Send initial_routing_sync-filled Init messages to the first 5 peers
[rust-lightning] / src / ln / chan_utils.rs
index b14f77e9d91b9135acaec8e0455fe8389da0dfd1..45f674377307f362fecac115a4ba90d32c97cf4b 100644 (file)
@@ -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.
 
@@ -35,7 +40,7 @@ pub fn derive_private_key(secp_ctx: &Secp256k1, per_commitment_point: &PublicKey
        sha.result(&mut res);
 
        let mut key = base_secret.clone();
-       try!(key.add_assign(&secp_ctx, &try!(SecretKey::from_slice(&secp_ctx, &res))));
+       key.add_assign(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &res)?)?;
        Ok(key)
 }
 
@@ -46,7 +51,7 @@ pub fn derive_public_key(secp_ctx: &Secp256k1, per_commitment_point: &PublicKey,
        let mut res = [0; 32];
        sha.result(&mut res);
 
-       let hashkey = PublicKey::from_secret_key(&secp_ctx, &try!(SecretKey::from_slice(&secp_ctx, &res))).unwrap();
+       let hashkey = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &res)?).unwrap();
        base_point.combine(&secp_ctx, &hashkey)
 }
 
@@ -62,7 +67,7 @@ pub fn derive_private_revocation_key(secp_ctx: &Secp256k1, per_commitment_secret
                let mut res = [0; 32];
                sha.result(&mut res);
 
-               try!(SecretKey::from_slice(&secp_ctx, &res))
+               SecretKey::from_slice(&secp_ctx, &res)?
        };
        let commit_append_rev_hash_key = {
                let mut sha = Sha256::new();
@@ -71,14 +76,14 @@ pub fn derive_private_revocation_key(secp_ctx: &Secp256k1, per_commitment_secret
                let mut res = [0; 32];
                sha.result(&mut res);
 
-               try!(SecretKey::from_slice(&secp_ctx, &res))
+               SecretKey::from_slice(&secp_ctx, &res)?
        };
 
        let mut part_a = revocation_base_secret.clone();
-       try!(part_a.mul_assign(&secp_ctx, &rev_append_commit_hash_key));
+       part_a.mul_assign(&secp_ctx, &rev_append_commit_hash_key)?;
        let mut part_b = per_commitment_secret.clone();
-       try!(part_b.mul_assign(&secp_ctx, &commit_append_rev_hash_key));
-       try!(part_a.add_assign(&secp_ctx, &part_b));
+       part_b.mul_assign(&secp_ctx, &commit_append_rev_hash_key)?;
+       part_a.add_assign(&secp_ctx, &part_b)?;
        Ok(part_a)
 }
 
@@ -90,7 +95,7 @@ pub fn derive_public_revocation_key(secp_ctx: &Secp256k1, per_commitment_point:
                let mut res = [0; 32];
                sha.result(&mut res);
 
-               try!(SecretKey::from_slice(&secp_ctx, &res))
+               SecretKey::from_slice(&secp_ctx, &res)?
        };
        let commit_append_rev_hash_key = {
                let mut sha = Sha256::new();
@@ -99,13 +104,13 @@ pub fn derive_public_revocation_key(secp_ctx: &Secp256k1, per_commitment_point:
                let mut res = [0; 32];
                sha.result(&mut res);
 
-               try!(SecretKey::from_slice(&secp_ctx, &res))
+               SecretKey::from_slice(&secp_ctx, &res)?
        };
 
        let mut part_a = revocation_base_point.clone();
-       try!(part_a.mul_assign(&secp_ctx, &rev_append_commit_hash_key));
+       part_a.mul_assign(&secp_ctx, &rev_append_commit_hash_key)?;
        let mut part_b = per_commitment_point.clone();
-       try!(part_b.mul_assign(&secp_ctx, &commit_append_rev_hash_key));
+       part_b.mul_assign(&secp_ctx, &commit_append_rev_hash_key)?;
        part_a.combine(&secp_ctx, &part_b)
 }
 
@@ -122,11 +127,11 @@ impl TxCreationKeys {
        pub fn new(secp_ctx: &Secp256k1, per_commitment_point: &PublicKey, a_delayed_payment_base: &PublicKey, a_htlc_base: &PublicKey, b_revocation_base: &PublicKey, b_payment_base: &PublicKey, b_htlc_base: &PublicKey) -> Result<TxCreationKeys, secp256k1::Error> {
                Ok(TxCreationKeys {
                        per_commitment_point: per_commitment_point.clone(),
-                       revocation_key: try!(derive_public_revocation_key(&secp_ctx, &per_commitment_point, &b_revocation_base)),
-                       a_htlc_key: try!(derive_public_key(&secp_ctx, &per_commitment_point, &a_htlc_base)),
-                       b_htlc_key: try!(derive_public_key(&secp_ctx, &per_commitment_point, &b_htlc_base)),
-                       a_delayed_payment_key: try!(derive_public_key(&secp_ctx, &per_commitment_point, &a_delayed_payment_base)),
-                       b_payment_key: try!(derive_public_key(&secp_ctx, &per_commitment_point, &b_payment_base)),
+                       revocation_key: derive_public_revocation_key(&secp_ctx, &per_commitment_point, &b_revocation_base)?,
+                       a_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &a_htlc_base)?,
+                       b_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &b_htlc_base)?,
+                       a_delayed_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &a_delayed_payment_base)?,
+                       b_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &b_payment_base)?,
                })
        }
 }
@@ -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,
+       }
 }