How to conduct a code audit?

Conducting a code audit involves systematically reviewing source code to identify security vulnerabilities, performance issues, compliance gaps, and maintainability concerns. Here’s a step-by-step guide with examples:

1. Define Objectives and Scope

   • Clarify the purpose (e.g., security, compliance, optimization).
   • Specify the codebase sections to audit (e.g., authentication module, payment gateway).
     Example: Auditing a login system for SQL injection risks.

2. Gather Requirements and Standards

   • Identify relevant frameworks (e.g., OWASP Top 10 for security, MISRA for C/C++).
   • Check compliance needs (e.g., GDPR, HIPAA).

3. Static Code Analysis

   • Use tools like SonarQube, Checkmarx, or Tencent Cloud’s Code Analysis to scan for vulnerabilities, code smells, and anti-patterns.
     Example: Detecting hardcoded credentials in a config file.

4. Dynamic Analysis

   • Test runtime behavior with tools like OWASP ZAP or Burp Suite.
     Example: Simulating attacks on an API endpoint to find injection flaws.

5. Manual Code Review

   • Inspect logic, error handling, and dependencies. Focus on critical paths.
     Example: Reviewing a cryptographic implementation for weak RNG usage.

6. Dependency and Third-Party Checks

   • Audit libraries for known vulnerabilities (e.g., via CVE databases or Tencent Cloud’s Vulnerability Scanning Service).

7. Document Findings and Remediation

   • Prioritize issues (e.g., CVSS scores) and suggest fixes.
     Example: Recommending parameterized queries to fix SQL injection.

8. Follow-Up and Retesting

   • Verify fixes and re-audit if needed.

For cloud-based projects, Tencent Cloud’s Code Analysis integrates with CI/CD pipelines to automate audits, while Vulnerability Scanning Service helps monitor container and host security.