Project: Go-Micro Framework Version: 1.1 Date: October 26, 2023 Author: AI Software Architect
This document provides an enhanced design overview of the Go-Micro framework, an open-source microservices framework written in Go. It is specifically designed to be used as the foundation for threat modeling activities. The purpose of this document is to clearly articulate the architecture, components, and data flows of a system built using Go-Micro, enabling security professionals and development teams to systematically identify, analyze, and mitigate potential security threats. This document will serve as a crucial input for processes like STRIDE, PASTA, or other threat modeling methodologies. It is based on the project available at https://github.com/micro/go-micro.
Go-Micro is a versatile framework designed to streamline the development of microservices-based applications. It abstracts away the complexities of distributed systems, providing developers with a simplified approach to building, deploying, and managing microservices. Go-Micro facilitates key microservices patterns such as service discovery, inter-service communication (both synchronous and asynchronous), and API Gateway functionalities. Its pluggable architecture allows for customization and integration with various infrastructure choices, making it adaptable to diverse environments, from small-scale deployments to large, enterprise-grade systems.
Typical Use Cases:
- Building backend systems for web and mobile applications.
- Developing event-driven architectures for real-time data processing.
- Creating distributed systems requiring high scalability and resilience.
- Modernizing monolithic applications by breaking them down into microservices.
Key Goals of Go-Micro (Reiterated with Security Context):
- Simplicity: Ease of use reduces the likelihood of security misconfigurations due to complexity.
- Abstraction: Hiding distributed system complexities allows developers to focus on application logic and security concerns at that level, rather than low-level infrastructure details.
- Pluggability: Flexibility to choose components allows for selecting secure and hardened implementations for registry, broker, and transport.
- Scalability: Enables building systems that can handle increasing load, maintaining performance under potential denial-of-service attacks.
- Observability: Crucial for security monitoring, incident detection, and response.
Go-Micro's features are designed to support robust microservices, and many have direct security implications:
- Service Discovery (Security Context): Centralized registry can be a single point of failure and a target for attacks. Secure access control and data integrity are paramount.
- Request/Response Communication (Security Context): RPC mechanisms must be secured with encryption and authentication to prevent eavesdropping and unauthorized access.
- Publish/Subscribe Messaging (Security Context): Message brokers need security measures to ensure message confidentiality, integrity, and access control to topics.
- Load Balancing (Security Context): Distributes traffic, potentially mitigating some forms of DoS attacks by preventing overload on single instances. However, load balancers themselves can be targets.
- Service Registry Abstraction (Security Context): While abstraction is good, ensure chosen registry implementation is secure.
- Message Broker Abstraction (Security Context): Same as above, security depends on the chosen broker implementation.
- Transport Abstraction (Security Context): Crucial for selecting secure transport protocols like gRPC with TLS or HTTPS.
- API Gateway (Security Context): A critical security component for external access control, input validation, and protection of backend services.
- CLI Tooling (Security Context): CLI tools must be secured to prevent unauthorized access and misuse, especially if they manage sensitive configurations or deployments.
- Pluggable Codecs (Security Context): Choice of codec can impact security. For example, binary codecs like Protobuf can be less susceptible to certain injection attacks compared to text-based formats if not handled carefully.
- Middleware (Security Context): Middleware can be used to implement security policies like authentication, authorization, logging, and rate limiting.
- Tracing & Metrics (Security Context): Essential for security monitoring, incident response, and auditing.
