Implement EntropySource for InMemorySigner
[rust-lightning] / lightning / src / chain / keysinterface.rs
index a2611e7df87f79fefad954aa3b9133addaeb650e..8d522a3b46dd80a7cfe9e83d9f211480b9d47490 100644 (file)
@@ -33,10 +33,10 @@ 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};
-#[cfg(anchors)]
-use crate::util::events::HTLCDescriptor;
+use crate::util::ser::{Writeable, Writer, Readable, ReadableArgs};
 use crate::chain::transaction::OutPoint;
+#[cfg(anchors)]
+use crate::events::bump_transaction::HTLCDescriptor;
 use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI;
 use crate::ln::{chan_utils, PaymentPreimage};
 use crate::ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction, ClosingTransaction};
@@ -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};
@@ -55,7 +56,7 @@ use crate::util::invoice::construct_invoice_preimage;
 /// Used as initial key material, to be expanded into multiple secret keys (but not to be used
 /// directly). This is used within LDK to encrypt/decrypt inbound payment data.
 ///
-/// (C-not exported) as we just use `[u8; 32]` directly
+/// This is not exported to bindings users as we just use `[u8; 32]` directly
 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
 pub struct KeyMaterial(pub [u8; 32]);
 
@@ -135,7 +136,7 @@ impl_writeable_tlv_based!(StaticPaymentOutputDescriptor, {
 /// outpoint describing which `txid` and output `index` is available, the full output which exists
 /// at that `txid`/`index`, and any keys or other information required to sign.
 ///
-/// [`SpendableOutputs`]: crate::util::events::Event::SpendableOutputs
+/// [`SpendableOutputs`]: crate::events::Event::SpendableOutputs
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum SpendableOutputDescriptor {
        /// An output to a script which was provided via [`SignerProvider`] directly, either from
@@ -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(),
                }
        }
 
@@ -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();
@@ -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(),
                })
        }
 }
@@ -1064,6 +1102,12 @@ impl KeysManager {
                        Err(_) => panic!("Your rng is busted"),
                }
        }
+
+       /// Gets the "node_id" secret key used to sign gossip announcements, decode onion data, etc.
+       pub fn get_node_secret_key(&self) -> SecretKey {
+               self.node_secret
+       }
+
        /// Derive an old [`WriteableEcdsaChannelSigner`] containing per-channel secrets based on a key derivation parameters.
        pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
                let chan_id = u64::from_be_bytes(params[0..8].try_into().unwrap());
@@ -1101,6 +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,
@@ -1112,6 +1157,7 @@ impl KeysManager {
                        commitment_seed,
                        channel_value_satoshis,
                        params.clone(),
+                       prng_seed,
                )
        }
 
@@ -1317,7 +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 {
@@ -1458,6 +1504,17 @@ impl PhantomKeysManager {
        pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemorySigner {
                self.inner.derive_channel_keys(channel_value_satoshis, params)
        }
+
+       /// Gets the "node_id" secret key used to sign gossip announcements, decode onion data, etc.
+       pub fn get_node_secret_key(&self) -> SecretKey {
+               self.inner.get_node_secret_key()
+       }
+
+       /// Gets the "node_id" secret key of the phantom node used to sign invoices, decode the
+       /// last-hop onion data, etc.
+       pub fn get_phantom_node_secret_key(&self) -> SecretKey {
+               self.phantom_secret
+       }
 }
 
 // Ensure that EcdsaChannelSigner can have a vtable