Query for unspent utxos checks to ensure that spending tx is mined.

Also make it an error to try to send a memo to a transparent address.

zcash_client_backend/Cargo.toml

@@ -22,6 +22,7 @@ group = "0.8"
 hex = "0.4"
 hdwallet = { version = "0.3.0", optional = true }
 jubjub = "0.5.1"
+log = "0.4"
 nom = "6.1"
 percent-encoding = "2.1.0"
 proptest = { version = "0.10.1", optional = true }
@@ -29,7 +30,7 @@ protobuf = "2.20"
 rand_core = "0.5.1"
 ripemd160 = { version = "0.9.1", optional = true }
 secp256k1 = { version = "0.19", optional = true }
-sha2 = "0.9"
+sha2 = { version = "0.9", optional = true }
 subtle = "2.2.3"
 time = "0.2"
 zcash_note_encryption = { version = "0.0", path = "../components/zcash_note_encryption" }
@@ -47,8 +48,8 @@ zcash_client_sqlite = { version = "0.3", path = "../zcash_client_sqlite" }
 zcash_proofs = { version = "0.5", path = "../zcash_proofs" }
 
 [features]
-transparent-inputs = ["ripemd160", "secp256k1"]
+transparent-inputs = ["ripemd160", "hdwallet", "sha2", "secp256k1"]
-test-dependencies = ["proptest", "zcash_primitives/test-dependencies", "hdwallet"]
+test-dependencies = ["proptest", "zcash_primitives/test-dependencies", "hdwallet", "sha2"]
 
 [badges]
 maintenance = { status = "actively-developed" }

zcash_client_backend/src/data_api/error.rs

@@ -59,6 +59,12 @@ pub enum Error<NoteId> {
     /// The wallet attempted a sapling-only operation at a block
     /// height when Sapling was not yet active.
     SaplingNotActive,
+
+    /// A memo is required when constructing a Sapling output
+    MemoRequired,
+
+    /// It is forbidden to provide a memo when constructing a transparent output.
+    MemoForbidden,
 }
 
 impl ChainInvalid {
@@ -99,6 +105,8 @@ impl<N: fmt::Display> fmt::Display for Error<N> {
             Error::Builder(e) => write!(f, "{:?}", e),
             Error::Protobuf(e) => write!(f, "{}", e),
             Error::SaplingNotActive => write!(f, "Could not determine Sapling upgrade activation height."),
+            Error::MemoRequired => write!(f, "A memo is required when sending to a Sapling address."),
+            Error::MemoForbidden => write!(f, "It is not possible to send a memo to a transparent address."),
         }
     }
 }

zcash_client_backend/src/data_api/wallet.rs

@@ -1,6 +1,5 @@
-//! Functions for scanning the chain and extracting relevant information.
+use std::convert::TryFrom;
 use std::fmt::Debug;
-
 use zcash_primitives::{
     consensus::{self, BranchId, NetworkUpgrade},
     memo::MemoBytes,
@@ -40,6 +39,8 @@ where
     P: consensus::Parameters,
     D: WalletWrite<Error = E>,
 {
+    debug!("decrypt_and_store: {:?}", tx);
+
     // Fetch the ExtendedFullViewingKeys we are tracking
     let extfvks = data.get_extended_full_viewing_keys()?;
 
@@ -54,16 +55,32 @@ where
         .ok_or(Error::SaplingNotActive)?;
 
     let outputs = decrypt_transaction(params, height, tx, &extfvks);
-    if outputs.is_empty() {
+    if !outputs.is_empty() {
-        Ok(())
-    } else {
         data.store_received_tx(&ReceivedTransaction {
             tx,
             outputs: &outputs,
         })?;
-
-        Ok(())
     }
+
+    // store z->t transactions in the same way the would be stored by create_spend_to_address
+    if !tx.vout.is_empty() {
+        // TODO: clarify with Kris the simplest way to determine account and iterate over outputs
+        // i.e. there are probably edge cases where we need to combine vouts into one "sent" transaction for the total value
+        data.store_sent_tx(&SentTransaction {
+            tx: &tx,
+            created: time::OffsetDateTime::now_utc(),
+            output_index: usize::try_from(0).unwrap(),
+            account: AccountId(0),
+            recipient_address: &RecipientAddress::Transparent(
+                tx.vout[0].script_pubkey.address().unwrap(),
+            ),
+            value: tx.vout[0].value,
+            memo: None,
+            utxos_spent: vec![],
+        })?;
+    }
+
+    Ok(())
 }
 
