path: root/src/bls_c.cpp

#define MCLBN_DONT_EXPORT
#define BLS_DLL_EXPORT

#include <bls/bls.h>

#include "../mcl/src/bn_c_impl.hpp"

/*
    BLS signature
    e : G1 x G2 -> Fp12
    Q in G2 ; fixed global parameter
    H : {str} -> G1
    s : secret key
    sQ ; public key
    s H(m) ; signature of m
    verify ; e(sQ, H(m)) = e(Q, s H(m))
*/

static G2 g_Q;
static mcl::Array<Fp6> g_Qcoeff; // precomputed Q
static const G2& getQ() { return g_Q; }
static const mcl::Array<Fp6>& getQcoeff() { return g_Qcoeff; }

int blsInitNotThreadSafe(int curve, int maxUnitSize)
{
    int ret = mclBn_init(curve, maxUnitSize);
    if (ret < 0) return ret;
    bool b;
    mapToG2(&b, g_Q, 1);
    if (!b) return -100;
    if (!precomputeG2(g_Qcoeff, getQ())) return -101;
    return 0;
}

#ifdef __EMSCRIPTEN__
extern "C" BLS_DLL_API void *blsMalloc(size_t n)
{
    return malloc(n);
}
extern "C" BLS_DLL_API void blsFree(void *p)
{
    free(p);
}
#endif

#ifndef __EMSCRIPTEN__
    #if defined(CYBOZU_CPP_VERSION) && CYBOZU_CPP_VERSION >= CYBOZU_CPP_VERSION_CPP11
    #include <mutex>
        #define USE_STD_MUTEX
    #else
    #include <cybozu/mutex.hpp>
        #define USE_CYBOZU_MUTEX
    #endif
#endif

int blsInit(int curve, int maxUnitSize)
{
    int ret = 0;
#ifdef USE_STD_MUTEX
    static std::mutex m;
    std::lock_guard<std::mutex> lock(m);
#elif defined(USE_CYBOZU_MUTEX)
    static cybozu::Mutex m;
    cybozu::AutoLock lock(m);
#endif
    static int g_curve = -1;
    if (g_curve != curve) {
        ret = blsInitNotThreadSafe(curve, maxUnitSize);
        g_curve = curve;
    }
    return ret;
}

static inline const mclBnG1 *cast(const G1* x) { return (const mclBnG1*)x; }
static inline const mclBnG2 *cast(const G2* x) { return (const mclBnG2*)x; }

/*
    e(P1, Q1) == e(P2, Q2)
    <=> finalExp(ML(P1, Q1)) == finalExp(ML(P2, Q2))
    <=> finalExp(ML(P1, Q1) / ML(P2, Q2)) == 1
    <=> finalExp(ML(P1, Q1) * ML(-P2, Q2)) == 1
    Q1 is precomputed
*/
bool isEqualTwoPairings(const G1& P1, const Fp6* Q1coeff, const G1& P2, const G2& Q2)
{
    mcl::Array<Fp6> Q2coeff;
    if (!precomputeG2(Q2coeff, Q2)) return false;
    Fp12 e;
    precomputedMillerLoop2(e, P1, Q1coeff, -P2, Q2coeff.data());
    finalExp(e, e);
    return e.isOne();
}

mclSize blsGetOpUnitSize() // FpUint64Size
{
    return Fp::getUnitSize() * sizeof(mcl::fp::Unit) / sizeof(uint64_t);
}

int blsGetCurveOrder(char *buf, mclSize maxBufSize)
{
    return Fr::getModulo(buf, maxBufSize);
}

int blsGetFieldOrder(char *buf, mclSize maxBufSize)
{
    return Fp::getModulo(buf, maxBufSize);
}

void blsGetGeneratorOfG2(blsPublicKey *pub)
{
    *(G2*)pub = getQ();
}

void blsGetPublicKey(blsPublicKey *pub, const blsSecretKey *sec)
{
    mclBnG2_mul(&pub->v, cast(&getQ()), &sec->v);
}
void blsSign(blsSignature *sig, const blsSecretKey *sec, const void *m, mclSize size)
{
    G1 Hm;
    hashAndMapToG1(Hm, m, size);
    mclBnG1_mulCT(&sig->v, cast(&Hm), &sec->v);
}
int blsSecretKeyShare(blsSecretKey *sec, const blsSecretKey* msk, mclSize k, const blsId *id)
{
    return mclBn_FrEvaluatePolynomial(&sec->v, &msk->v, k, &id->v);
}

