Function ContextualCheckDynaFedHeader

src/validation.cpp:3700–3780

static bool ContextualCheckDynaFedHeader(const CBlockHeader& block, BlockValidationState& state, const CChainParams& params, const CBlockIndex* pindexPrev)
{
    // When not active, it's a NOP
    if (!DeploymentActiveAfter(pindexPrev, params.GetConsensus(), Consensus::DEPLOYMENT_DYNA_FED)) {
        return true;
    }

    const DynaFedParams& dynafed_params = block.m_dynafed_params;

    // Dynamic blocks must at least publish current signblockscript in full
    if (dynafed_params.m_current.IsNull()) {
        return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "invalid-dyna-fed", "dynamic block headers must have non-empty current signblockscript field");
    }

    // Make sure extension bits aren't active, reserved for future HF
    uint32_t reserved_mask = (1<<23) | (1<<24) | (1<<25) | (1<<26);
    if ((block.nVersion & reserved_mask) != 0) {
        return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "invalid-dyna-fed", "dynamic block header has unknown HF extension bits set");
    }

    const DynaFedParamEntry expected_current_params = ComputeNextBlockCurrentParameters(pindexPrev, params.GetConsensus());

    if (expected_current_params != dynafed_params.m_current) {
        return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "invalid-dyna-fed", "dynamic block header's current parameters do not match expected");
    }

    // Lastly, enforce rules on proposals if they make changes.
    if (!dynafed_params.m_proposed.IsNull()) {
        // Compare the new proposed parameters with the current full parameters.
        const DynaFedParamEntry current = ComputeNextBlockFullCurrentParameters(pindexPrev, params.GetConsensus());
        const DynaFedParamEntry& proposed = dynafed_params.m_proposed;

        if (proposed.m_signblockscript != current.m_signblockscript) {
            // signblockscript proposals *must* be segwit versions
            int block_version = 0;
            std::vector<unsigned char> block_program;
            if (!proposed.m_signblockscript.IsWitnessProgram(block_version, block_program)) {
                return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "invalid-dyna-fed", "proposed signblockscript must be native segwit scriptPubkey");
            }
        }

        if (proposed.m_fedpeg_program != current.m_fedpeg_program || proposed.m_fedpegscript != current.m_fedpegscript) {
            int fedpeg_version = 0;
            std::vector<unsigned char> fedpeg_program;
            if (!proposed.m_fedpeg_program.IsWitnessProgram(fedpeg_version, fedpeg_program)) {
                return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "invalid-dyna-fed", "proposed fedpeg program must be native segwit scriptPubkey");
            }

            // for v0, fedpegscript's scriptPubKey must match. v1+ is unencumbered.
            if (fedpeg_version == 0) {
                uint256 fedpeg_program;
                CSHA256().Write(proposed.m_fedpegscript.data(), proposed.m_fedpegscript.size()).Finalize(fedpeg_program.begin());
                CScript computed_program = CScript() << OP_0 << ToByteVector(fedpeg_program);
                if (computed_program != proposed.m_fedpeg_program) {
                    return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "invalid-dyna-fed", "proposed v0 segwit fedpegscript must match proposed fedpeg witness program");
                }

                // fedpegscript proposals *must not* start with OP_DEPTH