Security Guidance

Security Guidance Skill

Skill: Security Guidance Role: Architect Created: 2026-01-09 Version: 1.0.0

Purpose

Provides security expertise and guidance across all aspects of application development. Identifies vulnerabilities, recommends security best practices, and ensures secure architecture and implementation patterns.

When to Activate This Skill

Trigger Conditions:

• Authentication/authorization design
• Data handling and storage decisions
• API security review
• Third-party integration security
• Security vulnerability assessment
• Compliance requirements (GDPR, HIPAA, etc.)
• Incident response planning

Context Signals:

• "Is this secure?"
• "How should we handle sensitive data?"
• "Security review needed"
• "Authentication design"
• "Authorization strategy"
• "Encryption requirements"

Core Capabilities

1. Security Architecture

• Design authentication systems
• Plan authorization strategies
• Implement security layers (defense in depth)
• Design secure data flows
• Plan encryption strategies

2. Vulnerability Detection

• Identify common security vulnerabilities
• Review code for security issues
• Assess third-party dependencies
• Evaluate API security
• Check for OWASP Top 10 vulnerabilities

3. Data Protection

• Design data encryption strategies
• Plan secure storage solutions
• Implement privacy protections
• Handle PII (Personally Identifiable Information)
• Plan data retention and deletion

4. Compliance & Standards

• GDPR compliance guidance
• HIPAA requirements (if applicable)
• PCI DSS for payment data
• Industry-specific regulations
• Security audit preparation

[TECH_STACK_SPECIFIC] Best Practices

Authentication

[TECH_STACK_SPECIFIC]

• Session Management: [Framework session handling]
• Password Storage: [Hashing algorithm and configuration]
• Multi-Factor Auth: [MFA implementation approach]
• OAuth/SSO: [Third-party auth integration]
• Token Management: [JWT or session token handling]

Authorization

[TECH_STACK_SPECIFIC]

• Permission System: [Role-based, attribute-based, etc.]
• Access Control: [How to check permissions]
• Policy Enforcement: [Where to enforce authorization]
• Privilege Escalation: [Admin/sudo mechanisms]

Input Validation

[TECH_STACK_SPECIFIC]

• Validation Layer: [Where validation happens]
• Sanitization: [XSS prevention methods]
• SQL Injection: [ORM protection mechanisms]
• File Uploads: [Safe file handling]
• API Input: [Request validation]

Secure Communication

[TECH_STACK_SPECIFIC]

• HTTPS Enforcement: [SSL/TLS configuration]
• Certificate Management: [Cert rotation and storage]
• API Security: [API key, OAuth, JWT]
• CORS Configuration: [Cross-origin policies]
• CSP Headers: [Content Security Policy]

Data Protection

[TECH_STACK_SPECIFIC]

• Encryption at Rest: [Database encryption]
• Encryption in Transit: [TLS configuration]
• Sensitive Data: [PII handling and masking]
• Secrets Management: [Environment variables, vaults]
• Backup Security: [Secure backup strategies]

Tools Required

MCP Servers

[MCP_TOOLS]

Agent OS Workflows

• agent-os/workflows/execute-tasks.md - Execute security improvements and reviews
• agent-os/product/architecture-decision.md - Security architecture decisions
• .agent-os/specs/[feature]/sub-specs/security-spec.md - Feature security specs

External Tools

• Dependency vulnerability scanners
• Static Application Security Testing (SAST)
• Dynamic Application Security Testing (DAST)
• Penetration testing tools
• Security audit logs

Quality Checklist

Authentication & Authorization

• Authentication mechanism is secure and modern
• Passwords are hashed with strong algorithm (bcrypt, Argon2)
• Session management is secure (HttpOnly, Secure flags)
• Authorization checks are on every protected resource
• Role/permission system is properly implemented

Data Protection

• Sensitive data is encrypted at rest
• All communications use HTTPS/TLS
• PII is handled according to regulations
• Secrets are not in source code
• Database backups are encrypted

Input Validation

• All user input is validated
• SQL injection prevention is in place
• XSS protection is implemented
• CSRF tokens are used for state-changing operations
• File uploads are validated and sanitized

API Security

• API authentication is required
• Rate limiting is implemented
• CORS is configured appropriately
• API responses don't leak sensitive data
• Error messages don't reveal system details

Dependency Security

• Dependencies are up to date
• No known vulnerabilities in dependencies
• Dependency sources are trusted
• License compliance is verified
• Supply chain security is considered

Logging & Monitoring

• Security events are logged
• Sensitive data is not logged
• Failed login attempts are tracked
• Anomalous behavior is detected
• Incident response plan exists

Integration with Other Skills

Works Closely With

• pattern-enforcement - Security patterns compliance
• api-designing - API security architecture
• data-modeling - Secure data structure design
• dependency-checking - Vulnerability assessment

Provides Input To

• Development team - Security requirements
• DevOps team - Infrastructure security
• Compliance team - Audit requirements
• Product team - Security constraints

Receives Input From

• Compliance requirements - Regulatory needs
• Security audits - Vulnerability findings
• Incident reports - Real-world attack patterns
• Threat intelligence - Emerging security threats

Examples

Example 1: Password Storage

Scenario: Design secure password storage

Implementation:

[TECH_STACK_SPECIFIC]

BAD - Plain text or weak hashing:
password = request.POST['password']
user.password = hashlib.md5(password).hexdigest()  # INSECURE!

