path: root/src/fp.cpp

#include <mcl/op.hpp>
#include <mcl/util.hpp>
#include <cybozu/crypto.hpp>
#include <cybozu/endian.hpp>
#include "conversion.hpp"
#include "fp_generator.hpp"
#include "low_func.hpp"
#ifdef MCL_USE_LLVM
#include "proto.hpp"
#include "low_func_llvm.hpp"
#endif
#include <cybozu/atoi.hpp>
#include <cybozu/itoa.hpp>

#ifdef _MSC_VER
    #pragma warning(disable : 4127)
#endif

namespace mcl {

namespace fp {

#ifdef MCL_USE_XBYAK
FpGenerator *Op::createFpGenerator()
{
    return new FpGenerator();
}
void Op::destroyFpGenerator(FpGenerator *fg)
{
    delete fg;
}
#else
FpGenerator *Op::createFpGenerator()
{
    return 0;
}
void Op::destroyFpGenerator(FpGenerator *)
{
}
#endif

inline void setUnitAsLE(void *p, Unit x)
{
#if CYBOZU_OS_BIT == 32
    cybozu::Set32bitAsLE(p, x);
#else
    cybozu::Set64bitAsLE(p, x);
#endif
}
inline Unit getUnitAsLE(const void *p)
{
#if CYBOZU_OS_BIT == 32
    return cybozu::Get32bitAsLE(p);
#else
    return cybozu::Get64bitAsLE(p);
#endif
}

const char *verifyStr(bool *isMinus, int *base, const std::string& str)
{
    const char *p = str.c_str();
    if (*p == '-') {
        *isMinus = true;
        p++;
    } else {
        *isMinus = false;
    }
    if (p[0] == '0') {
        if (p[1] == 'x') {
            if (*base == 0 || *base == 16 || *base == (16 | IoPrefix)) {
                *base = 16;
                p += 2;
            } else {
                throw cybozu::Exception("fp:verifyStr:0x conflicts with") << *base;
            }
        } else if (p[1] == 'b') {
            if (*base == 0 || *base == 2 || *base == (2 | IoPrefix)) {
                *base = 2;
                p += 2;
            } else {
                throw cybozu::Exception("fp:verifyStr:0b conflicts with") << *base;
            }
        }
    }
    if (*base == 0) *base = 10;
    if (*p == '\0') throw cybozu::Exception("fp:verifyStr:str is empty");
    return p;
}

const char *ModeToStr(Mode mode)
{
    switch (mode) {
    case FP_AUTO: return "auto";
    case FP_GMP: return "gmp";
    case FP_GMP_MONT: return "gmp_mont";
    case FP_LLVM: return "llvm";
    case FP_LLVM_MONT: return "llvm_mont";
    case FP_XBYAK: return "xbyak";
    default:
        throw cybozu::Exception("ModeToStr") << mode;
    }
}

Mode StrToMode(const std::string& s)
{
    static const struct {
        const char *s;
        Mode mode;
    } tbl[] = {
        { "auto", FP_AUTO },
        { "gmp", FP_GMP },
        { "gmp_mont", FP_GMP_MONT },
        { "llvm", FP_LLVM },
        { "llvm_mont", FP_LLVM_MONT },
        { "xbyak", FP_XBYAK },
    };
    for (size_t i = 0; i < CYBOZU_NUM_OF_ARRAY(tbl); i++) {
        if (s == tbl[i].s) return tbl[i].mode;
    }
    throw cybozu::Exception("StrToMode") << s;
}

void dumpUnit(Unit x)
{
#if CYBOZU_OS_BIT == 32
    printf("%08x", (uint32_t)x);
#else
    printf("%016llx", (unsigned long long)x);
#endif
}
void UnitToHex(char *buf, size_t maxBufSize, Unit x)
{
#if CYBOZU_OS_BIT == 32
    CYBOZU_SNPRINTF(buf, maxBufSize, "%08x", (uint32_t)x);
#else
    CYBOZU_SNPRINTF(buf, maxBufSize, "%016llx ", (unsigned long long)x);
#endif
}

