use std::fmt::Display;
use crate::{blob, blob_envelope};
blob!(
SaplingIncomingViewingKey,
32,
r#"A Sapling Incoming Viewing Key (IVK), which allows detection and decryption of
incoming transactions to a Sapling shielded address.
`SaplingIncomingViewingKey` is a 32-byte key that enables a wallet to detect when
funds have been sent to its associated Sapling address and to decrypt the incoming
transaction details, without granting the ability to spend those funds.
# Zcash Concept Relation
In Zcash's Sapling protocol, the privacy features rely on a system of keys with
different capabilities:
- **Full Viewing Keys** can detect both incoming and outgoing transactions
- **Incoming Viewing Keys** (derived from full viewing keys) can only detect
incoming transactions
- **Spending Keys** provide full control, including spending capability
IVKs enable "watch-only" wallet functionality, where users can monitor their
funds without risking theft if the wallet is compromised.
# Data Preservation
During wallet migration, incoming viewing keys are preserved exactly as they
exist in the source wallet, maintaining the ability to detect and view incoming
transactions in the migrated wallet.
# Examples
```
use zewif::sapling::SaplingIncomingViewingKey;
use zewif::Blob;
// Wrap the raw bytes of an encoded Sapling incoming viewing key.
let raw_bytes = [0u8; 32]; // In practice, this would be actual key material
let ivk = SaplingIncomingViewingKey::new(raw_bytes);
// The key can be converted to CBOR for storage or transmission
let hex: dcbor::CBOR = ivk.into();
```"#
);
impl Copy for SaplingIncomingViewingKey {}
impl Display for SaplingIncomingViewingKey {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.to_hex())
}
}
blob_envelope!(SaplingIncomingViewingKey);