fix using same seed sequence for channel key geneartion

Author: yuntai

src/chain/keysinterface.rs

@@ -6,7 +6,7 @@ use bitcoin::blockdata::transaction::{OutPoint, TxOut};
 use bitcoin::blockdata::script::{Script, Builder};
 use bitcoin::blockdata::opcodes;
 use bitcoin::network::constants::Network;
-use bitcoin::util::hash::Hash160;
+use bitcoin::util::hash::{Hash160,Sha256dHash};
 use bitcoin::util::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber};
 
 use secp256k1::key::{SecretKey, PublicKey};
@@ -17,7 +17,10 @@ use crypto::hkdf::{hkdf_extract,hkdf_expand};
 
 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};
 
@@ -195,11 +198,16 @@ impl KeysInterface for KeysManager {
 	}
 
 	fn get_channel_keys(&self, _inbound: bool) -> ChannelKeys {
+		let mut seed = [0u8; 32 + 4 + 8 + 33];
+		rng::fill_bytes(&mut seed[..32]);
+		let now = SystemTime::now().duration_since(UNIX_EPOCH).expect("Time went backwards");
+		seed[32..32+4].copy_from_slice(&byte_utils::be32_to_array(now.subsec_micros()));
+		seed[32+4..32+4+8].copy_from_slice(&byte_utils::be64_to_array(now.as_secs()));
+
 		let child_ix = self.channel_child_index.fetch_add(1, Ordering::SeqCst);
 		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");
 		let child_pubkey = ExtendedPubKey::from_private(&self.secp_ctx, &child_privkey);
-		let mut seed = [0u8; 32];
-		seed.copy_from_slice(&child_pubkey.public_key.serialize()[1..33]);
-		ChannelKeys::new_from_seed(&seed)
+		seed[32+4+8..].copy_from_slice(&child_pubkey.public_key.serialize());
+		ChannelKeys::new_from_seed(&Sha256dHash::from_data(&seed).as_bytes())
 	}
 }