Method Derive

src/pubkey.cpp:335–359

}

bool CPubKey::Derive(CPubKey& pubkeyChild, ChainCode &ccChild, unsigned int nChild, const ChainCode& cc, std::vector<unsigned char>* tweak) 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);
    if (tweak) {
        tweak->clear();
        *tweak = std::vector<unsigned char>(out, out+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;