X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning-invoice%2Fsrc%2Flib.rs;h=11406a4644dd0f0e0c5133dc89cf8c84c55f7bbb;hb=b5f0ebab77961ce243fcf5a5fad3d4e161f4952a;hp=461ae9b92ad1a9e4d9bb993c13bae59353e89dd0;hpb=e26c3df71a4fa8fd6220cd10d068525ebff63783;p=rust-lightning

diff --git a/lightning-invoice/src/lib.rs b/lightning-invoice/src/lib.rs
index 461ae9b9..11406a46 100644
--- a/lightning-invoice/src/lib.rs
+++ b/lightning-invoice/src/lib.rs
@@ -168,7 +168,7 @@ pub fn check_platform() {
 ///
 /// (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> {
+pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> {
 	currency: Currency,
 	amount: Option<u64>,
 	si_prefix: Option<SiPrefix>,
@@ -180,6 +180,7 @@ pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> {
 	phantom_h: std::marker::PhantomData<H>,
 	phantom_t: std::marker::PhantomData<T>,
 	phantom_c: std::marker::PhantomData<C>,
+	phantom_s: std::marker::PhantomData<S>,
 }
 
 /// Represents a syntactically and semantically correct lightning BOLT11 invoice.
@@ -427,7 +428,7 @@ pub mod constants {
 	pub const TAG_FEATURES: u8 = 5;
 }
 
-impl InvoiceBuilder<tb::False, tb::False, tb::False, tb::False> {
+impl InvoiceBuilder<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 {
@@ -443,14 +444,15 @@ impl InvoiceBuilder<tb::False, tb::False, tb::False, tb::False> {
 			phantom_h: std::marker::PhantomData,
 			phantom_t: std::marker::PhantomData,
 			phantom_c: std::marker::PhantomData,
+			phantom_s: std::marker::PhantomData,
 		}
 	}
 }
 
-impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C> {
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, C, S> {
 	/// Helper function to set the completeness flags.
-	fn set_flags<DN: tb::Bool, HN: tb::Bool, TN: tb::Bool, CN: tb::Bool>(self) -> InvoiceBuilder<DN, HN, TN, CN> {
-		InvoiceBuilder::<DN, HN, TN, CN> {
+	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> {
 			currency: self.currency,
 			amount: self.amount,
 			si_prefix: self.si_prefix,
@@ -462,6 +464,7 @@ impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T,
 			phantom_h: std::marker::PhantomData,
 			phantom_t: std::marker::PhantomData,
 			phantom_c: std::marker::PhantomData,
+			phantom_s: std::marker::PhantomData,
 		}
 	}
 
@@ -482,12 +485,6 @@ impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T,
 		self
 	}
 
-	/// Sets the payment secret
-	pub fn payment_secret(mut self, payment_secret: PaymentSecret) -> Self {
-		self.tagged_fields.push(TaggedField::PaymentSecret(payment_secret));
-		self
-	}
-
 	/// Sets the expiry time
 	pub fn expiry_time(mut self, expiry_time: Duration) -> Self {
         match ExpiryTime::from_duration(expiry_time) {
@@ -511,16 +508,9 @@ impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: 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, C: tb::Bool> InvoiceBuilder<D, H, tb::True, C> {
+impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::True, C, S> {
 	/// Builds a `RawInvoice` if no `CreationError` occurred while construction any of the fields.
 	pub fn build_raw(self) -> Result<RawInvoice, CreationError> {
 
@@ -553,9 +543,9 @@ impl<D: tb::Bool, H: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, tb::True, C> {
 	}
 }
 
-impl<H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<tb::False, H, T, C> {
+impl<H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<tb::False, H, T, C, S> {
 	/// 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> {
+	pub fn description(mut self, description: String) -> InvoiceBuilder<tb::True, H, T, C, S> {
 		match Description::new(description) {
 			Ok(d) => self.tagged_fields.push(TaggedField::Description(d)),
 			Err(e) => self.error = Some(e),
@@ -564,23 +554,23 @@ impl<H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<tb::False, H, T, C> {
 	}
 
 	/// 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> {
+	pub fn description_hash(mut self, description_hash: sha256::Hash) -> InvoiceBuilder<tb::True, H, T, C, S> {
 		self.tagged_fields.push(TaggedField::DescriptionHash(Sha256(description_hash)));
 		self.set_flags()
 	}
 }
 
-impl<D: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, tb::False, T, C> {
+impl<D: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, tb::False, T, C, S> {
 	/// 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> {
+	pub fn payment_hash(mut self, hash: sha256::Hash) -> InvoiceBuilder<D, tb::True, T, C, S> {
 		self.tagged_fields.push(TaggedField::PaymentHash(Sha256(hash)));
 		self.set_flags()
 	}
 }
 
-impl<D: tb::Bool, H: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, tb::False, C> {
+impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::False, C, S> {
 	/// Sets the timestamp.
-	pub fn timestamp(mut self, time: SystemTime) -> InvoiceBuilder<D, H, tb::True, C> {
+	pub fn timestamp(mut self, time: SystemTime) -> InvoiceBuilder<D, H, tb::True, C, S> {
 		match PositiveTimestamp::from_system_time(time) {
 			Ok(t) => self.timestamp = Some(t),
 			Err(e) => self.error = Some(e),
@@ -590,22 +580,34 @@ impl<D: tb::Bool, H: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, tb::False, C> {
 	}
 
