/// [`KeysInterface::get_inbound_payment_key_material`].
///
/// [`KeysInterface::get_inbound_payment_key_material`]: crate::chain::keysinterface::KeysInterface::get_inbound_payment_key_material
-pub(super) struct ExpandedKey {
+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).
metadata_key: [u8; 32],
}
impl ExpandedKey {
- pub(super) fn new(key_material: &KeyMaterial) -> ExpandedKey {
+ /// Create a new [`ExpandedKey`] for generating an inbound payment hash and secret.
+ ///
+ /// 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);
Self {
}
}
-pub(super) fn create<Signer: Sign, K: Deref>(keys: &ExpandedKey, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32, keys_manager: &K, highest_seen_timestamp: u64) -> Result<(PaymentHash, PaymentSecret), ()>
+/// Equivalent to [`crate::ln::channelmanager::ChannelManager::create_inbound_payment`], but no
+/// `ChannelManager` is required. Useful for generating invoices for [phantom node payments] without
+/// a `ChannelManager`.
+///
+/// `keys` is generated by calling [`KeysInterface::get_inbound_payment_key_material`] and then
+/// calling [`ExpandedKey::new`] with its result. It is recommended to cache this value and not
+/// regenerate it for each new inbound payment.
+///
+/// `current_time` is a Unix timestamp representing the current time.
+///
+/// [phantom node payments]: crate::chain::keysinterface::PhantomKeysManager
+pub fn create<Signer: Sign, K: Deref>(keys: &ExpandedKey, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32, keys_manager: &K, current_time: u64) -> Result<(PaymentHash, PaymentSecret), ()>
where K::Target: KeysInterface<Signer = Signer>
{
- let metadata_bytes = construct_metadata_bytes(min_value_msat, Method::LdkPaymentHash, invoice_expiry_delta_secs, highest_seen_timestamp)?;
+ let metadata_bytes = construct_metadata_bytes(min_value_msat, Method::LdkPaymentHash, invoice_expiry_delta_secs, current_time)?;
let mut iv_bytes = [0 as u8; IV_LEN];
let rand_bytes = keys_manager.get_secure_random_bytes();
Ok((ldk_pmt_hash, payment_secret))
}
-pub(super) fn create_from_hash(keys: &ExpandedKey, min_value_msat: Option<u64>, payment_hash: PaymentHash, invoice_expiry_delta_secs: u32, highest_seen_timestamp: u64) -> Result<PaymentSecret, ()> {
- let metadata_bytes = construct_metadata_bytes(min_value_msat, Method::UserPaymentHash, invoice_expiry_delta_secs, highest_seen_timestamp)?;
+/// Equivalent to [`crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash`],
+/// but no `ChannelManager` is required. Useful for generating invoices for [phantom node payments]
+/// without a `ChannelManager`.
+///
+/// See [`create`] for information on the `keys` and `current_time` parameters.
+///
+/// [phantom node payments]: crate::chain::keysinterface::PhantomKeysManager
+pub fn create_from_hash(keys: &ExpandedKey, min_value_msat: Option<u64>, payment_hash: PaymentHash, invoice_expiry_delta_secs: u32, current_time: u64) -> Result<PaymentSecret, ()> {
+ let metadata_bytes = construct_metadata_bytes(min_value_msat, Method::UserPaymentHash, invoice_expiry_delta_secs, current_time)?;
let mut hmac = HmacEngine::<Sha256>::new(&keys.user_pmt_hash_key);
hmac.input(&metadata_bytes);
/// [`KeysInterface::get_inbound_payment_key_material`]: crate::chain::keysinterface::KeysInterface::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, highest_seen_timestamp: u64, keys: &ExpandedKey, logger: &L) -> Result<Option<PaymentPreimage>, ()>
+pub(super) fn verify<L: Deref>(payment_hash: PaymentHash, payment_data: &msgs::FinalOnionHopData, highest_seen_timestamp: u64, keys: &ExpandedKey, logger: &L) -> Result<Option<PaymentPreimage>, ()>
where L::Target: Logger
{
let (iv_bytes, metadata_bytes) = decrypt_metadata(payment_data.payment_secret, keys);