In computer networks, proxy servers play an important role, especially in HTTP and HTTPS communications. HTTP and HTTPS proxies play different roles in network requests and data transmission. They each have their own characteristics and together form the basis of network request proxies.

This article will delve into the operation of HTTP and HTTPS proxies to help readers better understand the working mechanisms of these two proxies.

1. How HTTP proxy operates

An HTTP proxy is an intermediate server between the client and the server. It receives the client's HTTP request, forwards it to the target server, and then returns the server's response to the client. The main functions of HTTP proxy include forwarding, caching, filtering and recording of network requests.

Request forwarding

When a client needs to access a network resource, it sends an HTTP request to the HTTP proxy. After receiving the request, the HTTP proxy will forward the request to the target server based on the URL information in the request. During the forwarding process, the proxy server may perform some processing on the request, such as modifying the request header, adding authentication information, etc.

cache

In order to improve access speed, HTTP proxies usually implement a caching mechanism. When the proxy server receives a request from a client, it first checks whether there is already a copy of the resource in the local cache. If there is it in the cache, the cached data will be returned directly to the client without making a request to the target server. This caching mechanism can effectively reduce network bandwidth consumption and improve user access speed.

filter

HTTP proxy can also implement filtering functions to filter client requests to block some illegal or dangerous requests. For example, the proxy server can configure rules to prohibit access to certain websites or ports, or to restrict access to certain users or IP addresses.

Record

The HTTP proxy can also record all network request and response data passing through it, which is of great significance for network monitoring, data analysis, and security auditing. By recording data, administrators can understand network usage, detect abnormal behaviors in a timely manner, and ensure network security.

2. How HTTPS proxy operates

HTTPS is a secure version of HTTP, which adds an SSL/TLS encryption layer to HTTP to ensure data confidentiality and integrity. HTTPS proxies operate similarly to HTTP proxies, but their implementation is more complex due to the encryption and decryption operations involved.

encrypted communication

When a client establishes a connection with an HTTPS proxy, they perform an SSL/TLS handshake process, negotiate encryption parameters and establish a secure encrypted channel. In subsequent communications, the client will encrypt the HTTP request and send it to the HTTPS proxy, and the proxy server will forward the encrypted request to the target server.

After the server responds, the proxy server decrypts the encrypted response data and sends it to the client. This encrypted communication ensures the security of data during transmission.

proxy certificate

Since HTTPS communication involves certificate verification, the HTTPS proxy needs to be configured with a valid proxy certificate. When a client establishes a connection with an HTTPS proxy, the proxy server provides its certificate to the client for authentication.

The client verifies the validity of the proxy certificate to ensure that communication with the proxy server is secure. Therefore, when configuring an HTTPS proxy, you need to ensure the credibility and validity of the proxy certificate.

Transparent proxy and non-transparent proxy

HTTPS proxies can be divided into two types: transparent proxies and non-transparent proxies. A transparent proxy does not modify any content of the request when forwarding it, and the client can clearly know that it is using a proxy server. A non-transparent proxy will modify or disguise the request so that the target server cannot detect the existence of the proxy.

In practical applications, transparent proxies are usually used in legitimate network monitoring and data analysis scenarios, while non-transparent proxies are more commonly used to bypass certain network restrictions or for privacy protection.

3. Summary

HTTP and HTTPS proxies play an important role in network communication. They improve the efficiency and security of network access through functions such as forwarding requests, caching, filtering, and logging. HTTP proxies mainly handle plaintext HTTP requests, while HTTPS proxies need to operate on the basis of encrypted communication.

In practical applications, we need to select the appropriate proxy type according to specific needs and reasonably configure the parameters and rules of the proxy server to ensure the stability and security of the network. 

At the same time, with the continuous development of network technology, we also need to pay attention to the latest developments and trends in proxy technology in order to better respond to future challenges and needs.