zcash_keys: Keep the Ufvk and Uivk encodings private.

zcash_client_sqlite/src/wallet.rs

@@ -74,7 +74,6 @@ use std::io::{self, Cursor};
 use std::num::NonZeroU32;
 use std::ops::RangeInclusive;
 use tracing::debug;
-use zcash_address::unified::{Encoding, Uivk};
 use zcash_keys::keys::{
     AddressGenerationError, HdSeedFingerprint, UnifiedAddressRequest, UnifiedIncomingViewingKey,
 };
@@ -120,7 +119,7 @@ use {
     crate::UtxoId,
     rusqlite::Row,
     std::collections::BTreeSet,
-    zcash_address::unified::Ivk,
+    zcash_address::unified::{Encoding, Ivk, Uivk},
     zcash_client_backend::wallet::{TransparentAddressMetadata, WalletTransparentOutput},
     zcash_primitives::{
         legacy::{
@@ -347,7 +346,7 @@ pub(crate) fn add_account<P: consensus::Parameters>(
             ":hd_seed_fingerprint": hd_seed_fingerprint.as_ref().map(|fp| fp.as_bytes()),
             ":hd_account_index": hd_account_index.map(u32::from),
             ":ufvk": viewing_key.ufvk().map(|ufvk| ufvk.encode(params)),
-            ":uivk": viewing_key.uivk().to_uivk().encode(&params.network_type()),
+            ":uivk": viewing_key.uivk().encode(params),
             ":orchard_fvk_item_cache": orchard_item,
             ":sapling_fvk_item_cache": sapling_item,
             ":p2pkh_fvk_item_cache": transparent_item,
@@ -1503,18 +1502,9 @@ pub(crate) fn get_account<P: Parameters>(
                 ))
             } else {
                 let uivk_str: String = row.get("uivk")?;
-                let (network, uivk) = Uivk::decode(&uivk_str).map_err(|e| {
-                    SqliteClientError::CorruptedData(format!("Failure to decode UIVK: {e}"))
-                })?;
-                if network != params.network_type() {
-                    return Err(SqliteClientError::CorruptedData(
-                        "UIVK network type does not match wallet network type".to_string(),
-                    ));
-                }
                 ViewingKey::Incoming(Box::new(
-                    UnifiedIncomingViewingKey::from_uivk(&uivk).map_err(|e| {
-                        SqliteClientError::CorruptedData(format!("Failure to decode UIVK: {e}"))
-                    })?,
+                    UnifiedIncomingViewingKey::decode(params, &uivk_str[..])
+                        .map_err(SqliteClientError::BadAccountData)?,
                 ))
             };
 

zcash_client_sqlite/src/wallet/init/migrations/full_account_ids.rs

@@ -5,7 +5,6 @@ use rusqlite::{named_params, Transaction};
 use schemer_rusqlite::RusqliteMigration;
 use secrecy::{ExposeSecret, SecretVec};
 use uuid::Uuid;
-use zcash_address::unified::Encoding;
 use zcash_client_backend::{data_api::AccountKind, keys::UnifiedSpendingKey};
 use zcash_keys::keys::{HdSeedFingerprint, UnifiedFullViewingKey};
 use zcash_primitives::consensus;
@@ -122,8 +121,7 @@ impl<P: consensus::Parameters> RusqliteMigration for Migration<P> {
 
                     let uivk = ufvk_parsed
                         .to_unified_incoming_viewing_key()
-                        .to_uivk()
-                        .encode(&self.params.network_type());
+                        .encode(&self.params);
 
                     #[cfg(feature = "transparent-inputs")]
                     let transparent_item = ufvk_parsed.transparent().map(|k| k.serialize());

zcash_keys/CHANGELOG.md

@@ -12,8 +12,6 @@ and this library adheres to Rust's notion of
 - `impl Display for zcash_keys::keys::AddressGenerationError`
 - `impl std::error::Error for zcash_keys::keys::AddressGenerationError`
 - `zcash_keys::keys::DecodingError`
-- `zcash_keys::keys::UnifiedFullViewingKey::from_ufvk`
-- `zcash_keys::keys::UnifiedFullViewingKey::to_ufvk`
 - `zcash_keys::keys::UnifiedFullViewingKey::to_unified_incoming_viewing_key`
 - `zcash_keys::keys::UnifiedIncomingViewingKey`
 

zcash_keys/src/keys.rs

@@ -740,13 +740,13 @@ impl UnifiedFullViewingKey {
             ));
         }
 
-        Self::from_ufvk(&ufvk).map_err(|e| e.to_string())
+        Self::parse(&ufvk).map_err(|e| e.to_string())
     }
 
