Function IsSolvable

src/script/sign.cpp:435–452

}

bool IsSolvable(const CKeyStore& store, const CScript& script)
{
    // This check is to make sure that the script we created can actually be solved for and signed by us
    // if we were to have the private keys. This is just to make sure that the script is valid and that,
    // if found in a transaction, we would still accept and relay that transaction. In particular,
    // it will reject witness outputs that require signing with an uncompressed public key.
    DummySignatureCreator creator(&store);
    SignatureData sigs;
    // Make sure that STANDARD_SCRIPT_VERIFY_FLAGS includes SCRIPT_VERIFY_WITNESS_PUBKEYTYPE, the most
    // important property this function is designed to test for.
    static_assert(STANDARD_SCRIPT_VERIFY_FLAGS & SCRIPT_VERIFY_WITNESS_PUBKEYTYPE, "IsSolvable requires standard script flags to include WITNESS_PUBKEYTYPE");
    if (ProduceSignature(creator, script, sigs)) {
        // VerifyScript check is just defensive, and should never fail.
        assert(VerifyScript(sigs.scriptSig, script, &sigs.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, creator.Checker()));
        return true;
    }
    return false;
}