Is there any mock target than I can hit that just hangs up during an SSL handshake and the connection would then timeout
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we have one client and server our application running as bridge between client and server.
our module responsible for forwarding the traffic between client and server.
During SSL handshake i am trying to interrupt the client hello and respond to the client with serverhello.
we are able to interrupt and send the serverhello to the client but SSL handshake is failed.
captured the packets during SSL handshake.
i could see Server hello reached to the client interface but Client machine retransmitting the clienthello again and again could any one help on this what went wrong why the client not processing serverhello.
I have TLS program and I did some experiments on it.
I start confidential TLS server session and try to connect to it with pure Telnet client.
As expected, the handshake failed and the server is available to the next client but on the Telnet client side I didn't receive any indication that the handshake failed and that the server is accepting other clients.
I can see in Wireshark that even after the handshake failed the Telnet client can send strings; I see [PSH, ACK] from the client answered by [ACK] from the server.
Adding Wireshark snapshot, Telnet failed the handshake, Telnet keep sending messages, followed by success in the TLS handshake and more Telnet messages:
Why is the server ACKing the Telnet client if the handshake failed and he is accepting other clients?
As expected, the handshake failed ...
I cannot see a failed TLS handshake in the packet capture and I'm not sure how you come to this conclusion.
All I can see that the client on source port 60198 (presumable your telnet) is sending 3 bytes several times and the server just ACK'ing these without sending anything back and without closing the connection. Likely the server is still expecting data in the hope that at some time it will be a complete TLS record. Only then it will be processed by the TLS stack and then it might realize that something is wrong with the client.
... the server is available to the next client
It is pretty normal for a server to handle multiple clients in parallel. In contrary, it would be unusual if the server could not do this.
I have a problem with the configuration of ocserv on CentOS 8. When I try to connect, a DTLS handshake problem occurs on the client side:
16:50:51 LIB: DTLS handshake timed out
16:50:51 LIB: DTLS handshake failed: Resource temporarily unavailable, try again.
I tried to re-configure according to some guides, but no results. I'd appreciate any help.
If a web server fails to complete TLS handshake and returns error to TLS client (i.e. browser), does a typical TLS client such as chrome browser retry the handshake a few times before giving up? And if it does retry how many retries? Also is there a TLS handshake timeout in chrome, past that would it retry or just give up ?
In the past browsers tried the TLS handshake itself with an older TLS version in the hope that it will succeed then. Today browsers usually don't do this anymore, i.e. if the initial connection fails they don't retry.
Also is there a TLS handshake timeout in chrome
There is one, i.e. the browser will not wait forever for the server to reply but give up after a while.
I've set out to handle tls operations manually on a websockets server, due to the cockeyed way php supports listening on secured transports.From RFC6455:
If /secure/ is true, the client MUST perform a TLS handshake over the
connection after opening the connection and before sending the
handshake data [RFC2818]. If this fails (e.g., the server's
certificate could not be verified), then the client MUST Fail the
WebSocket Connection and abort the connection. Otherwise, all
further communication on this channel MUST run through the encrypted
tunnel [RFC5246].
According to this, the first thing I should receive is the clientHello message which signifies the beginning of a TLS handshake.But all I receive on the server is the websocket handshake request, encrypted.
I am baffled by this.Is there no TLS handshake at all?