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#include <bls/bls.hpp>
#include <cybozu/option.hpp>
#include <cybozu/itoa.hpp>
#include <fstream>
const std::string pubFile = "sample/publickey";
const std::string secFile = "sample/secretkey";
const std::string signFile = "sample/sign";
std::string makeName(const std::string& name, const bls::Id& id)
{
const std::string suf = ".txt";
if (id.isZero()) return name + suf;
std::ostringstream os;
os << name << '.' << id << suf;
return os.str();
}
template<class T>
void save(const std::string& file, const T& t, const bls::Id& id = 0)
{
const std::string name = makeName(file, id);
std::ofstream ofs(name.c_str(), std::ios::binary);
if (!(ofs << t)) {
throw cybozu::Exception("can't save") << name;
}
}
template<class T>
void load(T& t, const std::string& file, const bls::Id& id = 0)
{
const std::string name = makeName(file, id);
std::ifstream ifs(name.c_str(), std::ios::binary);
if (!(ifs >> t)) {
throw cybozu::Exception("can't load") << name;
}
}
int init()
{
printf("make %s and %s files\n", secFile.c_str(), pubFile.c_str());
bls::SecretKey sec;
sec.init();
save(secFile, sec);
bls::PublicKey pub;
sec.getPublicKey(pub);
save(pubFile, pub);
return 0;
}
int sign(const std::string& m, int id)
{
printf("sign message `%s` by id=%d\n", m.c_str(), id);
bls::SecretKey sec;
load(sec, secFile, id);
bls::Sign s;
sec.sign(s, m);
save(signFile, s, id);
return 0;
}
int verify(const std::string& m, int id)
{
printf("verify message `%s` by id=%d\n", m.c_str(), id);
bls::PublicKey pub;
load(pub, pubFile, id);
bls::Sign s;
load(s, signFile, id);
if (s.verify(pub, m)) {
puts("verify ok");
return 0;
} else {
puts("verify err");
return 1;
}
}
int share(size_t n, size_t k)
{
printf("%d-out-of-%d threshold sharing\n", (int)k, (int)n);
bls::SecretKey sec;
load(sec, secFile);
bls::SecretKeyVec msk;
sec.getMasterSecretKey(msk, k);
bls::SecretKeyVec secVec(n);
bls::IdVec ids(n);
for (size_t i = 0; i < n; i++) {
int id = i + 1;
ids[i] = id;
secVec[i].set(msk, id);
}
for (size_t i = 0; i < n; i++) {
save(secFile, secVec[i], ids[i]);
bls::PublicKey pub;
secVec[i].getPublicKey(pub);
save(pubFile, pub, ids[i]);
}
return 0;
}
int recover(const bls::IdVec& ids)
{
printf("recover from");
for (size_t i = 0; i < ids.size(); i++) {
std::cout << ' ' << ids[i];
}
printf("\n");
bls::SignVec signVec(ids.size());
for (size_t i = 0; i < signVec.size(); i++) {
load(signVec[i], signFile, ids[i]);
}
bls::Sign s;
s.recover(signVec, ids);
save(signFile, s);
return 0;
}
int main(int argc, char *argv[])
try
{
bls::init();
std::string mode;
std::string m;
size_t n;
size_t k;
int id;
bls::IdVec ids;
cybozu::Option opt;
opt.appendParam(&mode, "init|sign|verify|share|recover");
opt.appendOpt(&n, 10, "n", ": k-out-of-n threshold");
opt.appendOpt(&k, 3, "k", ": k-out-of-n threshold");
opt.appendOpt(&m, "", "m", ": message to be signed");
opt.appendOpt(&id, 0, "id", ": id of secretKey");
opt.appendVec(&ids, "ids", ": select k id in [0, n). this option should be last");
opt.appendHelp("h");
if (!opt.parse(argc, argv)) {
goto ERR_EXIT;
}
if (mode == "init") {
return init();
} else if (mode == "sign") {
if (m.empty()) goto ERR_EXIT;
return sign(m, id);
} else if (mode == "verify") {
if (m.empty()) goto ERR_EXIT;
return verify(m, id);
} else if (mode == "share") {
return share(n, k);
} else if (mode == "recover") {
if (ids.empty()) {
fprintf(stderr, "use -ids option. ex. share -ids 1 3 5\n");
goto ERR_EXIT;
}
return recover(ids);
} else {
fprintf(stderr, "bad mode %s\n", mode.c_str());
}
ERR_EXIT:
opt.usage();
return 1;
} catch (std::exception& e) {
fprintf(stderr, "ERR %s\n", e.what());
return 1;
}
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