// "123af" => { 0xaf, 0x23, 0x01 }
std::string hexStrToLittleEndian(const char *buf, size_t bufSize)
{
    std::string s;
    s.reserve((bufSize + 1) / 2);
    while (bufSize >= 2) {
        uint8_t c = cybozu::hextoi(&buf[bufSize - 2], 2);
        s += char(c);
        bufSize -= 2;
    }
    if (bufSize == 1) {
        uint8_t c = cybozu::hextoi(&buf[0], 1);
        s += char(c);
    }
    return s;
}

// { 0xaf, 0x23, 0x01 } => "0123af"
std::string littleEndianToHexStr(const char *buf, size_t bufSize)
{
    std::string s;
    s.resize(bufSize * 2);
    for (size_t i = 0; i < bufSize; i++) {
        cybozu::itohex(&s[i * 2], 2, (uint8_t)buf[bufSize - 1 - i], false);
    }
    return s;
}

bool isEnableJIT()
{
#if defined(MCL_USE_XBYAK)
    /* -1:not init, 0:disable, 1:enable */
    static int status = -1;
    if (status == -1) {
        const size_t size = 4096;
        uint8_t *p = (uint8_t*)malloc(size * 2);
        uint8_t *aligned = Xbyak::CodeArray::getAlignedAddress(p, size);
        bool ret = Xbyak::CodeArray::protect(aligned, size, true);
        status = ret ? 1 : 0;
        if (ret) {
            Xbyak::CodeArray::protect(aligned, size, false);
        }
        free(p);
    }
    return status != 0;
#else
    return false;
#endif
}

std::string hash(size_t bitSize, const char *msg, size_t msgSize)
{
    cybozu::crypto::Hash::Name name;
    if (bitSize <= 160) {
        name = cybozu::crypto::Hash::N_SHA1;
    } else if (bitSize <= 224) {
        name = cybozu::crypto::Hash::N_SHA224;
    } else if (bitSize <= 256) {
        name = cybozu::crypto::Hash::N_SHA256;
    } else if (bitSize <= 384) {
        name = cybozu::crypto::Hash::N_SHA384;
    } else {
        name = cybozu::crypto::Hash::N_SHA512;
    }
    return cybozu::crypto::Hash::digest(name, msg, msgSize);
}

static inline void set_mpz_t(mpz_t& z, const Unit* p, int n)
{
    int s = n;
    while (s > 0) {
        if (p[s - 1]) break;
        s--;
    }
    z->_mp_alloc = n;
    z->_mp_size = s;
    z->_mp_d = (mp_limb_t*)const_cast<Unit*>(p);
}

static inline void fp_invOpC(Unit *y, const Unit *x, const Op& op)
{
    const int N = (int)op.N;
    mpz_class my;
    mpz_t mx, mp;
    set_mpz_t(mx, x, N);
    set_mpz_t(mp, op.p, N);
    mpz_invert(my.get_mpz_t(), mx, mp);
    gmp::getArray(y, N, my);
}

/*
    inv(xR) = (1/x)R^-1 -toMont-> 1/x -toMont-> (1/x)R
*/
static void fp_invMontOpC(Unit *y, const Unit *x, const Op& op)
{
    fp_invOpC(y, x, op);
    op.fp_mul(y, y, op.R3, op.p);
}

/*
    large (N * 2) specification of AddPre, SubPre
*/
template<size_t N, bool enable>
struct SetFpDbl {
    static inline void exec(Op&) {}
};

template<size_t N>
struct SetFpDbl<N, true> {
    static inline void exec(Op& op)
    {
//      if (!op.isFullBit) {
            op.fpDbl_addPre = AddPre<N * 2, Ltag>::f;
            op.fpDbl_subPre = SubPre<N * 2, Ltag>::f;
//      }
    }
};

