X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fkeysinterface.rs;h=3c115bc770bf24ab8fe12cd7947cfddc42edb8d0;hb=5254d6b3d92d3be7869d7b9c6d622fe86222d224;hp=26d1f07c7c43c38fc378d42431ffa2dde190ab92;hpb=48d73b3264a034f456e60540e438eb9a6aea14a6;p=rust-lightning diff --git a/lightning/src/chain/keysinterface.rs b/lightning/src/chain/keysinterface.rs index 26d1f07c..3c115bc7 100644 --- a/lightning/src/chain/keysinterface.rs +++ b/lightning/src/chain/keysinterface.rs @@ -1,8 +1,17 @@ +// This file is Copyright its original authors, visible in version control +// history. +// +// This file is licensed under the Apache License, Version 2.0 or the MIT license +// , at your option. +// You may not use this file except in accordance with one or both of these +// licenses. + //! keysinterface provides keys into rust-lightning and defines some useful enums which describe //! spendable on-chain outputs which the user owns and is responsible for using just as any other //! on-chain output which is theirs. -use bitcoin::blockdata::transaction::{Transaction, OutPoint, TxOut}; +use bitcoin::blockdata::transaction::{Transaction, TxOut, SigHashType}; use bitcoin::blockdata::script::{Script, Builder}; use bitcoin::blockdata::opcodes; use bitcoin::network::constants::Network; @@ -22,9 +31,10 @@ use bitcoin::secp256k1; use util::byte_utils; use util::ser::{Writeable, Writer, Readable}; +use chain::transaction::OutPoint; use ln::chan_utils; -use ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, LocalCommitmentTransaction}; -use ln::msgs; +use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, LocalCommitmentTransaction, PreCalculatedTxCreationKeys}; +use ln::msgs::UnsignedChannelAnnouncement; use std::sync::atomic::{AtomicUsize, Ordering}; use std::io::Error; @@ -223,7 +233,7 @@ pub trait ChannelKeys : Send+Clone { // TODO: Document the things someone using this interface should enforce before signing. // TODO: Add more input vars to enable better checking (preferably removing commitment_tx and // making the callee generate it via some util function we expose)! - fn sign_remote_commitment(&self, feerate_per_kw: u32, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()>; + fn sign_remote_commitment(&self, feerate_per_kw: u32, commitment_tx: &Transaction, keys: &PreCalculatedTxCreationKeys, htlcs: &[&HTLCOutputInCommitment], secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()>; /// Create a signature for a local commitment transaction. This will only ever be called with /// the same local_commitment_tx (or a copy thereof), though there are currently no guarantees @@ -238,7 +248,7 @@ pub trait ChannelKeys : Send+Clone { /// transactions which will be broadcasted later, after the channel has moved on to a newer /// state. Thus, needs its own method as sign_local_commitment may enforce that we only ever /// get called once. - #[cfg(test)] + #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))] fn unsafe_sign_local_commitment(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1) -> Result; /// Create a signature for each HTLC transaction spending a local commitment transaction. @@ -307,7 +317,7 @@ pub trait ChannelKeys : Send+Clone { /// Note that if this fails or is rejected, the channel will not be publicly announced and /// our counterparty may (though likely will not) close the channel on us for violating the /// protocol. - fn sign_channel_announcement(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1) -> Result; + fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1) -> Result; /// Set the remote channel basepoints and remote/local to_self_delay. /// This is done immediately on incoming channels and as soon as the channel is accepted on outgoing channels. @@ -332,12 +342,10 @@ pub trait KeysInterface: Send + Sync { /// Get a new set of ChannelKeys for per-channel secrets. These MUST be unique even if you /// restarted with some stale data! fn get_channel_keys(&self, inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner; - /// Get a secret and PRNG seed for constructing an onion packet - fn get_onion_rand(&self) -> (SecretKey, [u8; 32]); - /// Get a unique temporary channel id. Channels will be referred to by this until the funding - /// transaction is created, at which point they will use the outpoint in the funding - /// transaction. - fn get_channel_id(&self) -> [u8; 32]; + /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting + /// onion packets and for temporary channel IDs. There is no requirement that these be + /// persisted anywhere, though they must be unique across restarts. + fn get_secure_random_bytes(&self) -> [u8; 32]; } #[derive(Clone)] @@ -461,14 +469,15 @@ impl ChannelKeys for InMemoryChannelKeys { fn pubkeys(&self) -> &ChannelPublicKeys { &self.local_channel_pubkeys } fn key_derivation_params(&self) -> (u64, u64) { self.key_derivation_params } - fn sign_remote_commitment(&self, feerate_per_kw: u32, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()> { + fn sign_remote_commitment(&self, feerate_per_kw: u32, commitment_tx: &Transaction, pre_keys: &PreCalculatedTxCreationKeys, htlcs: &[&HTLCOutputInCommitment], secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()> { if commitment_tx.input.len() != 1 { return Err(()); } + let keys = pre_keys.trust_key_derivation(); let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); let accepted_data = self.accepted_channel_data.as_ref().expect("must accept before signing"); let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &accepted_data.remote_channel_pubkeys.funding_pubkey); - let commitment_sighash = hash_to_message!(&bip143::SighashComponents::new(&commitment_tx).sighash_all(&commitment_tx.input[0], &channel_funding_redeemscript, self.channel_value_satoshis)[..]); + let commitment_sighash = hash_to_message!(&bip143::SigHashCache::new(commitment_tx).signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]); let commitment_sig = secp_ctx.sign(&commitment_sighash, &self.funding_key); let commitment_txid = commitment_tx.txid(); @@ -478,7 +487,7 @@ impl ChannelKeys for InMemoryChannelKeys { if let Some(_) = htlc.transaction_output_index { let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, feerate_per_kw, accepted_data.local_to_self_delay, htlc, &keys.a_delayed_payment_key, &keys.revocation_key); let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys); - let htlc_sighash = hash_to_message!(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]); + let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]); let our_htlc_key = match chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key) { Ok(s) => s, Err(_) => return Err(()), @@ -498,7 +507,7 @@ impl ChannelKeys for InMemoryChannelKeys { Ok(local_commitment_tx.get_local_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx)) } - #[cfg(test)] + #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))] fn unsafe_sign_local_commitment(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1) -> Result { let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); let remote_channel_pubkeys = &self.accepted_channel_data.as_ref().expect("must accept before signing").remote_channel_pubkeys; @@ -539,8 +548,8 @@ impl ChannelKeys for InMemoryChannelKeys { }; chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.local_to_self_delay(), &remote_delayedpubkey) }; - let sighash_parts = bip143::SighashComponents::new(&justice_tx); - let sighash = hash_to_message!(&sighash_parts.sighash_all(&justice_tx.input[input], &witness_script, amount)[..]); + let mut sighash_parts = bip143::SigHashCache::new(justice_tx); + let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]); return Ok(secp_ctx.sign(&sighash, &revocation_key)) } @@ -553,8 +562,8 @@ impl ChannelKeys for InMemoryChannelKeys { } else { return Err(()) } } else { return Err(()) } } else { return Err(()) }; - let sighash_parts = bip143::SighashComponents::new(&htlc_tx); - let sighash = hash_to_message!(&sighash_parts.sighash_all(&htlc_tx.input[input], &witness_script, amount)[..]); + let mut sighash_parts = bip143::SigHashCache::new(htlc_tx); + let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]); return Ok(secp_ctx.sign(&sighash, &htlc_key)) } Err(()) @@ -569,12 +578,12 @@ impl ChannelKeys for InMemoryChannelKeys { let remote_channel_data = self.accepted_channel_data.as_ref().expect("must accept before signing"); let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_data.remote_channel_pubkeys.funding_pubkey); - let sighash = hash_to_message!