From 0664f5fe1f77f08d235aa3750b59428257b0b91d Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter@wuille.net>
Date: Fri, 11 Sep 2020 14:33:30 -0700
Subject: Support for Schnorr signatures and integration in SignatureCheckers
 (BIP 340)

This enables the schnorrsig module in libsecp256k1, adds the relevant types
and functions to src/pubkey, as well as in higher-level `SignatureChecker`
classes. The (verification side of the) BIP340 test vectors is also added.
---
 src/pubkey.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

(limited to 'src/pubkey.cpp')

diff --git a/src/pubkey.cpp b/src/pubkey.cpp
index fc14f41a0c..69e3d91392 100644
--- a/src/pubkey.cpp
+++ b/src/pubkey.cpp
@@ -7,6 +7,7 @@
 
 #include <secp256k1.h>
 #include <secp256k1_recovery.h>
+#include <secp256k1_schnorrsig.h>
 
 namespace
 {
@@ -166,6 +167,20 @@ int ecdsa_signature_parse_der_lax(const secp256k1_context* ctx, secp256k1_ecdsa_
     return 1;
 }
 
+XOnlyPubKey::XOnlyPubKey(Span<const unsigned char> bytes)
+{
+    assert(bytes.size() == 32);
+    std::copy(bytes.begin(), bytes.end(), m_keydata.begin());
+}
+
+bool XOnlyPubKey::VerifySchnorr(const uint256& msg, Span<const unsigned char> sigbytes) const
+{
+    assert(sigbytes.size() == 64);
+    secp256k1_xonly_pubkey pubkey;
+    if (!secp256k1_xonly_pubkey_parse(secp256k1_context_verify, &pubkey, m_keydata.data())) return false;
+    return secp256k1_schnorrsig_verify(secp256k1_context_verify, sigbytes.data(), msg.begin(), &pubkey);
+}
+
 bool CPubKey::Verify(const uint256 &hash, const std::vector<unsigned char>& vchSig) const {
     if (!IsValid())
         return false;
-- 
cgit v1.2.3


From 8bbed4b7acf4c76eaea8c0e10f3cbf6ba4e53809 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter@wuille.net>
Date: Fri, 11 Sep 2020 14:33:45 -0700
Subject: Implement Taproot validation (BIP 341)

This includes key path spending and script path spending, but not the
Tapscript execution implementation (leaf 0xc0 remains unemcumbered in
this commit).

Includes constants for various aspects of the consensus rules suggested
by Jeremy Rubin.
---
 src/pubkey.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'src/pubkey.cpp')

diff --git a/src/pubkey.cpp b/src/pubkey.cpp
index 69e3d91392..4d734fc891 100644
--- a/src/pubkey.cpp
+++ b/src/pubkey.cpp
@@ -181,6 +181,13 @@ bool XOnlyPubKey::VerifySchnorr(const uint256& msg, Span<const unsigned char> si
     return secp256k1_schnorrsig_verify(secp256k1_context_verify, sigbytes.data(), msg.begin(), &pubkey);
 }
 
+bool XOnlyPubKey::CheckPayToContract(const XOnlyPubKey& base, const uint256& hash, bool parity) const
+{
+    secp256k1_xonly_pubkey base_point;
+    if (!secp256k1_xonly_pubkey_parse(secp256k1_context_verify, &base_point, base.data())) return false;
+    return secp256k1_xonly_pubkey_tweak_add_check(secp256k1_context_verify, m_keydata.begin(), parity, &base_point, hash.begin());
+}
+
 bool CPubKey::Verify(const uint256 &hash, const std::vector<unsigned char>& vchSig) const {
     if (!IsValid())
         return false;
-- 
cgit v1.2.3