Function IsValidPeginWitness

src/pegins.cpp:245–387

}

bool IsValidPeginWitness(const CScriptWitness& pegin_witness, const std::vector<std::pair<CScript, CScript>>& fedpegscripts, const COutPoint& prevout, std::string& err_msg, bool check_depth, bool* depth_failed) {
    if (depth_failed) {
        *depth_failed = false;
    }

    // 0) Return false if !consensus.has_parent_chain
    if (!Params().GetConsensus().has_parent_chain) {
        err_msg = "Parent chain is not enabled on this network.";
        return false;
    }

    // Format on stack is as follows:
    // 1) value - the value of the pegin output
    // 2) asset type - the asset type being pegged in
    // 3) genesis blockhash - genesis block of the parent chain
    // 4) claim script - script to be evaluated for spend authorization
    // 5) serialized transaction - serialized bitcoin transaction
    // 6) txout proof - merkle proof connecting transaction to header
    //
    // First 4 values(plus prevout) are enough to validate a peg-in without any internal knowledge
    // of Bitcoin serialization. This is useful for further abstraction by outsourcing
    // the other validity checks to RPC calls.

    const std::vector<std::vector<unsigned char> >& stack = pegin_witness.stack;
    // Must include all elements
    if (stack.size() != 6) {
        err_msg = "Not enough stack items.";
        return false;
    }

    CDataStream stream(stack[0], SER_NETWORK, PROTOCOL_VERSION);
    CAmount value;
    try {
        stream >> value;
    } catch (...) {
        err_msg = "Could not deserialize value.";
        return false;
    }

    if (!MoneyRange(value)) {
        err_msg = "Value was not in valid value range.";
        return false;
    }

    // Get asset type
    if (stack[1].size() != 32) {
        err_msg = "Asset type was not 32 bytes.";
        return false;
    }
    CAsset asset(stack[1]);

    // Get genesis blockhash
    if (stack[2].size() != 32) {
        err_msg = "Parent genesis blockchaash was not 32 bytes.";
        return false;
    }
    uint256 gen_hash(stack[2]);