Support setting the new payment metadata field in invoices
[rust-lightning] / lightning-invoice / src / lib.rs
index e0ba4dda398732d80995e416a40654e9ab89f531..8177e835a1e86d13f1129f142f7a401c1d2dddac 100644 (file)
@@ -218,10 +218,13 @@ pub const DEFAULT_MIN_FINAL_CLTV_EXPIRY_DELTA: u64 = 18;
 ///  * `D`: exactly one [`TaggedField::Description`] or [`TaggedField::DescriptionHash`]
 ///  * `H`: exactly one [`TaggedField::PaymentHash`]
 ///  * `T`: the timestamp is set
+///  * `C`: the CLTV expiry is set
+///  * `S`: the payment secret is set
+///  * `M`: payment metadata is set
 ///
 /// This is not exported to bindings users as we likely need to manually select one set of boolean type parameters.
 #[derive(Eq, PartialEq, Debug, Clone)]
-pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> {
+pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool, M: tb::Bool> {
        currency: Currency,
        amount: Option<u64>,
        si_prefix: Option<SiPrefix>,
@@ -234,6 +237,7 @@ pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S:
        phantom_t: core::marker::PhantomData<T>,
        phantom_c: core::marker::PhantomData<C>,
        phantom_s: core::marker::PhantomData<S>,
+       phantom_m: core::marker::PhantomData<M>,
 }
 
 /// Represents a syntactically and semantically correct lightning BOLT11 invoice.
@@ -488,7 +492,7 @@ pub mod constants {
        pub const TAG_FEATURES: u8 = 5;
 }
 
-impl InvoiceBuilder<tb::False, tb::False, tb::False, tb::False, tb::False> {
+impl InvoiceBuilder<tb::False, tb::False, tb::False, tb::False, tb::False, tb::False> {
        /// Construct new, empty `InvoiceBuilder`. All necessary fields have to be filled first before
        /// `InvoiceBuilder::build(self)` becomes available.
        pub fn new(currrency: Currency) -> Self {
@@ -505,14 +509,15 @@ impl InvoiceBuilder<tb::False, tb::False, tb::False, tb::False, tb::False> {
                        phantom_t: core::marker::PhantomData,
                        phantom_c: core::marker::PhantomData,
                        phantom_s: core::marker::PhantomData,
+                       phantom_m: core::marker::PhantomData,
                }
        }
 }
 
-impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, C, S> {
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool, M: tb::Bool> InvoiceBuilder<D, H, T, C, S, M> {
        /// Helper function to set the completeness flags.
-       fn set_flags<DN: tb::Bool, HN: tb::Bool, TN: tb::Bool, CN: tb::Bool, SN: tb::Bool>(self) -> InvoiceBuilder<DN, HN, TN, CN, SN> {
-               InvoiceBuilder::<DN, HN, TN, CN, SN> {
+       fn set_flags<DN: tb::Bool, HN: tb::Bool, TN: tb::Bool, CN: tb::Bool, SN: tb::Bool, MN: tb::Bool>(self) -> InvoiceBuilder<DN, HN, TN, CN, SN, MN> {
+               InvoiceBuilder::<DN, HN, TN, CN, SN, MN> {
                        currency: self.currency,
                        amount: self.amount,
                        si_prefix: self.si_prefix,
@@ -525,6 +530,7 @@ impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBui
                        phantom_t: core::marker::PhantomData,
                        phantom_c: core::marker::PhantomData,
                        phantom_s: core::marker::PhantomData,
+                       phantom_m: core::marker::PhantomData,
                }
        }
 
@@ -569,7 +575,7 @@ impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBui
        }
 }
 
-impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::True, C, S> {
+impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool, M: tb::Bool> InvoiceBuilder<D, H, tb::True, C, S, M> {
        /// Builds a [`RawInvoice`] if no [`CreationError`] occurred while construction any of the
        /// fields.
        pub fn build_raw(self) -> Result<RawInvoice, CreationError> {
@@ -603,9 +609,9 @@ impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb
        }
 }
 
