git / moonbite-core / src/pubkey.cpp · raw
// Copyright (c) 2009-2019 The Bitcoin Core developers// Copyright (c) 2017 The Zcash developers// Distributed under the MIT software license, see the accompanying// file COPYING or http://www.opensource.org/licenses/mit-license.php.#include <pubkey.h>#include <secp256k1.h>#include <secp256k1_recovery.h>#include <secp256k1_schnorrsig.h>namespace{/* Global secp256k1_context object used for verification. */secp256k1_context* secp256k1_context_verify = nullptr;} // namespace/** This function is taken from the libsecp256k1 distribution and implements * DER parsing for ECDSA signatures, while supporting an arbitrary subset of * format violations. * * Supported violations include negative integers, excessive padding, garbage * at the end, and overly long length descriptors. This is safe to use in * Bitcoin because since the activation of BIP66, signatures are verified to be * strict DER before being passed to this module, and we know it supports all * violations present in the blockchain before that point. */int ecdsa_signature_parse_der_lax(const secp256k1_context* ctx, secp256k1_ecdsa_signature* sig, const unsigned char *input, size_t inputlen) { size_t rpos, rlen, spos, slen; size_t pos = 0; size_t lenbyte; unsigned char tmpsig[64] = {0}; int overflow = 0; /* Hack to initialize sig with a correctly-parsed but invalid signature. */ secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig); /* Sequence tag byte */ if (pos == inputlen || input[pos] != 0x30) { return 0; } pos++; /* Sequence length bytes */ if (pos == inputlen) { return 0; } lenbyte = input[pos++]; if (lenbyte & 0x80) { lenbyte -= 0x80; if (lenbyte > inputlen - pos) { return 0; } pos += lenbyte; } /* Integer tag byte for R */ if (pos == inputlen || input[pos] != 0x02) { return 0; } pos++; /* Integer length for R */ if (pos == inputlen) { return 0; } lenbyte = input[pos++]; if (lenbyte & 0x80) { lenbyte -= 0x80; if (lenbyte > inputlen - pos) { return 0; } while (lenbyte > 0 && input[pos] == 0) { pos++; lenbyte--; } static_assert(sizeof(size_t) >= 4, "size_t too small"); if (lenbyte >= 4) { return 0; } rlen = 0; while (lenbyte > 0) { rlen = (rlen << 8) + input[pos]; pos++; lenbyte--; } } else { rlen = lenbyte; } if (rlen > inputlen - pos) { return 0; } rpos = pos; pos += rlen; /* Integer tag byte for S */ if (pos == inputlen || input[pos] != 0x02) { return 0; } pos++; /* Integer length for S */ if (pos == inputlen) { return 0; } lenbyte = input[pos++]; if (lenbyte & 0x80) { lenbyte -= 0x80; if (lenbyte > inputlen - pos) { return 0; } while (lenbyte > 0 && input[pos] == 0) { pos++; lenbyte--; } static_assert(sizeof(size_t) >= 4, "size_t too small"); if (lenbyte >= 4) { return 0; } slen = 0; while (lenbyte > 0) { slen = (slen << 8) + input[pos]; pos++; lenbyte--; } } else { slen = lenbyte; } if (slen > inputlen - pos) { return 0; } spos = pos; /* Ignore leading zeroes in R */ while (rlen > 0 && input[rpos] == 0) { rlen--; rpos++; } /* Copy R value */ if (rlen > 32) { overflow = 1; } else { memcpy(tmpsig + 32 - rlen, input + rpos, rlen); } /* Ignore leading zeroes in S */ while (slen > 0 && input[spos] == 0) { slen--; spos++; } /* Copy S value */ if (slen > 32) { overflow = 1; } else { memcpy(tmpsig + 64 - slen, input + spos, slen); } if (!overflow) { overflow = !secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig); } if (overflow) { /* Overwrite the result again with a correctly-parsed but invalid signature if parsing failed. */ memset(tmpsig, 0, 64); secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig); } 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 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; secp256k1_pubkey pubkey; secp256k1_ecdsa_signature sig; assert(secp256k1_context_verify && "secp256k1_context_verify must be initialized to use CPubKey."); if (!secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey, vch, size())) { return false; } if (!ecdsa_signature_parse_der_lax(secp256k1_context_verify, &sig, vchSig.data(), vchSig.size())) { return false; } /* libsecp256k1's ECDSA verification requires lower-S signatures, which have * not historically been enforced in Bitcoin, so normalize them first. */ secp256k1_ecdsa_signature_normalize(secp256k1_context_verify, &sig, &sig); return