 #[allow(clippy::needless_doctest_main)]
@@ -224,12 +241,22 @@ where
 
     match to {
         RecipientAddress::Shielded(to) => {
-            builder.add_sapling_output(ovk, to.clone(), value, memo.clone())
+            memo.clone().ok_or(Error::MemoRequired).and_then(|memo| {
+                builder
+                    .add_sapling_output(ovk, to.clone(), value, memo)
+                    .map_err(Error::Builder)
+            })
         }
-
+        RecipientAddress::Transparent(to) => {
-        RecipientAddress::Transparent(to) => builder.add_transparent_output(&to, value),
+            if memo.is_some() {
-    }
+                Err(Error::MemoForbidden)
-    .map_err(Error::Builder)?;
+            } else {
+                builder
+                    .add_transparent_output(&to, value)
+                    .map_err(Error::Builder)
+            }
+        }
+    }?;
 
     let consensus_branch_id = BranchId::for_height(params, height);
     let (tx, tx_metadata) = builder
@@ -329,12 +356,7 @@ where
 
     // add the sapling output to shield the funds
     builder
-        .add_sapling_output(
+        .add_sapling_output(Some(ovk), z_address.clone(), amount_to_shield, memo.clone())
-            Some(ovk),
-            z_address.clone(),
-            amount_to_shield,
-            Some(memo.clone()),
-        )
         .map_err(Error::Builder)?;
 
     let consensus_branch_id = BranchId::for_height(params, latest_anchor);

zcash_client_backend/src/lib.rs

@@ -8,6 +8,9 @@
 // Temporary until we have addressed all Result<T, ()> cases.
 #![allow(clippy::result_unit_err)]
 
+#[macro_use]
+extern crate log;
+
 pub mod address;
 pub mod data_api;
 mod decrypt;

zcash_client_sqlite/src/lib.rs

@@ -149,6 +149,10 @@ impl<P: consensus::Parameters> WalletDb<P> {
                     "INSERT INTO utxos (address, prevout_txid, prevout_idx, script, value_zat, height)
                     VALUES (:address, :prevout_txid, :prevout_idx, :script, :value_zat, :height)"
                 )?,
+                #[cfg(feature = "transparent-inputs")]
+                stmt_delete_utxos: self.conn.prepare(
+                    "DELETE FROM utxos WHERE address = :address AND height > :above_height"
+                )?,
                 stmt_insert_received_note: self.conn.prepare(
                     "INSERT INTO received_notes (tx, output_index, account, diversifier, value, rcm, memo, nf, is_change)
                     VALUES (:tx, :output_index, :account, :diversifier, :value, :rcm, :memo, :nf, :is_change)",
@@ -313,6 +317,8 @@ pub struct DataConnStmtCache<'a, P> {
 
     #[cfg(feature = "transparent-inputs")]
     stmt_insert_received_transparent_utxo: Statement<'a>,
+    #[cfg(feature = "transparent-inputs")]
+    stmt_delete_utxos: Statement<'a>,
     stmt_insert_received_note: Statement<'a>,
     stmt_update_received_note: Statement<'a>,
     stmt_select_received_note: Statement<'a>,

zcash_client_sqlite/src/wallet.rs

@@ -605,11 +605,13 @@ pub fn get_unspent_transparent_utxos<P: consensus::Parameters>(
     anchor_height: BlockHeight,
 ) -> Result<Vec<WalletTransparentOutput>, SqliteClientError> {
     let mut stmt_blocks = wdb.conn.prepare(
-        "SELECT address, prevout_txid, prevout_idx, script, value_zat, height 
+        "SELECT u.address, u.prevout_txid, u.prevout_idx, u.script, u.value_zat, u.height, tx.block as block
-         FROM utxos 
+         FROM utxos u
-         WHERE address = ? 
+         LEFT OUTER JOIN transactions tx
-         AND height <= ?
+         ON tx.id_tx = u.spent_in_tx
-         AND spent_in_tx IS NULL",
+         WHERE u.address = ?
+         AND u.height <= ?
+         AND block IS NULL",
     )?;
 
     let addr_str = address.encode(&wdb.params);
@@ -789,6 +791,22 @@ pub fn put_received_transparent_utxo<'a, P: consensus::Parameters>(
     Ok(UtxoId(stmts.wallet_db.conn.last_insert_rowid()))
 }
 
+#[cfg(feature = "transparent-inputs")]
+pub fn delete_utxos_above<'a, P: consensus::Parameters>(
+    stmts: &mut DataConnStmtCache<'a, P>,
+    taddr: &TransparentAddress,
+    height: BlockHeight,
+) -> Result<usize, SqliteClientError> {
+    let sql_args: &[(&str, &dyn ToSql)] = &[
+        (&":address", &taddr.encode(&stmts.wallet_db.params)),
+        (&":above_height", &u32::from(height)),
+    ];
+
+    let rows = stmts.stmt_delete_utxos.execute_named(&sql_args)?;
+
+    Ok(rows)
+}
+
 // Assumptions:
 // - A transaction will not contain more than 2^63 shielded outputs.
 // - A note value will never exceed 2^63 zatoshis.

