zebra/zebra-chain/src/primitives/viewing_key/sapling.rs

88 lines
3.3 KiB
Rust

//! Defines types and implements methods for parsing Sapling viewing keys and converting them to `zebra-chain` types
use zcash_client_backend::encoding::decode_extended_full_viewing_key;
use zcash_primitives::{
constants::*,
sapling::keys::{FullViewingKey as SaplingFvk, SaplingIvk},
zip32::DiversifiableFullViewingKey as SaplingDfvk,
};
use crate::parameters::Network;
/// A Zcash Sapling viewing key
#[derive(Debug, Clone)]
pub enum SaplingViewingKey {
/// An incoming viewing key for Sapling
Ivk(Box<SaplingIvk>),
/// A full viewing key for Sapling
Fvk(Box<SaplingFvk>),
/// A diversifiable full viewing key for Sapling
Dfvk(Box<SaplingDfvk>),
}
impl SaplingViewingKey {
/// Accepts an encoded Sapling extended full viewing key to decode
///
/// Returns a [`SaplingViewingKey::Dfvk`] if successful, or None otherwise
fn parse_extended_full_viewing_key(sapling_key: &str, network: Network) -> Option<Self> {
decode_extended_full_viewing_key(network.sapling_efvk_hrp(), sapling_key)
// this should fail often, so a debug-level log is okay
.map_err(|err| debug!(?err, "could not decode Sapling extended full viewing key"))
.ok()
.map(|efvk| Box::new(efvk.to_diversifiable_full_viewing_key()))
.map(Self::Dfvk)
}
/// Accepts an encoded Sapling diversifiable full viewing key to decode
///
/// Returns a [`SaplingViewingKey::Dfvk`] if successful, or None otherwise
fn parse_diversifiable_full_viewing_key(_sapling_key: &str, _network: Network) -> Option<Self> {
// TODO: Parse Sapling diversifiable full viewing key
None
}
/// Accepts an encoded Sapling full viewing key to decode
///
/// Returns a [`SaplingViewingKey::Fvk`] if successful, or None otherwise
fn parse_full_viewing_key(_sapling_key: &str, _network: Network) -> Option<Self> {
// TODO: Parse Sapling full viewing key
None
}
/// Accepts an encoded Sapling incoming viewing key to decode
///
/// Returns a [`SaplingViewingKey::Ivk`] if successful, or None otherwise
fn parse_incoming_viewing_key(_sapling_key: &str, _network: Network) -> Option<Self> {
// TODO: Parse Sapling incoming viewing key
None
}
/// Accepts an encoded Sapling viewing key to decode
///
/// Returns a [`SaplingViewingKey`] if successful, or None otherwise
pub(super) fn parse(key: &str, network: Network) -> Option<Self> {
// TODO: Try types with prefixes first if some don't have prefixes?
Self::parse_extended_full_viewing_key(key, network)
.or_else(|| Self::parse_diversifiable_full_viewing_key(key, network))
.or_else(|| Self::parse_full_viewing_key(key, network))
.or_else(|| Self::parse_incoming_viewing_key(key, network))
}
}
impl Network {
/// Returns the human-readable prefix for an Zcash Sapling extended full viewing key
/// for this network.
pub fn sapling_efvk_hrp(&self) -> &'static str {
if self.is_a_test_network() {
// Assume custom testnets have the same HRP
//
// TODO: add the regtest HRP here
testnet::HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY
} else {
mainnet::HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY
}
}
}