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Wallet

The Wallet manages ed25519 key pairs, signs messages, and optionally connects to an RPC node for on-chain queries.

Key Management​

Create a New Wallet​

use savitri_sdk::Wallet;

// Random keypair (cryptographically secure)
let wallet = Wallet::new();
println!("Address: {}", wallet.address());  // 64 hex chars (32-byte pubkey)

Import from Private Key​

// From raw bytes
let private_key: [u8; 32] = [/* your key */];
let wallet = Wallet::from_private_key(&private_key)?;

// From hex string
let wallet = Wallet::from_private_key_hex("aabbccdd...64hexchars")?;

// With 0x prefix
let wallet = Wallet::from_private_key_hex("0xaabbccdd...64hexchars")?;

Export Keys​

// Public key (safe to share)
let pubkey = wallet.public_key();
println!("Public key: {}", hex::encode(pubkey.as_bytes()));

// Address (derived from public key)
println!("Address: {}", wallet.address());

// Private key (NEVER share or log)
let privkey: [u8; 32] = wallet.private_key();

Signing​

Sign a Message​

let message = b"Hello, Savitri!";
let signature: [u8; 64] = wallet.sign_message(message);

Verify a Signature​

wallet.verify_signature(message, &signature)?;
// Returns Ok(()) if valid, Err if invalid

The signing scheme uses Ed25519 (ed25519-dalek). For transaction signing, the message is first SHA-256 hashed:

message = from_hex || to_hex || amount_le_u64 || nonce_le_u64 || fee_le_u128
hash    = SHA-256(message)
sig     = Ed25519_sign(hash)

RPC Integration​

Connect a wallet to a node for on-chain queries:

// Create with RPC connection
let wallet = Wallet::with_rpc("http://localhost:8545")?;

// Or connect later
let mut wallet = Wallet::new();
wallet.connect_rpc("http://localhost:8545")?;

// Query balance (requires RPC)
let balance: String = wallet.get_balance().await?;
println!("Balance: {}", balance);

// Query nonce (requires RPC)
let nonce: u64 = wallet.get_nonce().await?;
println!("Nonce: {}", nonce);

// Access underlying RPC client
if let Some(rpc) = wallet.rpc() {
    let height = rpc.get_block_number().await?;
    println!("Height: {}", height);
}

Security​

  • Zeroization: Private key material is zeroized when the wallet is dropped (Drop trait via zeroize crate).
  • Clone behavior: Cloned wallets do NOT inherit the RPC connection (they start disconnected).
  • No persistence: The wallet does not save keys to disk. Use your own secure storage.
{
    let wallet = Wallet::new();
    // ... use wallet ...
} // wallet dropped here — private key bytes are zeroed in memory