Merge pull request #72 from zcash/builder-prep

Builder preparations

src/bundle.rs

@@ -114,18 +114,46 @@ impl<T> Action<T> {
 pub struct Flags {
     /// Flag denoting whether Orchard spends are enabled in the transaction.
     ///
-    /// If `true`, spent notes within [`Action`]s in the transaction's [`Bundle`] are
-    /// guaranteed to be dummy notes. If `false`, the spent notes may be either real or
+    /// If `false`, spent notes within [`Action`]s in the transaction's [`Bundle`] are
+    /// guaranteed to be dummy notes. If `true`, the spent notes may be either real or
     /// dummy notes.
     spends_enabled: bool,
     /// Flag denoting whether Orchard outputs are enabled in the transaction.
     ///
-    /// If `true`, created notes within [`Action`]s in the transaction's [`Bundle`] are
-    /// guaranteed to be dummy notes. If `false`, the created notes may be either real or
+    /// If `false`, created notes within [`Action`]s in the transaction's [`Bundle`] are
+    /// guaranteed to be dummy notes. If `true`, the created notes may be either real or
     /// dummy notes.
     outputs_enabled: bool,
 }
 
+impl Flags {
+    /// Construct a set of flags from its constituent parts
+    pub fn from_parts(spends_enabled: bool, outputs_enabled: bool) -> Self {
+        Flags {
+            spends_enabled,
+            outputs_enabled,
+        }
+    }
+
+    /// Flag denoting whether Orchard spends are enabled in the transaction.
+    ///
+    /// If `false`, spent notes within [`Action`]s in the transaction's [`Bundle`] are
+    /// guaranteed to be dummy notes. If `true`, the spent notes may be either real or
+    /// dummy notes.
+    pub fn spends_enabled(&self) -> bool {
+        self.spends_enabled
+    }
+
+    /// Flag denoting whether Orchard outputs are enabled in the transaction.
+    ///
+    /// If `false`, created notes within [`Action`]s in the transaction's [`Bundle`] are
+    /// guaranteed to be dummy notes. If `true`, the created notes may be either real or
+    /// dummy notes.
+    pub fn outputs_enabled(&self) -> bool {
+        self.outputs_enabled
+    }
+}
+
 /// Defines the authorization type of an Orchard bundle.
 pub trait Authorization {
     /// The authorization type of an Orchard action.
@@ -203,34 +231,36 @@ impl<T: Authorization> Bundle<T> {
     }
 
     /// Transitions this bundle from one authorization state to another.
-    pub fn authorize<U: Authorization>(
+    pub fn authorize<R, U: Authorization>(
         self,
-        mut spend_auth: impl FnMut(&T, T::SpendAuth) -> U::SpendAuth,
-        step: impl FnOnce(T) -> U,
+        context: &mut R,
+        mut spend_auth: impl FnMut(&mut R, &T, T::SpendAuth) -> U::SpendAuth,
+        step: impl FnOnce(&mut R, T) -> U,
     ) -> Bundle<U> {
         let authorization = self.authorization;
         Bundle {
             actions: self
                 .actions
-                .map(|a| a.map(|a_auth| spend_auth(&authorization, a_auth))),
+                .map(|a| a.map(|a_auth| spend_auth(context, &authorization, a_auth))),
             flags: self.flags,
             value_balance: self.value_balance,
             anchor: self.anchor,
-            authorization: step(authorization),
+            authorization: step(context, authorization),
         }
     }
 
     /// Transitions this bundle from one authorization state to another.
-    pub fn try_authorize<U: Authorization, E>(
+    pub fn try_authorize<R, U: Authorization, E>(
         self,
-        mut spend_auth: impl FnMut(&T, T::SpendAuth) -> Result<U::SpendAuth, E>,
-        step: impl FnOnce(T) -> Result<U, E>,
+        context: &mut R,
+        mut spend_auth: impl FnMut(&mut R, &T, T::SpendAuth) -> Result<U::SpendAuth, E>,
+        step: impl FnOnce(&mut R, T) -> Result<U, E>,
     ) -> Result<Bundle<U>, E> {
         let authorization = self.authorization;
         let new_actions = self
             .actions
             .into_iter()
-            .map(|a| a.try_map(|a_auth| spend_auth(&authorization, a_auth)))
+            .map(|a| a.try_map(|a_auth| spend_auth(context, &authorization, a_auth)))
             .collect::<Result<Vec<_>, E>>()?;
 
