Add Features feature to invoices.
authorValentine Wallace <vwallace@protonmail.com>
Fri, 16 Apr 2021 19:29:33 +0000 (15:29 -0400)
committerValentine Wallace <vwallace@protonmail.com>
Mon, 26 Apr 2021 16:29:46 +0000 (12:29 -0400)
lightning-invoice/src/de.rs
lightning-invoice/src/lib.rs
lightning-invoice/src/ser.rs
lightning/src/ln/features.rs

index fe77a93a99b03f9707563f56ea556c56d5ac7c76..c06281e4b4db86c00b95812ad4794b57dffe9112 100644 (file)
@@ -433,6 +433,8 @@ impl FromBase32 for TaggedField {
                                Ok(TaggedField::Route(RouteHint::from_base32(field_data)?)),
                        constants::TAG_PAYMENT_SECRET =>
                                Ok(TaggedField::PaymentSecret(PaymentSecret::from_base32(field_data)?)),
+                       constants::TAG_FEATURES =>
+                               Ok(TaggedField::Features(InvoiceFeatures::from_base32(field_data)?)),
                        _ => {
                                // "A reader MUST skip over unknown fields"
                                Err(ParseError::Skip)
@@ -993,16 +995,17 @@ mod test {
        }
 
        #[test]
-       fn test_payment_secret_deserialization() {
-               use bech32::CheckBase32;
+       fn test_payment_secret_and_features_de_and_ser() {
+               use lightning::ln::features::InvoiceFeatures;
                use secp256k1::recovery::{RecoveryId, RecoverableSignature};
                use TaggedField::*;
-               use {SiPrefix, SignedRawInvoice, Signature, RawInvoice, RawTaggedField, RawHrp, RawDataPart,
+               use {SiPrefix, SignedRawInvoice, Signature, RawInvoice, RawHrp, RawDataPart,
                                 Currency, Sha256, PositiveTimestamp};
 
-               assert_eq!( // BOLT 11 payment secret invoice. The unknown fields are invoice features.
-                       "lnbc25m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5vdhkven9v5sxyetpdeessp5zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygs9q5sqqqqqqqqqqqqqqqpqsq67gye39hfg3zd8rgc80k32tvy9xk2xunwm5lzexnvpx6fd77en8qaq424dxgt56cag2dpt359k3ssyhetktkpqh24jqnjyw6uqd08sgptq44qu".parse(),
-                       Ok(SignedRawInvoice {
+               // Feature bits 9, 15, and 99 are set.
+               let expected_features = InvoiceFeatures::from_le_bytes(vec![0, 130, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8]);
+               let invoice_str = "lnbc25m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5vdhkven9v5sxyetpdeessp5zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygs9q5sqqqqqqqqqqqqqqqpqsq67gye39hfg3zd8rgc80k32tvy9xk2xunwm5lzexnvpx6fd77en8qaq424dxgt56cag2dpt359k3ssyhetktkpqh24jqnjyw6uqd08sgptq44qu";
+               let invoice = SignedRawInvoice {
                                        raw_invoice: RawInvoice {
                                                hrp: RawHrp {
                                                        currency: Currency::Bitcoin,
@@ -1017,10 +1020,7 @@ mod test {
                                                                ).unwrap())).into(),
                                                                Description(::Description::new("coffee beans".to_owned()).unwrap()).into(),
                                                                PaymentSecret(::PaymentSecret([17; 32])).into(),
-                                                               RawTaggedField::UnknownSemantics(vec![5, 0, 20, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-                                                                                                                                                                                                                       0, 0, 0, 0, 1, 0, 16,
-                                                                                                                                                                                                                       0].check_base32().unwrap())],
-                                                                       }
+                                                               Features(expected_features).into()]}
                                                                },
                                        hash: [0xb1, 0x96, 0x46, 0xc3, 0xbc, 0x56, 0x76, 0x1d, 0x20, 0x65, 0x6e, 0x0e, 0x32,
                                                                        0xec, 0xd2, 0x69, 0x27, 0xb7, 0x62, 0x6e, 0x2a, 0x8b, 0xe6, 0x97, 0x71, 0x9f,
@@ -1033,8 +1033,12 @@ mod test {
                                                                                        0x60, 0x82, 0xea, 0xac, 0x81, 0x39, 0x11, 0xda, 0xe0, 0x1a, 0xf3, 0xc1],
                                                                                RecoveryId::from_i32(1).unwrap()
                                                                ).unwrap()),
-                       })
-               )
+                       };
+               assert_eq!(invoice_str, invoice.to_string());
+               assert_eq!(
+                       invoice_str.parse(),
+                       Ok(invoice)
+               );
        }
 
