Support setting the new payment metadata field in invoices

diff --git a/lightning-invoice/src/lib.rs b/lightning-invoice/src/lib.rs
index 73965211004a228324c73ad33144e6a0f1814cac..09b7f2601485084c467f3e8ba90c8aa757e82e01 100644 (file)
--- a/lightning-invoice/src/lib.rs
+++ b/lightning-invoice/src/lib.rs
@@ -163,10 +163,13 @@ pub const DEFAULT_MIN_FINAL_CLTV_EXPIRY: u64 = 18;
 ///  * `D`: exactly one `Description` or `DescriptionHash`
 ///  * `H`: exactly one `PaymentHash`
 ///  * `T`: the timestamp is set
+///  * `C`: the CLTV expiry is set
+///  * `S`: the payment secret is set
+///  * `M`: payment metadata is set
 ///
 /// (C-not exported) 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>,
@@ -179,6 +182,7 @@ 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.
@@ -432,7 +436,7 @@ 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 {
@@ -449,14 +453,15 @@ 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,
@@ -469,6 +474,7 @@ 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,
                }
        }
 
@@ -512,7 +518,7 @@ 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> {
 
@@ -545,9 +551,9 @@ 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),
@@ -556,24 +562,24 @@ 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()
        }
 }
 
-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),
@@ -583,7 +589,7 @@ 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.
-       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),
@@ -594,34 +600,94 @@ 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`.
-       pub fn min_final_cltv_expiry(mut self, min_final_cltv_expiry: u64) -> InvoiceBuilder<D, H, T, tb::True, S> {
+       pub fn min_final_cltv_expiry(mut self, min_final_cltv_expiry: u64) -> InvoiceBuilder<D, H, T, tb::True, S, M> {
                self.tagged_fields.push(TaggedField::MinFinalCltvExpiry(MinFinalCltvExpiry(min_final_cltv_expiry)));
                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 features = InvoiceFeatures::empty()
-                       .set_variable_length_onion_required()
-                       .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;
+               self.tagged_fields = self.tagged_fields
+                       .drain(..)
+                       .map(|field| match field {
+                               TaggedField::Features(f) => {
+                                       found_features = true;
+                                       TaggedField::Features(f
+                                               .set_variable_length_onion_required()
+                                               .set_payment_secret_required())
+                               },
+                               _ => field,
+                       })
+                       .collect();
                self.tagged_fields.push(TaggedField::PaymentSecret(payment_secret));
-               self.tagged_fields.push(TaggedField::Features(features));
+               if !found_features {
+                       let features = InvoiceFeatures::empty()
+                               .set_variable_length_onion_required()
+                               .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;
+               self.tagged_fields = self.tagged_fields
+                       .drain(..)
+                       .map(|field| match field {
+                               TaggedField::Features(f) => {
+                                       found_features = true;
+                                       TaggedField::Features(f.set_payment_metadata_optional())
+                               },
+                               _ => field,
+                       })
+                       .collect();
+               if !found_features {
+                       let features = InvoiceFeatures::empty()
+                               .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 the payment secret and relevant features.
+       pub fn require_payment_metadata(mut self) -> InvoiceBuilder<D, H, T, C, S, tb::True> {
+               self.tagged_fields = self.tagged_fields
+                       .drain(..)
+                       .map(|field| match field {
+                               TaggedField::Features(f) => {
+                                       TaggedField::Features(f.set_payment_metadata_required())
+                               },
+                               _ => field,
+                       })
+                       .collect();
+               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 {
                self.tagged_fields = self.tagged_fields
@@ -635,7 +701,7 @@ 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.

