X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=src%2Fln%2Fchan_utils.rs;h=0cace11c1cb0dd601474229d738a23526ed6029d;hb=73932d75dcf890f32a7992494a156b2f8e7def44;hp=dd5515c88046ac18b0686e7a810d5cfdeed65c3e;hpb=b94365f3f560b095350bd36d4eb9bf63268679b0;p=rust-lightning

diff --git a/src/ln/chan_utils.rs b/src/ln/chan_utils.rs
index dd5515c8..0cace11c 100644
--- a/src/ln/chan_utils.rs
+++ b/src/ln/chan_utils.rs
@@ -1,15 +1,20 @@
 use bitcoin::blockdata::script::{Script,Builder};
 use bitcoin::blockdata::opcodes;
-use bitcoin::util::hash::Hash160;
+use bitcoin::blockdata::transaction::{TxIn,TxOut,Transaction};
+use bitcoin::util::hash::{Hash160,Sha256dHash};
 
 use secp256k1::key::{PublicKey,SecretKey};
 use secp256k1::Secp256k1;
 use secp256k1;
 
 use crypto::digest::Digest;
-use crypto::sha2::Sha256;
 use crypto::ripemd160::Ripemd160;
 
+use util::sha2::Sha256;
+
+pub const HTLC_SUCCESS_TX_WEIGHT: u64 = 703;
+pub const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663;
+
 // Various functions for key derivation and transaction creation for use within channels. Primarily
 // used in Channel and ChannelMonitor.
 
@@ -135,18 +140,18 @@ impl TxCreationKeys {
 /// the revocation key
 pub fn get_revokeable_redeemscript(revocation_key: &PublicKey, to_self_delay: u16, delayed_payment_key: &PublicKey) -> Script {
 	Builder::new().push_opcode(opcodes::All::OP_IF)
-	                             .push_slice(&revocation_key.serialize())
-	                             .push_opcode(opcodes::All::OP_ELSE)
-	                             .push_int(to_self_delay as i64)
-	                             .push_opcode(opcodes::OP_CSV)
-	                             .push_opcode(opcodes::All::OP_DROP)
-	                             .push_slice(&delayed_payment_key.serialize())
-	                             .push_opcode(opcodes::All::OP_ENDIF)
-	                             .push_opcode(opcodes::All::OP_CHECKSIG)
-	                             .into_script()
+	              .push_slice(&revocation_key.serialize())
+	              .push_opcode(opcodes::All::OP_ELSE)
+	              .push_int(to_self_delay as i64)
+	              .push_opcode(opcodes::OP_CSV)
+	              .push_opcode(opcodes::All::OP_DROP)
+	              .push_slice(&delayed_payment_key.serialize())
+	              .push_opcode(opcodes::All::OP_ENDIF)
+	              .push_opcode(opcodes::All::OP_CHECKSIG)
+	              .into_script()
 }
 
-#[derive(Clone)]
+#[derive(Clone, PartialEq)]
 pub struct HTLCOutputInCommitment {
 	pub offered: bool,
 	pub amount_msat: u64,
@@ -156,7 +161,7 @@ pub struct HTLCOutputInCommitment {
 }
 
 #[inline]
-pub fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, a_htlc_key: &PublicKey, b_htlc_key: &PublicKey, revocation_key: &PublicKey, offered: bool) -> Script {
+pub fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, a_htlc_key: &PublicKey, b_htlc_key: &PublicKey, revocation_key: &PublicKey) -> Script {
 	let payment_hash160 = {
 		let mut ripemd = Ripemd160::new();
 		ripemd.input(&htlc.payment_hash);
@@ -164,7 +169,7 @@ pub fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, a
 		ripemd.result(&mut res);
 		res
 	};
-	if offered {
+	if htlc.offered {
 		Builder::new().push_opcode(opcodes::All::OP_DUP)
 		              .push_opcode(opcodes::All::OP_HASH160)
 		              .push_slice(&Hash160::from_data(&revocation_key.serialize())[..])
@@ -229,6 +234,36 @@ pub fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, a
 /// note here that 'a_revocation_key' is generated using b_revocation_basepoint and a's
 /// commitment secret. 'htlc' does *not* need to have its previous_output_index filled.
 #[inline]
-pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, keys: &TxCreationKeys, offered: bool) -> Script {
-	get_htlc_redeemscript_with_explicit_keys(htlc, &keys.a_htlc_key, &keys.b_htlc_key, &keys.revocation_key, offered)
+pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, keys: &TxCreationKeys) -> Script {
+	get_htlc_redeemscript_with_explicit_keys(htlc, &keys.a_htlc_key, &keys.b_htlc_key, &keys.revocation_key)
+}
+
+pub fn build_htlc_transaction(prev_hash: &Sha256dHash, feerate_per_kw: u64, to_self_delay: u16, htlc: &HTLCOutputInCommitment, a_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction {
+	let mut txins: Vec<TxIn> = Vec::new();
+	txins.push(TxIn {
+		prev_hash: prev_hash.clone(),
+		prev_index: htlc.transaction_output_index,
+		script_sig: Script::new(),
+		sequence: 0,
+		witness: Vec::new(),
+	});
+
+	let total_fee = if htlc.offered {
+			feerate_per_kw * HTLC_TIMEOUT_TX_WEIGHT / 1000
+		} else {
+			feerate_per_kw * HTLC_SUCCESS_TX_WEIGHT / 1000
+		};
+
+	let mut txouts: Vec<TxOut> = Vec::new();
+	txouts.push(TxOut {
+		script_pubkey: get_revokeable_redeemscript(revocation_key, to_self_delay, a_delayed_payment_key).to_v0_p2wsh(),
+		value: htlc.amount_msat / 1000 - total_fee //TODO: BOLT 3 does not specify if we should add amount_msat before dividing or if we should divide by 1000 before subtracting (as we do here)
+	});
+
+	Transaction {
+		version: 2,
+		lock_time: if htlc.offered { htlc.cltv_expiry } else { 0 },
+		input: txins,
+		output: txouts,
+	}
 }