        #[test]
index 315cf641c8ec80a953ae25fc654be5eba9951888..3d75d4d65dc057c148d11886ae03a702da9205ea 100644 (file)
@@ -24,6 +24,7 @@ extern crate secp256k1;
 use bech32::u5;
 use bitcoin_hashes::Hash;
 use bitcoin_hashes::sha256;
+use lightning::ln::features::InvoiceFeatures;
 #[cfg(any(doc, test))]
 use lightning::routing::network_graph::RoutingFees;
 use lightning::routing::router::RouteHintHop;
@@ -329,6 +330,7 @@ pub enum TaggedField {
        Fallback(Fallback),
        Route(RouteHint),
        PaymentSecret(PaymentSecret),
+       Features(InvoiceFeatures),
 }
 
 /// SHA-256 hash
@@ -401,6 +403,7 @@ pub mod constants {
        pub const TAG_FALLBACK: u8 = 9;
        pub const TAG_ROUTE: u8 = 3;
        pub const TAG_PAYMENT_SECRET: u8 = 16;
+       pub const TAG_FEATURES: u8 = 5;
 }
 
 impl InvoiceBuilder<tb::False, tb::False, tb::False> {
@@ -491,6 +494,13 @@ impl<D: tb::Bool, H: tb::Bool, T: tb::Bool> InvoiceBuilder<D, H, T> {
                }
                self
        }
+
+       /// Adds a features field which indicates the set of supported protocol extensions which the
+       /// origin node supports.
+       pub fn features(mut self, features: InvoiceFeatures) -> Self {
+               self.tagged_fields.push(TaggedField::Features(features));
+               self
+       }
 }
 
 impl<D: tb::Bool, H: tb::Bool> InvoiceBuilder<D, H, tb::True> {
@@ -810,6 +820,10 @@ impl RawInvoice {
                find_extract!(self.known_tagged_fields(), TaggedField::PaymentSecret(ref x), x)
        }
 
+       pub fn features(&self) -> Option<&InvoiceFeatures> {
+               find_extract!(self.known_tagged_fields(), TaggedField::Features(ref x), x)
+       }
+
        pub fn fallbacks(&self) -> Vec<&Fallback> {
                self.known_tagged_fields().filter_map(|tf| match tf {
                        &TaggedField::Fallback(ref f) => Some(f),
@@ -997,6 +1011,11 @@ impl Invoice {
                self.signed_invoice.payment_secret()
        }
 
+       /// Get the invoice features if they were included in the invoice
+       pub fn features(&self) -> Option<&InvoiceFeatures> {
+               self.signed_invoice.features()
+       }
+
        /// Recover the payee's public key (only to be used if none was included in the invoice)
        pub fn recover_payee_pub_key(&self) -> PublicKey {
                self.signed_invoice.recover_payee_pub_key().expect("was checked by constructor").0
@@ -1054,6 +1073,7 @@ impl TaggedField {
                        TaggedField::Fallback(_) => constants::TAG_FALLBACK,
                        TaggedField::Route(_) => constants::TAG_ROUTE,
                        TaggedField::PaymentSecret(_) => constants::TAG_PAYMENT_SECRET,
+                       TaggedField::Features(_) => constants::TAG_FEATURES,
                };
 
