HDWallet

Hierarchical Deterministic (HD) Wallet for Midnight blockchain.

Implements BIP-32 key derivation following Midnight's specific derivation path:

m / 44' / 2400' / account' / role / index

Features:

• BIP-32 compliant key derivation using BitcoinJ

• Midnight-specific derivation paths (coin type 2400)

• Support for multiple accounts and roles

• Secure key management with hierarchical memory wiping

Usage:

// Create HD wallet from BIP-39 seed
val seed = BIP39.mnemonicToSeed(mnemonic)
try {
    val wallet = HDWallet.fromSeed(seed)
    try {
        // Derive key at path: m/44'/2400'/0'/0/0
        val key = wallet
            .selectAccount(0)
            .selectRole(MidnightKeyRole.NIGHT_EXTERNAL)
            .deriveKeyAt(0)

        // Use key...
    } finally {
        // Always clear wallet when done
        wallet.clear()
    }
} finally {
    // Always wipe seed from memory
    Arrays.fill(seed, 0.toByte())
}

Security:

• ALWAYS call clear when done to wipe keys from memory

• ALWAYS wipe the seed array after calling fromSeed

• Use try-finally blocks to ensure cleanup even on exceptions

• This class tracks ALL derived keys and clears them hierarchically

Thread Safety:

• This class is NOT thread-safe

• Do not share instances across threads

• Create separate instances for concurrent use

References:

• BIP-32: https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki

• BIP-44: https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki

• Midnight SDK: https://github.com/midnightntwrk/midnight-wallet