git / moonbite-core / src/key.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 <key.h>#include <crypto/common.h>#include <crypto/hmac_sha512.h>#include <random.h>#include <secp256k1.h>#include <secp256k1_recovery.h>static secp256k1_context* secp256k1_context_sign = nullptr;/** These functions are taken from the libsecp256k1 distribution and are very ugly. *//** * This parses a format loosely based on a DER encoding of the ECPrivateKey type from * section C.4 of SEC 1 <http://www.secg.org/sec1-v2.pdf>, with the following caveats: * * * The octet-length of the SEQUENCE must be encoded as 1 or 2 octets. It is not *   required to be encoded as one octet if it is less than 256, as DER would require. * * The octet-length of the SEQUENCE must not be greater than the remaining *   length of the key encoding, but need not match it (i.e. the encoding may contain *   junk after the encoded SEQUENCE). * * The privateKey OCTET STRING is zero-filled on the left to 32 octets. * * Anything after the encoding of the privateKey OCTET STRING is ignored, whether *   or not it is validly encoded DER. * * out32 must point to an output buffer of length at least 32 bytes. */int ec_seckey_import_der(const secp256k1_context* ctx, unsigned char *out32, const unsigned char *seckey, size_t seckeylen) {    const unsigned char *end = seckey + seckeylen;    memset(out32, 0, 32);    /* sequence header */    if (end - seckey < 1 || *seckey != 0x30u) {        return 0;    }    seckey++;    /* sequence length constructor */    if (end - seckey < 1 || !(*seckey & 0x80u)) {        return 0;    }    ptrdiff_t lenb = *seckey & ~0x80u; seckey++;    if (lenb < 1 || lenb > 2) {        return 0;    }    if (end - seckey < lenb) {        return 0;    }    /* sequence length */    ptrdiff_t len = seckey[lenb-1] | (lenb > 1 ? seckey[lenb-2] << 8 : 0u);    seckey += lenb;    if (end - seckey < len) {        return 0;    }    /* sequence element 0: version number (=1) */    if (end - seckey < 3 || seckey[0] != 0x02u || seckey[1] != 0x01u || seckey[2] != 0x01u) {        return 0;    }    seckey += 3;    /* sequence element 1: octet string, up to 32 bytes */    if (end - seckey < 2 || seckey[0] != 0x04u) {        return 0;    }    ptrdiff_t oslen = seckey[1];    seckey += 2;    if (oslen > 32 || end - seckey < oslen) {        return 0;    }    memcpy(out32 + (32 - oslen), seckey, oslen);    if (!secp256k1_ec_seckey_verify(ctx, out32)) {        memset(out32, 0, 32);        return 0;    }    return 1;}/** * This serializes to a DER encoding of the ECPrivateKey type from section C.4 of SEC 1 * <http://www.secg.org/sec1-v2.pdf>. The optional parameters and publicKey fields are * included. * * seckey must point to an output buffer of length at least CKey::SIZE bytes. * seckeylen must initially be set to the size of the seckey buffer. Upon return it * will be set to the number of bytes used in the buffer. * key32 must point to a 32-byte raw private key. */int ec_seckey_export_der(const secp256k1_context *ctx, unsigned char *seckey, size_t *seckeylen, const unsigned char *key32, bool compressed) {    assert(*seckeylen >= CKey::SIZE);    secp256k1_pubkey pubkey;    size_t pubkeylen = 0;    if (!secp256k1_ec_pubkey_create(ctx, &pubkey, key32)) {        *seckeylen = 0;        return 0;    }    if (compressed) {        static const unsigned char begin[] = {            0x30,0x81,0xD3,0x02,0x01,0x01,0x04,0x20        };        static const unsigned char middle[] = {            0xA0,0x81,0x85,0x30,0x81,0x82,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,            0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,            0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,            0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,            0x21,0x02,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,            0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,            0x17,0x98,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,            0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,            0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x24,0x03,0x22,0x00        };        unsigned char *ptr = seckey;        memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);        memcpy(ptr, key32, 32); ptr += 32;        memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);        pubkeylen = CPubKey::COMPRESSED_SIZE;        secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_COMPRESSED);        ptr += pubkeylen;        *seckeylen = ptr - seckey;        assert(*seckeylen == CKey::COMPRESSED_SIZE);    } else {        static const unsigned char begin[] = {            0x30,0x82,0x01,0x13,0x02,0x01,0x01,0x04,0x20        };        static const unsigned char middle[] = {            0xA0,0x81,0xA5,0x30,0x81,0xA2,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,            0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,            0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,            0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,            0x41,0x04,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,            0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,            0x17,0x98,0x48,0x3A,0xDA,0x77,0x26,0xA3,0xC4,0x65,0x5D,0xA4,0xFB,0xFC,0x0E,0x11,            0x08,0xA8,0xFD,0x17,0xB4,0x48,0xA6,0x85,0x54,0x19,0x9C,0x47,0xD0,0x8F,0xFB,0x10,            0xD4,0xB8,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,            0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,            0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x44,0x03,0x42,0x00        };        unsigned char *ptr = seckey;        memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);        memcpy(ptr, key32, 32); ptr += 32;        memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);        pubkeylen = CPubKey::SIZE;        secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_UNCOMPRESSED);        ptr += pubkeylen;        *seckeylen = ptr - seckey;        assert(*seckeylen == CKey::SIZE);    }    return 1;}bool CKey::Check(const unsigned char *vch) {    return secp256k1_ec_seckey_verify(secp256k1_context_sign, vch);}void CKey::MakeNewKey(bool fCompressedIn) {    do {        GetStrongRandBytes(keydata.data(), keydata.size());    } while (!Check(keydata.data()));    fValid = true;    fCompressed = fCompressedIn;}bool CKey::Negate(){    assert(fValid);    return secp256k1_ec_seckey_negate(secp256k1_context_sign, keydata.data());}CPrivKey CKey::GetPrivKey() const {    assert(fValid);    CPrivKey seckey;    int ret;    size_t seckeylen;    seckey.resize(SIZE);    seckeylen = SIZE;    ret = ec_seckey_export_der(secp256k1_context_sign, seckey.data(), &seckeylen, begin(), fCompressed);    assert(ret);    seckey.resize(seckeylen);    return seckey;}CPubKey CKey::GetPubKey() const {    assert(fValid);    secp256k1_pubkey pubkey;    size_t clen = CPubKey::SIZE;    CPubKey result;    int ret = secp256k1_ec_pubkey_create(secp256k1_context_sign, &pubkey, begin());    assert(ret);    secp256k1_ec_pubkey_serialize(secp256k1_context_sign, (unsigned char*)result.begin(), &clen, &pubkey, fCompressed ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED);    assert(result.size() == clen);    assert(result.IsValid());    return result;}// Check that the sig has a low R value and will be less than 71 bytesbool SigHasLowR(const secp256k1_ecdsa_signature* sig){    unsigned char compact_sig[64];    secp256k1_ecdsa_signature_serialize_compact(secp256k1_context_sign, compact_sig, sig);    // In DER serialization, all values are interpreted as big-endian, signed integers. The highest bit in the integer indicates    // its signed-ness; 0 is positive, 1 is negative. When the value is interpreted as a negative integer, it must be converted    // to a positive value by prepending a 0x00 byte so that the highest bit is 0. We can avoid this prepending by ensuring that    // our highest bit is always 0, and thus we must check that the first byte is less than 0x80.    return compact_sig[0] < 0x80;}bool CKey::Sign(const uint256 &hash, std::vector<unsigned char>& vchSig, bool grind, uint32_t test_case) const {    if (!fValid)        return false;    vchSig.resize(CPubKey::SIGNATURE_SIZE);    size_t nSigLen = CPubKey::SIGNATURE_SIZE;    unsigned char extra_entropy[32] = {0};    WriteLE32(extra_entropy, test_case);    secp256k1_ecdsa_signature sig;    uint32_t counter = 0;    int ret = secp256k1_ecdsa_sign(secp256k1_context_sign, &sig, hash.begin(), begin(), secp256k1_nonce_function_rfc6979, (!grind && test_case) ? extra_entropy : nullptr);    // Grind for low R    while (ret && !SigHasLowR(&sig) && grind) {        WriteLE32(extra_entropy, ++counter);        ret = secp256k1_ecdsa_sign(secp256k1_context_sign, &sig, hash.begin(), begin(), secp256k1_nonce_function_rfc6979, extra_entropy);    }    assert(ret);    