HTTP Protocol
HTTP: Hypertext Transfer Protocol
allows Hypertext Markup Language (HTML) documents to be transferred from the Web server to the client's browser.
Principle: After
entering the URL, the browser will send an HTTP request to the Web server, and the Web server will proceed after receiving the request Process, generate the corresponding HTTP response, and then send it to the browser. The browser parses the HTML in the HTTP response.
Fiddler's basic interface: the
main menu bar: basically all the fiddler function
toolbars can be started in the menu : provide a
list of common command sessions (Web Session): display the captured each session information
function panel: provide many tabs, and provide Many functions are usually used by inspectors (Inspectors) such as cls to clear the Web Sessions
command line tool: you can enter simple commands
Inspectors tab:
you can view the packet structure of HTTP requests and HTTP responses. The raw tab can view the complete message, and the Header tab can only view the Header
Web Sessions tab in the message :
The list on the left of the fiddler window shows the summary information of each session.
Web Session list bar:
#: Fiddler generated ID
the Result: status code in response to the
Protocol: Protocol used by
Host: host name and port number of the server
URL: Path
Body: field HTTP response contains
Caching: cache-related field values
Content-Type: Response Content type value
Process: Process
capture corresponding to local windows :
Method 1:
Click file-> Capture Traffic
Method 2:
Click the Capturing button in the lower left corner to start capturing or stop capturing Packet
structure:
Request packet:
HTTP The request message contains three parts: start line, header, body
Start line: Method request method, such as POST, GET
Header:
Body:
Note: There is a blank line
response message between the head and the body : The
HTTP request message contains three parts: start line, header, body
start line: There are status codes and status code messages.
Header:
Body:
Note: There is a blank line between the header and the body.
Fiddler captures packets.
Fiddler is a web proxy server with a proxy address of 127.0.0.1. Its default working port is 8888
View port:
Menu Click Tools-> Fiddler options
proxy server in the column :
Web proxy server is the intermediate entity of the network, the proxy is located between the Web client and the Web server, and plays the role of middleman
client ----> web proxy ---- > Server
for web client:
The proxy plays the role of the server, receives the Request, and returns the Response.
For the web server: the
proxy plays the role of the client, sends the Request, receives the Response
function:
shared network: can meet the needs of a large number of LAN users to share the Internet at the same time, and
improve access speed: Most proxy servers have a buffer function, which can be read directly, and there is no need to connect to a remote Web server to
break through access restrictions: when access rights are restricted, a proxy server with authority can be used.
Hidden identities: Intranet users publish information externally and need to use the reverse proxy function of the proxy server. This will not affect the security performance of the internal network. It serves the purpose of hiding identity.
Note: When
fiddler starts, the proxy in the internet option will be modified to 127.0.0.1, port 8888.
When fiddler exits, the proxy will be canceled, which does not affect other programs.
Fiddler exits abnormally. The page cannot be accessed because fiddler does not automatically log out. Restart fiddler to
get Firefox:
Open Firefox ----> select options in the menu option tool ----> network settings ----> system proxy or manually configure the
decompression HTTP response:
click the Decode button to decompress
HTTPS protocol
HTTP protocol is not secure, browser The content sent to the server can be easily intercepted by the middleman.
HTTPS is encrypted HTTP, and the content on both sides is encrypted. Only the browser and the server know the content
HTTPS = HTTP + TLS / SSL to
obtain an HTTPS session:
By default, HTTPS sessions are not captured. Need to be set to
start fiddler ----> Tool ----> Fiddler Options ----> HTTPS
The connection failure problem will still occur after the above operation is completed. You need to install the fiddler certificate
(available online, just take a look, I believe you Will be installed, will not be resolved immediately without a private message)