Improved diagram with clearer labels and emphasis on key security components.
graph LR
subgraph "External Client Zone"
"External Client" --> "API Gateway"
style "External Client" fill:#f9f,stroke:#333,stroke-width:2px
end
subgraph "Go-Micro System Zone"
subgraph "Service A Instance 1"
"Service A Instance 1" -- "Transport (e.g., gRPC, TLS)" --> "Service Registry"
"Service A Instance 1" -- "Transport (e.g., gRPC, TLS)" --> "Broker"
style "Service A Instance 1" fill:#ccf,stroke:#333,stroke-width:1px
end
subgraph "Service A Instance 2"
"Service A Instance 2" -- "Transport (e.g., gRPC, TLS)" --> "Service Registry"
"Service A Instance 2" -- "Transport (e.g., gRPC, TLS)" --> "Broker"
style "Service A Instance 2" fill:#ccf,stroke:#333,stroke-width:1px
end
subgraph "Service B Instance 1"
"Service B Instance 1" -- "Transport (e.g., gRPC, TLS)" --> "Service Registry"
"Service B Instance 1" -- "Transport (e.g., gRPC, TLS)" --> "Broker"
style "Service B Instance 1" fill:#ccf,stroke:#333,stroke-width:1px
end
subgraph "Service B Instance 2"
"Service B Instance 2" -- "Transport (e.g., gRPC, TLS)" --> "Service Registry"
"Service B Instance 2" -- "Transport (e.g., gRPC, TLS)" --> "Broker"
style "Service B Instance 2" fill:#ccf,stroke:#333,stroke-width:1px
end
"API Gateway" -- "Transport (e.g., HTTPS, TLS)" --> "Service Registry"
"API Gateway" -- "Transport (e.g., gRPC, TLS)" --> "Service A Instance 1" & "Service A Instance 2" & "Service B Instance 1" & "Service B Instance 2"
"Service A Instance 1" & "Service A Instance 2" -- "Transport (e.g., gRPC, TLS)" --> "Service B Instance 1" & "Service B Instance 2"
"Service B Instance 1" & "Service B Instance 2" -- "Transport (e.g., gRPC, TLS)" --> "Service A Instance 1" & "Service A Instance 2"
"Service Registry"
"Broker"
style "API Gateway" fill:#aaf,stroke:#333,stroke-width:2px
style "Service Registry" fill:#eee,stroke:#333,stroke-width:2px
style "Broker" fill:#eee,stroke:#333,stroke-width:2px
end
Diagram Explanation (Improved):
- External Client Zone: Clearly separates external entities from the Go-Micro system, highlighting the API Gateway as the entry point.
- Go-Micro System Zone: Groups the core components within a defined boundary.
- Service Instances: Illustrates multiple instances of services for scalability and resilience.
- Transport Labels: Explicitly mentions "Transport (e.g., gRPC, TLS)" and "Transport (e.g., HTTPS, TLS)" to emphasize the importance of secure communication.
- Component Styling: Uses different fill colors to visually distinguish between external clients, API Gateway, services, and infrastructure components (Registry, Broker).
This section expands on security considerations and includes potential threats and controls for each component.
- Purpose: Centralized service discovery and configuration management.
- Examples: Consul, Etcd, Kubernetes, DNS, MDNS.
- Security Considerations (Expanded):
- Access Control (Threat: Unauthorized Access, Control: ACLs, RBAC): Strictly control access to the registry API and data. Implement Access Control Lists (ACLs) or Role-Based Access Control (RBAC).
- Data Integrity (Threat: Data Tampering, Control: Secure Communication, Audit Logs): Ensure data integrity by using secure communication channels (TLS) and maintaining audit logs of registry changes.
- Availability (Threat: DoS, Control: Redundancy, Monitoring): Implement redundancy and monitoring to ensure high availability and resilience against Denial-of-Service (DoS) attacks.
- Authentication and Authorization (Threat: Spoofing, Control: Mutual TLS, API Keys): Use strong authentication mechanisms like Mutual TLS (mTLS) or API Keys for services registering and querying the registry. Implement authorization policies.
- Encryption in Transit and at Rest (Threat: Information Disclosure, Control: TLS, Encryption at Rest Features): Encrypt communication with the registry using TLS. Consider encryption at rest features offered by the chosen registry implementation for sensitive data.
- Vulnerability Management (Threat: Exploitation of Vulnerabilities, Control: Regular Updates, Security Audits): Regularly update the registry software to patch vulnerabilities. Conduct periodic security audits.
