Implementing proof of reserves

Author: ulrichard

.gitignore

@@ -3,3 +3,5 @@ Cargo.lock
 
 *.swp
 .idea
+
+.vscode/

CHANGELOG.md

@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Proof of reserves
+- Added a separate module to construct "proof of reserve" PSBTs, and verify them.
+
 ### Wallet
 - Added an option that must be explicitly enabled to allow signing using non-`SIGHASH_ALL` sighashes (#350)
 

Cargo.toml

@@ -31,6 +31,9 @@ cc = { version = ">=1.0.64", optional = true }
 socks = { version = "0.3", optional = true }
 lazy_static = { version = "1.4", optional = true }
 tiny-bip39 = { version = "^0.8", optional = true }
+bitcoinconsensus = { git = "https://github.com/rust-bitcoin/rust-bitcoinconsensus", branch = "master", optional = true }
+bitcoin_hashes = { version = "^0.9", optional = true }
+base64 = { version = "^0.11", optional = true }
 
 # Needed by bdk_blockchain_tests macro
 bitcoincore-rpc = {  version = "0.13", optional = true }
@@ -56,6 +59,7 @@ key-value-db = ["sled"]
 async-interface = ["async-trait"]
 all-keys = ["keys-bip39"]
 keys-bip39 = ["tiny-bip39"]
+reserves = ["bitcoinconsensus", "bitcoin_hashes", "base64"]
 
 # Debug/Test features
 test-blockchains = ["bitcoincore-rpc", "electrum-client"]
@@ -67,6 +71,7 @@ env_logger = "0.7"
 base64 = "^0.11"
 clap = "2.33"
 serial_test = "0.4"
+rstest = "^0.7"
 
 [[example]]
 name = "address_validator"

src/error.rs

@@ -64,6 +64,10 @@ pub enum Error {
         /// Required fee absolute value (satoshi)
         required: u64,
     },
+    /// The proof of reserves is invalid. The reason is given in the string parameter.
+    ProofOfReservesInvalid(String),
+    /// Cannot verify the proof.
+    CannotVerifyProof,
     /// In order to use the [`TxBuilder::add_global_xpubs`] option every extended
     /// key in the descriptor must either be a master key itself (having depth = 0) or have an
     /// explicit origin provided

src/wallet/mod.rs

@@ -37,6 +37,8 @@ use log::{debug, error, info, trace};
 pub mod address_validator;
 pub mod coin_selection;
 pub mod export;
+#[cfg(feature = "reserves")]
+pub mod reserves;
 pub mod signer;
 pub mod time;
 pub mod tx_builder;