorla's book - SSL and TLS: Designing and Building Secure Systems, Addison-Wesley, 2001 ISBN 0-201-61598-3, if you really want more details. I've learnt about some of the points mentioned above from this book. The author occasionally mentions the differences between SSLv3 and TLS (v1.0 only at the time the book was written) when explaining some of the SSL/TLS message, but you do need the background explanation about these messages to have a chance to understand (and it's not appropriate to copy/paste from this book here).

Best Answer

Related Solutions

SSL Certificate – How to Download SSL Certificate from a Website

Security – Exact Protocol Level Differences Between SSL and TLS

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