     /// Parses a `UnifiedFullViewingKey` from its [ZIP 316] string encoding.
     ///
     /// [ZIP 316]: https://zips.z.cash/zip-0316
-    pub fn from_ufvk(ufvk: &Ufvk) -> Result<Self, DecodingError> {
+    pub fn parse(ufvk: &Ufvk) -> Result<Self, DecodingError> {
         #[cfg(feature = "orchard")]
         let mut orchard = None;
         #[cfg(feature = "sapling")]
@@ -823,7 +823,7 @@ impl UnifiedFullViewingKey {
     }
 
     /// Returns the string encoding of this `UnifiedFullViewingKey` for the given network.
-    pub fn to_ufvk(&self) -> Ufvk {
+    fn to_ufvk(&self) -> Ufvk {
         let items = std::iter::empty().chain(self.unknown.iter().map(|(typecode, data)| {
             unified::Fvk::Unknown {
                 typecode: *typecode,
@@ -973,8 +973,24 @@ impl UnifiedIncomingViewingKey {
         }
     }
 
+    /// Parses a `UnifiedFullViewingKey` from its [ZIP 316] string encoding.
+    ///
+    /// [ZIP 316]: https://zips.z.cash/zip-0316
+    pub fn decode<P: consensus::Parameters>(params: &P, encoding: &str) -> Result<Self, String> {
+        let (net, ufvk) = unified::Uivk::decode(encoding).map_err(|e| e.to_string())?;
+        let expected_net = params.network_type();
+        if net != expected_net {
+            return Err(format!(
+                "UIVK is for network {:?} but we expected {:?}",
+                net, expected_net,
+            ));
+        }
+
+        Self::parse(&ufvk).map_err(|e| e.to_string())
+    }
+
     /// Constructs a unified incoming viewing key from a parsed unified encoding.
-    pub fn from_uivk(uivk: &Uivk) -> Result<Self, DecodingError> {
+    fn parse(uivk: &Uivk) -> Result<Self, DecodingError> {
         #[cfg(feature = "orchard")]
         let mut orchard = None;
         #[cfg(feature = "sapling")]
@@ -1041,8 +1057,13 @@ impl UnifiedIncomingViewingKey {
         })
     }
 
+    /// Returns the string encoding of this `UnifiedFullViewingKey` for the given network.
+    pub fn encode<P: consensus::Parameters>(&self, params: &P) -> String {
+        self.render().encode(&params.network_type())
+    }
+
     /// Converts this unified incoming viewing key to a unified encoding.
-    pub fn to_uivk(&self) -> Uivk {
+    fn render(&self) -> Uivk {
         let items = std::iter::empty().chain(self.unknown.iter().map(|(typecode, data)| {
             unified::Ivk::Unknown {
                 typecode: *typecode,
@@ -1530,7 +1551,7 @@ mod tests {
             orchard,
         );
 
-        let encoded = uivk.to_uivk().encode(&NetworkType::Main);
+        let encoded = uivk.render().encode(&NetworkType::Main);
 
         // Test encoded form against known values; these test vectors contain Orchard receivers
         // that will be treated as unknown if the `orchard` feature is not enabled.
@@ -1548,9 +1569,8 @@ mod tests {
             assert_eq!(encoded, _encoded_no_t);
         }
 
-        let decoded =
-            UnifiedIncomingViewingKey::from_uivk(&Uivk::decode(&encoded).unwrap().1).unwrap();
-        let reencoded = decoded.to_uivk().encode(&NetworkType::Main);
+        let decoded = UnifiedIncomingViewingKey::parse(&Uivk::decode(&encoded).unwrap().1).unwrap();
+        let reencoded = decoded.render().encode(&NetworkType::Main);
         assert_eq!(encoded, reencoded);
 
         #[cfg(feature = "transparent-inputs")]
@@ -1570,7 +1590,7 @@ mod tests {
         );
 
         let decoded_with_t =
-            UnifiedIncomingViewingKey::from_uivk(&Uivk::decode(encoded_with_t).unwrap().1).unwrap();
+            UnifiedIncomingViewingKey::parse(&Uivk::decode(encoded_with_t).unwrap().1).unwrap();
         #[cfg(feature = "transparent-inputs")]
         assert_eq!(
             decoded_with_t.transparent.map(|t| t.serialize()),