_ Git - rapid-gossip-sync-server/blob - src/verifier.rs

   1 use std::convert::TryInto;
   2 use std::sync::Arc;
   3
   4 use bitcoin::{BlockHash, TxOut};
   5 use bitcoin::blockdata::block::Block;
   6 use bitcoin::hashes::Hash;
   7 use futures::executor;
   8 use lightning::chain;
   9 use lightning::chain::AccessError;
  10 use lightning_block_sync::BlockSource;
  11 use lightning_block_sync::http::BinaryResponse;
  12 use lightning_block_sync::rest::RestClient;
  13
  14 use crate::config;
  15
  16 pub(crate) struct ChainVerifier {
  17         rest_client: Arc<RestClient>,
  18 }
  19
  20 struct RestBinaryResponse(Vec<u8>);
  21
  22 impl ChainVerifier {
  23         pub(crate) fn new() -> Self {
  24                 let rest_client = RestClient::new(config::bitcoin_rest_endpoint()).unwrap();
  25                 ChainVerifier {
  26                         rest_client: Arc::new(rest_client),
  27                 }
  28         }
  29
  30         fn retrieve_block(&self, block_height: u32) -> Result<Block, AccessError> {
  31                 let rest_client = self.rest_client.clone();
  32                 executor::block_on(async move {
  33                         let block_hash_result = rest_client.request_resource::<BinaryResponse, RestBinaryResponse>(&format!("blockhashbyheight/{}.bin", block_height)).await;
  34                         let block_hash: Vec<u8> = block_hash_result.map_err(|error| {
  35                                 eprintln!("Could't find block hash at height {}: {}", block_height, error.to_string());
  36                                 AccessError::UnknownChain
  37                         })?.0;
  38                         let block_hash = BlockHash::from_slice(&block_hash).unwrap();
  39
  40                         let block_result = rest_client.get_block(&block_hash).await;
  41                         let block = block_result.map_err(|error| {
  42                                 eprintln!("Couldn't retrieve block {}: {:?} ({})", block_height, error, block_hash);
  43                                 AccessError::UnknownChain
  44                         })?;
  45                         Ok(block)
  46                 })
  47         }
  48 }
  49
  50 impl chain::Access for ChainVerifier {
  51         fn get_utxo(&self, _genesis_hash: &BlockHash, short_channel_id: u64) -> Result<TxOut, AccessError> {
  52                 let block_height = (short_channel_id >> 5 * 8) as u32; // block height is most significant three bytes
  53                 let transaction_index = ((short_channel_id >> 2 * 8) & 0xffffff) as u32;
  54                 let output_index = (short_channel_id & 0xffff) as u16;
  55
  56                 let block = self.retrieve_block(block_height)?;
  57                 let transaction = block.txdata.get(transaction_index as usize).ok_or_else(|| {
  58                         eprintln!("Transaction index {} out of bounds in block {} ({})", transaction_index, block_height, block.block_hash().to_string());
  59                         AccessError::UnknownTx
  60                 })?;
  61                 let output = transaction.output.get(output_index as usize).ok_or_else(|| {
  62                         eprintln!("Output index {} out of bounds in transaction {}", output_index, transaction.txid().to_string());
  63                         AccessError::UnknownTx
  64                 })?;
  65                 Ok(output.clone())
  66         }
  67 }
  68
  69 impl TryInto<RestBinaryResponse> for BinaryResponse {
  70         type Error = std::io::Error;
  71
  72         fn try_into(self) -> Result<RestBinaryResponse, Self::Error> {
  73                 Ok(RestBinaryResponse(self.0))
  74         }
  75 }