secp256k1_ecdsa_verify(secp256k1_context_verify, &sig, hash.begin(), &pubkey);}bool CPubKey::RecoverCompact(const uint256 &hash, const std::vector<unsigned char>& vchSig) { if (vchSig.size() != COMPACT_SIGNATURE_SIZE) return false; int recid = (vchSig[0] - 27) & 3; bool fComp = ((vchSig[0] - 27) & 4) != 0; secp256k1_pubkey pubkey; secp256k1_ecdsa_recoverable_signature sig; assert(secp256k1_context_verify && "secp256k1_context_verify must be initialized to use CPubKey."); if (!secp256k1_ecdsa_recoverable_signature_parse_compact(secp256k1_context_verify, &sig, &vchSig[1], recid)) { return false; } if (!secp256k1_ecdsa_recover(secp256k1_context_verify, &pubkey, &sig, hash.begin())) { return false; } unsigned char pub[SIZE]; size_t publen = SIZE; secp256k1_ec_pubkey_serialize(secp256k1_context_verify, pub, &publen, &pubkey, fComp ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED); Set(pub, pub + publen); return true;}bool CPubKey::IsFullyValid() const { if (!IsValid()) return false; secp256k1_pubkey pubkey; assert(secp256k1_context_verify && "secp256k1_context_verify must be initialized to use CPubKey."); return secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey, vch, size());}bool CPubKey::Decompress() { if (!IsValid()) return false; secp256k1_pubkey pubkey; assert(secp256k1_context_verify && "secp256k1_context_verify must be initialized to use CPubKey."); if (!secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey, vch, size())) { return false; } unsigned char pub[SIZE]; size_t publen = SIZE; secp256k1_ec_pubkey_serialize(secp256k1_context_verify, pub, &publen, &pubkey, SECP256K1_EC_UNCOMPRESSED); Set(pub, pub + publen); return true;}bool CPubKey::Derive(CPubKey& pubkeyChild, ChainCode &ccChild, unsigned int nChild, const ChainCode& cc) const { assert(IsValid()); assert((nChild >> 31) == 0); assert(size() == COMPRESSED_SIZE); unsigned char out[64]; BIP32Hash(cc, nChild, *begin(), begin()+1, out); memcpy(ccChild.begin(), out+32, 32); secp256k1_pubkey pubkey; assert(secp256k1_context_verify && "secp256k1_context_verify must be initialized to use CPubKey."); if (!secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey, vch, size())) { return false; } if (!secp256k1_ec_pubkey_tweak_add(secp256k1_context_verify, &pubkey, out)) { return false; } unsigned char pub[COMPRESSED_SIZE]; size_t publen = COMPRESSED_SIZE; secp256k1_ec_pubkey_serialize(secp256k1_context_verify, pub, &publen, &pubkey, SECP256K1_EC_COMPRESSED); pubkeyChild.Set(pub, pub + publen); return true;}void CExtPubKey::Encode(unsigned char code[BIP32_EXTKEY_SIZE]) const { code[0] = nDepth; memcpy(code+1, vchFingerprint, 4); code[5] = (nChild >> 24) & 0xFF; code[6] = (nChild >> 16) & 0xFF; code[7] = (nChild >> 8) & 0xFF; code[8] = (nChild >> 0) & 0xFF; memcpy(code+9, chaincode.begin(), 32); assert(pubkey.size() == CPubKey::COMPRESSED_SIZE); memcpy(code+41, pubkey.begin(), CPubKey::COMPRESSED_SIZE);}void CExtPubKey::Decode(const unsigned char code[BIP32_EXTKEY_SIZE]) { nDepth = code[0]; memcpy(vchFingerprint, code+1, 4); nChild = (code[5] << 24) | (code[6] << 16) | (code[7] << 8) | code[8]; memcpy(chaincode.begin(), code+9, 32); pubkey.Set(code+41, code+BIP32_EXTKEY_SIZE);}bool CExtPubKey::Derive(CExtPubKey &out, unsigned int _nChild) const { out.nDepth = nDepth + 1; CKeyID id = pubkey.GetID(); memcpy(&out.vchFingerprint[0], &id, 4); out.nChild = _nChild; return pubkey.Derive(out.pubkey, out.chaincode, _nChild, chaincode);}/* static */ bool CPubKey::CheckLowS(const std::vector<unsigned char>& vchSig) { secp256k1_ecdsa_signature sig; assert(secp256k1_context_verify && "secp256k1_context_verify must be initialized to use CPubKey."); if (!ecdsa_signature_parse_der_lax(secp256k1_context_verify, &sig, vchSig.data(), vchSig.size())) { return false; } return (!secp256k1_ecdsa_signature_normalize(secp256k1_context_verify, nullptr, &sig));}/* static */ int ECCVerifyHandle::refcount = 0;ECCVerifyHandle::ECCVerifyHandle(){ if (refcount == 0) { assert(secp256k1_context_verify == nullptr); secp256k1_context_verify = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY); assert(secp256k1_context_verify != nullptr); } refcount++;}ECCVerifyHandle::~ECCVerifyHandle(){ refcount--; if (refcount == 0) { assert(secp256k1_context_verify != nullptr); secp256k1_context_destroy(secp256k1_context_verify); secp256k1_context_verify = nullptr; }}