Merge pull request #2205 from wpaulino/sign-ecdsa-with-noncedata
[rust-lightning] / lightning / src / chain / keysinterface.rs
index 4ad15db876bb4cad83106c89ba7ba835409b1544..b1290708b95f70a71ebf6193cceb1677aa3150bd 100644 (file)
@@ -32,8 +32,8 @@ use bitcoin::secp256k1::ecdsa::RecoverableSignature;
 use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness};
 
 use crate::util::transaction_utils;
-use crate::util::crypto::{hkdf_extract_expand_twice, sign};
-use crate::util::ser::{Writeable, Writer, Readable};
+use crate::util::crypto::{hkdf_extract_expand_twice, sign, sign_with_aux_rand};
+use crate::util::ser::{Writeable, Writer, Readable, ReadableArgs};
 use crate::chain::transaction::OutPoint;
 #[cfg(anchors)]
 use crate::events::bump_transaction::HTLCDescriptor;
@@ -45,6 +45,7 @@ use crate::ln::script::ShutdownScript;
 
 use crate::prelude::*;
 use core::convert::TryInto;
+use core::ops::Deref;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use crate::io::{self, Error};
 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
@@ -553,7 +554,6 @@ pub trait SignerProvider {
        fn get_shutdown_scriptpubkey(&self) -> ShutdownScript;
 }
 
-#[derive(Clone)]
 /// A simple implementation of [`WriteableEcdsaChannelSigner`] that just keeps the private keys in memory.
 ///
 /// This implementation performs no policy checks and is insufficient by itself as
@@ -580,6 +580,30 @@ pub struct InMemorySigner {
        channel_value_satoshis: u64,
        /// Key derivation parameters.
        channel_keys_id: [u8; 32],
+       /// Seed from which all randomness produced is derived from.
+       rand_bytes_unique_start: [u8; 32],
+       /// Tracks the number of times we've produced randomness to ensure we don't return the same
+       /// bytes twice.
+       rand_bytes_index: AtomicCounter,
+}
+
+impl Clone for InMemorySigner {
+       fn clone(&self) -> Self {
+               Self {
+                       funding_key: self.funding_key.clone(),
+                       revocation_base_key: self.revocation_base_key.clone(),
+                       payment_key: self.payment_key.clone(),
+                       delayed_payment_base_key: self.delayed_payment_base_key.clone(),
+                       htlc_base_key: self.htlc_base_key.clone(),
+                       commitment_seed: self.commitment_seed.clone(),
+                       holder_channel_pubkeys: self.holder_channel_pubkeys.clone(),
+                       channel_parameters: self.channel_parameters.clone(),
+                       channel_value_satoshis: self.channel_value_satoshis,
+                       channel_keys_id: self.channel_keys_id,
+                       rand_bytes_unique_start: self.get_secure_random_bytes(),
+                       rand_bytes_index: AtomicCounter::new(),
+               }
+       }
 }
 
 impl InMemorySigner {
@@ -594,6 +618,7 @@ impl InMemorySigner {
                commitment_seed: [u8; 32],
                channel_value_satoshis: u64,
                channel_keys_id: [u8; 32],
+               rand_bytes_unique_start: [u8; 32],
        ) -> InMemorySigner {
                let holder_channel_pubkeys =
                        InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
@@ -610,6 +635,8 @@ impl InMemorySigner {
                        holder_channel_pubkeys,
                        channel_parameters: None,
                        channel_keys_id,
+                       rand_bytes_unique_start,
+                       rand_bytes_index: AtomicCounter::new(),
                }
        }
 
