Build protobufs for compact formats

Cargo.lock

@@ -398,6 +398,28 @@ dependencies = [
  "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "protobuf"
+version = "2.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "protobuf-codegen"
+version = "2.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "protobuf 2.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "protobuf-codegen-pure"
+version = "2.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "protobuf 2.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "protobuf-codegen 2.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "quote"
 version = "0.6.13"
@@ -516,6 +538,8 @@ version = "0.0.0"
 dependencies = [
  "bech32 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "pairing 0.14.2",
+ "protobuf 2.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "protobuf-codegen-pure 2.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_core 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_xorshift 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "zcash_primitives 0.0.0",
@@ -604,6 +628,9 @@ dependencies = [
 "checksum proc-macro-hack 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "463bf29e7f11344e58c9e01f171470ab15c925c6822ad75028cc1c0e1d1eb63b"
 "checksum proc-macro-hack-impl 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "38c47dcb1594802de8c02f3b899e2018c78291168a22c281be21ea0fb4796842"
 "checksum proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)" = "cf3d2011ab5c909338f7887f4fc896d35932e29146c12c8d01da6b22a80ba759"
+"checksum protobuf 2.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8aefcec9f142b524d98fc81d07827743be89dd6586a1ba6ab21fa66a500b3fa5"
+"checksum protobuf-codegen 2.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "31539be8028d6b9e8e1b3b7c74e2fa3555302e27b2cc20dbaee6ffba648f75e2"
+"checksum protobuf-codegen-pure 2.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "00993dc5fbbfcf9d8a005f6b6c29fd29fd6d86deba3ae3f41fd20c624c414616"
 "checksum quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)" = "6ce23b6b870e8f94f81fb0a363d65d86675884b34a09043c81e5562f11c1f8e1"
 "checksum rand 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d47eab0e83d9693d40f825f86948aa16eff6750ead4bdffc4ab95b8b3a7f052c"
 "checksum rand_chacha 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "03a2a90da8c7523f554344f921aa97283eadf6ac484a6d2a7d0212fa7f8d6853"

zcash_client_backend/.gitignore

@@ -0,0 +1,2 @@
+# Protobufs
+src/proto/

zcash_client_backend/Cargo.toml

@@ -9,8 +9,12 @@ edition = "2018"
 [dependencies]
 bech32 = "0.7"
 pairing = { path = "../pairing" }
+protobuf = "2"
 zcash_primitives = { path = "../zcash_primitives" }
 
+[build-dependencies]
+protobuf-codegen-pure = "2"
+
 [dev-dependencies]
 rand_core = "0.5"
 rand_xorshift = "0.2"

zcash_client_backend/build.rs

@@ -0,0 +1,11 @@
+use protobuf_codegen_pure;
+
+fn main() {
+    protobuf_codegen_pure::run(protobuf_codegen_pure::Args {
+        out_dir: "src/proto",
+        input: &["proto/compact_formats.proto"],
+        includes: &["proto"],
+        customize: Default::default(),
+    })
+    .expect("protoc");
+}

zcash_client_backend/proto/compact_formats.proto

@@ -0,0 +1,47 @@
+syntax = "proto3";
+package cash.z.wallet.sdk.rpc;
+option go_package = "walletrpc";
+
+// Remember that proto3 fields are all optional. A field that is not present will be set to its zero value.
+// bytes fields of hashes are in canonical little-endian format.
+
+// CompactBlock is a packaging of ONLY the data from a block that's needed to:
+//   1. Detect a payment to your shielded Sapling address
+//   2. Detect a spend of your shielded Sapling notes
+//   3. Update your witnesses to generate new Sapling spend proofs.
+message CompactBlock {
+    uint32 protoVersion = 1; // the version of this wire format, for storage
+    uint64 height = 2; // the height of this block
+    bytes hash = 3;
+    uint32 time = 4;
+    bytes header = 5; // (hash and time) OR (full header)
+    repeated CompactTx vtx = 6; // compact transactions from this block
+}
+
+message CompactTx {
+    // Index and hash will allow the receiver to call out to chain
+    // explorers or other data structures to retrieve more information
+    // about this transaction.
+    uint64 index = 1;
+    bytes hash = 2;
+
+    // The transaction fee: present if server can provide. In the case of a
+    // stateless server and a transaction with transparent inputs, this will be
+    // unset because the calculation requires reference to prior transactions.
+    // in a pure-Sapling context, the fee will be calculable as:
+    //    valueBalance + (sum(vPubNew) - sum(vPubOld) - sum(tOut))
+    uint32 fee = 3;
+
+    repeated CompactSpend spends = 4;
+    repeated CompactOutput outputs = 5;
+}
+
+message CompactSpend {
+    bytes nf = 1;
+}
+
+message CompactOutput {
+    bytes cmu = 1;
+    bytes epk = 2;
+    bytes ciphertext = 3;
+}

zcash_client_backend/src/lib.rs

@@ -6,3 +6,4 @@
 pub mod constants;
 pub mod encoding;
 pub mod keys;
+pub mod proto;

zcash_client_backend/src/proto/mod.rs

@@ -0,0 +1,3 @@
+//! Generated code for handling light client protobuf structs.
+
+pub mod compact_formats;