int blsSecretKeyRecover(blsSecretKey *sec, const blsSecretKey *secVec, const blsId *idVec, mclSize n)
{
    return mclBn_FrLagrangeInterpolation(&sec->v, &idVec->v, &secVec->v, n);
}

void blsGetPop(blsSignature *sig, const blsSecretKey *sec)
{
    blsPublicKey pub;
    blsGetPublicKey(&pub, sec);
    char buf[1024];
    mclSize n = mclBnG2_serialize(buf, sizeof(buf), &pub.v);
    assert(n);
    blsSign(sig, sec, buf, n);
}
int blsPublicKeyShare(blsPublicKey *pub, const blsPublicKey *mpk, mclSize k, const blsId *id)
{
    return mclBn_G2EvaluatePolynomial(&pub->v, &mpk->v, k, &id->v);
}
int blsPublicKeyRecover(blsPublicKey *pub, const blsPublicKey *pubVec, const blsId *idVec, mclSize n)
{
    return mclBn_G2LagrangeInterpolation(&pub->v, &idVec->v, &pubVec->v, n);
}
int blsSignatureRecover(blsSignature *sig, const blsSignature *sigVec, const blsId *idVec, mclSize n)
{
    return mclBn_G1LagrangeInterpolation(&sig->v, &idVec->v, &sigVec->v, n);
}

int blsVerify(const blsSignature *sig, const blsPublicKey *pub, const void *m, mclSize size)
{
    G1 Hm;
    hashAndMapToG1(Hm, m, size);
    /*
        e(sHm, Q) = e(Hm, sQ)
        e(sig, Q) = e(Hm, pub)
    */
    return isEqualTwoPairings(*cast(&sig->v), getQcoeff().data(), Hm, *cast(&pub->v));
}

int blsVerifyPop(const blsSignature *sig, const blsPublicKey *pub)
{
    char buf[1024];
    mclSize n = mclBnG2_serialize(buf, sizeof(buf), &pub->v);
    if (n == 0) return 0;
    return blsVerify(sig, pub, buf, n);
}

