Secret Hygiene

Secret Hygiene

Patterns for detecting, preventing, and remediating hardcoded secrets in codebases.

Detection Patterns

Common Secret Patterns

Watch for these patterns in code:

# AWS
AKIA[0-9A-Z]{16}                    # AWS Access Key ID
[0-9a-zA-Z/+]{40}                    # AWS Secret Access Key

# API Keys
sk_live_[0-9a-zA-Z]{24,}            # Stripe secret key
sk_test_[0-9a-zA-Z]{24,}            # Stripe test key
SG\.[0-9A-Za-z\-_]{22}\.[0-9A-Za-z\-_]{43}  # SendGrid
xoxb-[0-9]{11}-[0-9]{11}-[0-9a-zA-Z]{24}    # Slack bot token

# Tokens
ghp_[0-9a-zA-Z]{36}                 # GitHub personal access token
glpat-[0-9a-zA-Z\-_]{20}            # GitLab personal access token
eyJ[A-Za-z0-9-_]+\.eyJ[A-Za-z0-9-_]+  # JWT token

# Database
postgres://.*:.*@                    # PostgreSQL connection string
mysql://.*:.*@                       # MySQL connection string
mongodb(\+srv)?://.*:.*@             # MongoDB connection string
redis://.*:.*@                       # Redis connection string

# Private Keys
-----BEGIN (RSA |EC |OPENSSH )?PRIVATE KEY-----
-----BEGIN PGP PRIVATE KEY BLOCK-----

When to Flag

Flag code that contains:

• String literals matching secret patterns above
• Hardcoded connection strings with credentials
• Base64-encoded values assigned to secret, key, token, or password variables
• Configuration files with inline credentials

Remediation

Step 1: Move Secret to Infisical

# Add the secret to Infisical
infisical secrets set STRIPE_SECRET_KEY=sk_live_abc123 --env=dev
infisical secrets set STRIPE_SECRET_KEY=sk_live_xyz789 --env=production

Step 2: Replace Hardcoded Value

Python (Django):

# Before
STRIPE_KEY = "sk_live_abc123"

# After
import os
STRIPE_KEY = os.environ["STRIPE_SECRET_KEY"]

TypeScript (NestJS/Next.js/Hono):

// Before
const stripeKey = "sk_live_abc123"

// After
const stripeKey = process.env.STRIPE_SECRET_KEY!

Flutter (Dart):

// Before
const apiKey = "sk_live_abc123";

// After
final apiKey = const String.fromEnvironment('STRIPE_SECRET_KEY');

Step 3: Run with Infisical

# Development
infisical run --env=dev -- npm run dev

# Production
infisical run --env=production -- node server.js

.env Hygiene

.gitignore Requirements

Every project must have these in .gitignore:

# Environment files with secrets
.env
.env.local
.env.development.local
.env.test.local
.env.production.local
.env.*.local

# Keep example committed
!.env.example

.env.example Maintenance

Maintain .env.example with every secret key (no values):

# Generate from Infisical
infisical secrets generate-example-env --env=dev > .env.example

Format with comments:

# Application
NODE_ENV=
PORT=
APP_URL=

# Database
DATABASE_URL=
DB_POOL_SIZE=

# Authentication
JWT_SECRET=
SESSION_SECRET=

# External Services
STRIPE_SECRET_KEY=
SENDGRID_API_KEY=

Git Hygiene

Pre-Commit Scanning

Install the Infisical pre-commit hook:

infisical scan install --pre-commit-hook

Or use .pre-commit-config.yaml:

repos:
  - repo: local
    hooks:
      - id: infisical-scan
        name: Infisical Secret Scan
        entry: infisical scan git-changes --staged
        language: system
        pass_filenames: false

If a Secret Was Committed

1. Rotate immediately - the secret is compromised
2. Remove from code and replace with env var reference
3. Update in Infisical with the new rotated value
4. Do NOT just delete the commit - the secret exists in git history

# Rotate: generate new credential at the provider
# Update in Infisical
infisical secrets set COMPROMISED_KEY=new_rotated_value --env=production

# Revoke the old credential at the provider

Framework-Specific Patterns

Django

# settings.py
import os

SECRET_KEY = os.environ["DJANGO_SECRET_KEY"]
DEBUG = os.environ.get("DEBUG", "False").lower() == "true"

DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.postgresql",
        "NAME": os.environ["DB_NAME"],
        "USER": os.environ["DB_USER"],
        "PASSWORD": os.environ["DB_PASSWORD"],
        "HOST": os.environ["DB_HOST"],
        "PORT": os.environ.get("DB_PORT", "5432"),
    }
}

Run: infisical run --env=dev -- python manage.py runserver

Next.js

// next.config.js - server-side only
// NEXT_PUBLIC_ prefix exposes to browser - use sparingly
const config = {
  env: {
    // These are available server-side via process.env
    // Do NOT prefix with NEXT_PUBLIC_ unless intentionally public
  }
}

Run: infisical run --env=dev -- npm run dev

NestJS

// app.module.ts
@Module({
  imports: [
    ConfigModule.forRoot({
      // Infisical injects env vars, ConfigModule reads them
      isGlobal: true,
    }),
  ],
})
export class AppModule {}

Run: infisical run --env=dev -- npm run start:dev

Hono (Cloudflare Workers)

// For local dev with wrangler
// .dev.vars is the CF Workers equivalent of .env
// Export from Infisical:
// infisical export --env=dev > .dev.vars

Run: infisical run --env=dev -- wrangler dev

Anti-Patterns

Hardcoded Secrets in Code

# NEVER do this
API_KEY = "sk_live_abc123"
DB_PASSWORD = "supersecret"

Same Secrets Across Environments

Each environment (dev, staging, production) must have unique credentials. Sharing production secrets with development is a security risk.

Secrets as CLI Arguments

# NEVER - visible in process list and shell history
node server.js --db-password=secret123

# CORRECT
infisical run --env=production -- node server.js

Secrets in Docker Image Layers

# NEVER - persists in image history
ENV API_KEY=sk_live_abc123
RUN echo "password=secret" > /app/.env

# CORRECT - inject at runtime
CMD ["infisical", "run", "--env=production", "--", "node", "server.js"]

Secrets in Log Output

// NEVER
console.log(`Connecting with key: ${process.env.API_KEY}`)

// CORRECT
console.log("Connecting to API service...")

Committing .env Files

# Verify .env is not tracked
git ls-files --error-unmatch .env 2>/dev/null && echo "WARNING: .env is tracked!"

If .env is already tracked:

git rm --cached .env
echo ".env" >> .gitignore
git commit -m "fix: remove .env from tracking"