use bitcoin::hashes::{Hash, HashEngine, sha256};
use bitcoin::secp256k1::{Message, PublicKey, Secp256k1, self};
use bitcoin::secp256k1::schnorr::Signature;
+use core::convert::AsRef;
use crate::io;
-use crate::util::ser::{BigSize, Readable};
+use crate::util::ser::{BigSize, Readable, Writeable, Writer};
+#[allow(unused_imports)]
use crate::prelude::*;
/// Valid type range for signature TLV records.
(240, signature: Signature),
});
+/// A hash for use in a specific context by tweaking with a context-dependent tag as per [BIP 340]
+/// and computed over the merkle root of a TLV stream to sign as defined in [BOLT 12].
+///
+/// [BIP 340]: https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki
+/// [BOLT 12]: https://github.com/rustyrussell/lightning-rfc/blob/guilt/offers/12-offer-encoding.md#signature-calculation
+#[derive(Clone, Debug, PartialEq)]
+pub struct TaggedHash {
+ tag: &'static str,
+ merkle_root: sha256::Hash,
+ digest: Message,
+}
+
+impl TaggedHash {
+ /// Creates a tagged hash with the given parameters.
+ ///
+ /// Panics if `tlv_stream` is not a well-formed TLV stream containing at least one TLV record.
+ pub(super) fn new(tag: &'static str, tlv_stream: &[u8]) -> Self {
+ let tag_hash = sha256::Hash::hash(tag.as_bytes());
+ let merkle_root = root_hash(tlv_stream);
+ let digest = Message::from_slice(tagged_hash(tag_hash, merkle_root).as_byte_array()).unwrap();
+ Self {
+ tag,
+ merkle_root,
+ digest,
+ }
+ }
+
+ /// Returns the digest to sign.
+ pub fn as_digest(&self) -> &Message {
+ &self.digest
+ }
+
+ /// Returns the tag used in the tagged hash.
+ pub fn tag(&self) -> &str {
+ &self.tag
+ }
+
+ /// Returns the merkle root used in the tagged hash.
+ pub fn merkle_root(&self) -> sha256::Hash {
+ self.merkle_root
+ }
+}
+
+impl AsRef<TaggedHash> for TaggedHash {
+ fn as_ref(&self) -> &TaggedHash {
+ self
+ }
+}
+
/// Error when signing messages.
#[derive(Debug, PartialEq)]
-pub enum SignError<E> {
+pub enum SignError {
/// User-defined error when signing the message.
- Signing(E),
+ Signing,
/// Error when verifying the produced signature using the given pubkey.
Verification(secp256k1::Error),
}
-/// Signs a message digest consisting of a tagged hash of the given bytes, checking if it can be
-/// verified with the supplied pubkey.
+/// A function for signing a [`TaggedHash`].
+pub(super) trait SignFn<T: AsRef<TaggedHash>> {
+ /// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream.
+ fn sign(&self, message: &T) -> Result<Signature, ()>;
+}
+
+impl<F> SignFn<TaggedHash> for F
+where
+ F: Fn(&TaggedHash) -> Result<Signature, ()>,
+{
+ fn sign(&self, message: &TaggedHash) -> Result<Signature, ()> {
+ self(message)
+ }
+}
+
+/// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream, checking if it
+/// can be verified with the supplied `pubkey`.
+///
+/// Since `message` is any type that implements [`AsRef<TaggedHash>`], `sign` may be a closure that
+/// takes a message such as [`Bolt12Invoice`] or [`InvoiceRequest`]. This allows further message
+/// verification before signing its [`TaggedHash`].
///
-/// Panics if `bytes` is not a well-formed TLV stream containing at least one TLV record.
-pub(super) fn sign_message<F, E>(
- sign: F, tag: &str, bytes: &[u8], pubkey: PublicKey,
-) -> Result<Signature, SignError<E>>
+/// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
+/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
+pub(super) fn sign_message<F, T>(
+ f: F, message: &T, pubkey: PublicKey,
+) -> Result<Signature, SignError>
where
- F: FnOnce(&Message) -> Result<Signature, E>
+ F: SignFn<T>,
+ T: AsRef<TaggedHash>,
{
- let digest = message_digest(tag, bytes);
- let signature = sign(&digest).map_err(|e| SignError::Signing(e))?;
+ let signature = f.sign(message).map_err(|()| SignError::Signing)?;
+ let digest = message.as_ref().as_digest();
let pubkey = pubkey.into();
let secp_ctx = Secp256k1::verification_only();
- secp_ctx.verify_schnorr(&signature, &digest, &pubkey).map_err(|e| SignError::Verification(e))?;
+ secp_ctx.verify_schnorr(&signature, digest, &pubkey).map_err(|e| SignError::Verification(e))?;
Ok(signature)
}
-/// Verifies the signature with a pubkey over the given bytes using a tagged hash as the message
+/// Verifies the signature with a pubkey over the given message using a tagged hash as the message
/// digest.