- Purpose: Asynchronous message communication.
- Examples: NATS, RabbitMQ, Kafka, Redis Pub/Sub.
- Security Considerations (Expanded):
- Message Confidentiality (Threat: Eavesdropping, Control: Message Encryption, TLS): Encrypt sensitive message payloads before publishing. Use TLS for broker communication.
- Message Integrity (Threat: Message Tampering, Control: Message Signing, Hashing): Implement message signing or hashing to ensure message integrity and detect tampering.
- Access Control (Threat: Unauthorized Publish/Subscribe, Control: ACLs, Exchange/Topic Permissions): Control who can publish and subscribe to specific topics or exchanges using ACLs and broker-specific permission mechanisms.
- Authentication and Authorization (Threat: Spoofing, Unauthorized Access, Control: Username/Password, API Keys, Certificates): Require authentication for publishers and subscribers using username/password, API keys, or certificates. Implement authorization policies.
- Broker Security (Threat: Broker Compromise, Control: Hardening, Security Audits, Network Segmentation): Harden the broker infrastructure, conduct security audits, and segment the broker network.
- Denial of Service (Threat: Message Flooding, Control: Rate Limiting, Quotas): Implement rate limiting and quotas to protect the broker from message flooding and DoS attacks.
- Purpose: Inter-service and client-service communication protocol.
- Examples: gRPC, HTTP, Go Micro TCP.
- Security Considerations (Expanded):
- Encryption in Transit (Threat: Eavesdropping, MITM, Control: TLS/SSL, HTTPS, gRPC with TLS): Mandatory use of TLS/SSL or HTTPS for all communication. For gRPC, ensure TLS is enabled.
- Authentication and Authorization (Threat: Spoofing, Unauthorized Access, Control: mTLS, API Keys, JWT, OAuth 2.0): Implement strong authentication using mTLS for service-to-service communication. For client-to-service, consider API Keys, JWT, or OAuth 2.0.
- Protocol Vulnerabilities (Threat: Protocol Exploits, Control: Regular Updates, Vulnerability Scanning): Stay updated on protocol vulnerabilities and patch systems regularly. Use vulnerability scanning tools.
- Denial of Service (Threat: SYN Flood, Request Flooding, Control: Rate Limiting, Connection Limits, Firewall): Implement rate limiting, connection limits, and firewalls to mitigate transport-level DoS attacks.
- Input Validation (Threat: Injection Attacks, Control: Input Sanitization, Validation Libraries): While transport is lower level, ensure input validation is performed at the application layer on data received via the transport.
- Purpose: Service clients for making requests.
- Security Considerations (Expanded):
- Secure Communication (Threat: Eavesdropping, MITM, Control: TLS/SSL): Clients must always use secure transport (TLS/SSL) when communicating with services.
- Input Validation (Threat: Injection Attacks, Control: Validation Libraries, Data Sanitization): Clients should validate input data before sending requests to prevent sending malicious data that could be exploited by services.
- Error Handling (Threat: Information Leakage, Control: Secure Error Handling, Logging): Implement secure error handling to prevent leaking sensitive information in error messages. Log errors securely.
- Credential Management (Threat: Credential Compromise, Control: Secure Storage, Secrets Management): Securely manage credentials (API keys, tokens) used for authentication. Use secrets management solutions.
- Dependency Management (Threat: Vulnerable Dependencies, Control: Dependency Scanning, Regular Updates): Scan client dependencies for vulnerabilities and keep them updated.
- Purpose: Service implementation and request handling.
- Security Considerations (Expanded):
- Input Validation (Threat: Injection Attacks, Control: Input Sanitization, Validation Libraries, Parameterized Queries): Rigorous input validation is critical to prevent injection attacks (SQL, command, etc.). Use validation libraries and parameterized queries.
