X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=src%2Fchain%2Fkeysinterface.rs;h=4e35e6764d246ced9b431ad473bfe84bf13ecb7f;hb=7e59e1e3927f3baf586bc393bdd519449eaed08b;hp=84ebde34252c95a530c4c0bb6c5f6ef63d9f64ac;hpb=32a937890956a459c499e76767671050b357f29a;p=rust-lightning diff --git a/src/chain/keysinterface.rs b/src/chain/keysinterface.rs index 84ebde34..4e35e676 100644 --- a/src/chain/keysinterface.rs +++ b/src/chain/keysinterface.rs @@ -14,11 +14,16 @@ use secp256k1::Secp256k1; use secp256k1; use crypto::hkdf::{hkdf_extract,hkdf_expand}; +use crypto::digest::Digest; use util::sha2::Sha256; use util::logger::Logger; +use util::rng; +use util::byte_utils; +use std::time::{SystemTime, UNIX_EPOCH}; use std::sync::Arc; +use std::sync::atomic::{AtomicUsize, Ordering}; /// When on-chain outputs are created by rust-lightning an event is generated which informs the /// user thereof. This enum describes the format of the output and provides the OutPoint. @@ -32,19 +37,34 @@ pub enum SpendableOutputDescriptor { /// The output which is referenced by the given outpoint output: TxOut, }, - /// Outpoint commits to a P2WSH, should be spend by the following witness : + /// Outpoint commits to a P2WSH + /// P2WSH should be spend by the following witness : /// 0 /// With input nSequence set to_self_delay. - /// Outputs from a HTLC-Success/Timeout tx - DynamicOutput { + /// Outputs from a HTLC-Success/Timeout tx/commitment tx + DynamicOutputP2WSH { /// Outpoint spendable by user wallet outpoint: OutPoint, - /// local_delayedkey = delayed_payment_basepoint_secret + SHA256(per_commitment_point || delayed_payment_basepoint - local_delayedkey: SecretKey, - /// witness redeemScript encumbering output + /// local_delayedkey = delayed_payment_basepoint_secret + SHA256(per_commitment_point || delayed_payment_basepoint) OR + key: SecretKey, + /// witness redeemScript encumbering output. witness_script: Script, /// nSequence input must commit to self_delay to satisfy script's OP_CSV to_self_delay: u16, + /// The output which is referenced by the given outpoint + output: TxOut, + }, + /// Outpoint commits to a P2WPKH + /// P2WPKH should be spend by the following witness : + /// + /// Outputs to_remote from a commitment tx + DynamicOutputP2WPKH { + /// Outpoint spendable by user wallet + outpoint: OutPoint, + /// localkey = payment_basepoint_secret + SHA256(per_commitment_point || payment_basepoint + key: SecretKey, + /// The output which is reference by the given outpoint + output: TxOut, } } @@ -59,6 +79,8 @@ 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) -> ChannelKeys; + /// Get a secret for construting an onion packet + fn get_session_key(&self) -> SecretKey; } /// Set of lightning keys needed to operate a channel as described in BOLT 3 @@ -74,12 +96,19 @@ pub struct ChannelKeys { pub delayed_payment_base_key: SecretKey, /// Local htlc secret key used in commitment tx htlc outputs pub htlc_base_key: SecretKey, - /// Local secret key used in justice tx, claim tx and preimage tx outputs - pub channel_monitor_claim_key: SecretKey, /// Commitment seed pub commitment_seed: [u8; 32], } +impl_writeable!(ChannelKeys, 0, { + funding_key, + revocation_base_key, + payment_base_key, + delayed_payment_base_key, + htlc_base_key, + commitment_seed +}); + impl ChannelKeys { /// Generate a set of lightning keys needed to operate a channel by HKDF-expanding a given /// random 32-byte seed @@ -104,9 +133,6 @@ impl ChannelKeys { hkdf_expand(Sha256::new(), &prk, b"rust-lightning htlc base key info", &mut okm); let htlc_base_key = SecretKey::from_slice(&secp_ctx, &okm).expect("Sha256 is broken"); - hkdf_expand(Sha256::new(), &prk, b"rust-lightning channel monitor claim key info", &mut okm); - let channel_monitor_claim_key = SecretKey::from_slice(&secp_ctx, &okm).expect("Sha256 is broken"); - hkdf_expand(Sha256::new(), &prk, b"rust-lightning local commitment seed info", &mut okm); ChannelKeys { @@ -115,7 +141,6 @@ impl ChannelKeys { payment_base_key: payment_base_key, delayed_payment_base_key: delayed_payment_base_key, htlc_base_key: htlc_base_key, - channel_monitor_claim_key: channel_monitor_claim_key, commitment_seed: okm } } @@ -134,6 +159,9 @@ pub struct KeysManager { destination_script: Script, shutdown_pubkey: PublicKey, channel_master_key: ExtendedPrivKey, + channel_child_index: AtomicUsize, + session_master_key: ExtendedPrivKey, + session_child_index: AtomicUsize, logger: Arc, } @@ -160,12 +188,16 @@ impl KeysManager { Err(_) => panic!("Your RNG is busted"), }; let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3)).expect("Your RNG is busted"); + let session_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4)).expect("Your RNG is busted"); KeysManager { secp_ctx, node_secret, destination_script, shutdown_pubkey, channel_master_key, + channel_child_index: AtomicUsize::new(0), + session_master_key, + session_child_index: AtomicUsize::new(0), logger, } @@ -189,11 +221,40 @@ impl KeysInterface for KeysManager { } fn get_channel_keys(&self, _inbound: bool) -> ChannelKeys { - let channel_pubkey = ExtendedPubKey::from_private(&self.secp_ctx, &self. channel_master_key); - let mut seed = [0; 32]; - for (arr, slice) in seed.iter_mut().zip((&channel_pubkey.public_key.serialize()[0..32]).iter()) { - *arr = *slice; - } + // We only seriously intend to rely on the channel_master_key for true secure + // entropy, everything else just ensures uniqueness. We generally don't expect + // all clients to have non-broken RNGs here, so we also include the current + // time as a fallback to get uniqueness. + let mut sha = Sha256::new(); + + let mut seed = [0u8; 32]; + rng::fill_bytes(&mut seed[..]); + sha.input(&seed); + + let now = SystemTime::now().duration_since(UNIX_EPOCH).expect("Time went backwards"); + sha.input(&byte_utils::be32_to_array(now.subsec_nanos())); + sha.input(&byte_utils::be64_to_array(now.as_secs())); + + let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel); + let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32)).expect("Your RNG is busted"); + sha.input(&child_privkey.secret_key[..]); + + sha.result(&mut seed); ChannelKeys::new_from_seed(&seed) } + + fn get_session_key(&self) -> SecretKey { + let mut sha = Sha256::new(); + let mut res = [0u8; 32]; + + let now = SystemTime::now().duration_since(UNIX_EPOCH).expect("Time went backwards"); + sha.input(&byte_utils::be32_to_array(now.subsec_nanos())); + sha.input(&byte_utils::be64_to_array(now.as_secs())); + + 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("Your RNG is busted"); + sha.input(&child_privkey.secret_key[..]); + sha.result(&mut res); + SecretKey::from_slice(&self.secp_ctx, &res).expect("Your RNG is busted") + } }