Software Security Skill (Project CodeGuard)

This skill provides comprehensive security guidance to help AI coding agents generate secure code and prevent common vulnerabilities. It is based on Project CodeGuard, an open-source, model-agnostic security framework that embeds secure-by-default practices into AI coding workflows.

When to Use This Skill

This skill should be activated when:

Writing new code in any language
Reviewing or modifying existing code
Implementing security-sensitive features (authentication, cryptography, data handling, etc.)
Working with user input, databases, APIs, or external services
Configuring cloud infrastructure, CI/CD pipelines, or containers
Handling sensitive data, credentials, or cryptographic operations

How to Use This Skill

When writing or reviewing code:

Always-Apply Rules: Some rules MUST be checked on every code operation:

codeguard-1-hardcoded-credentials.md - Never hardcode secrets, passwords, API keys, or tokens
codeguard-1-crypto-algorithms.md - Use only modern, secure cryptographic algorithms
codeguard-1-digital-certificates.md - Validate and manage digital certificates securely

Context-Specific Rules: Apply rules from /rules directory based on the language of the feature being implemented using the table given below:

| Language | Rule Files to Apply | |----------|---------------------| | apex | codeguard-0-input-validation-injection.md | | c | codeguard-0-additional-cryptography.md, codeguard-0-api-web-services.md, codeguard-0-authentication-mfa.md, codeguard-0-authorization-access-control.md, codeguard-0-client-side-web-security.md, codeguard-0-data-storage.md, codeguard-0-file-handling-and-uploads.md, codeguard-0-framework-and-languages.md, codeguard-0-iac-security.md, codeguard-0-input-validation-injection.md, codeguard-0-logging.md, codeguard-0-safe-c-functions.md, codeguard-0-session-management-and-cookies.md, codeguard-0-xml-and-serialization.md | | cpp | codeguard-0-safe-c-functions.md | | d | codeguard-0-iac-security.md | | docker | codeguard-0-devops-ci-cd-containers.md, codeguard-0-supply-chain-security.md | | go | codeguard-0-additional-cryptography.md, codeguard-0-api-web-services.md, codeguard-0-authentication-mfa.md, codeguard-0-authorization-access-control.md, codeguard-0-file-handling-and-uploads.md, codeguard-0-input-validation-injection.md, codeguard-0-mcp-security.md, codeguard-0-session-management-and-cookies.md, codeguard-0-xml-and-serialization.md | | html | codeguard-0-client-side-web-security.md, codeguard-0-input-validation-injection.md, codeguard-0-session-management-and-cookies.md | | java | codeguard-0-additional-cryptography.md, codeguard-0-api-web-services.md, codeguard-0-authentication-mfa.md, codeguard-0-authorization-access-control.md, codeguard-0-file-handling-and-uploads.md, codeguard-0-framework-and-languages.md, codeguard-0-input-validation-injection.md, codeguard-0-mcp-security.md, codeguard-0-mobile-apps.md, codeguard-0-session-management-and-cookies.md, codeguard-0-xml-and-serialization.md | | javascript | codeguard-0-additional-cryptography.md, codeguard-0-api-web-services.md, codeguard-0-authentication-mfa.md, codeguard-0-authorization-access-control.md, codeguard-0-client-side-web-security.md, codeguard-0-cloud-orchestration-kubernetes.md, codeguard-0-data-storage.md, codeguard-0-devops-ci-cd-containers.md, codeguard-0-file-handling-and-uploads.md, codeguard-0-framework-and-languages.md, codeguard-0-iac-security.md, codeguard-0-input-validation-injection.md, codeguard-0-logging.md, codeguard-0-mcp-security.md, codeguard-0-mobile-apps.md, codeguard-0-privacy-data-protection.md, codeguard-0-session-management-and-cookies.md, codeguard-0-supply-chain-security.md | | kotlin | codeguard-0-additional-cryptography.md, codeguard-0-authentication-mfa.md, codeguard-0-framework-and-languages.md, codeguard-0-mobile-apps.md | | matlab | codeguard-0-additional-cryptography.md, codeguard-0-authentication-mfa.md, codeguard-0-mobile-apps.md, codeguard-0-privacy-data-protection.md | | perl | codeguard-0-mobile-apps.md | | php | codeguard-0-additional-cryptography.md, codeguard-0-api-web-services.md, codeguard-0-authentication-mfa.md, codeguard-0-authorization-access-control.md, codeguard-0-client-side-web-security.md, codeguard-0-file-handling-and-uploads.md, codeguard-0-framework-and-languages.md, codeguard-0-input-validation-injection.md, codeguard-0-session-management-and-cookies.md, codeguard-0-xml-and-serialization.md | | powershell | codeguard-0-devops-ci-cd-containers.md, codeguard-0-iac-security.md, codeguard-0-input-validation-injection.md | | python | codeguard-0-additional-cryptography.md, codeguard-0-api-web-services.md, codeguard-0-authentication-mfa.md, codeguard-0-authorization-access-control.md, codeguard-0-file-handling-and-uploads.md, codeguard-0-framework-and-languages.md, codeguard-0-input-validation-injection.md, codeguard-0-mcp-security.md, codeguard-0-session-management-and-cookies.md, codeguard-0-xml-and-serialization.md | | ruby | codeguard-0-additional-cryptography.md, codeguard-0-api-web-services.md, codeguard-0-authentication-mfa.md, codeguard-0-authorization-access-control.md, codeguard-0-file-handling-and-uploads.md, codeguard-0-framework-and-languages.md, codeguard-0-iac-security.md, codeguard-0-input-validation-injection.md, codeguard-0-session-management-and-cookies.md, codeguard-0-xml-and-serialization.md | | rust | codeguard-0-mcp-security.md | | shell | codeguard-0-devops-ci-cd-containers.md, codeguard-0-iac-security.md, codeguard-0-input-validation-injection.md | | sql | codeguard-0-data-storage.md, codeguard-0-input-validation-injection.md | | swift | codeguard-0-additional-cryptography.md, codeguard-0-authentication-mfa.md, codeguard-0-mobile-apps.md | | typescript | codeguard-0-additional-cryptography.md, codeguard-0-api-web-services.md, codeguard-0-authentication-mfa.md, codeguard-0-authorization-access-control.md, codeguard-0-client-side-web-security.md, codeguard-0-file-handling-and-uploads.md, codeguard-0-framework-and-languages.md, codeguard-0-input-validation-injection.md, codeguard-0-mcp-security.md, codeguard-0-session-management-and-cookies.md | | vlang | codeguard-0-client-side-web-security.md | | xml | codeguard-0-additional-cryptography.md, codeguard-0-api-web-services.md, codeguard-0-devops-ci-cd-containers.md, codeguard-0-framework-and-languages.md, codeguard-0-mobile-apps.md, codeguard-0-xml-and-serialization.md | | yaml | codeguard-0-additional-cryptography.md, codeguard-0-api-web-services.md, codeguard-0-authorization-access-control.md, codeguard-0-cloud-orchestration-kubernetes.md, codeguard-0-data-storage.md, codeguard-0-devops-ci-cd-containers.md, codeguard-0-framework-and-languages.md, codeguard-0-iac-security.md, codeguard-0-logging.md, codeguard-0-privacy-data-protection.md, codeguard-0-supply-chain-security.md |

Proactive Security: Don't just avoid vulnerabilities-actively implement secure patterns:

Use parameterized queries for database access
Validate and sanitize all user input
Apply least-privilege principles
Use modern cryptographic algorithms and libraries
Implement defense-in-depth strategies

CodeGuard Security Rules

The security rules are available in the rules/ directory.

Usage Workflow

When generating or reviewing code, follow this workflow:

1. Initial Security Check

Before writing any code:

Check: Will this handle credentials? → Apply codeguard-1-hardcoded-credentials
Check: What language am I using? → Identify applicable language-specific rules
Check: What security domains are involved? → Load relevant rule files

2. Code Generation

While writing code:

Apply secure-by-default patterns from relevant Project CodeGuard rules
Add security-relevant comments explaining choices

3. Security Review

After writing code:

Review against implementation checklists in each rule
Verify no hardcoded credentials or secrets
Validate that all the rules have been successfully followed when applicable.
Explain which security rules were applied
Highlight security features implemented