Fiddler simple packet capture

Article Directory

1. Introduction to Fiddler

Fiddler is an http protocol debugging proxy tool, which can record and check all http communications between your computer and the Internet, set breakpoints, and view all data "in and out" of Fiddler (referring to cookies, html, js, css and other files).
The principle of Fiddler packet capture
is actually equivalent to setting an HTTP/HTTPS proxy for Windows, similar to setting a proxy in the IE browser, such as [Internet Options] - [Connection] - [LAN Settings] - [Advanced] setting proxy [127.0.0.1:8888], Fiddler provides HTTP/HTTPS proxy service on port 8888.
This setting of Fiddler's global proxy is only valid for the following situations:

Browsers such as IE, Chrome, etc.
The program uses the WinInet library provided by Windows for HTTP/HTTPS communication.
The program embeds WebBrowser, and the more commonly used ones are IE controls and CEF.

For example, if the application uses the libcurl library for HTTP(s) requests, fiddler cannot capture the packets, because libcurl does not use the Windows WinInet library, and Okhttps3 cannot capture packets, but implements the http(s) protocol encapsulation by itself. If you want to capture these packages, you can install proxifer

Reference: https://blog.csdn.net/china_jeffery/article/details/93000824

2. Download Fiddler

Fiddler official website download address: https://www.telerik.com/download/fiddler

Choose according to your own needs, just fill in any address in the mailbox.
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Fool-style installation, just click the next step to use the default configuration

3. Function introduction

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Just briefly talk about the commonly used functions

1、Filters

Filter request: click filter, click Use Filter to enable filtering, configure Host, click Run Filterset now of Actions to take effect immediately
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2、Inspectors

Check, you can see detailed request and response information, you can use Automatic BreakPoints to enable breakpoint debugging, and you can modify request and response data.
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Sometimes the response results are compressed. If you want to see all the information, first cancel Chunked Transfer-Encoding and select None.

3、Automatic BreakPoints

Breakpoint debugging
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You can also enable breakpoint debugging from the following places. Click once for Before Requests, click twice for After Responses, and click three times for Disabled. After enabling breakpoints, you can modify the request header request parameters,

response headers, and response parameters. If you want to cancel the breakpoint and release all requests, click Go
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4、TextWizard

Commonly used text encryption and decryption algorithms, you can select the algorithm in Transform, as follows to decrypt JWT's PAYLOAD (payload) through Base64
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5. Other common functions

Replay: Replay request, for the request without replay attack, select the interface, click Replay to request success copy/
save: Select an interface, copy can copy the interface information, save can save the request response data
remove: Clear connection insert image description here
Hide host = Tunnle to, click Rules --> Hide CONNECTs

Disable interface compression for all interfaces
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This article is Fiddler's simple packet capture, and the next article will talk about practical ------> Fiddler captures small program packages and mobile apps