TEE Registry System

A decentralized provisioning system for Trusted Execution Environment (TEE) services with onchain governance, flexible storage backends, and secure service discovery.

Overview

The TEE Registry System enables secure provisioning of confidential computing services through cryptographic attestation, onchain governance, and flexible configuration management. It provides a complete solution for bootstrapping TEE instances with the required cryptographic materials, configurations, and secrets while ensuring all sensitive data remains protected.

Key Features

Attestation-Based Identity Verification

• Support for Intel TDX and Azure Confidential Computing (MAA)
• Mapping from TEE report data to workload identities
• Onchain verification of attestation reports (DCAP and MAA)
• Allowlisting mechanism for authorized identity access

Onchain Governance

• Standard onchain TEE service governance interface
• Role-based access control for operators and administrators
• Transparent and configurable governance model
• Mapping of workload identities to content-addressed configurations

Secure Secret Management

• Application-wide secrets derived from TEE KMS
• Pre-encrypted secrets with the application's public key
• Secure key management with optional Shamir's Secret Sharing recovery
• Transparent reference resolution in configuration templates

Content-Addressed Storage System

• Multiple, flexible storage backends for different needs
• Content addressing to decouple data from specific storage providers
• Support for various backend types:
  • File system (local development)
  • S3-compatible storage (cloud deployments)
  • IPFS storage (decentralized content)
  • On-chain storage (using smart contracts)
  • GitHub storage (read-only from repositories)
  • Vault storage (with TLS client authentication)

DNS-Based Service Discovery

• Domain names registered in onchain contracts
• Standard DNS for IP resolution and bootstrapping
• TLS-based authentication and authorization
• Application-wide certificate authority managed by TEE KMS

Flexible Key Management

• Support for simple and Shamir's Secret Sharing KMS implementations
• Secure bootstrapping with multi-administrator shares
• Optional onchain-driven onboarding using already bootstrapped instances

System Architecture

The system consists of the following main components:

Core Components

1. Governance Interfaces

   • WorkloadGovernance: Handles identity verification and allowlisting
   • ConfigGovernance: Manages configuration mapping and storage backends
   • OnchainDiscovery: Provides service metadata and domain name management

2. Storage System

   • Content-addressed storage with multiple backend implementations
   • Configuration and secret namespaces
   • Reference resolution for configuration templates

3. Key Management Service

   • Application CA and secrets key management
   • Optional Shamir's Secret Sharing recovery
   • Onchain-driven onboarding mechanism

4. Instance Tooling

   • Configuration resolver for retrieving and processing configurations
   • Service resolver for discovering and authenticating peers
   • Disk encryption management using application credentials

Workflow Overview

1. System Initialization and KMS Bootstrap

The system uses a secure KMS bootstrap process:

1. Initial Setup:

   • Onchain governance contracts are deployed
   • KMS is initialized with either generation or recovery mode
   • Administrators manage shares through secure channels

2. Configuration Preparation:

   • Configurations and secrets are stored in content-addressed storage backends
   • References to storage backends are registered in the governance contract
   • Workload identities are allowlisted for authorized access

2. TEE Instance Provisioning

Once the system is bootstrapped:

1. Instance Boot:

   • TEE instance boots with measured parameters
   • Instance generates TLS key pair and CSR
   • Optionally waits for operator signature

2. Identity Verification:

   • Instance submits attestation evidence to the registry
   • Registry verifies attestation against onchain governance contract
   • If valid, registry provides cryptographic materials

3. Configuration Resolution:

   • Instance resolves configuration using onchain governance contract
   • Retrieves content from registered storage backends
   • Decrypts secrets using application private key

4. Service Discovery:

   • Instance registers domain name in onchain contract
   • Other instances discover peers through DNS resolution
   • Secure connections established using TLS with CA verification

API Interfaces

Governance Interfaces

// WorkloadGovernance handles TEE identity verification
interface WorkloadGovernance {
    // Identity verification and allowlisting
    IdentityAllowed(identity [32]byte, operator [20]byte) (bool, error)
    DCAPIdentity(report DCAPReport, events []DCAPEvent) ([32]byte, error)
    MAAIdentity(report MAAReport) ([32]byte, error)
}

// ConfigGovernance manages configuration mapping
interface ConfigGovernance {
    // Configuration and storage management
    ConfigForIdentity(identity [32]byte, operator [20]byte) ([32]byte, error)
    StorageBackends() ([]string, error)
}

// OnchainDiscovery provides service information
interface OnchainDiscovery {
    // Service discovery
    PKI() (AppPKI, error)
    InstanceDomainNames() ([]string, error)
}

Utility Functions

// Resolve configuration from onchain governance
func ResolveConfiguration(
    configGovernance ConfigGovernance,
    storageFactory StorageBackendFactory,
    configHash [32]byte,
    appPrivkey AppPrivkey
) (InstanceConfig, error)

// Resolve service metadata for peer discovery
func ResolveServiceMetadata(
    discoveryContract OnchainDiscovery
) (ServiceMetadata, error)

// Map attestation to workload identity
func AttestationToIdentity(
    attestationType AttestationType,
    measurements map[int]string,
    governance WorkloadGovernance
) ([32]byte, error)

Storage Backend URIs

Storage backends are specified using URI format:

[scheme]://[auth@]host[:port][/path][?params]

Supported URIs:

• File System: file:///var/lib/registry/configs/ or file://./relative/path/
• S3: s3://bucket-name/prefix/?region=us-west-2 or s3://ACCESS_KEY:SECRET_KEY@bucket-name/path/
• IPFS: ipfs://ipfs.example.com:5001/ or ipfs://localhost:8080/?gateway=true&timeout=30s
• On-Chain: onchain://0x1234567890abcdef1234567890abcdef12345678
• GitHub: github://owner/repo
• Vault: vault://vault.example.com:8200/secret/data

License

MIT License