-///
-/// Panics if `bytes` is not a well-formed TLV stream containing at least one TLV record.
pub(super) fn verify_signature(
- signature: &Signature, tag: &str, bytes: &[u8], pubkey: PublicKey,
+ signature: &Signature, message: &TaggedHash, pubkey: PublicKey,
) -> Result<(), secp256k1::Error> {
- let digest = message_digest(tag, bytes);
+ let digest = message.as_digest();
let pubkey = pubkey.into();
let secp_ctx = Secp256k1::verification_only();
- secp_ctx.verify_schnorr(signature, &digest, &pubkey)
-}
-
-fn message_digest(tag: &str, bytes: &[u8]) -> Message {
- let tag = sha256::Hash::hash(tag.as_bytes());
- let merkle_root = root_hash(bytes);
- Message::from_slice(&tagged_hash(tag, merkle_root)).unwrap()
+ secp_ctx.verify_schnorr(signature, digest, &pubkey)
}
/// Computes a merkle root hash for the given data, which must be a well-formed TLV stream
/// containing at least one TLV record.
fn root_hash(data: &[u8]) -> sha256::Hash {
- let mut tlv_stream = TlvStream::new(&data[..]).peekable();
let nonce_tag = tagged_hash_engine(sha256::Hash::from_engine({
+ let first_tlv_record = TlvStream::new(&data[..]).next().unwrap();
let mut engine = sha256::Hash::engine();
engine.input("LnNonce".as_bytes());
- engine.input(tlv_stream.peek().unwrap().record_bytes);
+ engine.input(first_tlv_record.record_bytes);
engine
}));
let leaf_tag = tagged_hash_engine(sha256::Hash::hash("LnLeaf".as_bytes()));
let branch_tag = tagged_hash_engine(sha256::Hash::hash("LnBranch".as_bytes()));
let mut leaves = Vec::new();
- for record in tlv_stream {
- if !SIGNATURE_TYPES.contains(&record.r#type) {
- leaves.push(tagged_hash_from_engine(leaf_tag.clone(), &record));
- leaves.push(tagged_hash_from_engine(nonce_tag.clone(), &record.type_bytes));
- }
+ let tlv_stream = TlvStream::new(&data[..]);
+ for record in tlv_stream.skip_signatures() {
+ leaves.push(tagged_hash_from_engine(leaf_tag.clone(), &record.record_bytes));
+ leaves.push(tagged_hash_from_engine(nonce_tag.clone(), &record.type_bytes));
}
// Calculate the merkle root hash in place.
/// [`Iterator`] over a sequence of bytes yielding [`TlvRecord`]s. The input is assumed to be a
/// well-formed TLV stream.
-struct TlvStream<'a> {
+#[derive(Clone)]
+pub(super) struct TlvStream<'a> {
data: io::Cursor<&'a [u8]>,
}
impl<'a> TlvStream<'a> {
- fn new(data: &'a [u8]) -> Self {
+ pub fn new(data: &'a [u8]) -> Self {
Self {
data: io::Cursor::new(data),
}
}
+
+ pub fn range<T>(self, types: T) -> impl core::iter::Iterator<Item = TlvRecord<'a>>
+ where
+ T: core::ops::RangeBounds<u64> + Clone,
+ {
+ let take_range = types.clone();
+ self.skip_while(move |record| !types.contains(&record.r#type))
+ .take_while(move |record| take_range.contains(&record.r#type))
+ }
+
+ fn skip_signatures(self) -> core::iter::Filter<TlvStream<'a>, fn(&TlvRecord) -> bool> {
+ self.filter(|record| !SIGNATURE_TYPES.contains(&record.r#type))
+ }
}
/// A slice into a [`TlvStream`] for a record.
-struct TlvRecord<'a> {
- r#type: u64,
+pub(super) struct TlvRecord<'a> {
+ pub(super) r#type: u64,
type_bytes: &'a [u8],
// The entire TLV record.
- record_bytes: &'a [u8],
-}
-
-impl AsRef<[u8]> for TlvRecord<'_> {
- fn as_ref(&self) -> &[u8] { &self.record_bytes }
+ pub(super) record_bytes: &'a [u8],
}
impl<'a> Iterator for TlvStream<'a> {
}
}
+/// Encoding for a pre-serialized TLV stream that excludes any signature TLV records.
+///
+/// Panics if the wrapped bytes are not a well-formed TLV stream.
