When managing secrets in AWS, you’re likely deciding between AWS Secrets Manager and AWS Systems Manager Parameter Store. Both are designed to store and manage sensitive data such as database credentials, API keys, and configuration settings. However, the right choice depends on your specific needs, feature requirements, and budget.
This article breaks down the key differences between AWS Secrets Manager and Parameter Store, with the latest developments in Parameter Store’s integration with AWS Resource Access Manager (RAM) for shared parameters.
1. Feature Set and Use Cases
AWS Secrets Manager: Purpose-Built for Secrets
AWS Secrets Manager is specifically designed to handle secrets such as passwords, API keys, and other sensitive credentials. One of its key strengths is automatic secret rotation, which simplifies the process of regularly updating secrets for enhanced security.
- Automatic Rotation: Secrets Manager supports automatic rotation for services like RDS and Redshift, with the option to customise rotation for third-party applications using AWS Lambda. This feature is crucial for applications that require frequent updates to secrets to ensure security and compliance.
- Versioning and History: Secrets Manager automatically maintains a version history for all stored secrets, allowing you to roll back changes if necessary.
- Fine-Grained Access Control: It offers detailed access control via AWS Identity and Access Management (IAM), allowing you to define which users or services can access particular secrets with precise policies.
AWS Parameter Store: Broad Scope for Secrets and Configurations
AWS Parameter Store, part of AWS Systems Manager, can store both secrets and configuration data in either plain text or encrypted form. It is a more general-purpose service designed to manage both non-sensitive parameters (e.g., configuration settings) and sensitive data (e.g., passwords).
- Hierarchy and Tagging: Parameters can be organised hierarchically, which is helpful for structuring configuration settings in environments with multiple stages (e.g.,
/prod/db/username
). - Shared Parameters with AWS RAM: Parameter Store integrates with AWS Resource Access Manager (RAM), allowing advanced parameters to be shared across multiple AWS accounts. This is especially useful for organisations that operate multiple AWS accounts or utilise AWS Organisations, as it allows centralised management of configuration data while enabling controlled sharing.
- Manual Rotation: Although Parameter Store supports encrypted secrets, it lacks automatic rotation. You can implement your own rotation process using AWS Lambda, but this requires custom development.
2. Cost Comparison
AWS Secrets Manager:
Secrets Manager charges based on the number of secrets stored and the volume of API requests. While it offers powerful features for managing secrets, its cost can increase significantly for large-scale applications, especially when dealing with frequent requests or numerous secrets.
- Pricing: Secrets Manager charges per secret stored and per 10,000 API calls. If your application requires regular access to a large number of secrets, this service may become expensive.
- Automatic Rotation Included: The price includes automatic rotation, making it valuable for scenarios where frequent secret updates are required.
AWS Parameter Store:
Parameter Store offers a free tier for up to 10,000 standard parameters, which makes it an appealing choice for applications that don’t require advanced features like automatic rotation.
- Pricing for Advanced Parameters: Storing sensitive data as SecureString parameters (encrypted) is considered an advanced feature and incurs additional costs. However, Parameter Store is still more affordable for applications that need to store a moderate number of secrets or configuration values.
- No Built-in Rotation: Without built-in rotation, Parameter Store requires you to manage the rotation process yourself, which adds complexity but keeps costs lower if you don’t need frequent updates.
3. Security and Compliance
AWS Secrets Manager:
- Automatic KMS Encryption: All secrets in Secrets Manager are automatically encrypted using AWS Key Management Service (KMS), with the option to use customer-managed keys for additional control.
- Audit Logging: Secrets Manager integrates with AWS CloudTrail to log every access, modification, or rotation event, making it easy to audit secret usage and ensure compliance with standards like HIPAA and PCI-DSS.
AWS Parameter Store:
- KMS Encryption for Sensitive Data: Parameter Store can encrypt sensitive data using AWS KMS if stored as SecureString parameters. While KMS encryption offers robust security, it must be explicitly selected for sensitive data.
- Shared Parameter Management: Through AWS RAM, Parameter Store enables secure sharing of advanced parameters between multiple AWS accounts, which allows central management while still enforcing security across accounts. This makes it ideal for multi-account environments, as access to shared parameters can be carefully controlled.
4. Access Control and Integrations
AWS Secrets Manager:
Secrets Manager offers precise access control through IAM policies, allowing you to define which users or services can access particular secrets. This is crucial for maintaining strict control over sensitive data.
- AWS Service Integration: Secrets Manager integrates seamlessly with AWS SDKs and services, making it easy to retrieve secrets from within your applications. It also works well with services like RDS for automatic secret rotation.
AWS Parameter Store:
While Parameter Store also offers access control through IAM, it now supports cross-account secret management via AWS RAM. This makes it easier to share and control access to sensitive data across multiple AWS accounts without needing to duplicate secrets in each account.
- AWS Organisations Integration: You can specify which AWS accounts or organisational units (OUs) have access to shared parameters, making it useful for large organisations looking to manage secrets centrally.
5. Use Cases
AWS Secrets Manager
- Automatic Rotation: If your application requires frequent secret rotation, such as database credentials that need to be regularly updated, Secrets Manager is the ideal solution. It automates the process, reducing manual overhead.
- Highly Sensitive Secrets: For managing highly sensitive information, such as API keys, production credentials, or tokens, Secrets Manager provides the best features in terms of security, fine-grained access control, and detailed audit logging.
AWS Parameter Store
- Multi-Account Environments: Parameter Store’s ability to share advanced parameters across multiple accounts makes it an excellent option for organisations managing multiple AWS accounts. It enables centralised management while allowing secure access to shared secrets.
- Cost-Effective Configuration Management: For applications that need to manage both configuration data and secrets, Parameter Store is a more affordable and versatile option. It’s particularly suited to situations where automatic secret rotation is not a priority.
6. Availability and Region Replication
AWS Secrets Manager
- Regional Replication: Secrets Manager supports the automatic replication of secrets across AWS regions, making it a good choice for multi-region deployments or disaster recovery scenarios.
AWS Parameter Store:
- Shared Parameters Across Accounts and Regions: Through AWS RAM, advanced parameters can now be shared across AWS accounts and regions, offering greater flexibility for cross-region and cross-account deployments. However, replication between regions must still be configured manually.
7. API Rate Limits
- Secrets Manager: Generally offers higher rate limits than Parameter Store, which can be important for high-traffic applications.
- Parameter Store: Has lower API call limits in the free tier, and you may encounter throttling if you make too many requests in a short period. This can be resolved by moving to the advanced tier at additional cost.
Summary: Which One is Better?
Choose AWS Secrets Manager if:
- You require automatic secret rotation for high-value credentials.
- You are managing highly sensitive data that demands detailed logging, security, and access control.
- You need a feature-rich, automated solution to handle secret lifecycle management.
Choose AWS Parameter Store if:
- You need a cost-effective solution for storing both configuration data and secrets.
- You operate in a multi-account environment and need to share parameters securely across accounts.
- Your application does not require automatic rotation or can manage rotation manually.
In summary, AWS Secrets Manager is the preferred choice for applications that require robust secret management with automatic rotation. In contrast, AWS Parameter Store is better suited for simpler, more budget-conscious use cases and multi-account environments. With the ability to share advanced parameters through AWS RAM, Parameter Store provides a strong solution for managing shared secrets across multiple AWS accounts.