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?
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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
I have a Windows Server allowing TLS 1.0, 1.1 and 1.2 protocol.
Is there any way to find out what TLS version is used by clients on the established connections? something similar as we have to get samba version for connections with Get-SmbConnection?
There is a windows 10 server in which tls1.0,ssl3 are disabled by IISCrypto for refusing weak ssl protocol from client requests. tls1.1 and tls1.2 are disabled on the client system and just ssl3 is enabled on it and will be expected any requests from client to server be refused.I'm using IIS10 and an asp mvc project website that is loaded on .I've searched and figure out there is no way to reject these request in asp mvc.The only way was using something like this System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
but doesn't work at all.By using wireshark and just look at Client Hello I realized the connection between server and client is stablished by tls1.2. I think my question is clear and no need to give code anymore.
Is there any help ?
Payment is requesting all traffic we sent to them be TLS 1.2, they are complaining now that we’re using TSL 1.0. For this
The first thing i did was, I have created a Windows 2012 R2 EC2 instance. In the regitry I have added the following under
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL:
In protocols,
I have created the keys along with Dword,
SSL 2.0 (Client (disabled) server(Enabled),
SSL 3.0 (Client (disabled) server(Enabled),
TLS 1.1 (client (disabled)-server(Enabled)),
TLS 1.2 (client (Enabled)- server(Enabled))
After doing this, I restarted the server. Once i restarted, the RDP could able to connect to the server after making the changes. ( I stucked up here)
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Assuming you are using .NET, you'll need to tell it to use the settings in SCHANNEL. Depending on your .NET version, it'll be something like:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft.NETFramework\v2.0.50727] "SystemDefaultTlsVersions"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft.NETFramework\v2.0.50727] "SystemDefaultTlsVersions"=dword:00000001
Alternatively, you could also use the "SchUseStrongCrypto" key or hard-code the values in ServicePointManager.SecurityProtocol.
Additional info:
https://support.microsoft.com/en-us/kb/3135244
https://blogs.msdn.microsoft.com/dataaccesstechnologies/2016/07/12/enable-tls-1-2-protocol-for-reporting-services-with-custom-net-application/#comment-3335
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.
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