//! Utilities to generate inbound payment information in service of invoice creation.
-use alloc::string::ToString;
use bitcoin::hashes::{Hash, HashEngine};
use bitcoin::hashes::cmp::fixed_time_eq;
use bitcoin::hashes::hmac::{Hmac, HmacEngine};
use bitcoin::hashes::sha256::Hash as Sha256;
-use crate::chain::keysinterface::{KeyMaterial, EntropySource};
+use crate::sign::{KeyMaterial, EntropySource};
use crate::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
use crate::ln::msgs;
use crate::ln::msgs::MAX_VALUE_MSAT;
-use crate::util::chacha20::ChaCha20;
-use crate::util::crypto::hkdf_extract_expand_thrice;
+use crate::crypto::chacha20::ChaCha20;
+use crate::crypto::utils::hkdf_extract_expand_5x;
use crate::util::errors::APIError;
use crate::util::logger::Logger;
-use core::convert::TryInto;
+#[allow(unused_imports)]
+use crate::prelude::*;
+
use core::ops::Deref;
-const IV_LEN: usize = 16;
+pub(crate) const IV_LEN: usize = 16;
const METADATA_LEN: usize = 16;
const METADATA_KEY_LEN: usize = 32;
const AMT_MSAT_LEN: usize = 8;
/// A set of keys that were HKDF-expanded from an initial call to
/// [`NodeSigner::get_inbound_payment_key_material`].
///
-/// [`NodeSigner::get_inbound_payment_key_material`]: crate::chain::keysinterface::NodeSigner::get_inbound_payment_key_material
+/// [`NodeSigner::get_inbound_payment_key_material`]: crate::sign::NodeSigner::get_inbound_payment_key_material
pub struct ExpandedKey {
/// The key used to encrypt the bytes containing the payment metadata (i.e. the amount and
/// expiry, included for payment verification on decryption).
/// The key used to authenticate a user-provided payment hash and metadata as previously
/// registered with LDK.
user_pmt_hash_key: [u8; 32],
+ /// The base key used to derive signing keys and authenticate messages for BOLT 12 Offers.
+ offers_base_key: [u8; 32],
+ /// The key used to encrypt message metadata for BOLT 12 Offers.
+ offers_encryption_key: [u8; 32],
}
impl ExpandedKey {
///
/// It is recommended to cache this value and not regenerate it for each new inbound payment.
pub fn new(key_material: &KeyMaterial) -> ExpandedKey {
- let (metadata_key, ldk_pmt_hash_key, user_pmt_hash_key) =
- hkdf_extract_expand_thrice(b"LDK Inbound Payment Key Expansion", &key_material.0);
+ let (
+ metadata_key,
+ ldk_pmt_hash_key,
+ user_pmt_hash_key,
+ offers_base_key,
+ offers_encryption_key,
+ ) = hkdf_extract_expand_5x(b"LDK Inbound Payment Key Expansion", &key_material.0);
Self {
metadata_key,
ldk_pmt_hash_key,
user_pmt_hash_key,
+ offers_base_key,
+ offers_encryption_key,
+ }
+ }
+
+ /// Returns an [`HmacEngine`] used to construct [`Offer::metadata`].
+ ///
+ /// [`Offer::metadata`]: crate::offers::offer::Offer::metadata
+ pub(crate) fn hmac_for_offer(
+ &self, nonce: Nonce, iv_bytes: &[u8; IV_LEN]
+ ) -> HmacEngine<Sha256> {
+ let mut hmac = HmacEngine::<Sha256>::new(&self.offers_base_key);
+ hmac.input(iv_bytes);
+ hmac.input(&nonce.0);
+ hmac
+ }
+
+ /// Encrypts or decrypts the given `bytes`. Used for data included in an offer message's
+ /// metadata (e.g., payment id).
+ pub(crate) fn crypt_for_offer(&self, mut bytes: [u8; 32], nonce: Nonce) -> [u8; 32] {
+ ChaCha20::encrypt_single_block_in_place(&self.offers_encryption_key, &nonce.0, &mut bytes);
+ bytes
+ }
+}
+
+/// A 128-bit number used only once.
+///
+/// Needed when constructing [`Offer::metadata`] and deriving [`Offer::signing_pubkey`] from
+/// [`ExpandedKey`]. Must not be reused for any other derivation without first hashing.
+///
+/// [`Offer::metadata`]: crate::offers::offer::Offer::metadata
+/// [`Offer::signing_pubkey`]: crate::offers::offer::Offer::signing_pubkey
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub(crate) struct Nonce(pub(crate) [u8; Self::LENGTH]);
+
+impl Nonce {
+ /// Number of bytes in the nonce.
+ pub const LENGTH: usize = 16;
+
+ /// Creates a `Nonce` from the given [`EntropySource`].
