diff --git a/Cargo.toml b/Cargo.toml index d36fba9b8..124e6e8a5 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -65,6 +65,10 @@ required-features = ["hashes", "std"] name = "generate_keys" required-features = ["rand", "std"] +[[example]] +name = "musig" +required-features = ["rand", "std"] + [workspace] members = ["secp256k1-sys"] exclude = ["no_std_test"] diff --git a/examples/musig.rs b/examples/musig.rs new file mode 100644 index 000000000..f3265910d --- /dev/null +++ b/examples/musig.rs @@ -0,0 +1,81 @@ +extern crate secp256k1; + +use secp256k1::{Keypair, Message, PublicKey, Scalar, Secp256k1, SecretKey }; +use secp256k1::musig::{MusigKeyAggCache, MusigPubNonce, MusigSessionId, MusigPartialSignature, new_musig_nonce_pair, MusigAggNonce, MusigSession}; + +fn main() { + + let secp = Secp256k1::new(); + let mut rng = rand::thread_rng(); + + let (seckey1, pubkey1) = secp.generate_keypair(&mut rng); + + let seckey2 = SecretKey::new(&mut rng); + let pubkey2 = PublicKey::from_secret_key(&secp, &seckey2); + + let pubkeys = [pubkey1, pubkey2]; + let pubkeys_ref: Vec<&PublicKey> = pubkeys.iter().collect(); + let pubkeys_ref = pubkeys_ref.as_slice(); + + let mut musig_key_agg_cache = MusigKeyAggCache::new(&secp, pubkeys_ref); + + let plain_tweak: [u8; 32] = *b"this could be a BIP32 tweak....\0"; + let xonly_tweak: [u8; 32] = *b"this could be a Taproot tweak..\0"; + + let plain_tweak = Scalar::from_be_bytes(plain_tweak).unwrap(); + musig_key_agg_cache.pubkey_ec_tweak_add(&secp, &plain_tweak).unwrap(); + + let xonly_tweak = Scalar::from_be_bytes(xonly_tweak).unwrap(); + let tweaked_agg_pk = musig_key_agg_cache.pubkey_xonly_tweak_add(&secp, &xonly_tweak).unwrap(); + + let agg_pk = musig_key_agg_cache.agg_pk(); + + assert_eq!(agg_pk, tweaked_agg_pk.x_only_public_key().0); + + let msg_bytes: [u8; 32] = *b"this_could_be_the_hash_of_a_msg!"; + let msg = Message::from_digest_slice(&msg_bytes).unwrap(); + + let musig_session_id1 = MusigSessionId::new(&mut rng); + + let nonce_pair1 = + new_musig_nonce_pair(&secp, musig_session_id1, Some(&musig_key_agg_cache), Some(seckey1), pubkey1, Some(msg), None).unwrap(); + + let musig_session_id2 = MusigSessionId::new(&mut rng); + + let nonce_pair2 = + new_musig_nonce_pair(&secp, musig_session_id2, Some(&musig_key_agg_cache), Some(seckey2), pubkey2, Some(msg), None).unwrap(); + + let sec_nonce1 = nonce_pair1.0; + let pub_nonce1 = nonce_pair1.1; + + let sec_nonce2 = nonce_pair2.0; + let pub_nonce2 = nonce_pair2.1; + + let nonces = [pub_nonce1, pub_nonce2]; + let nonces_ref: Vec<&MusigPubNonce> = nonces.iter().collect(); + let nonces_ref = nonces_ref.as_slice(); + + let agg_nonce = MusigAggNonce::new(&secp, nonces_ref); + + let session = MusigSession::new(&secp, &musig_key_agg_cache, agg_nonce, msg); + + let keypair1 = Keypair::from_secret_key(&secp, &seckey1); + let partial_sign1 = session.partial_sign(&secp, sec_nonce1, &keypair1, &musig_key_agg_cache).unwrap(); + + let keypair2 = Keypair::from_secret_key(&secp, &seckey2); + let partial_sign2 = session.partial_sign(&secp, sec_nonce2, &keypair2, &musig_key_agg_cache).unwrap(); + + let is_partial_signature_valid = session.partial_verify(&secp, &musig_key_agg_cache, partial_sign1, pub_nonce1, pubkey1); + assert!(is_partial_signature_valid); + + let is_partial_signature_valid = session.partial_verify(&secp, &musig_key_agg_cache, partial_sign2, pub_nonce2, pubkey2); + assert!(is_partial_signature_valid); + + let partial_sigs = [partial_sign1, partial_sign2]; + let partial_sigs_ref: Vec<&MusigPartialSignature> = partial_sigs.iter().collect(); + let partial_sigs_ref = partial_sigs_ref.as_slice(); + + let sig64 = session.partial_sig_agg(partial_sigs_ref); + + assert!(secp.verify_schnorr(&sig64, &msg_bytes, &agg_pk).is_ok()); +}