How client's SSL/TLS certificate is sent from a client (browser) to a server - http

I'm wondering, how (on the HTTP level), client's SSL/TLS certificate is sent over from a client (browser) to a server.
Is it sent within the header, cookies, is there some additional 'preflight' requests done before the actual HTTP request.
Do you have some insight on this?

The Client certificate is not sent on the HTTP level at all. It is sent on the SSL/TLS level within the initial TLS handshake if it was requested by the server. For details and nice pictures see https://blogs.msdn.microsoft.com/kaushal/2015/05/27/client-certificate-authentication/

Related

What information does a server know about the client that does the request?

When a web server receives a http(s) GET request from a client, it has access to some information such as:
The client IP
The request itself :
the headers (including the cookies)
the content
and... that's all ?
I am wondering if there is something else.
Indeed, I am trying to make a server that can access to a page where it can collect some information to update its database. The site denied access to my server but not to web browsers, even if I replicate the IP, the headers and the content.
Thanks for your help.
Yes, it's only what is contained in the request itself. The server cannot reach back to the client to "pull" information, it only has the information contained in the HTTP request and the underlying TCP/IP packet. That's:
the requesting IP address
the HTTP headers, including requested URL and HTTP method
the HTTP request body, if any
if it's HTTPS, any data exchanged during the TLS handshake, which is usually not very relevant for identifying anything significant
All of that information is voluntarily provided by the requesting client.

Post request in HTTP and HTTPS protocol

We are trying to make a secure communication between our embedded system and web server.Firstly we implement HTTP connection to in our microcontroller. I am just connecting to 80 port of my web server and send simple GET request to this port as example below :
GET /foo.php?msg=test HTTP/1.1
HOST: foo.com
My questions is,How we will turn this to HTTPS ? Which port i should connect ?
Will be any difference on structure of GET request above ? Will i have to do some encryption manually or connect to "https" link instead "http" is enuogh for secure communication.
Thanks for any information
The only difference between a HTTP request and a HTTPS request is that the first is send over a plain TCP connection while the other is send over a TLS connection, i.e.:
with HTTP you establish a TCP connection and send the request over this connection
with HTTPS you establish a TCP connection, upgrade this connection to TLS (including proper certificate validation etc!) and then send the same request as you did with HTTP over this connection.
Apart from that I recommend to either use an established library for HTTP or carefully read the standard. Although HTTP looks simply it is actually not and there are many questions here where users try to do a simply HTTP request and trip over behavior they did not expect.
For example in your case the server might send the response with chunked encoding, with content-length or simply end it with connection close. And it might wait for further requests on the same connection since HTTP/1.1 implicitly enables HTTP keep-alive. Does your code really account for all these cases?

Difference between http and https authentication

In school we got one teacher who always asks question which look easy but they are not easy.
So, can anybody please tell me in a very accurate way whats the difference between http and https authentication?
HTTPS is HTTP inside a SSL/TLS tunnel.
Like a postcard (HTTP) in an envelop (SSL/TLS).
SSL/TLS has 3 main properties :
authentication of the server : a trusted authority has signed the certificate used by the server
confidentiality : only the client and the server can decrypt the data
integrity : the data cannot be modified during the transport without the receiver notice it.
Note: SSL/TLS can be used with a certificate not signed by a trusted authority (but the client will show a warning about that)
HTTP does not scramble the data to be transmitted. That's why there is a higher chance that transmitted information is available to hackers. It operates at TCP/IP level. It uses port 80 by default.
HTTPS is a short abbreviation of Hyper Text Transfer Protocol Secure. It is highly advanced and secure version of HTTP. It uses the port no. 443 for Data Communication. It allows the secure transactions by encrypting the entire communication with SSL. It is a combination of SSL/TLS protocol and HTTP. It provides encrypted and secure identification of a network server.
Limitations of HTTPS---
HTTPS protocol can't stop stealing confidential information from the pages cached on the browser.
SSL data can be encrypted only during transmission on the network. So it can't clear the text in the browser memory.
Fot HTTP the browser performs basic handshake with the server as per the rules of HTTP protocol. It does not validate the authenticity of the server. However for HTTPS the browser validates the authenticity of the server using the SSL certificate with the client. If the certificate is authentic then ssl keys are exchanged between browser and server and all messages are encrypted thus preventing a man in the middle attack. In http there is no ssl certificate and all data is sent in plain text which is vulnerable to man in the middle attack

How can i see http requests sent from client to Jersey Web service

As the title explains, I want to see the http requests that are sent by my android app client to my Jersey Web service.
Also, I'm using
https://github.com/kevinsawicki/http-request
class for sending the requests, but I'm not sure if they are SSL encrypted. Can I see if they are encrypted by looking at the http requests that arrive at my Web service?
If you have access to the server on which your web service is running, you can use Wireshark : https://www.wireshark.org/
This will trace and decode the tcp/ip protocol for you, and indeed show you if it's encrypted under SSL.
Assuming you own the server, and have full access, you can also install the Private Key from your server into Wireshark, and it will then show you decoded SSL traffic.

http push - http streaming method with ssl - do proxies interfere whith https traffic?

My Question is related to the HTTP Streaming Method for realizing HTTP Server Push:
The "HTTP streaming" mechanism keeps a request open indefinitely. It
never terminates the request or closes the connection, even after the
server pushes data to the client. This mechanism significantly
reduces the network latency because the client and the server do not
need to open and close the connection.
The HTTP streaming mechanism is based on the capability of the server
to send several pieces of information on the same response, without
terminating the request or the connection. This result can be
achieved by both HTTP/1.1 and HTTP/1.0 servers.
The HTTP protocol allows for intermediaries
(proxies, transparent proxies, gateways, etc.) to be involved in
the transmission of a response from server to the client. There
is no requirement for an intermediary to immediately forward a
partial response and it is legal for it to buffer the entire
response before sending any data to the client (e.g., caching
transparent proxies). HTTP streaming will not work with such
intermediaries.
Do I avoid the descibed problems whith proxy servers if i use HTTPS?
HTTPS doesn't use HTTP proxies - this would make security void. HTTPS connection can be routed via some HTTP proxy or just HTTP redirector by using HTTP CONNECT command, which establishes transparent tunnel to the destination host. This tunnel is completely opaque to the proxy, and proxy can't get to know, what is transferred (it can attempt to modify the dataflow, but SSL layer will detect modification and send an alert and/or close connection), i.e. what has been encrypted by SSL.
Update: for your task you can try to use one of NULL cipher suites (if the server allows) to reduce the number of operations, such as perform no encryption, anonymous key exchange etc. (this will not affect proxy's impossibility to alter your data).

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