ExtendedPrivKey、ExtendedPubKey 扩展公私钥。从标准的公私钥扩展而来。

ExtendedPrivKey

/// Extended private key
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub struct ExtendedPrivKey {
    /// The network this key is to be used on
    pub network: [u8; 4],
    /// How many derivations this key is from the master (which is 0)
    pub depth: u8,
    /// Fingerprint of the parent key (0 for master)
    pub parent_fingerprint: Fingerprint,
    /// Child number of the key used to derive from parent (0 for master)
    pub child_number: ChildNumber,
    /// Secret key
    pub secret_key: SecretKey,
    /// Chain code
    pub chain_code: ChainCode,
}

ExtendedPubKey

/// Extended public key
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub struct ExtendedPubKey {
    /// The network this key is to be used on
    pub network: [u8; 4],
    /// How many derivations this key is from the master (which is 0)
    pub depth: u8,
    /// Fingerprint of the parent key
    pub parent_fingerprint: Fingerprint,
    /// Child number of the key used to derive from parent (0 for master)
    pub child_number: ChildNumber,
    /// Public key
    pub public_key: PublicKey,
    /// Chain code
    pub chain_code: ChainCode,
}