I am trying to build a code to check the TLS version of the servers. We have some servers whose TLS version are using v1.0 as a minimum requirement but those can still negotiate with v1.2.
I am trying to check which are all our servers who still negotiate with v1.0
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I'm using sim800 module to connect to a server using TLS. Due to a security policy in our company, the module must not continue the connection establishment if the remote host tries to use and older version of SSL/TLS.
Is there a command or setting in sim800 that can be used to choose the TLS/SSL version when connecting to a server?
*I have searched its SSL and AT command manuals and couldn't find anything useful.
There's a TLS firmware of sim800 and you can upgrade to it, this firmware use TLS version 1.2 but you can't select the version of TLS,infact sim800 use latest version of TLS that firmware supported.
TLS Firmware version
1418B09SIM800C24_TLS
I have java app deployed to tomcat server 8.5.32.
I configured the server to use only TLS 1.2 so if the user send a request to the app(tomcat server) using browser and the browser is old(supports only TLS 1.0 and TLS 1.1) then i want to know that someone tries to reach my app but no handshake is made and I want to make a record in DB.
Is there any way I can know that client is using TLS version that my server is not supporting it and somehow get that info what is the TLS version of the client? OR at least to know that client is using older TLS version?
I have a Ubuntu 16.04 Server and I would like to know witch version of TLS is already installed on my server.
And how to upgrade to version 1.3 if version version is under v1.3
Thank you
While you don't specify it you are probably asking about the TLS support in your web and/or mail server. For the common servers on Linux the support is implemented with OpenSSL. Since you are using Ubuntu 16.04 you by default have OpenSSL version 1.0.2 which supports TLS up to TLS 1.2. But note that configuration of the servers might cause the actual protocol support to be limited.
There is no official TLS 1.3 yet, i.e. the protocol is still not finalized. Support for TLS 1.3 is expected to be available in OpenSSL 1.1.1 which is still in development.
Sniffing the packets with some application like Wireshark would reveal the information; the protocol version used in a connection is in the ServerHello message or
use http://ssl-checker.online-domain-tools.com tool to verify
I would suggest that you use the SSL test website by Qualys. If you ran your webserver with SSLProtocol +All for just a quick test, it would tell you what SSLProtocols are being served with your pages and a recommendation on which ones should and should not be used.
On a side note, I made a recurring task to test my sites; I found something even today that had changed since I last checked 3 months ago.
https://www.ssllabs.com/ssltest/index.html
Having trouble with chrome v 4x.xx and WebLogic not automatically handshaking via tls 1.0 minimum. While calling a RESTful service from JavaScript front end I keep getting net::ERR_SSL_FALLBACK_BEYOND_MINIMUM_VERSION since Google have dropped support for SSL V3.0. I have tried adding the flag forcing this to JAVA_OPTIONS and on another occasion to the starting arguments for WebLogic, despite knowing these only become suported in 10.3.6. Is there another way?
So it turns out WebLogic 10.3.2.0 has a bug in it. When the client makes contact with the server for the first time it tells the server which SSL/TLS certificate version it supports - UP TO. The latest Chrome I believe supports TLS v1.2, so this is the only information sent to WebLogic. WebLogic has problems recognising that 1.2 is greater than 1.0, (which is the highest version available on WebLogic 10.3.2.0 (AFAIK, it is on ours) and should therefore be trusted, so terminates the connection.
source - https://productforums.google.com/forum/#!topic/chrome/iwX2PbNGk8E
I have a very basic question: how does client_hello or server_hello in SSL handshake determine what SSL/TLS version can it support? I mean, as far as I understand, first client and then server send out the highest possible SSL version they support. But, how is this determined?
Is it the version field in a certificate?
Best regards,
HL
This is all described in the TLS specification, appendix E. This is phrased slightly differently in the TLS 1.0, 1.1 and 1.2 specification, but the principle remains the same.
Essentially, the client asks for the highest version it can support and the server responds with the highest version it can support up to the client's version:
min(max. client supported version, max. server supported version)
This works as long as there the resulting version is indeed supported by both parties.
The client is responsible for initiating an SSL handshake by sending the ClientHello message. If this isn't the first message that is sent, the server responds with an error and shuts down the socket.
The client advertises to the server which cipher specs it supports, it's not required to support all of them.
The client sends the server the client's SSL version number, cipher settings, session-specific data, and other information that the server needs to communicate with the client using SSL.
The client also sends a challenge token, which the server must encrypt using the newly negotiated key before sending back the encrypted value, in its hello message. The client verifies that the decrypted token is the same as what was sent. If it's not, the handshake is rejected.
View the complete demo here