Implementing Secure Secret Storage Solutions

Implementing Secure Secret Storage Solutions

Modern secret management platforms provide centralized, secure storage with fine-grained access controls and comprehensive audit logging. These platforms encrypt secrets at rest and in transit while providing APIs for programmatic access. Choosing the right platform depends on existing infrastructure, compliance requirements, and operational complexity tolerance.

HashiCorp Vault has emerged as the leading open-source secret management platform, offering sophisticated features like dynamic secrets, encryption as a service, and secret rotation. Vault's plugin architecture supports various authentication methods and secret engines, making it adaptable to diverse environments. Its policy engine enables precise access control, ensuring teams only access secrets they legitimately need.

# Example Vault configuration for IaC secret management
# Enable KV v2 secret engine for static secrets
path "secret/data/infrastructure/*" {
  capabilities = ["create", "read", "update", "delete", "list"]
}

# Enable AWS secret engine for dynamic credentials
path "aws/creds/deploy-role" {
  capabilities = ["read"]
}

# Enable database secret engine for dynamic DB credentials
path "database/creds/app-role" {
  capabilities = ["read"]
}

# Terraform configuration using Vault
terraform {
  required_providers {
    vault = {
      source  = "hashicorp/vault"
      version = "~> 3.0"
    }
  }
}

provider "vault" {
  # Best practice: Use environment variables or instance metadata
  # address = "https://vault.example.com:8200"
  # token   = "s.XXXXXXXXXX"
}

# Static secret retrieval
data "vault_generic_secret" "api_keys" {
  path = "secret/data/infrastructure/external-apis"
}

# Dynamic AWS credentials
data "vault_aws_access_credentials" "deploy" {
  backend = "aws"
  role    = "deploy-role"
  type    = "sts"
}

# Dynamic database credentials
data "vault_database_secret_backend_creds" "app" {
  backend = "database"
  role    = "app-role"
}

# Using secrets in resources
resource "aws_lambda_function" "processor" {
  function_name = "data-processor"
  
  environment {
    variables = {
      API_KEY      = data.vault_generic_secret.api_keys.data["external_api_key"]
      DB_HOST      = aws_db_instance.main.endpoint
      DB_USERNAME  = data.vault_database_secret_backend_creds.app.username
      DB_PASSWORD  = data.vault_database_secret_backend_creds.app.password
    }
  }
  
  # Use dynamic AWS credentials
  provider = aws.deploy
}

provider "aws" {
  alias = "deploy"
  
  access_key = data.vault_aws_access_credentials.deploy.access_key
  secret_key = data.vault_aws_access_credentials.deploy.secret_key
  token      = data.vault_aws_access_credentials.deploy.security_token
}

Cloud provider secret management services offer native integration with their respective platforms. AWS Secrets Manager, Azure Key Vault, and Google Secret Manager provide managed solutions with automatic rotation, cross-region replication, and tight integration with other cloud services. These solutions excel for cloud-native deployments but may complicate multi-cloud strategies.