+ pub fn from_entropy_source<ES: Deref>(entropy_source: ES) -> Self
+ where
+ ES::Target: EntropySource,
+ {
+ let mut bytes = [0u8; Self::LENGTH];
+ let rand_bytes = entropy_source.get_secure_random_bytes();
+ bytes.copy_from_slice(&rand_bytes[..Self::LENGTH]);
+
+ Nonce(bytes)
+ }
+
+ /// Returns a slice of the underlying bytes of size [`Nonce::LENGTH`].
+ pub fn as_slice(&self) -> &[u8] {
+ &self.0
+ }
+}
+
+impl TryFrom<&[u8]> for Nonce {
+ type Error = ();
+
+ fn try_from(bytes: &[u8]) -> Result<Self, ()> {
+ if bytes.len() != Self::LENGTH {
+ return Err(());
}
+
+ let mut copied_bytes = [0u8; Self::LENGTH];
+ copied_bytes.copy_from_slice(bytes);
+
+ Ok(Self(copied_bytes))
}
}
/// Note that if `min_final_cltv_expiry_delta` is set to some value, then the payment will not be receivable
/// on versions of LDK prior to 0.0.114.
///
-/// [phantom node payments]: crate::chain::keysinterface::PhantomKeysManager
-/// [`NodeSigner::get_inbound_payment_key_material`]: crate::chain::keysinterface::NodeSigner::get_inbound_payment_key_material
+/// [phantom node payments]: crate::sign::PhantomKeysManager
+/// [`NodeSigner::get_inbound_payment_key_material`]: crate::sign::NodeSigner::get_inbound_payment_key_material
pub fn create<ES: Deref>(keys: &ExpandedKey, min_value_msat: Option<u64>,
invoice_expiry_delta_secs: u32, entropy_source: &ES, current_time: u64,
min_final_cltv_expiry_delta: Option<u16>) -> Result<(PaymentHash, PaymentSecret), ()>
let mut hmac = HmacEngine::<Sha256>::new(&keys.ldk_pmt_hash_key);
hmac.input(&iv_bytes);
hmac.input(&metadata_bytes);
- let payment_preimage_bytes = Hmac::from_engine(hmac).into_inner();
+ let payment_preimage_bytes = Hmac::from_engine(hmac).to_byte_array();
- let ldk_pmt_hash = PaymentHash(Sha256::hash(&payment_preimage_bytes).into_inner());
+ let ldk_pmt_hash = PaymentHash(Sha256::hash(&payment_preimage_bytes).to_byte_array());
let payment_secret = construct_payment_secret(&iv_bytes, &metadata_bytes, &keys.metadata_key);
Ok((ldk_pmt_hash, payment_secret))
}
/// Note that if `min_final_cltv_expiry_delta` is set to some value, then the payment will not be receivable
/// on versions of LDK prior to 0.0.114.
///
-/// [phantom node payments]: crate::chain::keysinterface::PhantomKeysManager
+/// [phantom node payments]: crate::sign::PhantomKeysManager
pub fn create_from_hash(keys: &ExpandedKey, min_value_msat: Option<u64>, payment_hash: PaymentHash,
invoice_expiry_delta_secs: u32, current_time: u64, min_final_cltv_expiry_delta: Option<u16>) -> Result<PaymentSecret, ()> {
let metadata_bytes = construct_metadata_bytes(min_value_msat, if min_final_cltv_expiry_delta.is_some() {
let mut hmac = HmacEngine::<Sha256>::new(&keys.user_pmt_hash_key);
hmac.input(&metadata_bytes);
hmac.input(&payment_hash.0);
- let hmac_bytes = Hmac::from_engine(hmac).into_inner();
+ let hmac_bytes = Hmac::from_engine(hmac).to_byte_array();
let mut iv_bytes = [0 as u8; IV_LEN];
iv_bytes.copy_from_slice(&hmac_bytes[..IV_LEN]);
let (iv_slice, encrypted_metadata_slice) = payment_secret_bytes.split_at_mut(IV_LEN);
iv_slice.copy_from_slice(iv_bytes);
- let chacha_block = ChaCha20::get_single_block(metadata_key, iv_bytes);
- for i in 0..METADATA_LEN {
- encrypted_metadata_slice[i] = chacha_block[i] ^ metadata_bytes[i];
- }
+ ChaCha20::encrypt_single_block(
+ metadata_key, iv_bytes, encrypted_metadata_slice, metadata_bytes
+ );
PaymentSecret(payment_secret_bytes)
}
///
/// See [`ExpandedKey`] docs for more info on the individual keys used.