GOOD - Strong hashing with salt:
from bcrypt import hashpw, gensalt

# Storing password
password = request.POST['password']
user.password_hash = hashpw(password.encode('utf-8'), gensalt(rounds=12))

# Verifying password
def verify_password(user, password):
    return hashpw(password.encode('utf-8'), user.password_hash) == user.password_hash

REQUIREMENTS:
- Use bcrypt, Argon2, or scrypt
- Minimum work factor/rounds: 12 for bcrypt
- Never store plain text passwords
- Salt is handled automatically by bcrypt
- Pepper (secret key) can be added for extra security

Example 2: Authorization Pattern

Scenario: Implement resource-level authorization

Implementation:

[TECH_STACK_SPECIFIC]

# Policy-based authorization
class PostPolicy:
    def __init__(self, user, post):
        self.user = user
        self.post = post

    def can_update(self):
        return (
            self.user.is_admin() or
            self.post.author_id == self.user.id
        )

    def can_delete(self):
        return self.user.is_admin()

# In controller
def update_post(request, post_id):
    post = Post.find(post_id)
    policy = PostPolicy(request.user, post)

    if not policy.can_update():
        return forbidden("You cannot update this post")

    # Proceed with update
    post.update(request.POST)
    return success(post)

PRINCIPLES:
- Check authorization on every protected action
- Centralize authorization logic in policy classes
- Fail closed (deny by default)
- Log authorization failures
- Don't leak resource existence in error messages

Example 3: API Security Headers

Scenario: Configure security headers for API responses

Implementation:

[TECH_STACK_SPECIFIC]

# Security headers middleware
SECURITY_HEADERS = {
    # Prevent clickjacking
    'X-Frame-Options': 'DENY',

    # XSS Protection
    'X-Content-Type-Options': 'nosniff',
    'X-XSS-Protection': '1; mode=block',

    # Content Security Policy
    'Content-Security-Policy': "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'",

    # Force HTTPS
    'Strict-Transport-Security': 'max-age=31536000; includeSubDomains',

    # Referrer Policy
    'Referrer-Policy': 'strict-origin-when-cross-origin',

    # Permissions Policy
    'Permissions-Policy': 'geolocation=(), microphone=(), camera=()'
}

# CORS Configuration
CORS_CONFIG = {
    'allowed_origins': ['https://app.example.com'],
    'allowed_methods': ['GET', 'POST', 'PUT', 'DELETE'],
    'allowed_headers': ['Content-Type', 'Authorization'],
    'expose_headers': ['X-Request-ID'],
    'max_age': 3600,
    'allow_credentials': True
}

Example 4: Sensitive Data Handling

Scenario: Handle and store PII securely

Implementation:

[TECH_STACK_SPECIFIC]

# Encrypt sensitive fields
class User:
    # Public fields
    id = Column(Integer, primary_key=True)
    email = Column(String, unique=True)

    # Encrypted fields
    ssn_encrypted = Column(LargeBinary)
    phone_encrypted = Column(LargeBinary)

    @property
    def ssn(self):
        if self.ssn_encrypted:
            return decrypt(self.ssn_encrypted)
        return None

    @ssn.setter
    def ssn(self, value):
        self.ssn_encrypted = encrypt(value)

    # Masking for logs/display
    def masked_ssn(self):
        if self.ssn:
            return f"***-**-{self.ssn[-4:]}"
        return None

# Logging - never log sensitive data
def log_user_action(user, action):
    logger.info(f"User {user.id} performed {action}")
    # DON'T: logger.info(f"User {user.email} SSN:{user.ssn}")

# Database queries - use parameterized queries
# GOOD:
User.query.filter(User.email == email).first()

# BAD (SQL Injection risk):
db.execute(f"SELECT * FROM users WHERE email = '{email}'")

PRINCIPLES:
- Encrypt PII at rest
- Mask/redact in logs and error messages
- Minimize PII collection (data minimization)
- Implement right to deletion (GDPR)
- Use parameterized queries always
- Audit access to sensitive data

Example 5: Secrets Management

Scenario: Securely manage API keys and credentials

Implementation:

[TECH_STACK_SPECIFIC]

# Environment-based secrets (development)
# .env (NOT in version control)
DATABASE_URL=postgresql://user:pass@localhost/db
API_KEY=sk_live_abc123xyz
JWT_SECRET=random-secret-string-here

# Code
import os
api_key = os.environ.get('API_KEY')

# Production secrets management
# Use cloud provider secret managers:
# - AWS Secrets Manager
# - Google Cloud Secret Manager
# - Azure Key Vault
# - HashiCorp Vault

# Accessing secrets in production
from cloud_secrets import get_secret

api_key = get_secret('api-key')

CHECKLIST:
✗ Never commit secrets to git
✗ Never hardcode secrets in code
✗ Never log secrets
✓ Use environment variables in development
✓ Use secret managers in production
✓ Rotate secrets regularly
✓ Use different secrets per environment
✓ Audit secret access
✓ Encrypt secrets at rest

# .gitignore
.env
.env.*
secrets/
credentials.json
*.pem
*.key

Skill Activation Flow

1. IDENTIFY: Security requirements and constraints
2. ASSESS: Current implementation or design
3. ANALYZE: Potential vulnerabilities and risks
4. RECOMMEND: Security improvements and best practices
5. PRIORITIZE: Risks by severity and likelihood
6. DOCUMENT: Security decisions and rationale
7. VALIDATE: Implementation against security standards
8. MONITOR: Ongoing security posture

Success Metrics

• Zero critical security vulnerabilities in production
• Compliance with relevant regulations
• Secure authentication and authorization
• Encrypted sensitive data
• No secrets in source code
• Security incidents detected and resolved quickly
• Team awareness of security best practices

Notes

• Security is everyone's responsibility, not just the architect's
• Defense in depth - multiple layers of security
• Fail secure - deny by default, allow explicitly
• Principle of least privilege - minimum necessary access
• Keep security simple - complexity is the enemy of security
• Stay updated on emerging threats and vulnerabilities
• Security is a continuous process, not a one-time task
• Balance security with usability - overly restrictive security fails