teems/App/appconfig.cpp

#include <iostream>
#include "Untrusted.hpp"
#include "appconfig.hpp"

// The next line suppresses a deprecation warning within boost
#define BOOST_BIND_GLOBAL_PLACEHOLDERS
#include "boost/property_tree/ptree.hpp"
#include "boost/property_tree/json_parser.hpp"

// Split a hostport string like "127.0.0.1:12000" at the rightmost colon
// into a host part "127.0.0.1" and a port part "12000".
static bool split_host_port(std::string &host, std::string &port,
    const std::string &hostport)
{
    size_t colon = hostport.find_last_of(':');
    if (colon == std::string::npos) {
        std::cerr << "Cannot parse \"" << hostport << "\" as host:port\n";
        return false;
    }
    host = hostport.substr(0, colon);
    port = hostport.substr(colon+1);
    return true;
}

// Convert a single hex character into its value from 0 to 15. Return
// true on success, false if it wasn't a hex character.
static inline bool hextoval(unsigned char &val, char hex)
{
    if (hex >= '0' && hex <= '9') {
        val = ((unsigned char)hex)-'0';
    } else if (hex >= 'a' && hex <= 'f') {
        val = ((unsigned char)hex)-'a'+10;
    } else if (hex >= 'A' && hex <= 'F') {
        val = ((unsigned char)hex)-'A'+10;
    } else {
        return false;
    }
    return true;
}

// Convert a 2*len hex character string into a len-byte buffer. Return
// true on success, false on failure.
static bool hextobuf(unsigned char *buf, const char *str, size_t len)
{
    if (strlen(str) != 2*len) {
        std::cerr << "Hex string was not the expected size\n";
        return false;
    }
    for (size_t i=0;i<len;++i) {
        unsigned char hi, lo;
        if (!hextoval(hi, str[2*i]) || !hextoval(lo, str[2*i+1])) {
            std::cerr << "Cannot parse string as hex\n";
            return false;
        }
        buf[i] = (unsigned char)((hi << 4) + lo);
    }
    return true;
}

bool config_parse(Config &config, const std::string configstr,
    const std::string &myname)
{
    bool found_my_node = false;
    bool found_params = false;
    bool ret = true;

    std::istringstream configstream(configstr);
    boost::property_tree::ptree conftree;

    read_json(configstream, conftree);

    for (auto & entry : conftree) {
        if (!entry.first.compare("params")) {
            for (auto & pentry : entry.second) {
                if (!pentry.first.compare("msgsize")) {
                    config.msgsize = pentry.second.get_value<uint16_t>();
                } else {
                    std::cerr << "Unknown field in params: " <<
                        pentry.first << "\n";
                    ret = false;
                }
            }
            found_params = true;
        } else if (!entry.first.compare("nodes")) {
            for (auto & node : entry.second) {
                NodeConfig nc;
                nc.weight = 1;  // default
                for (auto & nentry : node.second) {
                    if (!nentry.first.compare("name")) {
                        nc.name = nentry.second.get_value<std::string>();
                        if (!myname.compare(nc.name)) {
                            config.my_node_num =
                                nodenum_t(config.nodes.size());
                            found_my_node = true;
                        }
                    } else if (!nentry.first.compare("pubkey")) {
                        ret &= hextobuf((unsigned char *)&nc.pubkey,
                            nentry.second.get_value<std::string>().c_str(),
                            sizeof(nc.pubkey));
                    } else if (!nentry.first.compare("weight")) {
                        nc.weight = nentry.second.get_value<std::uint8_t>();
                    } else if (!nentry.first.compare("listen")) {
                        ret &= split_host_port(nc.listenhost, nc.listenport,
                            nentry.second.get_value<std::string>());
                    } else if (!nentry.first.compare("clisten")) {
                        ret &= split_host_port(nc.clistenhost, nc.clistenport,
                            nentry.second.get_value<std::string>());
                    } else {
                        std::cerr << "Unknown field in host config: " <<
                            nentry.first << "\n";
                        ret = false;
                    }
                }
                config.nodes.push_back(std::move(nc));
            }
        } else {
            std::cerr << "Unknown key in config: " <<
                entry.first << "\n";
            ret = false;
        }
    }

    if (!found_params) {
        std::cerr << "Could not find params in config\n";
        ret = false;
    }
    if (!found_my_node) {
        std::cerr << "Could not find my own node entry in config\n";
        ret = false;
    }

    if (!ret) return ret;

    // Now load the config into the enclave
    EnclaveAPIParams apiparams;
    apiparams.msgsize = config.msgsize;
    nodenum_t num_nodes = (nodenum_t)(config.nodes.size());
    std::vector<EnclaveAPINodeConfig> apinodeconfigs;
    apinodeconfigs.resize(num_nodes);
    for (nodenum_t i=0; i<num_nodes; ++i) {
        memmove(&apinodeconfigs[i].pubkey,
            &config.nodes[i].pubkey, sizeof(apinodeconfigs[i].pubkey));
        apinodeconfigs[i].weight = config.nodes[i].weight;
    }
    ret &= ecall_config_load(&apiparams, apinodeconfigs.data(),
        num_nodes, config.my_node_num);
    if (!ret) {
        std::cerr << "Loading config into enclave failed\n";
    }

    return ret;
}