+pub(super) struct WithoutSignatures<'a>(pub &'a [u8]);
+
+impl<'a> Writeable for WithoutSignatures<'a> {
+ #[inline]
+ fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+ let tlv_stream = TlvStream::new(self.0);
+ for record in tlv_stream.skip_signatures() {
+ writer.write_all(record.record_bytes)?;
+ }
+ Ok(())
+ }
+}
+
#[cfg(test)]
mod tests {
+ use super::{SIGNATURE_TYPES, TlvStream, WithoutSignatures};
+
use bitcoin::hashes::{Hash, sha256};
- use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey};
- use core::convert::Infallible;
+ use bitcoin::hashes::hex::FromHex;
+ use bitcoin::secp256k1::{KeyPair, Message, Secp256k1, SecretKey};
+ use bitcoin::secp256k1::schnorr::Signature;
use crate::offers::offer::{Amount, OfferBuilder};
- use crate::offers::invoice_request::InvoiceRequest;
+ use crate::offers::invoice_request::{InvoiceRequest, UnsignedInvoiceRequest};
use crate::offers::parse::Bech32Encode;
+ use crate::offers::test_utils::{payer_pubkey, recipient_pubkey};
+ use crate::util::ser::Writeable;
#[test]
fn calculates_merkle_root_hash() {
macro_rules! tlv2 { () => { "02080000010000020003" } }
macro_rules! tlv3 { () => { "03310266e4598d1d3c415f572a8488830b60f7e744ed9235eb0b1ba93283b315c0351800000000000000010000000000000002" } }
assert_eq!(
- super::root_hash(&hex::decode(tlv1!()).unwrap()),
- sha256::Hash::from_slice(&hex::decode("b013756c8fee86503a0b4abdab4cddeb1af5d344ca6fc2fa8b6c08938caa6f93").unwrap()).unwrap(),
+ super::root_hash(&<Vec<u8>>::from_hex(tlv1!()).unwrap()),
+ sha256::Hash::from_slice(&<Vec<u8>>::from_hex("b013756c8fee86503a0b4abdab4cddeb1af5d344ca6fc2fa8b6c08938caa6f93").unwrap()).unwrap(),
);
assert_eq!(
- super::root_hash(&hex::decode(concat!(tlv1!(), tlv2!())).unwrap()),
- sha256::Hash::from_slice(&hex::decode("c3774abbf4815aa54ccaa026bff6581f01f3be5fe814c620a252534f434bc0d1").unwrap()).unwrap(),
+ super::root_hash(&<Vec<u8>>::from_hex(concat!(tlv1!(), tlv2!())).unwrap()),
+ sha256::Hash::from_slice(&<Vec<u8>>::from_hex("c3774abbf4815aa54ccaa026bff6581f01f3be5fe814c620a252534f434bc0d1").unwrap()).unwrap(),
);
assert_eq!(
- super::root_hash(&hex::decode(concat!(tlv1!(), tlv2!(), tlv3!())).unwrap()),
- sha256::Hash::from_slice(&hex::decode("ab2e79b1283b0b31e0b035258de23782df6b89a38cfa7237bde69aed1a658c5d").unwrap()).unwrap(),
+ super::root_hash(&<Vec<u8>>::from_hex(concat!(tlv1!(), tlv2!(), tlv3!())).unwrap()),
+ sha256::Hash::from_slice(&<Vec<u8>>::from_hex("ab2e79b1283b0b31e0b035258de23782df6b89a38cfa7237bde69aed1a658c5d").unwrap()).unwrap(),
);
}
fn calculates_merkle_root_hash_from_invoice_request() {
let secp_ctx = Secp256k1::new();
let recipient_pubkey = {
- let secret_key = SecretKey::from_slice(&hex::decode("4141414141414141414141414141414141414141414141414141414141414141").unwrap()).unwrap();
+ let secret_key = SecretKey::from_slice(&<Vec<u8>>::from_hex("4141414141414141414141414141414141414141414141414141414141414141").unwrap()).unwrap();
KeyPair::from_secret_key(&secp_ctx, &secret_key).public_key()
};
let payer_keys = {
- let secret_key = SecretKey::from_slice(&hex::decode("4242424242424242424242424242424242424242424242424242424242424242").unwrap()).unwrap();
+ let secret_key = SecretKey::from_slice(&<Vec<u8>>::from_hex("4242424242424242424242424242424242424242424242424242424242424242").unwrap()).unwrap();
KeyPair::from_secret_key(&secp_ctx, &secret_key)
};
.build_unchecked()
.request_invoice(vec![0; 8], payer_keys.public_key()).unwrap()
.build_unchecked()
- .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &payer_keys)))
+ .sign(|message: &UnsignedInvoiceRequest|
+ Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &payer_keys))
+ )
.unwrap();
assert_eq!(
invoice_request.to_string(),
);
assert_eq!(
super::root_hash(&invoice_request.bytes[..]),
- sha256::Hash::from_slice(&hex::decode("608407c18ad9a94d9ea2bcdbe170b6c20c462a7833a197621c916f78cf18e624").unwrap()).unwrap(),
+ sha256::Hash::from_slice(&<Vec<u8>>::from_hex("608407c18ad9a94d9ea2bcdbe170b6c20c462a7833a197621c916f78cf18e624").unwrap()).unwrap(),
+ );
+ assert_eq!(
+ invoice_request.signature(),
+ Signature::from_slice(&<Vec<u8>>::from_hex("b8f83ea3288cfd6ea510cdb481472575141e8d8744157f98562d162cc1c472526fdb24befefbdebab4dbb726bbd1b7d8aec057f8fa805187e5950d2bbe0e5642").unwrap()).unwrap(),
+ );
+ }
+
+ #[test]
+ fn compute_tagged_hash() {
+ let unsigned_invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+ .amount_msats(1000)
+ .build().unwrap()
+ .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
+ .payer_note("bar".into())
+ .build().unwrap();
+
+ // Simply test that we can grab the tag and merkle root exposed by the accessor
+ // functions, then use them to succesfully compute a tagged hash.
