How to set up GSDF with a proxy like Shadowsocks?

You need to uncomment the proxy configuration lines in the script and add 'proxies=self.proxies' to the requests, as per the README. This allows access through proxies, but it requires manual code editing, which can be error-prone.

GSDF vs Sublist3r for subdomain enumeration?

GSDF focuses on SSL certificate data from Google, making it lightweight and specific, while Sublist3r aggregates from multiple sources like search engines. For SSL-based discovery, GSDF is efficient; for broader reconnaissance, Sublist3r is better.

Can GSDF find subdomains without SSL certificates?

No, GSDF only discovers subdomains listed in Google's SSL transparency report. Subdomains that don't use SSL or have certificates logged elsewhere won't be detected, limiting its scope.

Is GSDF compatible with Python 3?

The README specifies Python 2.x, and with no updates since 2018, it likely isn't compatible with Python 3 without modifications. Users may need to port the code, which can be challenging due to deprecated libraries.

How accurate is GSDF for penetration testing?

GSDF provides accurate data from Google's logs, but it's limited to SSL certificates. It's useful for initial reconnaissance on SSL-enabled subdomains, but should be combined with other tools for a complete attack surface analysis.

Does GSDF output results in JSON format?

The terminal version outputs in a table and saves to a text file. The API library returns data as a dictionary, which can be converted to JSON, but there's no built-in JSON output option, requiring additional scripting for structured data.

Open-Awesome

GSDF

Apache-2.0Pythonv1.1

A Python tool that queries Google's SSL transparency report to discover subdomains and identify expired certificates.

GitHub

184 stars52 forks0 contributors

What is GSDF?

GoogleSSLdomainFinder (GSDF) is a Python-based security tool that queries Google's SSL certificate transparency report to discover subdomains associated with a target domain. It helps identify potential attack surfaces by revealing subdomains that have issued SSL certificates, including those with expired certificates that may indicate neglected services. The tool outputs results in a terminal table and saves them to a file for further analysis.

Target Audience

Security researchers, penetration testers, and network administrators who need to perform subdomain enumeration as part of reconnaissance or vulnerability assessment workflows.

Value Proposition

GSDF provides a lightweight, scriptable alternative to commercial subdomain discovery tools by leveraging free, public certificate transparency data from Google. Its ability to detect expired certificates adds unique value for identifying potentially vulnerable or forgotten subdomains.

Overview

A domain searcher named GoogleSSLdomainFinder - 基于谷歌SSL透明证书的子域名查询工具

Use Cases

Best For

Performing subdomain enumeration during penetration testing engagements
Identifying expired SSL certificates on discovered subdomains
Integrating subdomain discovery into automated security scanning pipelines
Conducting reconnaissance on target domains without aggressive scanning
Educational purposes for learning about certificate transparency and subdomain discovery
Quickly assessing the attack surface of a domain using publicly available data

Not Ideal For

Teams requiring real-time or continuous subdomain monitoring
Projects needing comprehensive enumeration from multiple sources like DNS or web archives
Environments where Python 2.x is deprecated or not supported
Users preferring graphical interfaces over command-line tools

Pros & Cons

Pros

Free Public Data Access

Leverages Google's SSL transparency report, a free and extensive source, to discover subdomains without aggressive scanning, as stated in the project philosophy.

Expired Certificate Flagging

Identifies subdomains with expired SSL certificates, a unique feature added in v2.0 that helps pinpoint potential vulnerabilities or neglected services.

Automation-Friendly API

Provides a Python library (GSDFA) for programmatic integration, allowing easy use in security automation workflows, as shown in the API usage example.

Proxy Configuration Support

Includes options for proxies like Shadowsocks, making it usable in restricted networks, though setup requires manual code changes per the README.

Cons

Deprecated Python Version

Specifically requires Python 2.x, which is no longer maintained, leading to compatibility issues and security risks in modern environments.

Single Data Source Limitation

Relies solely on Google's certificate transparency logs, missing subdomains without SSL certificates or from other sources, reducing comprehensiveness.

Manual Proxy Setup

Enabling proxy support necessitates uncommenting and modifying code in the script, adding complexity and potential errors for users.

Lack of Recent Updates

Last significant update was in 2018, indicating potential abandonment and lack of support for evolving Python libraries or security standards.

Frequently Asked Questions

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