secp256k1_ecdsa_signature_serialize_der(secp256k1_context_sign, vchSig.data(), &nSigLen, &sig);    vchSig.resize(nSigLen);    return true;}bool CKey::VerifyPubKey(const CPubKey& pubkey) const {    if (pubkey.IsCompressed() != fCompressed) {        return false;    }    unsigned char rnd[8];    std::string str = "Bitcoin key verification\n";    GetRandBytes(rnd, sizeof(rnd));    uint256 hash;    CHash256().Write(MakeUCharSpan(str)).Write(rnd).Finalize(hash);    std::vector<unsigned char> vchSig;    Sign(hash, vchSig);    return pubkey.Verify(hash, vchSig);}bool CKey::SignCompact(const uint256 &hash, std::vector<unsigned char>& vchSig) const {    if (!fValid)        return false;    vchSig.resize(CPubKey::COMPACT_SIGNATURE_SIZE);    int rec = -1;    secp256k1_ecdsa_recoverable_signature sig;    int ret = secp256k1_ecdsa_sign_recoverable(secp256k1_context_sign, &sig, hash.begin(), begin(), secp256k1_nonce_function_rfc6979, nullptr);    assert(ret);    ret = secp256k1_ecdsa_recoverable_signature_serialize_compact(secp256k1_context_sign, &vchSig[1], &rec, &sig);    assert(ret);    assert(rec != -1);    vchSig[0] = 27 + rec + (fCompressed ? 4 : 0);    return true;}bool CKey::Load(const CPrivKey &seckey, const CPubKey &vchPubKey, bool fSkipCheck=false) {    if (!ec_seckey_import_der(secp256k1_context_sign, (unsigned char*)begin(), seckey.data(), seckey.size()))        return false;    fCompressed = vchPubKey.IsCompressed();    fValid = true;    if (fSkipCheck)        return true;    return VerifyPubKey(vchPubKey);}bool CKey::Derive(CKey& keyChild, ChainCode &ccChild, unsigned int nChild, const ChainCode& cc) const {    assert(IsValid());    assert(IsCompressed());    std::vector<unsigned char, secure_allocator<unsigned char>> vout(64);    if ((nChild >> 31) == 0) {        CPubKey pubkey = GetPubKey();        assert(pubkey.size() == CPubKey::COMPRESSED_SIZE);        BIP32Hash(cc, nChild, *pubkey.begin(), pubkey.begin()+1, vout.data());    } else {        assert(size() == 32);        BIP32Hash(cc, nChild, 0, begin(), vout.data());    }    memcpy(ccChild.begin(), vout.data()+32, 32);    memcpy((unsigned char*)keyChild.begin(), begin(), 32);    bool ret = secp256k1_ec_seckey_tweak_add(secp256k1_context_sign, (unsigned char*)keyChild.begin(), vout.data());    keyChild.fCompressed = true;    keyChild.fValid = ret;    return ret;}bool CExtKey::Derive(CExtKey &out, unsigned int _nChild) const {    out.nDepth = nDepth + 1;    CKeyID id = key.GetPubKey().GetID();    memcpy(&out.vchFingerprint[0], &id, 4);    out.nChild = _nChild;    return key.Derive(out.key, out.chaincode, _nChild, chaincode);}void CExtKey::SetSeed(const unsigned char *seed, unsigned int nSeedLen) {    static const unsigned char hashkey[] = {'B','i','t','c','o','i','n',' ','s','e','e','d'};    std::vector<unsigned char, secure_allocator<unsigned char>> vout(64);    CHMAC_SHA512(hashkey, sizeof(hashkey)).Write(seed, nSeedLen).Finalize(vout.data());    key.Set(vout.data(), vout.data() + 32, true);    memcpy(chaincode.begin(), vout.data() + 32, 32);    nDepth = 0;    nChild = 0;    memset(vchFingerprint, 0, sizeof(vchFingerprint));}CExtPubKey CExtKey::Neuter() const {    CExtPubKey ret;    ret.nDepth = nDepth;    memcpy(&ret.vchFingerprint[0], &vchFingerprint[0], 4);    ret.nChild = nChild;    ret.pubkey = key.GetPubKey();    ret.chaincode = chaincode;    return ret;}void CExtKey::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);    code[41] = 0;    assert(key.size() == 32);    memcpy(code+42, key.begin(), 32);}void CExtKey::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);    key.Set(code+42, code+BIP32_EXTKEY_SIZE, true);}bool ECC_InitSanityCheck() {    CKey key;    key.MakeNewKey(true);    CPubKey pubkey = key.GetPubKey();    return key.VerifyPubKey(pubkey);}void ECC_Start() {    assert(secp256k1_context_sign == nullptr);    secp256k1_context *ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN);    assert(ctx != nullptr);    {        // Pass in a random blinding seed to the secp256k1 context.        std::vector<unsigned char, secure_allocator<unsigned char>> vseed(32);        GetRandBytes(vseed.data(), 32);        bool ret = secp256k1_context_randomize(ctx, vseed.data());        assert(ret);    }    secp256k1_context_sign = ctx;}void ECC_Stop() {    secp256k1_context *ctx = secp256k1_context_sign;    secp256k1_context_sign = nullptr;    if (ctx) {        secp256k1_context_destroy(ctx);    }}