secp256k1-zkp-sys: Add Rust FFI for Musig2 module

Author: GeneFerneau

secp256k1-zkp-sys/build.rs

@@ -43,6 +43,9 @@ fn main() {
         .define("ENABLE_MODULE_GENERATOR", Some("1"))
         .define("ENABLE_MODULE_RANGEPROOF", Some("1"))
         .define("ENABLE_MODULE_ECDSA_ADAPTOR", Some("1"))
+        .define("ENABLE_MODULE_EXTRAKEYS", Some("1"))
+        .define("ENABLE_MODULE_MUSIG", Some("1"))
+        .define("ENABLE_MODULE_SCHNORRSIG", Some("1"))
         .define("ECMULT_GEN_PREC_BITS", Some("4"))
         // TODO these three should be changed to use libgmp, at least until secp PR 290 is merged
         .define("USE_NUM_NONE", Some("1"))

secp256k1-zkp-sys/src/zkp.rs

@@ -1,5 +1,6 @@
 use core::{fmt, hash};
-use {types::*, Context, PublicKey, Signature};
+use {types::*, Context, KeyPair, PublicKey, Signature, XOnlyPublicKey};
+use {secp256k1_xonly_pubkey_from_pubkey};
 
 /// Rangeproof maximum length
 pub const RANGEPROOF_MAX_LENGTH: size_t = 5134;
@@ -334,6 +335,157 @@ extern "C" {
         adaptor_sig162: *const EcdsaAdaptorSignature,
         enckey: *const PublicKey,
     ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_pubkey_combine"
+    )]
+    pub fn secp256k1_musig_pubkey_combine(
+        cx: *const Context,
+        scratch: *mut ScratchSpace,
+        combined_pk: *mut XOnlyPublicKey,
+        pre_session: *mut MusigPreSession,
+        pubkeys: *const *const XOnlyPublicKey,
+        n_pubkeys: size_t,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_pubkey_tweak_add"
+    )]
+    pub fn secp256k1_musig_pubkey_tweak_add(
+        cx: *const Context,
+        pre_session: *mut MusigPreSession,
+        output_pubkey: *mut PublicKey,
+        internal_pubkey: *const XOnlyPublicKey,
+        tweak32: *const c_uchar,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_session_init"
+    )]
+    pub fn secp256k1_musig_session_init(
+        cx: *const Context,
+        secnonce: *mut MusigSecNonce,
+        pubnonce: *mut c_uchar,
+        session_id32: *const c_uchar,
+        seckey: *const c_uchar,
+        msg32: *const c_uchar,
+        combined_pk: *const XOnlyPublicKey,
+        extra_intput32: *const c_uchar,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_nonces_combine"
+    )]
+    pub fn secp256k1_musig_nonces_combine(
+        cx: *const Context,
+        combined_pubnonce: *const c_uchar,
+        pubnonces: *const *const c_uchar,
+        n_pubnonces: size_t,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_process_nonces"
+    )]
+    pub fn secp256k1_musig_process_nonces(
+        cx: *const Context,
+        session_cache: *mut MusigSessionCache,
+        sig_template: *mut MusigTemplate,
+        nonce_parity: *mut c_int,
+        pubnonces: *const *const c_uchar,
+        n_pubnonces: size_t,
+        msg32: *const c_uchar,
+        combined_pk: *const XOnlyPublicKey,
+        pre_session: *const MusigPreSession,
+        adaptor: *const PublicKey,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_partial_signature_serialize"
+    )]
+    pub fn secp256k1_musig_partial_signature_serialize(
+        cx: *const Context,
+        out32: *mut c_uchar,
+        sig: *const MusigPartialSignature,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_partial_signature_parse"
+    )]
+    pub fn secp256k1_musig_partial_signature_parse(
+        cx: *const Context,
+        sig: *mut MusigPartialSignature,
+        in32: *const c_uchar,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_partial_sign"
+    )]
+    pub fn secp256k1_musig_partial_sign(
+        cx: *const Context,
+        partial_sig: *mut MusigPartialSignature,
+        secnonce: *mut MusigSecNonce,
+        keypair: *const KeyPair,
+        pre_session: *const MusigPreSession,
+        session_cache: *const MusigSessionCache,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_partial_sig_verify"
+    )]
+    pub fn secp256k1_musig_partial_sig_verify(
+        cx: *const Context,
+        partial_sig: *const MusigPartialSignature,
+        pubnonce: *const c_uchar,
+        pubkey: *const XOnlyPublicKey,
+        pre_session: *const MusigPreSession,
+        session_cache: *const MusigSessionCache,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_partial_sig_combine"
+    )]
+    pub fn secp256k1_musig_partial_sig_combine(
+        cx: *const Context,
+        sig64: *mut c_uchar,
+        sig_template: *const MusigTemplate,
+        partial_sigs: *const *const MusigPartialSignature,
+        n_sigs: size_t,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_partial_sig_adapt"
+    )]
+    pub fn secp256k1_musig_partial_sig_adapt(
+        cx: *const Context,
+        adaptor_sig: *mut MusigPartialSignature,
+        partial_sig: *const MusigPartialSignature,
+        sec_adaptor32: *const c_uchar,
+        nonce_parity: c_int,
+    ) -> c_int;
+
+    #[cfg_attr(
+        not(feature = "external-symbols"),
+        link_name = "rustsecp256k1zkp_v0_4_0_musig_extract_secret_adaptor"
+    )]
+    pub fn secp256k1_musig_extract_secret_adaptor(
+        cx: *const Context,
+        sec_adaptor32: *mut c_uchar,
+        sig64: *const c_uchar,
+        partial_sigs: *const MusigPartialSignature,
+        n_partial_sigs: size_t,
+        nonce_parity: c_int,
+    ) -> c_int;
 }
 