zcash_primitives/src/transaction/builder.rs

@@ -110,7 +110,7 @@ impl<P: consensus::Parameters> SaplingOutput<P> {
         ovk: Option<OutgoingViewingKey>,
         to: PaymentAddress,
         value: Amount,
-        memo: Option<MemoBytes>,
+        memo: MemoBytes,
     ) -> Result<Self, Error> {
         Self::new_internal(params, height, rng, ovk, to, value, memo)
     }
@@ -122,7 +122,7 @@ impl<P: consensus::Parameters> SaplingOutput<P> {
         ovk: Option<OutgoingViewingKey>,
         to: PaymentAddress,
         value: Amount,
-        memo: Option<MemoBytes>,
+        memo: MemoBytes,
     ) -> Result<Self, Error> {
         let g_d = to.g_d().ok_or(Error::InvalidAddress)?;
         if value.is_negative() {
@@ -142,7 +142,7 @@ impl<P: consensus::Parameters> SaplingOutput<P> {
             ovk,
             to,
             note,
-            memo: memo.unwrap_or_else(MemoBytes::empty),
+            memo,
             _params: PhantomData::default(),
         })
     }
@@ -521,7 +521,7 @@ impl<'a, P: consensus::Parameters, R: RngCore> Builder<'a, P, R> {
         ovk: Option<OutgoingViewingKey>,
         to: PaymentAddress,
         value: Amount,
-        memo: Option<MemoBytes>,
+        memo: MemoBytes,
     ) -> Result<(), Error> {
         let output = SaplingOutput::new_internal(
             &self.params,
@@ -645,7 +645,12 @@ impl<'a, P: consensus::Parameters, R: RngCore> Builder<'a, P, R> {
                 return Err(Error::NoChangeAddress);
             };
 
-            self.add_sapling_output(Some(change_address.0), change_address.1, change, None)?;
+            self.add_sapling_output(
+                Some(change_address.0),
+                change_address.1,
+                change,
+                MemoBytes::empty(),
+            )?;
         }
 
         //
@@ -965,6 +970,7 @@ mod tests {
     use crate::{
         consensus::{self, Parameters, H0, TEST_NETWORK},
         legacy::TransparentAddress,
+        memo::MemoBytes,
         merkle_tree::{CommitmentTree, IncrementalWitness},
         sapling::{prover::mock::MockTxProver, Node, Rseed},
         transaction::components::{amount::Amount, amount::DEFAULT_FEE},
@@ -985,7 +991,12 @@ mod tests {
 
         let mut builder = Builder::new(TEST_NETWORK, H0);
         assert_eq!(
-            builder.add_sapling_output(Some(ovk), to, Amount::from_i64(-1).unwrap(), None),
+            builder.add_sapling_output(
+                Some(ovk),
+                to,
+                Amount::from_i64(-1).unwrap(),
+                MemoBytes::empty()
+            ),
             Err(Error::InvalidAmount)
         );
     }
@@ -1104,7 +1115,12 @@ mod tests {
         {
             let mut builder = Builder::new(TEST_NETWORK, H0);
             builder
-                .add_sapling_output(ovk, to.clone(), Amount::from_u64(50000).unwrap(), None)
+                .add_sapling_output(
+                    ovk,
+                    to.clone(),
+                    Amount::from_u64(50000).unwrap(),
+                    MemoBytes::empty(),
+                )
                 .unwrap();
             assert_eq!(
                 builder.build(consensus::BranchId::Sapling, &MockTxProver),
@@ -1153,7 +1169,12 @@ mod tests {
                 )
                 .unwrap();
             builder
-                .add_sapling_output(ovk, to.clone(), Amount::from_u64(30000).unwrap(), None)
+                .add_sapling_output(
+                    ovk,
+                    to.clone(),
+                    Amount::from_u64(30000).unwrap(),
+                    MemoBytes::empty(),
+                )
                 .unwrap();
             builder
                 .add_transparent_output(
@@ -1194,7 +1215,12 @@ mod tests {
                 .add_sapling_spend(extsk, *to.diversifier(), note2, witness2.path().unwrap())
                 .unwrap();
             builder
-                .add_sapling_output(ovk, to, Amount::from_u64(30000).unwrap(), None)
+                .add_sapling_output(
+                    ovk,
+                    to,
+                    Amount::from_u64(30000).unwrap(),
+                    MemoBytes::empty(),
+                )
                 .unwrap();
             builder
                 .add_transparent_output(