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:

1. 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

2. 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

3. 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