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Motor WASM Plugin: UCAN Source

The Motor WASM plugin is a WebAssembly-based plugin that provides Multi-Party Computation (MPC) powered UCAN (User-Controlled Authorization Networks) token generation and management.

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Overview

The Motor plugin enables secure, decentralized token creation and management through an MPC-based architecture. It provides the following key capabilities:
  • Secure token generation
  • MPC-based signing
  • Flexible UCAN token creation
  • Integrated enclave management

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Environment Configuration

To use the Motor plugin, you need to set the following PDK environment variables: 
{
  "chain_id": "sonr-testnet-1",  // Blockchain network
  "enclave": { ... },            // MPC enclave configuration
  "vault_config": { ... }        // Optional vault configuration
}

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UCAN Token Creation

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Creating Origin Tokens

type NewOriginTokenRequest struct {
    AudienceDID  string                   // Target DID
    Attenuations []map[string]any // Optional restrictions
    Facts        []string                 // Additional claims
    NotBefore    int64                    // Token activation time
    ExpiresAt    int64                    // Token expiration time
}
Example usage: 
request := NewOriginTokenRequest{
    AudienceDID: "did:example:target-did",
    Attenuations: []{
        {"capability": "read", "resource": "/data"}
    },
    Facts: ["authenticated_user"],
    NotBefore: time.Now().Unix(),
    ExpiresAt: time.Now().Add(24 * time.Hour).Unix()
}

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Creating Attenuated Tokens

type NewAttenuatedTokenRequest struct {
    ParentToken  string                   // Previous token to derive from
    AudienceDID  string                   // Target DID
    Attenuations []map[string]any // Token restrictions
    Facts        []string                 // Additional claims
    NotBefore    int64                    // Token activation time
    ExpiresAt    int64                    // Token expiration time
}

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Signing and Verification

The Motor plugin provides methods for data signing and verification: 
// Sign data using MPC enclave
func SignData(data []byte) (signature []byte, err error)

// Verify signed data
func VerifyData(data, signature []byte) (valid bool, err error)

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Error Handling

The plugin returns structured error responses with detailed error messages: 
type UCANTokenResponse struct {
    Token   string  // Generated token
    Issuer  string  // Token issuer DID
    Address string  // Blockchain address
    Error   string  // Error message (if any)
}

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Best Practices

  1. Always validate the enclave before generating tokens
  2. Use the shortest possible token lifetime
  3. Implement granular attenuations
  4. Validate tokens before using them

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Security Considerations

  • MPC ensures no single party controls the entire signing process
  • Tokens are cryptographically signed using distributed key shares
  • Supports multiple key types: Ed25519, Secp256k1, RSA

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Advanced Configuration

For advanced MPC enclave configurations, refer to the DWN configuration documentation.