codesnips
yaml 
repos:
  - repo: https://github.com/gitleaks/gitleaks
    rev: v8.18.4
    hooks:
      - id: gitleaks
  - repo: https://github.com/Yelp/detect-secrets

Git secret scanning with pre commit hooks

git secrets scanning
by Kai Nakamura 1 tab
bash 
#!/usr/bin/env bash
set -euo pipefail

export VAULT_ADDR="https://vault.internal:8200"
export VAULT_TOKEN="${VAULT_TOKEN:?missing VAULT_TOKEN}"

Secrets management with environment isolation and Vault

secrets-management vault environment-variables
by Kai Nakamura 1 tab
python 
import psycopg

with psycopg.connect(conninfo) as connection:
    with connection.cursor() as cursor:
        cursor.execute(
            'SELECT id, email FROM users WHERE email = %s',

Parameterized queries in Python with psycopg

python sql-injection psycopg
by Kai Nakamura 1 tab
ruby 
Rails.application.config.session_store(
  :cookie_store,
  key: '_codesnips_session',
  secure: Rails.env.production?,
  httponly: true,
  same_site: :lax,

Session cookie hardening for browser based authentication

sessions cookies authentication
by Kai Nakamura 1 tab
nginx 
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
add_header X-Content-Type-Options "nosniff" always;
add_header X-Frame-Options "DENY" always;
add_header Referrer-Policy "strict-origin-when-cross-origin" always;
add_header Permissions-Policy "camera=(), microphone=(), geolocation=()" always;

Core HTTP security headers at the reverse proxy layer

http-headers nginx hsts
by Kai Nakamura 1 tab
nginx 
add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'nonce-$request_id'; style-src 'self' https://fonts.googleapis.com 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' https://fonts.gstatic.com data:; connect-src 'self' https://api.example.com; frame-ancestors 'none'; base-uri 'self'; object-src 'none'" always;

Content Security Policy header design for modern web apps

csp http-headers browser-security
by Kai Nakamura 1 tab
ruby 
raw_token = SecureRandom.urlsafe_base64(32)
token_digest = Digest::SHA256.hexdigest(raw_token)

PasswordReset.create!(
  user: user,
  token_digest: token_digest,

Secure random token generation for sessions and recovery flows

randomness tokens authentication
by Kai Nakamura 1 tab
python 
from defusedxml.ElementTree import fromstring

payload = request.data.decode('utf-8')
root = fromstring(payload)
invoice_number = root.findtext('invoice_number')

XXE safe XML parsing with external entity resolution disabled

xxe xml parsing
by Kai Nakamura 1 tab
ruby 
require 'ipaddr'
require 'resolv'

uri = URI.parse(params[:url])
allowed_hosts = %w[images.example-cdn.com api.partner.com]

SSRF mitigation with URL allowlists and egress controls

ssrf network-security secure-coding
by Kai Nakamura 1 tab
ruby 
base_path = Rails.root.join('storage', 'exports').realpath
requested = base_path.join(params[:filename].to_s).cleanpath

unless requested.to_s.start_with?(base_path.to_s) && requested.file?
  raise ActionController::RoutingError, 'Not Found'
end

Preventing path traversal in download endpoints

path-traversal file-security secure-coding
by Kai Nakamura 1 tab
ruby 
allowed_types = ['image/png', 'image/jpeg', 'application/pdf']
uploaded = params.require(:document)

raise ActionController::BadRequest, 'file too large' if uploaded.size > 10.megabytes
raise ActionController::BadRequest, 'type not allowed' unless allowed_types.include?(uploaded.content_type)

Hardening file uploads with MIME checks and storage isolation

file-uploads validation malware
by Kai Nakamura 1 tab
ruby 
RegistrationSchema = Dry::Schema.Params do
  required(:email).filled(:string, format?: URI::MailTo::EMAIL_REGEXP)
  required(:password).filled(:string, min_size?: 12)
  optional(:marketing_opt_in).filled(:bool)
  optional(:country).filled(:string, included_in?: %w[US CA GB AU])
end

Input validation with allowlists and explicit schemas

input-validation schemas secure-coding
by Kai Nakamura 1 tab