_ Git - rust-lightning/blob - lightning/src/chain/transaction.rs

   1 //! Contains simple structs describing parts of transactions on the chain.
   2
   3 use bitcoin::hash_types::Txid;
   4 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
   5
   6 /// A reference to a transaction output.
   7 ///
   8 /// Differs from bitcoin::blockdata::transaction::OutPoint as the index is a u16 instead of u32
   9 /// due to LN's restrictions on index values. Should reduce (possibly) unsafe conversions this way.
  10 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
  11 pub struct OutPoint {
  12         /// The referenced transaction's txid.
  13         pub txid: Txid,
  14         /// The index of the referenced output in its transaction's vout.
  15         pub index: u16,
  16 }
  17
  18 impl OutPoint {
  19         /// Convert an `OutPoint` to a lightning channel id.
  20         pub fn to_channel_id(&self) -> [u8; 32] {
  21                 let mut res = [0; 32];
  22                 res[..].copy_from_slice(&self.txid[..]);
  23                 res[30] ^= ((self.index >> 8) & 0xff) as u8;
  24                 res[31] ^= ((self.index >> 0) & 0xff) as u8;
  25                 res
  26         }
  27
  28         /// Converts this OutPoint into the OutPoint field as used by rust-bitcoin
  29         pub fn into_bitcoin_outpoint(self) -> BitcoinOutPoint {
  30                 BitcoinOutPoint {
  31                         txid: self.txid,
  32                         vout: self.index as u32,
  33                 }
  34         }
  35 }
  36
  37 impl_writeable!(OutPoint, 0, { txid, index });
  38
  39 #[cfg(test)]
  40 mod tests {
  41         use chain::transaction::OutPoint;
  42
  43         use bitcoin::blockdata::transaction::Transaction;
  44         use bitcoin::consensus::encode;
  45
  46         use hex;
  47
  48         #[test]
  49         fn test_channel_id_calculation() {
  50                 let tx: Transaction = encode::deserialize(&hex::decode("020000000001010e0adef48412e4361325ac1c6e36411299ab09d4f083b9d8ddb55fbc06e1b0c00000000000feffffff0220a1070000000000220020f81d95e040bd0a493e38bae27bff52fe2bb58b93b293eb579c01c31b05c5af1dc072cfee54a3000016001434b1d6211af5551905dc2642d05f5b04d25a8fe80247304402207f570e3f0de50546aad25a872e3df059d277e776dda4269fa0d2cc8c2ee6ec9a022054e7fae5ca94d47534c86705857c24ceea3ad51c69dd6051c5850304880fc43a012103cb11a1bacc223d98d91f1946c6752e358a5eb1a1c983b3e6fb15378f453b76bd00000000").unwrap()[..]).unwrap();
  51                 assert_eq!(&OutPoint {
  52                         txid: tx.txid(),
  53                         index: 0
  54                 }.to_channel_id(), &hex::decode("3e88dd7165faf7be58b3c5bb2c9c452aebef682807ea57080f62e6f6e113c25e").unwrap()[..]);
  55                 assert_eq!(&OutPoint {
  56                         txid: tx.txid(),
  57                         index: 1
  58                 }.to_channel_id(), &hex::decode("3e88dd7165faf7be58b3c5bb2c9c452aebef682807ea57080f62e6f6e113c25f").unwrap()[..]);
  59         }
  60 }