X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;ds=sidebyside;f=lightning%2Fsrc%2Fln%2Fchan_utils.rs;h=9b44d11964534e9fb968cb6ebc49597225626d8d;hb=499d84c165426b6f05bb414f5a49a7423eb9e0c5;hp=b1171f543989c8d9deb7c6d68a18fb61e5e27af5;hpb=e4b516dd8a62166c206e7aa5363a0c07add1d3a9;p=rust-lightning

diff --git a/lightning/src/ln/chan_utils.rs b/lightning/src/ln/chan_utils.rs
index b1171f54..9b44d119 100644
--- a/lightning/src/ln/chan_utils.rs
+++ b/lightning/src/ln/chan_utils.rs
@@ -8,8 +8,7 @@
 // licenses.
 
 //! Various utilities for building scripts and deriving keys related to channels. These are
-//! largely of interest for those implementing chain::keysinterface::ChannelKeys message signing
-//! by hand.
+//! largely of interest for those implementing chain::keysinterface::Sign message signing by hand.
 
 use bitcoin::blockdata::script::{Script,Builder};
 use bitcoin::blockdata::opcodes;
@@ -21,7 +20,7 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::hashes::ripemd160::Hash as Ripemd160;
 use bitcoin::hash_types::{Txid, PubkeyHash};
 
-use ln::channelmanager::{PaymentHash, PaymentPreimage};
+use ln::{PaymentHash, PaymentPreimage};
 use ln::msgs::DecodeError;
 use util::ser::{Readable, Writeable, Writer, MAX_BUF_SIZE};
 use util::byte_utils;
@@ -32,14 +31,15 @@ use bitcoin::secp256k1::{Secp256k1, Signature, Message};
 use bitcoin::secp256k1::Error as SecpError;
 use bitcoin::secp256k1;
 
-use std::cmp;
+use core::cmp;
 use ln::chan_utils;
 use util::transaction_utils::sort_outputs;
 use ln::channel::INITIAL_COMMITMENT_NUMBER;
 use std::io::Read;
-use std::ops::Deref;
+use core::ops::Deref;
 use chain;
 
+// Maximum size of a serialized HTLCOutputInCommitment
 const HTLC_OUTPUT_IN_COMMITMENT_SIZE: usize = 1 + 8 + 4 + 32 + 5;
 
 pub(crate) const MAX_HTLCS: u16 = 483;
@@ -321,7 +321,8 @@ pub struct TxCreationKeys {
 	/// Broadcaster's Payment Key (which isn't allowed to be spent from for some delay)
 	pub broadcaster_delayed_payment_key: PublicKey,
 }
-impl_writeable!(TxCreationKeys, 33*6,
+
+impl_writeable!(TxCreationKeys, 33*5,
 	{ per_commitment_point, revocation_key, broadcaster_htlc_key, countersignatory_htlc_key, broadcaster_delayed_payment_key });
 
 /// One counterparty's public keys which do not change over the life of a channel.
@@ -384,11 +385,16 @@ impl TxCreationKeys {
 	}
 }
 
+/// The maximum length of a script returned by get_revokeable_redeemscript.
+// Calculated as 6 bytes of opcodes, 1 byte push plus 2 bytes for contest_delay, and two public
+// keys of 33 bytes (+ 1 push).
+pub const REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH: usize = 6 + 3 + 34*2;
+
 /// A script either spendable by the revocation
 /// key or the broadcaster_delayed_payment_key and satisfying the relative-locktime OP_CSV constrain.
 /// Encumbering a `to_holder` output on a commitment transaction or 2nd-stage HTLC transactions.
 pub fn get_revokeable_redeemscript(revocation_key: &PublicKey, contest_delay: u16, broadcaster_delayed_payment_key: &PublicKey) -> Script {
-	Builder::new().push_opcode(opcodes::all::OP_IF)
+	let res = Builder::new().push_opcode(opcodes::all::OP_IF)
 	              .push_slice(&revocation_key.serialize())
 	              .push_opcode(opcodes::all::OP_ELSE)
 	              .push_int(contest_delay as i64)
@@ -397,7 +403,9 @@ pub fn get_revokeable_redeemscript(revocation_key: &PublicKey, contest_delay: u1
 	              .push_slice(&broadcaster_delayed_payment_key.serialize())
 	              .push_opcode(opcodes::all::OP_ENDIF)
 	              .push_opcode(opcodes::all::OP_CHECKSIG)
-	              .into_script()
+	              .into_script();
+	debug_assert!(res.len() <= REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH);
+	res
 }
 
 #[derive(Clone, PartialEq)]
@@ -421,7 +429,10 @@ pub struct HTLCOutputInCommitment {
 	pub transaction_output_index: Option<u32>,
 }
 
-impl_writeable!(HTLCOutputInCommitment, HTLC_OUTPUT_IN_COMMITMENT_SIZE, {
+impl_writeable_len_match!(HTLCOutputInCommitment, {
+		{ HTLCOutputInCommitment { transaction_output_index: None, .. }, HTLC_OUTPUT_IN_COMMITMENT_SIZE - 4 },
+		{ _, HTLC_OUTPUT_IN_COMMITMENT_SIZE }
+	}, {
 	offered,
 	amount_msat,
 	cltv_expiry,