-impl<H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<tb::False, H, T, C, S> {
+impl<H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool, M: tb::Bool> InvoiceBuilder<tb::False, H, T, C, S, M> {
        /// Set the description. This function is only available if no description (hash) was set.
-       pub fn description(mut self, description: String) -> InvoiceBuilder<tb::True, H, T, C, S> {
+       pub fn description(mut self, description: String) -> InvoiceBuilder<tb::True, H, T, C, S, M> {
                match Description::new(description) {
                        Ok(d) => self.tagged_fields.push(TaggedField::Description(d)),
                        Err(e) => self.error = Some(e),
@@ -614,13 +620,13 @@ impl<H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<tb::Fals
        }
 
        /// Set the description hash. This function is only available if no description (hash) was set.
-       pub fn description_hash(mut self, description_hash: sha256::Hash) -> InvoiceBuilder<tb::True, H, T, C, S> {
+       pub fn description_hash(mut self, description_hash: sha256::Hash) -> InvoiceBuilder<tb::True, H, T, C, S, M> {
                self.tagged_fields.push(TaggedField::DescriptionHash(Sha256(description_hash)));
                self.set_flags()
        }
 
        /// Set the description or description hash. This function is only available if no description (hash) was set.
-       pub fn invoice_description(self, description: InvoiceDescription) -> InvoiceBuilder<tb::True, H, T, C, S> {
+       pub fn invoice_description(self, description: InvoiceDescription) -> InvoiceBuilder<tb::True, H, T, C, S, M> {
                match description {
                        InvoiceDescription::Direct(desc) => {
                                self.description(desc.clone().into_inner())
@@ -632,18 +638,18 @@ impl<H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<tb::Fals
        }
 }
 
-impl<D: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, tb::False, T, C, S> {
+impl<D: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool, M: tb::Bool> InvoiceBuilder<D, tb::False, T, C, S, M> {
        /// Set the payment hash. This function is only available if no payment hash was set.
-       pub fn payment_hash(mut self, hash: sha256::Hash) -> InvoiceBuilder<D, tb::True, T, C, S> {
+       pub fn payment_hash(mut self, hash: sha256::Hash) -> InvoiceBuilder<D, tb::True, T, C, S, M> {
                self.tagged_fields.push(TaggedField::PaymentHash(Sha256(hash)));
                self.set_flags()
        }
 }
 
-impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::False, C, S> {
+impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool, M: tb::Bool> InvoiceBuilder<D, H, tb::False, C, S, M> {
        /// Sets the timestamp to a specific [`SystemTime`].
        #[cfg(feature = "std")]
-       pub fn timestamp(mut self, time: SystemTime) -> InvoiceBuilder<D, H, tb::True, C, S> {
+       pub fn timestamp(mut self, time: SystemTime) -> InvoiceBuilder<D, H, tb::True, C, S, M> {
                match PositiveTimestamp::from_system_time(time) {
                        Ok(t) => self.timestamp = Some(t),
                        Err(e) => self.error = Some(e),
@@ -654,7 +660,7 @@ impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb
 
        /// Sets the timestamp to a duration since the Unix epoch, dropping the subsecond part (which
        /// is not representable in BOLT 11 invoices).
-       pub fn duration_since_epoch(mut self, time: Duration) -> InvoiceBuilder<D, H, tb::True, C, S> {
+       pub fn duration_since_epoch(mut self, time: Duration) -> InvoiceBuilder<D, H, tb::True, C, S, M> {
                match PositiveTimestamp::from_duration_since_epoch(time) {
                        Ok(t) => self.timestamp = Some(t),
                        Err(e) => self.error = Some(e),
@@ -665,34 +671,82 @@ impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb
 
        /// Sets the timestamp to the current system time.
        #[cfg(feature = "std")]
-       pub fn current_timestamp(mut self) -> InvoiceBuilder<D, H, tb::True, C, S> {
+       pub fn current_timestamp(mut self) -> InvoiceBuilder<D, H, tb::True, C, S, M> {
                let now = PositiveTimestamp::from_system_time(SystemTime::now());
                self.timestamp = Some(now.expect("for the foreseeable future this shouldn't happen"));
                self.set_flags()
        }
 }
 
-impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, tb::False, S> {
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, S: tb::Bool, M: tb::Bool> InvoiceBuilder<D, H, T, tb::False, S, M> {
        /// Sets `min_final_cltv_expiry_delta`.
-       pub fn min_final_cltv_expiry_delta(mut self, min_final_cltv_expiry_delta: u64) -> InvoiceBuilder<D, H, T, tb::True, S> {
+       pub fn min_final_cltv_expiry_delta(mut self, min_final_cltv_expiry_delta: u64) -> InvoiceBuilder<D, H, T, tb::True, S, M> {
                self.tagged_fields.push(TaggedField::MinFinalCltvExpiryDelta(MinFinalCltvExpiryDelta(min_final_cltv_expiry_delta)));
                self.set_flags()
        }
 }
 
-impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::False> {
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, M: tb::Bool> InvoiceBuilder<D, H, T, C, tb::False, M> {
        /// Sets the payment secret and relevant features.
-       pub fn payment_secret(mut self, payment_secret: PaymentSecret) -> InvoiceBuilder<D, H, T, C, tb::True> {
-               let mut features = InvoiceFeatures::empty();
-               features.set_variable_length_onion_required();
-               features.set_payment_secret_required();
+       pub fn payment_secret(mut self, payment_secret: PaymentSecret) -> InvoiceBuilder<D, H, T, C, tb::True, M> {
+               let mut found_features = false;
+               for field in self.tagged_fields.iter_mut() {
+                       if let TaggedField::Features(f) = field {
+                               found_features = true;
+                               f.set_variable_length_onion_required();
+                               f.set_payment_secret_required();
+                       }
+               }
                self.tagged_fields.push(TaggedField::PaymentSecret(payment_secret));
-               self.tagged_fields.push(TaggedField::Features(features));
+               if !found_features {
+                       let mut features = InvoiceFeatures::empty();
+                       features.set_variable_length_onion_required();
+                       features.set_payment_secret_required();
+                       self.tagged_fields.push(TaggedField::Features(features));
+               }
                self.set_flags()
        }
 }
 
-impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::True> {
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, C, S, tb::False> {
+       /// Sets the payment metadata.
+       ///
+       /// By default features are set to *optionally* allow the sender to include the payment metadata.
+       /// If you wish to require that the sender include the metadata (and fail to parse the invoice if
+       /// they don't support payment metadata fields), you need to call
+       /// [`InvoiceBuilder::require_payment_metadata`] after this.
+       pub fn payment_metadata(mut self, payment_metadata: Vec<u8>) -> InvoiceBuilder<D, H, T, C, S, tb::True> {
+               self.tagged_fields.push(TaggedField::PaymentMetadata(payment_metadata));
+               let mut found_features = false;
+               for field in self.tagged_fields.iter_mut() {
+                       if let TaggedField::Features(f) = field {
+                               found_features = true;
+                               f.set_payment_metadata_optional();
+                       }
+               }
+               if !found_features {
+                       let mut features = InvoiceFeatures::empty();
+                       features.set_payment_metadata_optional();
+                       self.tagged_fields.push(TaggedField::Features(features));
+               }
+               self.set_flags()
+       }
+}
+
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, C, S, tb::True> {
+       /// Sets forwarding of payment metadata as required. A reader of the invoice which does not
+       /// support sending payment metadata will fail to read the invoice.
+       pub fn require_payment_metadata(mut self) -> InvoiceBuilder<D, H, T, C, S, tb::True> {
+               for field in self.tagged_fields.iter_mut() {
+                       if let TaggedField::Features(f) = field {
+                               f.set_payment_metadata_required();
+                       }
+               }
+               self
+       }
+}
+
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, M: tb::Bool> InvoiceBuilder<D, H, T, C, tb::True, M> {
        /// Sets the `basic_mpp` feature as optional.
        pub fn basic_mpp(mut self) -> Self {
                for field in self.tagged_fields.iter_mut() {
@@ -704,7 +758,7 @@ impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T,
        }
 }
 
-impl InvoiceBuilder<tb::True, tb::True, tb::True, tb::True, tb::True> {
+impl<M: tb::Bool> InvoiceBuilder<tb::True, tb::True, tb::True, tb::True, tb::True, M> {
        /// Builds and signs an invoice using the supplied `sign_function`. This function MAY NOT fail
        /// and MUST produce a recoverable signature valid for the given hash and if applicable also for
        /// the included payee public key.