template<size_t N, class Tag, bool enableFpDbl>
void setOp2(Op& op)
{
    op.fp_shr1 = Shr1<N, Tag>::f;
    op.fp_neg = Neg<N, Tag>::f;
    if (op.isFullBit) {
        op.fp_add = Add<N, true, Tag>::f;
        op.fp_sub = Sub<N, true, Tag>::f;
    } else {
        op.fp_add = Add<N, false, Tag>::f;
        op.fp_sub = Sub<N, false, Tag>::f;
    }
    if (op.isMont) {
        if (op.isFullBit) {
            op.fp_mul = Mont<N, true, Tag>::f;
            op.fp_sqr = SqrMont<N, true, Tag>::f;
        } else {
            op.fp_mul = Mont<N, false, Tag>::f;
            op.fp_sqr = SqrMont<N, false, Tag>::f;
        }
        op.fpDbl_mod = MontRed<N, Tag>::f;
    } else {
        op.fp_mul = Mul<N, Tag>::f;
        op.fp_sqr = Sqr<N, Tag>::f;
        op.fpDbl_mod = Dbl_Mod<N, Tag>::f;
    }
    op.fp_mulUnit = MulUnit<N, Tag>::f;
    op.fpDbl_mulPre = MulPre<N, Tag>::f;
    op.fpDbl_sqrPre = SqrPre<N, Tag>::f;
    op.fp_mulUnitPre = MulUnitPre<N, Tag>::f;
    op.fpN1_mod = N1_Mod<N, Tag>::f;
    op.fpDbl_add = DblAdd<N, Tag>::f;
    op.fpDbl_sub = DblSub<N, Tag>::f;
    op.fp_addPre = AddPre<N, Tag>::f;
    op.fp_subPre = SubPre<N, Tag>::f;
    op.fp2_mulNF = Fp2MulNF<N, Tag>::f;
    SetFpDbl<N, enableFpDbl>::exec(op);
}

template<size_t N>
void setOp(Op& op, Mode mode)
{
    // generic setup
    op.fp_isZero = isZeroC<N>;
    op.fp_clear = clearC<N>;
    op.fp_copy = copyC<N>;
    if (op.isMont) {
        op.fp_invOp = fp_invMontOpC;
    } else {
        op.fp_invOp = fp_invOpC;
    }
    setOp2<N, Gtag, true>(op);
#ifdef MCL_USE_LLVM
    if (mode != fp::FP_GMP && mode != fp::FP_GMP_MONT) {
#if CYBOZU_HOST == CYBOZU_HOST_INTEL
        Xbyak::util::Cpu cpu;
        if (cpu.has(Xbyak::util::Cpu::tBMI2)) {
            setOp2<N, LBMI2tag, (N * UnitBitSize <= 256)>(op);
        } else
#endif
        {
            setOp2<N, Ltag, (N * UnitBitSize <= 256)>(op);
        }
    }
#else
    (void)mode;
#endif
}

#ifdef MCL_USE_XBYAK
inline void invOpForMontC(Unit *y, const Unit *x, const Op& op)
{
    Unit r[maxUnitSize];
    int k = op.fp_preInv(r, x);
    /*
        S = UnitBitSize
        xr = 2^k
        R = 2^(N * S)
        get r2^(-k)R^2 = r 2^(N * S * 2 - k)
    */
    op.fp_mul(y, r, op.invTbl.data() + k * op.N, op.p);
}

static void initInvTbl(Op& op)
{
    const size_t N = op.N;
    const Unit *p = op.p;
    const size_t invTblN = N * sizeof(Unit) * 8 * 2;
    op.invTbl.resize(invTblN * N);
    Unit *tbl = op.invTbl.data() + (invTblN - 1) * N;
    Unit t[maxUnitSize] = {};
    t[0] = 2;
    op.toMont(tbl, t);
    for (size_t i = 0; i < invTblN - 1; i++) {
        op.fp_add(tbl - N, tbl, tbl, p);
        tbl -= N;
    }
}
#endif

static void initForMont(Op& op, const Unit *p, Mode mode)
{
    const size_t N = op.N;
    {
        mpz_class t = 1, R;
        gmp::getArray(op.one, N, t);
        R = (t << (N * UnitBitSize)) % op.mp;
        t = (R * R) % op.mp;
        gmp::getArray(op.R2, N, t);
        t = (R * R * R) % op.mp;
        gmp::getArray(op.R3, N, t);
    }
    op.rp = getMontgomeryCoeff(p[0]);
    if (mode != FP_XBYAK) return;
#ifdef MCL_USE_XBYAK
    if (op.fg == 0) op.fg = Op::createFpGenerator();
    op.fg->init(op);

