@lit-protocol/aw-tool-sign-eddsa

AW-Tool Sign EdDSA Documentation

The aw-tool-sign-eddsa package provides functionality for performing EdDSA signing operations using Lit Protocol's PKPs (Programmable Key Pairs). This tool enables secure signing of arbitrary messages while enforcing policy-based controls.

Files Overview (in src/lib)

1. lit-actions/tool.ts

Contains the main logic for executing a Lit Action to perform EdDSA signing operations.

Key Features:

• PKP Info Retrieval: Fetches PKP details and validates the tool policy
• Policy Validation: Checks if a policy exists and executes it if present
• Message Signing: Signs messages using EdDSA (Ed25519) via Lit Actions
• Error Handling: Comprehensive error handling with detailed responses

2. lit-actions/policy.ts

Defines and validates the EdDSA signing policy.

Key Features:

• Policy Validation: Validates policy parameters including:
  • Allowed message prefixes
  • Message size limits
• Message Validation: Ensures messages match allowed patterns
• Type Safety: Uses strong typing for policy parameters

3. lit-actions/utils/

Collection of utility functions for the signing process:

Key Components:

• solana-keypair.ts: Handles Solana keypair creation and management
• sign-message.ts: Core message signing functionality
• index.ts: Exports utility functions

Usage

The tool requires the following parameters:

{
  pkpEthAddress: string;    // PKP's Ethereum address
  message: string;         // Message to be signed
  ciphertext: string;      // Encrypted private key data
  dataToEncryptHash: string; // Hash of the encrypted data
}

Policy Parameters

The tool supports policy restrictions on:

• Allowed message prefixes
• Message content validation
• Signing frequency limits

Response Format

Success Response:

{
  status: 'success',
  signature: string,     // Base64-encoded signature
  publicKey: string     // Base58-encoded public key
}

Error Response:

{
  status: 'error',
  error: string,
  details: {
    message: string,
    type: string,
    stack?: string
  }
}

Security Features

• Policy Enforcement: Validates all signing operations against defined policies
• Access Control: Uses Lit Protocol's access control conditions
• Secure Key Management: Handles private keys securely through encryption
• Message Validation: Enforces message format and content restrictions

Dependencies

• @solana/web3.js: Solana blockchain interaction
• @lit-protocol/aw-tool: Core Agent Wallet tooling
• tweetnacl: For Ed25519 signature verification