diff --git a/lightning-invoice/tests/ser_de.rs b/lightning-invoice/tests/ser_de.rs
index 1eaeb31378513065e74a7c4958e9b8e0c8befa8e..8dc18d151a60e316a33202d8a880eac93f505e40 100644 (file)
--- a/lightning-invoice/tests/ser_de.rs
+++ b/lightning-invoice/tests/ser_de.rs
@@ -331,6 +331,56 @@ fn get_test_tuples() -> Vec<(String, SignedRawInvoice, bool, bool)> {
                        true, // Different features than set in InvoiceBuilder
                        true, // Some unknown fields
                ),
+               ( // Older version of the payment metadata test with a payment_pubkey set
+                       "lnbc10m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdp9wpshjmt9de6zqmt9w3skgct5vysxjmnnd9jx2mq8q8a04uqnp4q0n326hr8v9zprg8gsvezcch06gfaqqhde2aj730yg0durunfhv66sp5zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygs9q2gqqqqqqsgqy9gw6ymamd20jumvdgpfphkhp8fzhhdhycw36egcmla5vlrtrmhs9t7psfy3hkkdqzm9eq64fjg558znccds5nhsfmxveha5xe0dykgpspdha0".to_owned(),
+                       InvoiceBuilder::new(Currency::Bitcoin)
+                               .amount_milli_satoshis(1_000_000_000)
+                               .timestamp(UNIX_EPOCH + Duration::from_secs(1496314658))
+                               .payment_hash(sha256::Hash::from_hex(
+                                       "0001020304050607080900010203040506070809000102030405060708090102"
+                               ).unwrap())
+                               .description("payment metadata inside".to_owned())
+                               .payment_metadata(hex::decode("01fafaf0").unwrap())
+                               .require_payment_metadata()
+                               .payee_pub_key(PublicKey::from_slice(&hex::decode(
+                                               "03e7156ae33b0a208d0744199163177e909e80176e55d97a2f221ede0f934dd9ad"
+                                       ).unwrap()).unwrap())
+                               .payment_secret(PaymentSecret([0x11; 32]))
+                               .build_raw()
+                               .unwrap()
+                               .sign(|_| {
+                                       RecoverableSignature::from_compact(
+                                               &hex::decode("2150ed137ddb54f9736c6a0290ded709d22bddb7261d1d6518dffb467c6b1eef02afc182491bdacd00b65c83554c914a1c53c61b0a4ef04eccccdfb4365ed259").unwrap(),
+                                               RecoveryId::from_i32(1).unwrap()
+                                       )
+                               }).unwrap(),
+                       false, // Different features than set in InvoiceBuilder
+                       true, // Some unknown fields
+               ),
+               (
+                       "lnbc10m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdp9wpshjmt9de6zqmt9w3skgct5vysxjmnnd9jx2mq8q8a04uqsp5zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygs9q2gqqqqqqsgq7hf8he7ecf7n4ffphs6awl9t6676rrclv9ckg3d3ncn7fct63p6s365duk5wrk202cfy3aj5xnnp5gs3vrdvruverwwq7yzhkf5a3xqpd05wjc".to_owned(),
+                       InvoiceBuilder::new(Currency::Bitcoin)
+                               .amount_milli_satoshis(1_000_000_000)
+                               .timestamp(UNIX_EPOCH + Duration::from_secs(1496314658))
+                               .payment_hash(sha256::Hash::from_hex(
+                                       "0001020304050607080900010203040506070809000102030405060708090102"
+                               ).unwrap())
+                               .description("payment metadata inside".to_owned())
+                               .payment_metadata(hex::decode("01fafaf0").unwrap())
+                               .require_payment_metadata()
+                               .payment_secret(PaymentSecret([0x11; 32]))
+                               .build_raw()
+                               .unwrap()
+                               .sign(|_| {
+                                       RecoverableSignature::from_compact(
+                                               &hex::decode("f5d27be7d9c27d3aa521bc35d77cabd6bda18f1f61716445b19e27e4e17a887508ea8de5a8e1d94f561248f65434e61a221160dac1f1991b9c0f1057b269d898").unwrap(),
+                                               RecoveryId::from_i32(1).unwrap()
+                                       )
+                               }).unwrap(),
+                       false, // Different features than set in InvoiceBuilder
+                       true, // Some unknown fields
+               ),
+
        ]
 }