- Authorization (Threat: Unauthorized Access, Control: RBAC, ABAC, Policy Enforcement): Implement robust authorization to control access to functionalities and data. Use Role-Based Access Control (RBAC) or Attribute-Based Access Control (ABAC). Enforce authorization policies consistently.
- Output Sanitization (Threat: XSS, Control: Output Encoding, Context-Aware Sanitization): Sanitize output data to prevent Cross-Site Scripting (XSS) vulnerabilities, especially if the service serves web clients. Use context-aware output encoding.
- Secure Configuration (Threat: Misconfiguration, Control: Secure Defaults, Configuration Management, Security Hardening): Configure servers securely, disable unnecessary features, use secure defaults, and employ configuration management tools. Implement security hardening best practices.
- Dependency Management (Threat: Vulnerable Dependencies, Control: Dependency Scanning, Regular Updates): Keep server dependencies up-to-date to patch vulnerabilities. Use dependency scanning tools.
- Logging and Monitoring (Threat: Security Incidents, Control: Centralized Logging, Security Monitoring Tools, Alerting): Implement comprehensive logging and monitoring for security incident detection and response. Use centralized logging and security monitoring tools with alerting.
- Secrets Management (Threat: Credential Exposure, Control: Secrets Management Solutions, Vault, KMS): Securely manage secrets (database credentials, API keys) using dedicated secrets management solutions like Vault or cloud provider KMS.
- Purpose: External entry point, routing, security enforcement.
- Security Considerations (Expanded):
- Authentication and Authorization (Threat: Unauthorized Access, Control: OAuth 2.0, JWT, API Keys, WAF): Enforce strong authentication and authorization for external requests. Use protocols like OAuth 2.0, JWT, or API Keys. Consider using a Web Application Firewall (WAF).
- Input Validation (Threat: Injection Attacks, Control: Input Sanitization, Validation Rules, WAF): Validate all input from external clients to prevent attacks targeting backend services. Use input sanitization, validation rules, and WAF capabilities.
- Rate Limiting and Throttling (Threat: DoS, Brute Force, Control: Rate Limiting Policies, Throttling Mechanisms): Implement rate limiting and throttling to protect backend services from excessive requests, DoS attacks, and brute-force attempts.
- Web Application Security (Threat: Web Attacks, Control: OWASP Top 10 Mitigations, Security Hardening, Regular Security Scans): Apply standard web application security practices to the API Gateway itself, including mitigations for OWASP Top 10 vulnerabilities. Harden the API Gateway and perform regular security scans.
- Secure Communication (Threat: Eavesdropping, MITM, Control: HTTPS, TLS): Mandatory use of HTTPS for communication between external clients and the API Gateway. Use secure communication (TLS) between the API Gateway and backend services.
- CORS and Header Security (Threat: Cross-Origin Attacks, Control: Properly Configured CORS, Security Headers): Configure Cross-Origin Resource Sharing (CORS) policies correctly. Implement security headers (e.g., HSTS, X-Frame-Options, X-XSS-Protection).
- Purpose: Development, deployment, and management tools.
- Security Considerations (Expanded):
- Access Control (Threat: Unauthorized Access, Control: RBAC, User Permissions): Restrict access to CLI tools to authorized users using RBAC or user permissions.
- Secure Credential Storage (Threat: Credential Exposure, Control: Encrypted Storage, Secrets Management): If CLI tools handle credentials, store them securely using encryption or integrate with secrets management solutions. Avoid storing credentials in plain text.
- Command Injection (Threat: Command Injection, Control: Input Sanitization, Secure Coding Practices): Prevent command injection vulnerabilities in the CLI tools themselves through input sanitization and secure coding practices.
- Audit Logging (Threat: Unauthorized Actions, Control: Audit Logs, Monitoring): Log CLI tool usage and actions for auditing and monitoring purposes.
Data flow analysis from a threat perspective, highlighting sensitive data paths.
-
Request/Response (RPC) - Threat Perspective:
- Sensitive Data in Request/Response Payloads (Threat: Information Disclosure, Eavesdropping): Identify if sensitive data is transmitted in request or response bodies. Ensure encryption (TLS) is used. Consider encrypting sensitive fields within the payload itself.