 	/// Sets the timestamp to the current UNIX timestamp.
-	pub fn current_timestamp(mut self) -> InvoiceBuilder<D, H, tb::True, C> {
+	pub fn current_timestamp(mut self) -> InvoiceBuilder<D, H, tb::True, C, S> {
 		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> InvoiceBuilder<D, H, T, tb::False> {
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, tb::False, S> {
 	/// Sets `min_final_cltv_expiry`.
-	pub fn min_final_cltv_expiry(mut self, min_final_cltv_expiry: u64) -> InvoiceBuilder<D, H, T, tb::True> {
+	pub fn min_final_cltv_expiry(mut self, min_final_cltv_expiry: u64) -> InvoiceBuilder<D, H, T, tb::True, S> {
 		self.tagged_fields.push(TaggedField::MinFinalCltvExpiry(MinFinalCltvExpiry(min_final_cltv_expiry)));
 		self.set_flags()
 	}
 }
 
-impl InvoiceBuilder<tb::True, tb::True, tb::True, tb::True> {
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::False> {
+	/// 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();
+		self.tagged_fields.push(TaggedField::PaymentSecret(payment_secret));
+		self.tagged_fields.push(TaggedField::Features(features));
+		self.set_flags()
+	}
+}
+
+impl<S: tb::Bool> InvoiceBuilder<tb::True, tb::True, tb::True, tb::True, S> {
 	/// 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.
@@ -644,6 +646,7 @@ impl InvoiceBuilder<tb::True, tb::True, tb::True, tb::True> {
 		};
 
 		invoice.check_field_counts().expect("should be ensured by type signature of builder");
+		invoice.check_feature_bits().expect("should be ensured by type signature of builder");
 
 		Ok(invoice)
 	}
@@ -972,6 +975,41 @@ impl Invoice {
 		Ok(())
 	}
 
+	/// Check that feature bits are set as required
+	fn check_feature_bits(&self) -> Result<(), SemanticError> {
+		// "If the payment_secret feature is set, MUST include exactly one s field."
+		let payment_secret_count = self.tagged_fields().filter(|&tf| match *tf {
+			TaggedField::PaymentSecret(_) => true,
+			_ => false,
+		}).count();
+		if payment_secret_count > 1 {
+			return Err(SemanticError::MultiplePaymentSecrets);
+		}
+
+		// "A writer MUST set an s field if and only if the payment_secret feature is set."
+		let has_payment_secret = payment_secret_count == 1;
+		let features = self.tagged_fields().find(|&tf| match *tf {
+			TaggedField::Features(_) => true,
+			_ => false,
+		});
+		match features {
+			None if has_payment_secret => Err(SemanticError::InvalidFeatures),
+			None => Ok(()),
+			Some(TaggedField::Features(features)) => {
+				if features.supports_payment_secret() && has_payment_secret {
+					Ok(())
+				} else if has_payment_secret {
+					Err(SemanticError::InvalidFeatures)
+				} else if features.supports_payment_secret() {
+					Err(SemanticError::InvalidFeatures)
+				} else {
+					Ok(())
+				}
+			},
+			Some(_) => unreachable!(),
+		}
+	}
+
 	/// Check that the invoice is signed correctly and that key recovery works
 	pub fn check_signature(&self) -> Result<(), SemanticError> {
 		match self.signed_invoice.recover_payee_pub_key() {
@@ -1006,6 +1044,7 @@ impl Invoice {
 			signed_invoice: signed_invoice,
 		};
 		invoice.check_field_counts()?;
+		invoice.check_feature_bits()?;
 		invoice.check_signature()?;
 
 		Ok(invoice)
@@ -1298,6 +1337,12 @@ pub enum SemanticError {
 	/// The invoice contains multiple descriptions and/or description hashes which isn't allowed
 	MultipleDescriptions,
 
+	/// The invoice contains multiple payment secrets
+	MultiplePaymentSecrets,
+
+	/// The invoice's features are invalid
+	InvalidFeatures,
+
 	/// The recovery id doesn't fit the signature/pub key
 	InvalidRecoveryId,
 
@@ -1312,6 +1357,8 @@ impl Display for SemanticError {
 			SemanticError::MultiplePaymentHashes => f.write_str("The invoice has multiple payment hashes which isn't allowed"),
 			SemanticError::NoDescription => f.write_str("No description or description hash are part of the invoice"),
 			SemanticError::MultipleDescriptions => f.write_str("The invoice contains multiple descriptions and/or description hashes which isn't allowed"),
+			SemanticError::MultiplePaymentSecrets => f.write_str("The invoice contains multiple payment secrets"),
+			SemanticError::InvalidFeatures => f.write_str("The invoice's features are invalid"),
 			SemanticError::InvalidRecoveryId => f.write_str("The recovery id doesn't fit the signature/pub key"),
 			SemanticError::InvalidSignature => f.write_str("The invoice's signature is invalid"),
 		}