(&bip143::SighashComponents::new(closing_tx) - .sighash_all(&closing_tx.input[0], &channel_funding_redeemscript, self.channel_value_satoshis)[..]); + let sighash = hash_to_message!(&bip143::SigHashCache::new(closing_tx) + .signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]); Ok(secp_ctx.sign(&sighash, &self.funding_key)) } - fn sign_channel_announcement(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1) -> Result { + fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1) -> Result { let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]); Ok(secp_ctx.sign(&msghash, &self.funding_key)) } @@ -656,10 +665,8 @@ pub struct KeysManager { shutdown_pubkey: PublicKey, channel_master_key: ExtendedPrivKey, channel_child_index: AtomicUsize, - session_master_key: ExtendedPrivKey, - session_child_index: AtomicUsize, - channel_id_master_key: ExtendedPrivKey, - channel_id_child_index: AtomicUsize, + rand_bytes_master_key: ExtendedPrivKey, + rand_bytes_child_index: AtomicUsize, seed: [u8; 32], starting_time_secs: u64, @@ -668,7 +675,7 @@ pub struct KeysManager { impl KeysManager { /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg your - /// RNG is busted) this may panic (but more importantly, you will possibly lose funds). + /// CSRNG is busted) this may panic (but more importantly, you will possibly lose funds). /// starting_time isn't strictly required to actually be a time, but it must absolutely, /// without a doubt, be unique to this instance. ie if you start multiple times with the same /// seed, starting_time must be unique to each run. Thus, the easiest way to achieve this is to @@ -705,8 +712,7 @@ impl KeysManager { Err(_) => panic!("Your RNG is busted"), }; let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted"); - let session_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted"); - let channel_id_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted"); + let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted"); KeysManager { secp_ctx, @@ -715,10 +721,8 @@ impl KeysManager { shutdown_pubkey, channel_master_key, channel_child_index: AtomicUsize::new(0), - session_master_key, - session_child_index: AtomicUsize::new(0), - channel_id_master_key, - channel_id_child_index: AtomicUsize::new(0), + rand_bytes_master_key, + rand_bytes_child_index: AtomicUsize::new(0), seed: *seed, starting_time_secs, @@ -805,35 +809,20 @@ impl KeysInterface for KeysManager { self.shutdown_pubkey.clone() } - fn get_channel_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> InMemoryChannelKeys { + fn get_channel_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner { let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel); let ix_and_nanos: u64 = (child_ix as u64) << 32 | (self.starting_time_nanos as u64); self.derive_channel_keys(channel_value_satoshis, ix_and_nanos, self.starting_time_secs) } - fn get_onion_rand(&self) -> (SecretKey, [u8; 32]) { - let mut sha = self.derive_unique_start(); - - let child_ix = self.session_child_index.fetch_add(1, Ordering::AcqRel); - let child_privkey = self.session_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted"); - sha.input(&child_privkey.private_key.key[..]); - - let mut rng_seed = sha.clone(); - // Not exactly the most ideal construction, but the second value will get fed into - // ChaCha so it is another step harder to break. - rng_seed.input(b"RNG Seed Salt"); - sha.input(b"Session Key Salt"); - (SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("Your RNG is busted"), - Sha256::from_engine(rng_seed).into_inner()) - } - - fn get_channel_id(&self) -> [u8; 32] { + fn get_secure_random_bytes(&self) -> [u8; 32] { let mut sha = self.derive_unique_start(); - let child_ix = self.channel_id_child_index.fetch_add(1, Ordering::AcqRel); - let child_privkey = self.channel_id_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted"); + let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel); + let child_privkey = self.rand_bytes_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted"); sha.input(&child_privkey.private_key.key[..]); + sha.input(b"Unique Secure Random Bytes Salt"); Sha256::from_engine(sha).into_inner() } }