    if (op.isMont && N <= 4) {
        op.fp_invOp = &invOpForMontC;
        initInvTbl(op);
    }
#endif
}

void Op::init(const std::string& mstr, size_t maxBitSize, Mode mode)
{
    assert(sizeof(mp_limb_t) == sizeof(Unit));
    clear();
    if (maxBitSize > MCL_MAX_BIT_SIZE) {
        throw cybozu::Exception("Op:init:too large maxBitSize") << maxBitSize << MCL_MAX_BIT_SIZE;
    }
    { // set mp and p
        bool isMinus = false;
        int base = 0;
        const char *pstr = verifyStr(&isMinus, &base, mstr);
        if (isMinus) throw cybozu::Exception("Op:init:mstr is minus") << mstr;
        if (!gmp::setStr(mp, pstr, base)) {
            throw cybozu::Exception("Op:init:bad str") << mstr;
        }
        if (mp == 0) throw cybozu::Exception("Op:init:mstr is zero") << mstr;
    }
    gmp::getArray(p, (maxBitSize + fp::UnitBitSize - 1) / fp::UnitBitSize, mp);
    bitSize = gmp::getBitSize(mp);
/*
    priority : MCL_USE_XBYAK > MCL_USE_LLVM > none
    Xbyak > llvm_mont > llvm > gmp_mont > gmp
*/
#ifdef MCL_USE_XBYAK
    if (mode == fp::FP_AUTO) mode = fp::FP_XBYAK;
    if (mode == fp::FP_XBYAK && bitSize > 256) {
        mode = fp::FP_AUTO;
    }
    if (!fp::isEnableJIT()) {
        mode = fp::FP_AUTO;
    }
#else
    if (mode == fp::FP_XBYAK) mode = fp::FP_AUTO;
#endif
#ifdef MCL_USE_LLVM
    if (mode == fp::FP_AUTO) mode = fp::FP_LLVM_MONT;
#else
    if (mode == fp::FP_LLVM || mode == fp::FP_LLVM_MONT) mode = fp::FP_AUTO;
#endif
    isMont = mode == fp::FP_GMP_MONT || mode == fp::FP_LLVM_MONT || mode == fp::FP_XBYAK;
#ifndef NDEBUG
    fprintf(stderr, "mode=%s, isMont=%d, maxBitSize=%d"
#ifdef MCL_USE_XBYAK
        " MCL_USE_XBYAK"
#endif
#ifdef MCL_USE_LLVM
        " MCL_USE_LLVM"
#endif
    "\n", ModeToStr(mode), isMont, (int)maxBitSize);
#endif
    isFullBit = (bitSize % UnitBitSize) == 0;

