How to Use the Command 'httprobe' (with Examples)

The httprobe command is an efficient tool designed to help information security professionals, system administrators, and developers check for active HTTP and HTTPS servers across various domains. Given a list of domains, httprobe allows users to swiftly probe and verify which of these domains have working web servers. This makes it an invaluable asset in security auditing, penetration testing, and routine server maintenance.

Use Case 1: Probe a list of domains from a text file

Code:

cat input_file | httprobe

Motivation:

When dealing with a large number of domains, manually checking each one for an active web server is impractical and time-consuming. Automating this task ensures accuracy and efficiency, allowing users to focus their attention on the results. By using httprobe, you can swiftly identify which domains are accessible over HTTP or HTTPS, streamlining the process of network audits or server management.

Explanation:

• cat input_file: This part of the command uses cat to display the content of input_file, which contains a list of domains, each on a separate line.
• |: The pipe symbol channels the output of the preceding command (cat) as input to the next command (httprobe).
• httprobe: Probes each domain from the input for active HTTP and HTTPS servers.

Example Output:

http://example1.com
https://example2.com
http://example3.org

This output confirms which domains are accessible and via which protocol (HTTP or HTTPS).

Use Case 2: Only check for HTTP if HTTPS is not working

Code:

cat input_file | httprobe --prefer-https

Motivation:

In many cases, it is preferable to utilize HTTPS due to its additional security benefits over HTTP. When security is prioritized, it’s practical to first verify HTTPS availability before falling back to HTTP. This option allows users to intelligently probe domains, demonstrating a security-first approach.

Explanation:

• cat input_file: Outputs the domains listed in input_file.
• |: Directs this list to httprobe.
• httprobe --prefer-https: This command instructs httprobe to first attempt connections over HTTPS and only try HTTP if HTTPS fails, ensuring the secure protocol is prioritized.

Example Output:

https://securewebsite.com
http://fallbacksite.org

This example indicates that securewebsite.com supports HTTPS directly, whereas fallbacksite.org defaults to HTTP due to the absence of HTTPS support.

Use Case 3: Probe additional ports with a given protocol

Code:

cat input_file | httprobe -p https:2222

Motivation:

Standard HTTP and HTTPS ports are 80 and 443, respectively. However, some servers are configured to use non-standard ports for a variety of reasons, such as increased security or to run multiple services on different ports. By specifying a custom port, users can identify whether services are running and accessible on these non-standard ports, which is crucial for comprehensive network understanding or when dealing with customized server configurations.

Explanation:

• cat input_file: Retrieves domain names from the input_file.
• |: Sends this data list to httprobe.
• httprobe -p https:2222: This extension to the command specifies that httprobe should also probe HTTPS on port 2222, in addition to the default 443. The -p flag followed by the protocol and port number allows for customized network probing beyond typical conventions.

Example Output:

https://nonstandardport.com:2222
http://anotherexample.org

Here, nonstandardport.com has an active HTTPS server on port 2222, whereas anotherexample.org follows standard configuration.

Use Case 4: Display help

Code:

httprobe --help

Motivation:

Understanding the full range of features and options available with any command-line tool is essential for maximizing its utility. By outputting the help information, users gain immediate, comprehensive access to all available options and guidance on how to implement them. This ensures users are well-equipped to adapt their httprobe usage to various contexts and requirements.

Explanation:

• httprobe --help: This command outputs the helpful usage information about httprobe, including a list of all the options, their descriptions, and possible usage scenarios, enabling users to better understand and utilize the tool effectively.

Example Output:

Usage of httprobe:
  -p, --ports string    Probe ports on top of default ones
  --prefer-https        Only use HTTP if HTTPS is not supported
  ...

The output displays available flags, summarizing each function, directing users to configure the tool to match specific needs.

Conclusion:

httprobe proves itself as a powerful utility in the toolkit of anyone auditing, securing, or managing networks. From simplifying domain probes for active web servers to ensuring the highest security standards and accommodating flexible network configurations, httprobe delivers precision and simplicity. Adapting these commands according to specific operational needs unlocks its full potential, addressing myriad network management requirements efficiently and effectively.