///
-/// [`NodeSigner::get_inbound_payment_key_material`]: crate::chain::keysinterface::NodeSigner::get_inbound_payment_key_material
+/// [`NodeSigner::get_inbound_payment_key_material`]: crate::sign::NodeSigner::get_inbound_payment_key_material
/// [`create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
/// [`create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
pub(super) fn verify<L: Deref>(payment_hash: PaymentHash, payment_data: &msgs::FinalOnionHopData,
let mut hmac = HmacEngine::<Sha256>::new(&keys.user_pmt_hash_key);
hmac.input(&metadata_bytes[..]);
hmac.input(&payment_hash.0);
- if !fixed_time_eq(&iv_bytes, &Hmac::from_engine(hmac).into_inner().split_at_mut(IV_LEN).0) {
- log_trace!(logger, "Failing HTLC with user-generated payment_hash {}: unexpected payment_secret", log_bytes!(payment_hash.0));
+ if !fixed_time_eq(&iv_bytes, &Hmac::from_engine(hmac).to_byte_array().split_at_mut(IV_LEN).0) {
+ log_trace!(logger, "Failing HTLC with user-generated payment_hash {}: unexpected payment_secret", &payment_hash);
return Err(())
}
},
match derive_ldk_payment_preimage(payment_hash, &iv_bytes, &metadata_bytes, keys) {
Ok(preimage) => payment_preimage = Some(preimage),
Err(bad_preimage_bytes) => {
- log_trace!(logger, "Failing HTLC with payment_hash {} due to mismatching preimage {}", log_bytes!(payment_hash.0), log_bytes!(bad_preimage_bytes));
+ log_trace!(logger, "Failing HTLC with payment_hash {} due to mismatching preimage {}", &payment_hash, log_bytes!(bad_preimage_bytes));
return Err(())
}
}
},
Err(unknown_bits) => {
- log_trace!(logger, "Failing HTLC with payment hash {} due to unknown payment type {}", log_bytes!(payment_hash.0), unknown_bits);
+ log_trace!(logger, "Failing HTLC with payment hash {} due to unknown payment type {}", &payment_hash, unknown_bits);
return Err(());
}
}
let expiry = u64::from_be_bytes(expiry_bytes.try_into().unwrap());
if payment_data.total_msat < min_amt_msat {
- log_trace!(logger, "Failing HTLC with payment_hash {} due to total_msat {} being less than the minimum amount of {} msat", log_bytes!(payment_hash.0), payment_data.total_msat, min_amt_msat);
+ log_trace!(logger, "Failing HTLC with payment_hash {} due to total_msat {} being less than the minimum amount of {} msat", &payment_hash, payment_data.total_msat, min_amt_msat);
return Err(())
}
if expiry < highest_seen_timestamp {
- log_trace!(logger, "Failing HTLC with payment_hash {}: expired payment", log_bytes!(payment_hash.0));
+ log_trace!(logger, "Failing HTLC with payment_hash {}: expired payment", &payment_hash);
return Err(())
}
Ok(Method::LdkPaymentHash) | Ok(Method::LdkPaymentHashCustomFinalCltv) => {
derive_ldk_payment_preimage(payment_hash, &iv_bytes, &metadata_bytes, keys)
.map_err(|bad_preimage_bytes| APIError::APIMisuseError {
- err: format!("Payment hash {} did not match decoded preimage {}", log_bytes!(payment_hash.0), log_bytes!(bad_preimage_bytes))
+ err: format!("Payment hash {} did not match decoded preimage {}", &payment_hash, log_bytes!(bad_preimage_bytes))
})
},
Ok(Method::UserPaymentHash) | Ok(Method::UserPaymentHashCustomFinalCltv) => Err(APIError::APIMisuseError {
let (iv_slice, encrypted_metadata_bytes) = payment_secret.0.split_at(IV_LEN);
iv_bytes.copy_from_slice(iv_slice);
- let chacha_block = ChaCha20::get_single_block(&keys.metadata_key, &iv_bytes);
let mut metadata_bytes: [u8; METADATA_LEN] = [0; METADATA_LEN];
- for i in 0..METADATA_LEN {
- metadata_bytes[i] = chacha_block[i] ^ encrypted_metadata_bytes[i];
- }
+ ChaCha20::encrypt_single_block(
+ &keys.metadata_key, &iv_bytes, &mut metadata_bytes, encrypted_metadata_bytes
+ );
(iv_bytes, metadata_bytes)
}
let mut hmac = HmacEngine::<Sha256>::new(&keys.ldk_pmt_hash_key);
hmac.input(iv_bytes);
hmac.input(metadata_bytes);
- let decoded_payment_preimage = Hmac::from_engine(hmac).into_inner();
- if !fixed_time_eq(&payment_hash.0, &Sha256::hash(&decoded_payment_preimage).into_inner()) {
+ let decoded_payment_preimage = Hmac::from_engine(hmac).to_byte_array();
+ if !fixed_time_eq(&payment_hash.0, &Sha256::hash(&decoded_payment_preimage).to_byte_array()) {
return Err(decoded_payment_preimage);
}
return Ok(PaymentPreimage(decoded_payment_preimage))