                u5::try_from_u8(tag).expect("all tags defined are <32")
index 83888e8269da1af358cd8cbf851d6e8b2c0e06da..fdff7f4f61cc56d93a8c2d1d0cdbf2e6ff78f05a 100644 (file)
@@ -454,7 +454,9 @@ impl ToBase32 for TaggedField {
                        TaggedField::PaymentSecret(ref payment_secret) => {
                                  write_tagged_field(writer, constants::TAG_PAYMENT_SECRET, payment_secret)
                        },
-
+                       TaggedField::Features(ref features) => {
+                               write_tagged_field(writer, constants::TAG_FEATURES, features)
+                       },
                }
        }
 }
index 4a9526aff5687d3916230c9d0c6e28b7b0a2ce32..36f29ada14e4609709777d3594a3cfc9b7c2dd7a 100644 (file)
@@ -25,6 +25,8 @@
 use std::{cmp, fmt};
 use std::marker::PhantomData;
 
+use bitcoin::bech32;
+use bitcoin::bech32::{Base32Len, FromBase32, ToBase32, u5, WriteBase32};
 use ln::msgs::DecodeError;
 use util::ser::{Readable, Writeable, Writer};
 
@@ -51,6 +53,7 @@ mod sealed {
                        required_features: [$( $( $required_feature: ident )|*, )*],
                        optional_features: [$( $( $optional_feature: ident )|*, )*],
                }) => {
+                       #[derive(Eq, PartialEq)]
                        pub struct $context {}
 
                        impl Context for $context {
@@ -318,6 +321,7 @@ mod sealed {
 /// appears.
 ///
 /// (C-not exported) as we map the concrete feature types below directly instead
+#[derive(Eq)]
 pub struct Features<T: sealed::Context> {
        /// Note that, for convenience, flags is LITTLE endian (despite being big-endian on the wire)
        flags: Vec<u8>,
@@ -395,6 +399,68 @@ impl InvoiceFeatures {
        }
 }
 
+impl ToBase32 for InvoiceFeatures {
+       fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
+               // Explanation for the "4": the normal way to round up when dividing is to add the divisor
+               // minus one before dividing
+               let length_u5s = (self.flags.len() * 8 + 4) / 5 as usize;
+               let mut res_u5s: Vec<u5> = vec![u5::try_from_u8(0).unwrap(); length_u5s];
+               for (byte_idx, byte) in self.flags.iter().enumerate() {
+                       let bit_pos_from_left_0_indexed = byte_idx * 8;
+                       let new_u5_idx = length_u5s - (bit_pos_from_left_0_indexed / 5) as usize - 1;
+                       let new_bit_pos = bit_pos_from_left_0_indexed % 5;
+                       let shifted_chunk_u16 = (*byte as u16) << new_bit_pos;
+                       let curr_u5_as_u8 = res_u5s[new_u5_idx].to_u8();
+                       res_u5s[new_u5_idx] = u5::try_from_u8(curr_u5_as_u8 | ((shifted_chunk_u16 & 0x001f) as u8)).unwrap();
+                       if new_u5_idx > 0 {
+                               let curr_u5_as_u8 = res_u5s[new_u5_idx - 1].to_u8();
+                               res_u5s[new_u5_idx - 1] = u5::try_from_u8(curr_u5_as_u8 | (((shifted_chunk_u16 >> 5) & 0x001f) as u8)).unwrap();
+                       }
+                       if new_u5_idx > 1 {
+                               let curr_u5_as_u8 = res_u5s[new_u5_idx - 2].to_u8();
+                               res_u5s[new_u5_idx - 2] = u5::try_from_u8(curr_u5_as_u8 | (((shifted_chunk_u16 >> 10) & 0x001f) as u8)).unwrap();
+                       }
+               }
+               // Trim the highest feature bits.
+               while !res_u5s.is_empty() && res_u5s[0] == u5::try_from_u8(0).unwrap() {
+                       res_u5s.remove(0);
+               }
+               writer.write(&res_u5s)
+       }
+}
+
+impl Base32Len for InvoiceFeatures {
+       fn base32_len(&self) -> usize {
+               self.to_base32().len()
+       }
+}
+
+impl FromBase32 for InvoiceFeatures {
+       type Err = bech32::Error;
+
+       fn from_base32(field_data: &[u5]) -> Result<InvoiceFeatures, bech32::Error> {
+               // Explanation for the "7": the normal way to round up when dividing is to add the divisor
+               // minus one before dividing
+               let length_bytes = (field_data.len() * 5 + 7) / 8 as usize;
+               let mut res_bytes: Vec<u8> = vec![0; length_bytes];
+               for (u5_idx, chunk) in field_data.iter().enumerate() {
+                       let bit_pos_from_right_0_indexed = (field_data.len() - u5_idx - 1) * 5;
+                       let new_byte_idx = (bit_pos_from_right_0_indexed / 8) as usize;
+                       let new_bit_pos = bit_pos_from_right_0_indexed % 8;
+                       let chunk_u16 = chunk.to_u8() as u16;
+                       res_bytes[new_byte_idx] |= ((chunk_u16 << new_bit_pos) & 0xff) as u8;
+                       if new_byte_idx != length_bytes - 1 {
+                               res_bytes[new_byte_idx + 1] |= ((chunk_u16 >> (8-new_bit_pos)) & 0xff) as u8;
+                       }
+               }
+               // Trim the highest feature bits.
+               while !res_bytes.is_empty() && res_bytes[res_bytes.len() - 1] == 0 {
+                       res_bytes.pop();
+               }
+               Ok(InvoiceFeatures::from_le_bytes(res_bytes))
+       }
+}
+
 impl<T: sealed::Context> Features<T> {
        /// Create a blank Features with no features set
        pub fn empty() -> Self {
@@ -427,7 +493,8 @@ impl<T: sealed::Context> Features<T> {
                Features::<C> { flags, mark: PhantomData, }
        }
 
