Remove dependency on the hex crate

The same functionality is provided by bitcoin_hashes.

Refs #61

Cargo.toml

@@ -35,7 +35,6 @@ bitcoin_hashes = { version = "0.9.0", features = [ "serde" ] }
 bitcoincore-rpc = "0.12.0"
 miniscript = { version = "3.0.0", features = [ "serde" ] }
 chrono = { version = "0.4.19", default-features = false }
-hex = "0.4.2"
 serde = { version = "1.0.117", features = [ "derive" ] }
 serde_json = "1.0.59"
 lazy_static = "1.4.0"

src/electrum/server.rs

@@ -7,6 +7,7 @@ use std::sync::{Arc, Mutex};
 use std::thread;
 
 use bitcoin::Txid;
+use bitcoin_hashes::hex::ToHex;
 use serde_json::{from_str, from_value, Value};
 
 use crate::electrum::{electrum_height, QueryExt};
@@ -255,7 +256,7 @@ impl Connection {
             json!(self.query.get_tx_json(&txid)?)
         } else {
             let raw = self.query.get_tx_raw(&txid)?;
-            json!(hex::encode(&raw))
+            json!(raw.to_hex())
         })
     }
 

src/http.rs

@@ -9,7 +9,7 @@ use warp::sse::ServerSentEvent;
 use warp::{self, reply, Filter, Reply};
 
 use bitcoin::{Address, BlockHash, OutPoint, Txid};
-use bitcoin_hashes::hex::FromHex;
+use bitcoin_hashes::hex::{FromHex, ToHex};
 
 use crate::error::{fmt_error_chain, BwtError, Error, OptionExt};
 use crate::types::{BlockId, ScriptHash};
@@ -225,7 +225,7 @@ fn setup(
         .and(query.clone())
         .map(|txid: Txid, query: Arc<Query>| {
             let tx_raw = query.get_tx_raw(&txid)?;
-            Ok(hex::encode(tx_raw))
+            Ok(tx_raw.to_hex())
         })
         .map(handle_error);
 
@@ -236,7 +236,7 @@ fn setup(
         .and(query.clone())
         .map(|txid: Txid, query: Arc<Query>| {
             let proof = query.get_tx_proof(&txid)?;
-            Ok(hex::encode(proof))
+            Ok(proof.to_hex())
         })
         .map(handle_error);
 

src/query.rs

@@ -7,6 +7,7 @@ use serde::Serialize;
 use serde_json::Value;
 
 use bitcoin::{BlockHash, BlockHeader, Network, OutPoint, Transaction, Txid};
+use bitcoin_hashes::hex::FromHex;
 use bitcoincore_rpc::{json as rpcjson, Client as RpcClient, RpcApi};
 
 use crate::error::{BwtError, Context, OptionExt, Result};
@@ -184,7 +185,7 @@ impl Query {
         // and is incompatible with pruning, but works for non-wallet transactions too.
         else {
             let tx_hex = self.rpc.get_raw_transaction_hex(txid, None)?;
-            Ok(hex::decode(tx_hex)?)
+            Ok(Vec::from_hex(&tx_hex)?)
         }
     }
 
@@ -204,8 +205,8 @@ impl Query {
 
     pub fn broadcast(&self, tx_hex: &str) -> Result<Txid> {
         if let Some(broadcast_cmd) = &self.config.broadcast_cmd {
-            // need to deserialize to ensure validity (preventing code injection) and to determine the txid
-            let tx: Transaction = bitcoin::consensus::deserialize(&hex::decode(tx_hex)?)?;
+            // re-serialize the tx to ensure validity (preventing potential code injection) and to determine the txid
+            let tx: Transaction = bitcoin::consensus::deserialize(&Vec::from_hex(tx_hex)?)?;
             let cmd = broadcast_cmd.replacen("{tx_hex}", tx_hex, 1);
             debug!("broadcasting tx with cmd {}", broadcast_cmd);
             let status = Command::new("sh").arg("-c").arg(cmd).status()?;