+ let tagged_hash = unsigned_invoice_request.as_ref();
+ let expected_digest = unsigned_invoice_request.as_ref().as_digest();
+ let tag = sha256::Hash::hash(tagged_hash.tag().as_bytes());
+ let actual_digest = Message::from_slice(super::tagged_hash(tag, tagged_hash.merkle_root()).as_byte_array())
+ .unwrap();
+ assert_eq!(*expected_digest, actual_digest);
+ }
+
+ #[test]
+ fn skips_encoding_signature_tlv_records() {
+ let secp_ctx = Secp256k1::new();
+ let recipient_pubkey = {
+ let secret_key = SecretKey::from_slice(&[41; 32]).unwrap();
+ KeyPair::from_secret_key(&secp_ctx, &secret_key).public_key()
+ };
+ let payer_keys = {
+ let secret_key = SecretKey::from_slice(&[42; 32]).unwrap();
+ KeyPair::from_secret_key(&secp_ctx, &secret_key)
+ };
+
+ let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey)
+ .amount_msats(100)
+ .build_unchecked()
+ .request_invoice(vec![0; 8], payer_keys.public_key()).unwrap()
+ .build_unchecked()
+ .sign(|message: &UnsignedInvoiceRequest|
+ Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &payer_keys))
+ )
+ .unwrap();
+
+ let mut bytes_without_signature = Vec::new();
+ WithoutSignatures(&invoice_request.bytes).write(&mut bytes_without_signature).unwrap();
+
+ assert_ne!(bytes_without_signature, invoice_request.bytes);
+ assert_eq!(
+ TlvStream::new(&bytes_without_signature).count(),
+ TlvStream::new(&invoice_request.bytes).count() - 1,
);
}
+ #[test]
+ fn iterates_over_tlv_stream_range() {
+ let secp_ctx = Secp256k1::new();
+ let recipient_pubkey = {
+ let secret_key = SecretKey::from_slice(&[41; 32]).unwrap();
+ KeyPair::from_secret_key(&secp_ctx, &secret_key).public_key()
+ };
+ let payer_keys = {
+ let secret_key = SecretKey::from_slice(&[42; 32]).unwrap();
+ KeyPair::from_secret_key(&secp_ctx, &secret_key)
+ };
+
+ let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey)
+ .amount_msats(100)
+ .build_unchecked()
+ .request_invoice(vec![0; 8], payer_keys.public_key()).unwrap()
+ .build_unchecked()
+ .sign(|message: &UnsignedInvoiceRequest|
+ Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &payer_keys))
+ )
+ .unwrap();
+
+ let tlv_stream = TlvStream::new(&invoice_request.bytes).range(0..1)
+ .chain(TlvStream::new(&invoice_request.bytes).range(1..80))
+ .chain(TlvStream::new(&invoice_request.bytes).range(80..160))
+ .chain(TlvStream::new(&invoice_request.bytes).range(160..240))
+ .chain(TlvStream::new(&invoice_request.bytes).range(SIGNATURE_TYPES))
+ .map(|r| r.record_bytes.to_vec())
+ .flatten()
+ .collect::<Vec<u8>>();
+
+ assert_eq!(tlv_stream, invoice_request.bytes);
+ }
+
impl AsRef<[u8]> for InvoiceRequest {
fn as_ref(&self) -> &[u8] {
&self.bytes
projects / rust-lightning / blobdiff