 #[repr(C)]
@@ -510,3 +662,101 @@ impl EcdsaAdaptorSignature {
         &self.0
     }
 }
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct MusigPreSession {
+    pub magic: u64,
+    pub pk_hash: [c_uchar; 32],
+    pub second_pk: [c_uchar; 32],
+    pub pk_parity: c_int,
+    pub is_tweaked: c_int,
+    pub tweak: [c_uchar; 32],
+    pub internal_key_parity: c_int,
+}
+
+impl MusigPreSession {
+    pub fn new() -> Self {
+        Self {
+            magic: 0xf4ad_bbdf_7c7d_d304,
+            pk_hash: [0; 32],
+            second_pk: [0; 32],
+            pk_parity: 0,
+            is_tweaked: 0,
+            tweak: [0; 32],
+            internal_key_parity: 0,
+        }
+    }
+}
+
+#[repr(C)]
+pub struct ScratchSpace(c_int);
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct MusigPartialSignature {
+    pub data: [c_uchar; 32],
+}
+
+impl MusigPartialSignature {
+    pub fn new() -> Self {
+        Self { data: [0; 32] }
+    }
+}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct MusigTemplate {
+    pub data: [c_uchar; 64],
+}
+
+impl MusigTemplate {
+    pub fn new() -> Self {
+        Self { data: [0; 64] }
+    }
+}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct MusigSessionCache {
+    pub data: [c_uchar; 65],
+}
+
+impl MusigSessionCache {
+    pub fn new() -> Self {
+        Self { data: [0; 65] }
+    }
+}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct MusigSecNonce {
+    pub data: [c_uchar; 64],
+}
+
+impl MusigSecNonce {
+    pub fn new() -> Self {
+        Self { data: [0; 64] }
+    }
+}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct MusigPubNonce {
+    pub data: [c_uchar; 66],
+}
+
+impl MusigPubNonce {
+    pub fn new() -> Self {
+        Self { data: [0; 66] }
+    }
+}
+
+pub fn xonly_from_pubkey(cx: *const Context, pubkey: *const PublicKey) -> (XOnlyPublicKey, c_int) {
+    unsafe {
+        let mut xonly = XOnlyPublicKey::new();
+        let mut parity = 0;
+        secp256k1_xonly_pubkey_from_pubkey(cx, &mut xonly, &mut parity, pubkey);
+        (xonly, parity)
+    }
+}