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author | josibake <josibake@protonmail.com> | 2024-02-13 17:41:59 +0100 |
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committer | josibake <josibake@protonmail.com> | 2024-05-14 10:24:31 +0200 |
commit | b946f8a4c51be42e52d63a6d578158c0b2a6b7ed (patch) | |
tree | be4593a291f6ff4bc0a0f99f340dcb50f38951d3 | |
parent | 2cedb42a928fbf3a1e0e8715e918497cbe64af0d (diff) | |
download | bitcoin-b946f8a4c51be42e52d63a6d578158c0b2a6b7ed.tar.xz |
crypto: add NUMS_H const
-rw-r--r-- | src/pubkey.cpp | 12 | ||||
-rw-r--r-- | src/pubkey.h | 5 | ||||
-rwxr-xr-x | test/functional/feature_framework_unit_tests.py | 1 | ||||
-rw-r--r-- | test/functional/test_framework/crypto/secp256k1.py | 8 |
4 files changed, 26 insertions, 0 deletions
diff --git a/src/pubkey.cpp b/src/pubkey.cpp index 11e1b4abb5..13e3c2dbe0 100644 --- a/src/pubkey.cpp +++ b/src/pubkey.cpp @@ -13,6 +13,7 @@ #include <secp256k1_schnorrsig.h> #include <span.h> #include <uint256.h> +#include <util/strencodings.h> #include <algorithm> #include <cassert> @@ -181,6 +182,17 @@ int ecdsa_signature_parse_der_lax(secp256k1_ecdsa_signature* sig, const unsigned return 1; } +/** Nothing Up My Sleeve (NUMS) point + * + * NUMS_H is a point with an unknown discrete logarithm, constructed by taking the sha256 of 'g' + * (uncompressed encoding), which happens to be a point on the curve. + * + * For an example script for calculating H, refer to the unit tests in + * ./test/functional/test_framework/crypto/secp256k1.py + */ +static const std::vector<unsigned char> NUMS_H_DATA{ParseHex("50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac0")}; +const XOnlyPubKey XOnlyPubKey::NUMS_H{NUMS_H_DATA}; + XOnlyPubKey::XOnlyPubKey(Span<const unsigned char> bytes) { assert(bytes.size() == 32); diff --git a/src/pubkey.h b/src/pubkey.h index 15d7e7bc07..ae34ddd0af 100644 --- a/src/pubkey.h +++ b/src/pubkey.h @@ -233,6 +233,11 @@ private: uint256 m_keydata; public: + /** Nothing Up My Sleeve point H + * Used as an internal key for provably disabling the key path spend + * see BIP341 for more details */ + static const XOnlyPubKey NUMS_H; + /** Construct an empty x-only pubkey. */ XOnlyPubKey() = default; diff --git a/test/functional/feature_framework_unit_tests.py b/test/functional/feature_framework_unit_tests.py index c9754e083c..f03f084bed 100755 --- a/test/functional/feature_framework_unit_tests.py +++ b/test/functional/feature_framework_unit_tests.py @@ -25,6 +25,7 @@ TEST_FRAMEWORK_MODULES = [ "crypto.muhash", "crypto.poly1305", "crypto.ripemd160", + "crypto.secp256k1", "script", "segwit_addr", "wallet_util", diff --git a/test/functional/test_framework/crypto/secp256k1.py b/test/functional/test_framework/crypto/secp256k1.py index 2e9e419da5..50a46dce37 100644 --- a/test/functional/test_framework/crypto/secp256k1.py +++ b/test/functional/test_framework/crypto/secp256k1.py @@ -15,6 +15,8 @@ Exports: * G: the secp256k1 generator point """ +import unittest +from hashlib import sha256 class FE: """Objects of this class represent elements of the field GF(2**256 - 2**32 - 977). @@ -344,3 +346,9 @@ class FastGEMul: # Precomputed table with multiples of G for fast multiplication FAST_G = FastGEMul(G) + +class TestFrameworkSecp256k1(unittest.TestCase): + def test_H(self): + H = sha256(G.to_bytes_uncompressed()).digest() + assert GE.lift_x(FE.from_bytes(H)) is not None + self.assertEqual(H.hex(), "50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac0") |