X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fkeysinterface.rs;h=338e81d17099cc0aecd193216aa7f228d60409b6;hb=7f49f6bf4d838196ff7b20e78207b4bfdad264c6;hp=b1290708b95f70a71ebf6193cceb1677aa3150bd;hpb=5f96d1334435e74545670a5dff24078edf749d60;p=rust-lightning

diff --git a/lightning/src/chain/keysinterface.rs b/lightning/src/chain/keysinterface.rs
index b1290708b..338e81d17 100644
--- a/lightning/src/chain/keysinterface.rs
+++ b/lightning/src/chain/keysinterface.rs
@@ -85,6 +85,8 @@ pub struct DelayedPaymentOutputDescriptor {
 }
 impl DelayedPaymentOutputDescriptor {
 	/// The maximum length a well-formed witness spending one of these should have.
+	/// Note: If you have the grind_signatures feature enabled, this will be at least 1 byte
+	/// shorter.
 	// Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
 	// redeemscript push length.
 	pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
@@ -117,6 +119,8 @@ pub struct StaticPaymentOutputDescriptor {
 }
 impl StaticPaymentOutputDescriptor {
 	/// The maximum length a well-formed witness spending one of these should have.
+	/// Note: If you have the grind_signatures feature enabled, this will be at least 1 byte
+	/// shorter.
 	// Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
 	// redeemscript push length.
 	pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
@@ -543,15 +547,21 @@ pub trait SignerProvider {
 
 	/// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
 	///
+	/// If this function returns an error, this will result in a channel failing to open.
+	///
 	/// This method should return a different value each time it is called, to avoid linking
 	/// on-chain funds across channels as controlled to the same user.
-	fn get_destination_script(&self) -> Script;
+	fn get_destination_script(&self) -> Result<Script, ()>;
 
 	/// Get a script pubkey which we will send funds to when closing a channel.
 	///
+	/// If this function returns an error, this will result in a channel failing to open or close.
+	/// In the event of a failure when the counterparty is initiating a close, this can result in a
+	/// channel force close.
+	///
 	/// This method should return a different value each time it is called, to avoid linking
 	/// on-chain funds across channels as controlled to the same user.
-	fn get_shutdown_scriptpubkey(&self) -> ShutdownScript;
+	fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()>;
 }
 
 /// A simple implementation of [`WriteableEcdsaChannelSigner`] that just keeps the private keys in memory.
@@ -1188,6 +1198,8 @@ impl KeysManager {
 						witness: Witness::new(),
 					});
 					witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
+					#[cfg(feature = "grind_signatures")]
+					{ witness_weight -= 1; } // Guarantees a low R signature
 					input_value += descriptor.output.value;
 					if !output_set.insert(descriptor.outpoint) { return Err(()); }
 				},
@@ -1199,6 +1211,8 @@ impl KeysManager {
 						witness: Witness::new(),
 					});
 					witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
+					#[cfg(feature = "grind_signatures")]
+					{ witness_weight -= 1; } // Guarantees a low R signature
 					input_value += descriptor.output.value;
 					if !output_set.insert(descriptor.outpoint) { return Err(()); }
 				},
@@ -1210,6 +1224,8 @@ impl KeysManager {
 						witness: Witness::new(),
 					});
 					witness_weight += 1 + 73 + 34;
+					#[cfg(feature = "grind_signatures")]
+					{ witness_weight -= 1; } // Guarantees a low R signature
 					input_value += output.value;
 					if !output_set.insert(*outpoint) { return Err(()); }
 				}
@@ -1366,12 +1382,12 @@ impl SignerProvider for KeysManager {
 		InMemorySigner::read(&mut io::Cursor::new(reader), self)
 	}
 
-	fn get_destination_script(&self) -> Script {
-		self.destination_script.clone()
+	fn get_destination_script(&self) -> Result<Script, ()> {
+		Ok(self.destination_script.clone())
 	}
 
-	fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
-		ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone())
+	fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()> {
+		Ok(ShutdownScript::new_p2wpkh_from_pubkey(self.shutdown_pubkey.clone()))
 	}
 }
 
@@ -1461,11 +1477,11 @@ impl SignerProvider for PhantomKeysManager {
 		self.inner.read_chan_signer(reader)
 	}
 
-	fn get_destination_script(&self) -> Script {
+	fn get_destination_script(&self) -> Result<Script, ()> {
 		self.inner.get_destination_script()
 	}
 
-	fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
+	fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()> {
 		self.inner.get_shutdown_scriptpubkey()
 	}
 }