#if defined(MCL_USE_LLVM) || defined(MCL_USE_XBYAK)
    if ((mode == FP_AUTO || mode == FP_LLVM || mode == FP_XBYAK)
        && mp == mpz_class("0xfffffffffffffffffffffffffffffffeffffffffffffffff")) {
        primeMode = PM_NICT_P192;
        isMont = false;
        isFastMod = true;
    }
    if ((mode == FP_AUTO || mode == FP_LLVM || mode == FP_XBYAK)
        && mp == mpz_class("0x1ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff")) {
        primeMode = PM_NICT_P521;
        isMont = false;
        isFastMod = true;
    }
#endif
    N = (bitSize + UnitBitSize - 1) / UnitBitSize;
    switch (N) {
    case 1:  setOp<1>(*this, mode); break;
    case 2:  setOp<2>(*this, mode); break;
    case 3:  setOp<3>(*this, mode); break;
    case 4:  setOp<4>(*this, mode); break; // 256 if 64-bit
#if MCL_MAX_UNIT_SIZE >= 6
    case 5:  setOp<5>(*this, mode); break;
    case 6:  setOp<6>(*this, mode); break;
#endif
#if MCL_MAX_UNIT_SIZE >= 8
    case 7:  setOp<7>(*this, mode); break;
    case 8:  setOp<8>(*this, mode); break;
#endif
#if MCL_MAX_UNIT_SIZE >= 9
    case 9:  setOp<9>(*this, mode); break; // 521 if 64-bit
#endif
#if MCL_MAX_UNIT_SIZE >= 10
    case 10: setOp<10>(*this, mode); break;
#endif
#if MCL_MAX_UNIT_SIZE >= 12
    case 11: setOp<11>(*this, mode); break;
    case 12: setOp<12>(*this, mode); break; // 768 if 64-bit
#endif
#if MCL_MAX_UNIT_SIZE >= 14
    case 13: setOp<13>(*this, mode); break;
    case 14: setOp<14>(*this, mode); break;
#endif
#if MCL_MAX_UNIT_SIZE >= 16
    case 15: setOp<15>(*this, mode); break;
    case 16: setOp<16>(*this, mode); break; // 1024 if 64-bit
#endif
#if MCL_MAX_UNIT_SIZE >= 17
    case 17: setOp<17>(*this, mode); break; // 521 if 32-bit
#endif
    default:
        throw cybozu::Exception("Op::init:not:support") << N << mstr;
    }
#ifdef MCL_USE_LLVM
    if (primeMode == PM_NICT_P192) {
        fp_mul = &mcl_fp_mulNIST_P192L;
        fp_sqr = &mcl_fp_sqr_NIST_P192L;
        fpDbl_mod = &mcl_fpDbl_mod_NIST_P192L;
    }
    if (primeMode == PM_NICT_P521) {
        fpDbl_mod = &mcl_fpDbl_mod_NIST_P521L;
    }
#endif
    fp::initForMont(*this, p, mode);
    sq.set(mp);
}

void arrayToStr(std::string& str, const Unit *x, size_t n, int ioMode)
{
    int base = ioMode & ~IoPrefix;
    bool withPrefix = (ioMode & IoPrefix) != 0;
    switch (base) {
    case 0:
    case 10:
        {
            mpz_class t;
            gmp::setArray(t, x, n);
            gmp::getStr(str, t, 10);
        }
        return;
    case 16:
        mcl::fp::toStr16(str, x, n, withPrefix);
        return;
    case 2:
        mcl::fp::toStr2(str, x, n, withPrefix);
        return;
    default:
        throw cybozu::Exception("fp:arrayToStr:bad base") << base;
    }
}

void copyUnitToByteAsLE(uint8_t *dst, const Unit *src, size_t byteSize)
{
    while (byteSize >= sizeof(Unit)) {
        setUnitAsLE(dst, *src++);
        dst += sizeof(Unit);
        byteSize -= sizeof(Unit);
    }
    if (byteSize == 0) return;
    Unit x = *src;
    while (byteSize) {
        *dst++ = static_cast<uint8_t>(x);
        x >>= 8;
        byteSize--;
    }
}

void copyByteToUnitAsLE(Unit *dst, const uint8_t *src, size_t byteSize)
{
    while (byteSize >= sizeof(Unit)) {
        *dst++ = getUnitAsLE(src);
        src += sizeof(Unit);
        byteSize -= sizeof(Unit);
    }
    if (byteSize == 0) return;
    Unit x = 0;
    for (size_t i = 0; i < byteSize; i++) {
        x |= Unit(src[i]) << (i * 8);
    }
    *dst = x;
}

int detectIoMode(int ioMode, const std::ios_base& ios)
{
    if (ioMode & ~IoPrefix) return ioMode;
    // IoAuto or IoPrefix
    const std::ios_base::fmtflags f = ios.flags();
    if (f & std::ios_base::oct) throw cybozu::Exception("mcl:fp:detectIoMode:oct is not supported");
    ioMode |= (f & std::ios_base::hex) ? IoHex : 0;
    if (f & std::ios_base::showbase) {
        ioMode |= IoPrefix;
    }
    return ioMode;
}