         Ok(Bundle {
@@ -238,19 +268,11 @@ impl<T: Authorization> Bundle<T> {
             flags: self.flags,
             value_balance: self.value_balance,
             anchor: self.anchor,
-            authorization: step(authorization)?,
+            authorization: step(context, authorization)?,
         })
     }
 }
 
-/// Marker for an unauthorized bundle with no proofs or signatures.
-#[derive(Debug)]
-pub struct Unauthorized {}
-
-impl Authorization for Unauthorized {
-    type SpendAuth = ();
-}
-
 /// Authorizing data for a bundle of actions, ready to be committed to the ledger.
 #[derive(Debug)]
 pub struct Authorized {

src/circuit.rs

@@ -180,13 +180,13 @@ mod tests {
 
         let (circuits, instances): (Vec<_>, Vec<_>) = iter::once(())
             .map(|()| {
-                let (fvk, spent_note) = Note::dummy(&mut rng, None);
+                let (_, fvk, spent_note) = Note::dummy(&mut rng, None);
                 let nf_old = spent_note.nullifier(&fvk);
                 let ak: SpendValidatingKey = fvk.into();
                 let alpha = pallas::Scalar::random(&mut rng);
                 let rk = ak.randomize(&alpha);
 
-                let (_, output_note) = Note::dummy(&mut rng, Some(nf_old.clone()));
+                let (_, _, output_note) = Note::dummy(&mut rng, Some(nf_old.clone()));
                 let cmx = output_note.commitment().into();
 
                 let value = spent_note.value() - output_note.value();

src/note.rs

@@ -65,8 +65,12 @@ impl Note {
     /// Defined in [Zcash Protocol Spec § 4.8.3: Dummy Notes (Orchard)][orcharddummynotes].
     ///
     /// [orcharddummynotes]: https://zips.z.cash/protocol/nu5.pdf#orcharddummynotes
-    pub(crate) fn dummy(rng: &mut impl RngCore, rho: Option<Nullifier>) -> (FullViewingKey, Self) {
-        let fvk: FullViewingKey = (&SpendingKey::random(rng)).into();
+    pub(crate) fn dummy(
+        rng: &mut impl RngCore,
+        rho: Option<Nullifier>,
+    ) -> (SpendingKey, FullViewingKey, Self) {
+        let sk = SpendingKey::random(rng);
+        let fvk: FullViewingKey = (&sk).into();
         let recipient = fvk.default_address();
 
         let note = Note {
@@ -76,7 +80,7 @@ impl Note {
             rseed: RandomSeed::random(rng),
         };
 
-        (fvk, note)
+        (sk, fvk, note)
     }
 
     /// Returns the value of this note.

src/value.rs

@@ -52,6 +52,14 @@ impl NoteValue {
         Default::default()
     }
 
+    /// Creates a note value from its raw numeric value.
+    ///
+    /// This only enforces that the value is an unsigned 64-bit integer. Callers should
+    /// enforce any additional constraints on the value's valid range themselves.
+    pub fn from_raw(value: u64) -> Self {
+        NoteValue(value)
+    }
+
     pub(crate) fn to_le_bits(self) -> BitArray<Lsb0, [u8; 8]> {
         BitArray::<Lsb0, _>::new(self.0.to_le_bytes())
     }
@@ -71,6 +79,16 @@ impl Sub for NoteValue {
 #[derive(Clone, Copy, Debug, Default)]
 pub struct ValueSum(i64);
 
+impl ValueSum {
+    /// Creates a value sum from its raw numeric value.
+    ///
+    /// This only enforces that the value is a signed 63-bit integer. Callers should
+    /// enforce any additional constraints on the value's valid range themselves.
+    pub fn from_raw(value: i64) -> Self {
+        ValueSum(value)
+    }
+}
+
 impl Add for ValueSum {
     type Output = Result<ValueSum, OverflowError>;