Build protobufs for compact formats

Cargo.lock

@@ -467,6 +467,28 @@ dependencies = [
  "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "protobuf"
+version = "2.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "protobuf-codegen"
+version = "2.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "protobuf 2.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "protobuf-codegen-pure"
+version = "2.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "protobuf 2.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "protobuf-codegen 2.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.2"
@@ -607,6 +629,8 @@ version = "0.1.0"
 dependencies = [
  "bech32 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "pairing 0.15.0",
+ "protobuf 2.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "protobuf-codegen-pure 2.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_core 0.5.1 (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 0.1.0",
@@ -700,6 +724,9 @@ dependencies = [
 "checksum ppv-lite86 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "e3cbf9f658cdb5000fcf6f362b8ea2ba154b9f146a61c7a20d647034c6b6561b"
 "checksum proc-macro-hack 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)" = "e688f31d92ffd7c1ddc57a1b4e6d773c0f2a14ee437a4b0a4f5a69c80eb221c8"
 "checksum proc-macro2 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e98a83a9f9b331f54b924e68a66acb1bb35cb01fb0a23645139967abefb697e8"
+"checksum protobuf 2.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "40361836defdd5871ff7e84096c6f6444af7fc157f8ef1789f54f147687caa20"
+"checksum protobuf-codegen 2.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "12c6abd78435445fc86898ebbd0521a68438063d4a73e23527b7134e6bf58b4a"
+"checksum protobuf-codegen-pure 2.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c1646acda5319f5b28b0bff4a484324df43ddae2c0f5a3f3e63c0b26095cd600"
 "checksum quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "053a8c8bcc71fcce321828dc897a98ab9760bef03a4fc36693c231e5b3216cfe"
 "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

@@ -14,8 +14,12 @@ edition = "2018"
 [dependencies]
 bech32 = "0.7"
 pairing = { version = "0.15.0", path = "../pairing" }
+protobuf = "2"
 zcash_primitives = { version = "0.1.0", 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

@@ -9,3 +9,4 @@
 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;