void streamToArray(bool *pIsMinus, Unit *x, size_t byteSize, std::istream& is, int ioMode)
{
    std::string str;
    if (ioMode & (IoArray | IoArrayRaw | IoFixedSizeByteSeq)) {
        str.resize(byteSize);
        is.read(&str[0], byteSize);
        *pIsMinus = false;
        fp::copyByteToUnitAsLE(x, reinterpret_cast<const uint8_t*>(str.c_str()), byteSize);
    } else {
        is >> str;
        // use low 8-bit ioMode for Fp
        ioMode &= 0xff;
        const char *p = verifyStr(pIsMinus, &ioMode, str);
        mpz_class mx;
        if (!gmp::setStr(mx, p, ioMode)) {
            throw cybozu::Exception("fp:streamToArray:bad format") << ioMode << str;
        }
        const size_t n = (byteSize + sizeof(Unit) - 1) / sizeof(Unit);
        gmp::getArray(x, n, mx);
    }
    if (!is) {
        throw cybozu::Exception("streamToArray:can't read") << byteSize;
    }
}

void copyAndMask(Unit *y, const void *x, size_t xByteSize, const Op& op, bool doMask)
{
    const size_t fpByteSize = sizeof(Unit) * op.N;
    if (xByteSize > fpByteSize) {
        if (!doMask) throw cybozu::Exception("fp:copyAndMask:bad size") << xByteSize << fpByteSize;
        xByteSize = fpByteSize;
    }
    // QQQ : fixed later for big endian
    copyByteToUnitAsLE(y, (const uint8_t*)x, xByteSize);
    for (size_t i = (xByteSize + sizeof(Unit) - 1) / sizeof(Unit); i < op.N; i++) {
        y[i] = 0;
    }
    if (!doMask) {
        if (isGreaterOrEqualArray(y, op.p, op.N)) throw cybozu::Exception("fp:copyAndMask:large x");
        return;
    }
    maskArray(y, op.N, op.bitSize - 1);
    assert(isLessArray(y, op.p, op.N));
}

static bool isInUint64(uint64_t *pv, const fp::Block& b)
{
    assert(fp::UnitBitSize == 32 || fp::UnitBitSize == 64);
    const size_t start = 64 / fp::UnitBitSize;
    for (size_t i = start; i < b.n; i++) {
        if (b.p[i]) return false;
    }
#if CYBOZU_OS_BIT == 32
    *pv = b.p[0] | (uint64_t(b.p[1]) << 32);
#else
    *pv = b.p[0];
#endif
    return true;
}

uint64_t getUint64(bool *pb, const fp::Block& b)
{
    uint64_t v;
    if (isInUint64(&v, b)) {
        if (pb) *pb = true;
        return v;
    }
    if (!pb) {
        std::string str;
        arrayToStr(str, b.p, b.n, 10);
        throw cybozu::Exception("fp::getUint64:large value") << str;
    }
    *pb = false;
    return 0;
}

#ifdef _MSC_VER
    #pragma warning(push)
    #pragma warning(disable : 4146)
#endif

int64_t getInt64(bool *pb, fp::Block& b, const fp::Op& op)
{
    bool isNegative = false;
    if (fp::isGreaterOrEqualArray(b.p, op.half, op.N)) {
        op.fp_neg(b.v_, b.p, op.p);
        b.p = b.v_;
        isNegative = true;
    }
    uint64_t v;
    if (fp::isInUint64(&v, b)) {
        const uint64_t c = uint64_t(1) << 63;
        if (isNegative) {
            if (v <= c) { // include c
                if (pb) *pb = true;
                // -1 << 63
                if (v == c) return int64_t(-9223372036854775807ll - 1);
                return int64_t(-v);
            }
        } else {
            if (v < c) { // not include c
                if (pb) *pb = true;
                return int64_t(v);
            }
        }
    }
    if (!pb) {
        std::string str;
        arrayToStr(str, b.p, b.n, 10);
        throw cybozu::Exception("fp::getInt64:large value") << str << isNegative;
    }
    *pb = false;
    return 0;
}

#ifdef _WIN32
    #pragma warning(pop)
#endif

void Op::initFp2(int _xi_a)
{
    this->xi_a = _xi_a;
//  if (N * UnitBitSize != 256) throw cybozu::Exception("Op2:init:not support size") << N;
}

} } // mcl::fp