-       /// Create a Features given a set of flags, in LE.
+       /// Create a Features given a set of flags, in little-endian. This is in reverse byte order from
+       /// most on-the-wire encodings.
        pub fn from_le_bytes(flags: Vec<u8>) -> Features<T> {
                Features {
                        flags,
@@ -627,6 +694,7 @@ impl<T: sealed::Context> Readable for Features<T> {
 #[cfg(test)]
 mod tests {
        use super::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
+       use bitcoin::bech32::{Base32Len, FromBase32, ToBase32, u5};
 
        #[test]
        fn sanity_test_known_features() {
@@ -741,4 +809,35 @@ mod tests {
                assert!(features.requires_payment_secret());
                assert!(features.supports_payment_secret());
        }
+
+       #[test]
+       fn invoice_features_encoding() {
+               let features_as_u5s = vec![
+                       u5::try_from_u8(6).unwrap(),
+                       u5::try_from_u8(10).unwrap(),
+                       u5::try_from_u8(25).unwrap(),
+                       u5::try_from_u8(1).unwrap(),
+                       u5::try_from_u8(10).unwrap(),
+                       u5::try_from_u8(0).unwrap(),
+                       u5::try_from_u8(20).unwrap(),
+                       u5::try_from_u8(2).unwrap(),
+                       u5::try_from_u8(0).unwrap(),
+                       u5::try_from_u8(6).unwrap(),
+                       u5::try_from_u8(0).unwrap(),
+                       u5::try_from_u8(16).unwrap(),
+                       u5::try_from_u8(1).unwrap(),
+               ];
+               let features = InvoiceFeatures::from_le_bytes(vec![1, 2, 3, 4, 5, 42, 100, 101]);
+
+               // Test length calculation.
+               assert_eq!(features.base32_len(), 13);
+
+               // Test serialization.
+               let features_serialized = features.to_base32();
+               assert_eq!(features_as_u5s, features_serialized);
+
+               // Test deserialization.
+               let features_deserialized = InvoiceFeatures::from_base32(&features_as_u5s).unwrap();
+               assert_eq!(features, features_deserialized);
+       }
 }