void blsIdSetInt(blsId *id, int x)
{
    mclBnFr_setInt(&id->v, x);
}
mclSize blsIdSerialize(void *buf, mclSize maxBufSize, const blsId *id)
{
    return mclBnFr_serialize(buf, maxBufSize, &id->v);
}
mclSize blsSecretKeySerialize(void *buf, mclSize maxBufSize, const blsSecretKey *sec)
{
    return mclBnFr_serialize(buf, maxBufSize, &sec->v);
}
mclSize blsPublicKeySerialize(void *buf, mclSize maxBufSize, const blsPublicKey *pub)
{
    return mclBnG2_serialize(buf, maxBufSize, &pub->v);
}
mclSize blsSignatureSerialize(void *buf, mclSize maxBufSize, const blsSignature *sig)
{
    return mclBnG1_serialize(buf, maxBufSize, &sig->v);
}
mclSize blsIdDeserialize(blsId *id, const void *buf, mclSize bufSize)
{
    return mclBnFr_deserialize(&id->v, buf, bufSize);
}
mclSize blsSecretKeyDeserialize(blsSecretKey *sig, const void *buf, mclSize bufSize)
{
    return mclBnFr_deserialize(&sig->v, buf, bufSize);
}
mclSize blsPublicKeyDeserialize(blsPublicKey *pub, const void *buf, mclSize bufSize)
{
    return mclBnG2_deserialize(&pub->v, buf, bufSize);
}
mclSize blsSignatureDeserialize(blsSignature *sig, const void *buf, mclSize bufSize)
{
    return mclBnG1_deserialize(&sig->v, buf, bufSize);
}
int blsIdIsEqual(const blsId *lhs, const blsId *rhs)
{
    return mclBnFr_isEqual(&lhs->v, &rhs->v);
}
int blsSecretKeyIsEqual(const blsSecretKey *lhs, const blsSecretKey *rhs)
{
    return mclBnFr_isEqual(&lhs->v, &rhs->v);
}
int blsPublicKeyIsEqual(const blsPublicKey *lhs, const blsPublicKey *rhs)
{
    return mclBnG2_isEqual(&lhs->v, &rhs->v);
}
int blsSignatureIsEqual(const blsSignature *lhs, const blsSignature *rhs)
{
    return mclBnG1_isEqual(&lhs->v, &rhs->v);
}
void blsSecretKeyAdd(blsSecretKey *sec, const blsSecretKey *rhs)
{
    mclBnFr_add(&sec->v, &sec->v, &rhs->v);
}
void blsSignatureAdd(blsSignature *sig, const blsSignature *rhs)
{
    mclBnG1_add(&sig->v, &sig->v, &rhs->v);
}
void blsPublicKeyAdd(blsPublicKey *pub, const blsPublicKey *rhs)
{
    mclBnG2_add(&pub->v, &pub->v, &rhs->v);
}
int blsIdSetLittleEndian(blsId *id, const void *buf, mclSize bufSize)
{
    return mclBnFr_setLittleEndian(&id->v, buf, bufSize);
}
int blsIdSetDecStr(blsId *id, const char *buf, mclSize bufSize)
{
    return mclBnFr_setStr(&id->v, buf, bufSize, 10);
}
int blsIdSetHexStr(blsId *id, const char *buf, mclSize bufSize)
{
    return mclBnFr_setStr(&id->v, buf, bufSize, 16);
}
mclSize blsIdGetLittleEndian(void *buf, mclSize maxBufSize, const blsId *id)
{
    return mclBnFr_serialize(buf, maxBufSize, &id->v);
}
mclSize blsIdGetDecStr(char *buf, mclSize maxBufSize, const blsId *id)
{
    return mclBnFr_getStr(buf, maxBufSize, &id->v, 10);
}
mclSize blsIdGetHexStr(char *buf, mclSize maxBufSize, const blsId *id)
{
    return mclBnFr_getStr(buf, maxBufSize, &id->v, 16);
}
int blsSecretKeySetLittleEndian(blsSecretKey *sec, const void *buf, mclSize bufSize)
{
    return mclBnFr_setLittleEndian(&sec->v, buf, bufSize);
}
int blsSecretKeySetDecStr(blsSecretKey *sec, const char *buf, mclSize bufSize)
{
    return mclBnFr_setStr(&sec->v, buf, bufSize, 10);
}
int blsSecretKeySetHexStr(blsSecretKey *sec, const char *buf, mclSize bufSize)
{
    return mclBnFr_setStr(&sec->v, buf, bufSize, 16);
}
mclSize blsSecretKeyGetLittleEndian(void *buf, mclSize maxBufSize, const blsSecretKey *sec)
{
    return mclBnFr_serialize(buf, maxBufSize, &sec->v);
}
mclSize blsSecretKeyGetDecStr(char *buf, mclSize maxBufSize, const blsSecretKey *sec)
{
    return mclBnFr_getStr(buf, maxBufSize, &sec->v, 10);
}
mclSize blsSecretKeyGetHexStr(char *buf, mclSize maxBufSize, const blsSecretKey *sec)
{
    return mclBnFr_getStr(buf, maxBufSize, &sec->v, 16);
}
int blsHashToSecretKey(blsSecretKey *sec, const void *buf, mclSize bufSize)
{
    return mclBnFr_setHashOf(&sec->v, buf, bufSize);
}
int blsSecretKeySetByCSPRNG(blsSecretKey *sec)
{
    return mclBnFr_setByCSPRNG(&sec->v);
}
int blsPublicKeySetHexStr(blsPublicKey *pub, const char *buf, mclSize bufSize)
{
    return mclBnG2_setStr(&pub->v, buf, bufSize, 16);
}
mclSize blsPublicKeyGetHexStr(char *buf, mclSize maxBufSize, const blsPublicKey *pub)
{
    return mclBnG2_getStr(buf, maxBufSize, &pub->v, 16);
}
int blsSignatureSetHexStr(blsSignature *sig, const char *buf, mclSize bufSize)
{
    return mclBnG1_setStr(&sig->v, buf, bufSize, 16);
}
mclSize blsSignatureGetHexStr(char *buf, mclSize maxBufSize, const blsSignature *sig)
{
    return mclBnG1_getStr(buf, maxBufSize, &sig->v, 16);
}
void blsDHKeyExchange(blsPublicKey *out, const blsSecretKey *sec, const blsPublicKey *pub)
{
    mclBnG2_mulCT(&out->v, &pub->v, &sec->v);
}