Cryptography and Key Management

/**
 * Standard Web Crypto API key pair interface
 */
interface CryptoKeyPair {
  privateKey: CryptoKey;
  publicKey: CryptoKey;
}

/**
 * Generate a new Ed25519 key pair using Web Crypto API
 * @returns Promise resolving to a CryptoKeyPair
 */
function generateKeyPair(): Promise<CryptoKeyPair>;

/**
 * Create key pair from raw byte array containing both private and public key data
 * @param bytes - ReadonlyUint8Array containing key pair data
 * @param extractable - Whether the keys should be extractable (optional, defaults to false)
 * @returns Promise resolving to a CryptoKeyPair
 */
function createKeyPairFromBytes(bytes: ReadonlyUint8Array, extractable?: boolean): Promise<CryptoKeyPair>;

/**
 * Create key pair from private key bytes only
 * @param bytes - 32-byte private key as ReadonlyUint8Array
 * @param extractable - Whether the keys should be extractable (defaults to false)
 * @returns Promise resolving to a CryptoKeyPair with derived public key
 */
function createKeyPairFromPrivateKeyBytes(bytes: ReadonlyUint8Array, extractable?: boolean): Promise<CryptoKeyPair>;

/**
 * Import private key from raw bytes
 * @param bytes - 32-byte private key as ReadonlyUint8Array
 * @param extractable - Whether the key should be extractable (optional, defaults to false)
 * @returns Promise resolving to a CryptoKey
 */
function createPrivateKeyFromBytes(bytes: ReadonlyUint8Array, extractable?: boolean): Promise<CryptoKey>;

/**
 * Derive public key from private key
 * @param privateKey - CryptoKey containing private key
 * @param extractable - Whether the public key should be extractable (defaults to false)
 * @returns Promise resolving to public key CryptoKey
 */
function getPublicKeyFromPrivateKey(privateKey: CryptoKey, extractable?: boolean): Promise<CryptoKey>;

import { generateKeyPair, createKeyPairFromPrivateKeyBytes, getAddressFromPublicKey } from "@solana/web3.js";

// Generate a new key pair
const keyPair = await generateKeyPair();
const { privateKey, publicKey } = keyPair;

// Derive address from public key
const address = await getAddressFromPublicKey(publicKey);
console.log("Address:", address);

// Import existing key pair from private key bytes
const existingPrivateKeyBytes = new Uint8Array(32); // Your private key bytes
const importedKeyPair = await createKeyPairFromPrivateKeyBytes(existingPrivateKeyBytes);

/**
 * Raw signature bytes (64 bytes for Ed25519)
 */
type SignatureBytes = Uint8Array & { readonly __brand: unique symbol };

/**
 * Sign arbitrary data with a private key
 * @param key - CryptoKey containing private key
 * @param data - Data to sign as ReadonlyUint8Array
 * @returns Promise resolving to signature bytes
 */
function signBytes(key: CryptoKey, data: ReadonlyUint8Array): Promise<SignatureBytes>;

/**
 * Verify a signature against data and public key
 * @param key - CryptoKey containing public key
 * @param signature - Signature bytes to verify
 * @param data - Original data that was signed as ReadonlyUint8Array
 * @returns Promise resolving to true if signature is valid
 */
function verifySignature(key: CryptoKey, signature: SignatureBytes, data: ReadonlyUint8Array): Promise<boolean>;

import { generateKeyPair, signBytes, verifySignature } from "@solana/web3.js";

// Generate key pair for signing
const { privateKey, publicKey } = await generateKeyPair();

// Sign some data
const message = new TextEncoder().encode("Hello, Solana!");
const signature = await signBytes(privateKey, message);

// Verify the signature
const isValid = await verifySignature(publicKey, signature, message);
console.log("Signature valid:", isValid); // true

/**
 * Branded string type for base58-encoded signatures
 */
type Signature = string & { readonly __brand: unique symbol };

/**
 * Type guard to check if a string is a valid Signature
 * @param putativeSignature - String to check
 * @returns True if input is a valid Signature
 */
function isSignature(putativeSignature: string): putativeSignature is Signature;

/**
 * Assert that a string is a valid Signature
 * @param putativeSignature - String to assert
 * @throws Error if input is not a valid Signature
 */
function assertIsSignature(putativeSignature: string): asserts putativeSignature is Signature;

/**
 * Convert a string to a Signature type (with validation)
 * @param putativeSignature - String to convert
 * @returns Signature type
 */
function signature(putativeSignature: string): Signature;

import { signature, isSignature } from "@solana/web3.js";

// Convert and validate signature string
const signatureString = "2Kb...ABC"; // Base58 signature string
const sig = signature(signatureString);

// Type guard usage
if (isSignature(signatureString)) {
  console.log("Valid signature format");
}

import { generateKeyPair } from "@solana/web3.js";

// Generate key pair
const keyPair = await generateKeyPair();

// For client-side storage (browser)
// Store in IndexedDB or secure key management system
// NEVER store private keys in localStorage or sessionStorage

// For server-side storage (Node.js)
// Store in encrypted format with proper key derivation
// Consider using hardware security modules (HSMs) for production

import { 
  createKeyPairFromPrivateKeyBytes,
  getAddressFromPublicKey 
} from "@solana/web3.js";

// Derive multiple addresses from a master key
async function deriveAddresses(masterPrivateKey: Uint8Array, count: number): Promise<Address[]> {
  const addresses: Address[] = [];
  
  for (let i = 0; i < count; i++) {
    // Create deterministic private key (implement your own derivation logic)
    const derivedPrivateKey = deriveChildKey(masterPrivateKey, i);
    
    // Create key pair
    const keyPair = await createKeyPairFromPrivateKeyBytes(derivedPrivateKey);
    
    // Get address
    const address = await getAddressFromPublicKey(keyPair.publicKey);
    addresses.push(address);
  }
  
  return addresses;
}

/**
 * Raw signature bytes (64 bytes for Ed25519)
 */
type SignatureBytes = Uint8Array & { readonly __brand: unique symbol };

/**
 * Branded string type for base58-encoded signatures
 */
type Signature = string & { readonly __brand: unique symbol };