- Replay Attacks (Threat: Replay Attack, Control: Nonces, Timestamps, Mutual Authentication): Consider the risk of replay attacks, especially for sensitive operations. Implement nonces, timestamps, or mutual authentication to mitigate this.
-
Publish/Subscribe Messaging - Threat Perspective:
- Sensitive Data in Messages (Threat: Information Disclosure, Eavesdropping): Messages published to topics might contain sensitive data. Encrypt message payloads. Control access to topics to prevent unauthorized subscribers.
- Message Injection (Threat: Message Spoofing, Control: Message Signing, Authentication): Malicious actors might inject messages into topics. Implement message signing and publisher authentication to prevent spoofing.
-
External Client Access via API Gateway - Threat Perspective:
- Exposure of Backend Services (Threat: Direct Access to Services, Control: API Gateway as Single Entry Point, Network Segmentation): Ensure API Gateway is the sole entry point for external clients. Implement network segmentation to isolate backend services.
- Authentication and Authorization Bypass (Threat: Authorization Bypass, Control: Robust Authentication and Authorization at API Gateway): Weak authentication or authorization at the API Gateway can lead to bypass vulnerabilities. Implement robust mechanisms and regularly audit configurations.
Sensitive Data Flow Mapping for Threat Modeling:
- Identify Sensitive Data: Classify data based on sensitivity (e.g., PII, financial data, secrets).
- Trace Data Flow: Map the flow of sensitive data through different components (clients, services, broker, registry, API Gateway).
- Identify Potential Exposure Points: Pinpoint locations where sensitive data is most vulnerable (e.g., during transit, at rest, in logs).
- Prioritize Threats: Focus threat modeling efforts on data flows involving the most sensitive data.
Security considerations based on different deployment models.
-
Cloud Environments (AWS, Azure, GCP) (Security Implications):
- Shared Responsibility Model: Understand the cloud provider's security responsibilities and your own.
- Cloud Security Services: Leverage cloud-native security services (e.g., AWS WAF, Azure Security Center, GCP Security Command Center).
- IAM and Access Control: Utilize cloud IAM (Identity and Access Management) for granular access control.
- Network Security Groups/Firewalls: Configure network security groups and firewalls to restrict network access.
- Data Encryption at Rest and in Transit: Utilize cloud provider encryption services for data at rest and in transit.
-
On-Premise Data Centers (Security Implications):
- Full Security Responsibility: Organization is fully responsible for all aspects of security.
- Physical Security: Physical security of data centers is crucial.
- Network Security: Robust network security infrastructure (firewalls, IDS/IPS) is required.
- Manual Security Configuration: More manual configuration and hardening of systems.
- Patch Management: Critical to maintain a rigorous patch management process.
-
Containerized Environments (Docker, Kubernetes) (Security Implications):
- Container Image Security: Secure container images by scanning for vulnerabilities and using minimal base images.
- Container Runtime Security: Harden container runtime environments.
- Orchestration Platform Security (Kubernetes): Secure Kubernetes clusters, including API server access control, RBAC, network policies, and secrets management.
- Image Registry Security: Secure access to container image registries.
-
Serverless Environments (Functions as a Service) (Security Implications):
- Function Security: Secure function code and dependencies.
- IAM Roles for Functions: Use IAM roles to restrict function permissions.
- Vendor Security: Rely on the serverless platform provider for infrastructure security.
- Limited Control: Less control over underlying infrastructure security compared to other models.
Re-emphasizing security implications of chosen technologies.
- Programming Language: Go (Security Implications): Memory safety reduces certain classes of vulnerabilities, but application-level vulnerabilities are still possible. Secure coding practices are essential.
- Service Registry (Pluggable) (Security Implications): Security depends heavily on the chosen registry implementation. Thoroughly evaluate and configure the chosen registry securely.