@@ -686,7 +713,7 @@ impl InMemorySigner {
                let remotepubkey = self.pubkeys().payment_point;
                let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, inner: remotepubkey}, Network::Testnet).script_pubkey();
                let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
-               let remotesig = sign(secp_ctx, &sighash, &self.payment_key);
+               let remotesig = sign_with_aux_rand(secp_ctx, &sighash, &self.payment_key, &self);
                let payment_script = bitcoin::Address::p2wpkh(&::bitcoin::PublicKey{compressed: true, inner: remotepubkey}, Network::Bitcoin).unwrap().script_pubkey();
 
                if payment_script != descriptor.output.script_pubkey { return Err(()); }
@@ -722,7 +749,7 @@ impl InMemorySigner {
                let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
                let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
                let sighash = hash_to_message!(&sighash::SighashCache::new(spend_tx).segwit_signature_hash(input_idx, &witness_script, descriptor.output.value, EcdsaSighashType::All).unwrap()[..]);
-               let local_delayedsig = sign(secp_ctx, &sighash, &delayed_payment_key);
+               let local_delayedsig = sign_with_aux_rand(secp_ctx, &sighash, &delayed_payment_key, &self);
                let payment_script = bitcoin::Address::p2wsh(&witness_script, Network::Bitcoin).script_pubkey();
 
                if descriptor.output.script_pubkey != payment_script { return Err(()); }
@@ -736,6 +763,15 @@ impl InMemorySigner {
        }
 }
 
+impl EntropySource for InMemorySigner {
+       fn get_secure_random_bytes(&self) -> [u8; 32] {
+               let index = self.rand_bytes_index.get_increment();
+               let mut nonce = [0u8; 16];
+               nonce[..8].copy_from_slice(&index.to_be_bytes());
+               ChaCha20::get_single_block(&self.rand_bytes_unique_start, &nonce)
+       }
+}
+
 impl ChannelSigner for InMemorySigner {
        fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
                let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
@@ -774,7 +810,7 @@ impl EcdsaChannelSigner for InMemorySigner {
                let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
 
                let built_tx = trusted_tx.built_transaction();
-               let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
+               let commitment_sig = built_tx.sign_counterparty_commitment(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx);
                let commitment_txid = built_tx.txid;
 
                let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len());
@@ -799,9 +835,9 @@ impl EcdsaChannelSigner for InMemorySigner {
                let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
                let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
                let trusted_tx = commitment_tx.trust();
-               let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
+               let sig = trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx);
                let channel_parameters = self.get_channel_parameters();
-               let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
+               let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), &self, secp_ctx)?;
                Ok((sig, htlc_sigs))
        }
 
@@ -810,9 +846,9 @@ impl EcdsaChannelSigner for InMemorySigner {
                let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
                let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
                let trusted_tx = commitment_tx.trust();
-               let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
+               let sig = trusted_tx.built_transaction().sign_holder_commitment(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, &self, secp_ctx);
                let channel_parameters = self.get_channel_parameters();
-               let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?;
+               let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), &self, secp_ctx)?;
                Ok((sig, htlc_sigs))
        }
 
@@ -826,7 +862,7 @@ impl EcdsaChannelSigner for InMemorySigner {
                };
                let mut sighash_parts = sighash::SighashCache::new(justice_tx);
                let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
-               return Ok(sign(secp_ctx, &sighash, &revocation_key))
+               return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self))
        }
 
        fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
@@ -840,7 +876,7 @@ impl EcdsaChannelSigner for InMemorySigner {
                };
                let mut sighash_parts = sighash::SighashCache::new(justice_tx);
                let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
-               return Ok(sign(secp_ctx, &sighash, &revocation_key))
+               return Ok(sign_with_aux_rand(secp_ctx, &sighash, &revocation_key, &self))
        }
 
        #[cfg(anchors)]
@@ -858,7 +894,7 @@ impl EcdsaChannelSigner for InMemorySigner {
                let our_htlc_private_key = chan_utils::derive_private_key(
                        &secp_ctx, &per_commitment_point, &self.htlc_base_key
                );
-               Ok(sign(&secp_ctx, &hash_to_message!(sighash), &our_htlc_private_key))
+               Ok(sign_with_aux_rand(&secp_ctx, &hash_to_message!(sighash), &our_htlc_private_key, &self))
        }
 
        fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
@@ -869,7 +905,7 @@ impl EcdsaChannelSigner for InMemorySigner {
                let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, self.opt_anchors(), &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey);
                let mut sighash_parts = sighash::SighashCache::new(htlc_tx);
                let sighash = hash_to_message!(&sighash_parts.segwit_signature_hash(input, &witness_script, amount, EcdsaSighashType::All).unwrap()[..]);
-               Ok(sign(secp_ctx, &sighash, &htlc_key))
+               Ok(sign_with_aux_rand(secp_ctx, &sighash, &htlc_key, &self))
        }
 
        fn sign_closing_transaction(&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
@@ -885,14 +921,14 @@ impl EcdsaChannelSigner for InMemorySigner {
                let sighash = sighash::SighashCache::new(&*anchor_tx).segwit_signature_hash(
                        input, &witness_script, ANCHOR_OUTPUT_VALUE_SATOSHI, EcdsaSighashType::All,
                ).unwrap();
-               Ok(sign(secp_ctx, &hash_to_message!(&sighash[..]), &self.funding_key))
+               Ok(sign_with_aux_rand(secp_ctx, &hash_to_message!(&sighash[..]), &self.funding_key, &self))
        }
 
        fn sign_channel_announcement_with_funding_key(
                &self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>
        ) -> Result<Signature, ()> {
                let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
-               Ok(sign(secp_ctx, &msghash, &self.funding_key))
+               Ok(secp_ctx.sign_ecdsa(&msghash, &self.funding_key))
        }
 }
 
@@ -922,8 +958,8 @@ impl Writeable for InMemorySigner {
        }
 }
 
-impl Readable for InMemorySigner {
-       fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+impl<ES: Deref> ReadableArgs<ES> for InMemorySigner where ES::Target: EntropySource {
+       fn read<R: io::Read>(reader: &mut R, entropy_source: ES) -> Result<Self, DecodeError> {
                let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
 
                let funding_key = Readable::read(reader)?;
@@ -953,6 +989,8 @@ impl Readable for InMemorySigner {
                        holder_channel_pubkeys,
                        channel_parameters: counterparty_channel_data,
                        channel_keys_id: keys_id,
+                       rand_bytes_unique_start: entropy_source.get_secure_random_bytes(),
+                       rand_bytes_index: AtomicCounter::new(),
                })
        }
 }
@@ -1107,6 +1145,7 @@ impl KeysManager {
                let payment_key = key_step!(b"payment key", revocation_base_key);
                let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key);
                let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key);
+               let prng_seed = self.get_secure_random_bytes();
 
                InMemorySigner::new(
                        &self.secp_ctx,
@@ -1118,6 +1157,7 @@ impl KeysManager {
                        commitment_seed,
                        channel_value_satoshis,
                        params.clone(),
+                       prng_seed,
                )
        }
 
@@ -1233,7 +1273,7 @@ impl KeysManager {
                                        if payment_script != output.script_pubkey { return Err(()); };
 
                                        let sighash = hash_to_message!(&sighash::SighashCache::new(&spend_tx).segwit_signature_hash(input_idx, &witness_script, output.value, EcdsaSighashType::All).unwrap()[..]);
-                                       let sig = sign(secp_ctx, &sighash, &secret.private_key);
+                                       let sig = sign_with_aux_rand(secp_ctx, &sighash, &secret.private_key, &self);
                                        let mut sig_ser = sig.serialize_der().to_vec();
                                        sig_ser.push(EcdsaSighashType::All as u8);
                                        spend_tx.input[input_idx].witness.push(sig_ser);
@@ -1295,7 +1335,7 @@ impl NodeSigner for KeysManager {
 
        fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()> {
                let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
-               Ok(sign(&self.secp_ctx, &msg_hash, &self.node_secret))
+               Ok(self.secp_ctx.sign_ecdsa(&msg_hash, &self.node_secret))
        }
 }
 
@@ -1323,7 +1363,7 @@ impl SignerProvider for KeysManager {
        }
 
        fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::Signer, DecodeError> {
-               InMemorySigner::read(&mut io::Cursor::new(reader))
+               InMemorySigner::read(&mut io::Cursor::new(reader), self)
        }
 
        fn get_destination_script(&self) -> Script {