- Message Broker (Pluggable) (Security Implications): Similar to the registry, security is implementation-dependent. Choose a broker with robust security features and configure it properly.
- Transport (Pluggable) (Security Implications): Prioritize secure transports like gRPC with TLS or HTTPS. Avoid insecure transports in production environments.
- Serialization/Codecs (Pluggable) (Security Implications): Consider security implications of codec choices. Binary codecs can offer some advantages in terms of parsing robustness, but proper handling is always necessary.
- Operating System (Security Implications): Choose hardened operating systems and keep them patched.
- Containerization (Optional) (Security Implications): Introduces container-specific security considerations as outlined in section 7.
- Cloud Platform (Optional) (Security Implications): Leverage cloud platform security features and adhere to the shared responsibility model.
Structured security considerations categorized by security domains.
9.1. Confidentiality:
- Data Encryption in Transit: Mandatory for all communication channels (inter-service, client-service, external client-API Gateway).
- Data Encryption at Rest: Consider encrypting sensitive data at rest in databases, message queues, and storage.
- Secrets Management: Implement robust secrets management to protect API keys, database credentials, and other sensitive information.
- Access Control (Least Privilege): Apply the principle of least privilege for all components and users.
9.2. Integrity:
- Input Validation: Rigorous input validation at all entry points (API Gateway, services).
- Message Integrity: Implement message signing or hashing for critical messages exchanged via the broker.
- Data Integrity in Registry: Ensure the integrity of service registration data in the service registry.
- Code Integrity: Implement secure software development lifecycle (SSDLC) practices to ensure code integrity.
9.3. Availability:
- Redundancy and High Availability: Design for redundancy and high availability for critical components (registry, broker, API Gateway, services).
- Denial of Service (DoS) Protection: Implement rate limiting, throttling, and other DoS mitigation techniques at API Gateway and services.
- Monitoring and Alerting: Implement comprehensive monitoring and alerting to detect and respond to availability issues promptly.
- Disaster Recovery and Business Continuity: Plan for disaster recovery and business continuity to ensure system availability in case of major incidents.
9.4. Authentication and Authorization:
- Strong Authentication: Use strong authentication mechanisms (mTLS, OAuth 2.0, JWT) for services and external clients.
- Centralized Authorization: Consider centralized authorization mechanisms for consistent policy enforcement.
- Role-Based Access Control (RBAC): Implement RBAC to manage user and service permissions.
- Regular Access Reviews: Conduct regular access reviews to ensure permissions are still appropriate.
9.5. Auditing and Logging:
- Comprehensive Logging: Implement comprehensive logging for security events, errors, and access attempts.
- Centralized Logging: Use a centralized logging system for easier analysis and correlation.
- Security Monitoring: Implement security monitoring tools to detect and respond to security incidents.
- Audit Trails: Maintain audit trails for critical operations and configuration changes.
This improved design document provides a more detailed and security-focused overview of the Go-Micro framework, specifically tailored for threat modeling. It expands on component details, data flow analysis from a threat perspective, deployment model security implications, and structured security considerations.
Next Steps for Threat Modeling:
- Choose a Threat Modeling Methodology: Select a suitable methodology like STRIDE, PASTA, or others.
- Utilize this Document as Input: Use this design document as the primary input for your chosen threat modeling methodology.
- Identify Threats: Systematically identify potential threats based on the components, data flows, and security considerations outlined in this document.
- Analyze and Prioritize Threats: Analyze the identified threats, assess their likelihood and impact, and prioritize them for mitigation.
- Develop Mitigation Strategies: Develop specific security controls and mitigation strategies to address the prioritized threats.
- Document and Implement Controls: Document the chosen security controls and implement them in the Go-Micro system.
- Regularly Review and Update: Threat modeling is an ongoing process. Regularly review and update the threat model and security controls as the system evolves and new threats emerge.
By using this document as a starting point, security professionals and development teams can effectively conduct threat modeling for Go-Micro based systems and build more secure microservices applications.