#include "bn_ops.h"

#include <iostream>

namespace cryptofuzz {

namespace module {

namespace wolfCrypt_detail {

#if defined(CRYPTOFUZZ_WOLFCRYPT_ALLOCATION_FAILURES)

    extern bool disableAllocationFailures;

    extern bool haveAllocFailure;

#endif

} /* namespace wolfCrypt_detail */

namespace wolfCrypt_bignum {

Bignum::read_radix_error_t Bignum::read_radix(mp_int* dest, const std::string& str, const size_t base) {

    return read_radix(dest, str.c_str(), base);

}

Bignum::read_radix_error_t Bignum::read_radix(mp_int* dest, const char* str, const size_t base) {

    Bignum::read_radix_error_t ret;

    /* Create a temporary variable for storing the result of mp_read_radix,

     * because if mp_read_radix fails (e.g. due to allocation failure),

     * it will set the value of the destination variable to 0.

     *

     * See OSS-Fuzz 31709 / ZD 11834 for discussion. */

    auto newMp = (mp_int*)util::malloc(sizeof(mp_int));

    if ( mp_init(newMp) != MP_OKAY ) {

        util::free(newMp);

        return READ_RADIX_FAIL_MEMORY;

    }

    wolfCrypt_detail::haveAllocFailure = false;

    if ( mp_read_radix(newMp, str, base) != MP_OKAY ) {

        ret = wolfCrypt_detail::haveAllocFailure ? READ_RADIX_FAIL_MEMORY : READ_RADIX_FAIL_OTHER;

        goto end;

    }

    wolfCrypt_detail::haveAllocFailure = false;

    if ( mp_copy(newMp, dest) != MP_OKAY ) {

        ret = wolfCrypt_detail::haveAllocFailure ? READ_RADIX_FAIL_MEMORY : READ_RADIX_FAIL_OTHER;

        goto end;

    }

    ret = READ_RADIX_OK;

end:

    CF_NORET(mp_clear(newMp));

    util::free(newMp);

    return ret;

}

void Bignum::baseConversion(void) const {

#if !defined(WOLFSSL_SP_MATH)

    uint8_t base = 2;

    char* str = nullptr;

    try { base = ds.Get<uint8_t>(); } catch ( fuzzing::datasource::Datasource::OutOfData ) { }

#if defined(CRYPTOFUZZ_WOLFCRYPT_DEBUG)

    std::cout << "Convert to base " << std::to_string(base) << " and back" << std::endl;

#endif

    {

        int size;

        CF_CHECK_EQ(mp_radix_size(mp, base, &size), MP_OKAY);

        CF_ASSERT(size > 0, "Output of mp_radix_size is 0 or less");

        str = (char*)util::malloc(size);

#if defined(WOLFSSL_SP_MATH) || defined(WOLFSSL_SP_MATH_ALL) || !defined(USE_FAST_MATH)

        CF_CHECK_EQ(mp_toradix(mp, str, base), MP_OKAY);

#else

        wolfCrypt_detail::haveAllocFailure = false;

        CF_ASSERT(

                    mp_toradix(mp, str, base) == MP_OKAY ||

                    wolfCrypt_detail::haveAllocFailure ||

                    base < 2 ||

                    base > 64,

                    "wolfCrypt cannot convert mp to string");

        /* If allocation failure occurred, then do not use 'str' */

        CF_CHECK_FALSE(wolfCrypt_detail::haveAllocFailure);

#endif

        {

            const auto ret = read_radix(mp, str, base);

            CF_ASSERT(ret == READ_RADIX_OK || ret == READ_RADIX_FAIL_MEMORY, "wolfCrypt cannot parse the output of mp_toradix");

        }

    }

end:

    util::free(str);

#endif

}

void Bignum::binaryConversion(void) const {

    uint8_t* data = nullptr;

    CF_CHECK_EQ(mp_isneg(mp), 0);

#if LIBWOLFSSL_VERSION_HEX == 0x05005001

    {

        /* Old version of the binary conversion logic, which doesn't crash if

         * mp_to_unsigned_bin_len() succeeds with an undersized buffer.

         *

         * This logic is retained specifically to prevent the libecc

         * OSS-Fuzz fuzzer from crashing, because this uses an older version

         * of wolfCrypt (specifically 0x05005001), which still has the

         * mp_to_unsigned_bin_len() bug.

         */

        const auto size = mp_unsigned_bin_size(mp);

        CF_ASSERT(size >= 0, "mp_unsigned_bin_size returned negative value");

        data = util::malloc(size);

        CF_CHECK_EQ(mp_to_unsigned_bin_len(mp, data, size), MP_OKAY);

        /* Ensure no allocation failure occurs in mp_read_unsigned_bin

         * because this can leave the mp in a corrupted state

         */

        const auto cached_disableAllocationFailures = wolfCrypt_detail::disableAllocationFailures;

        wolfCrypt_detail::disableAllocationFailures = true;

        CF_ASSERT(mp_read_unsigned_bin(mp, data, size) == MP_OKAY, "Cannot parse output of mp_to_unsigned_bin_len");

        wolfCrypt_detail::disableAllocationFailures = cached_disableAllocationFailures;

    }

#else

    {

        bool randomSize = false;

        try { randomSize = ds.Get<bool>(); } catch ( fuzzing::datasource::Datasource::OutOfData ) { }

        size_t size = 0;

        int numBits = 0;

        if ( randomSize == false ) {

            const auto size2 = mp_unsigned_bin_size(mp);

            CF_ASSERT(size2 >= 0, "mp_unsigned_bin_size returned negative value");

            size = size2;

        } else {

            try {

                size = ds.Get<uint16_t>();

            } catch ( fuzzing::datasource::Datasource::OutOfData ) { }

            numBits = mp_count_bits(mp);

            CF_ASSERT(numBits >= 0, "mp_count_bits result is negative");

        }

        data = util::malloc(size);

        CF_CHECK_EQ(mp_to_unsigned_bin_len(mp, data, size), MP_OKAY);

        CF_ASSERT(

                size * 8 >= static_cast<size_t>(numBits),

                "mp_to_unsigned_bin_len succeeded with undersized buffer");

        /* Ensure no allocation failure occurs in mp_read_unsigned_bin

         * because this can leave the mp in a corrupted state

         */

        const auto cached_disableAllocationFailures = wolfCrypt_detail::disableAllocationFailures;

        wolfCrypt_detail::disableAllocationFailures = true;

        if ( randomSize == false ) {

            CF_ASSERT(mp_read_unsigned_bin(mp, data, size) == MP_OKAY, "Cannot parse output of mp_to_unsigned_bin_len");

        } else {

            /* mp_read_unsigned_bin can fail if the input buffer is too large.

             *

             * Read into a temp variable, and copy to mp if reading succeeds, otherwise

             * retain old value in mp.

             */

            Bignum tmp(ds);

            if ( mp_read_unsigned_bin(tmp.GetPtrDirect(), data, size) == MP_OKAY ) {

                /* ignore result */ mp_copy(tmp.GetPtrDirect(), mp);

            }

        }

        wolfCrypt_detail::disableAllocationFailures = cached_disableAllocationFailures;

    }

#endif

end:

    util::free(data);

}

void Bignum::invariants(void) const {

#if defined(WOLFSSL_SP_MATH) || defined(WOLFSSL_SP_MATH_ALL)

    CF_ASSERT(mp->used <= mp->size, "used is larger than size");

#elif !defined(USE_FAST_MATH)

    CF_ASSERT(mp->used <= mp->alloc, "used is larger than size");

#endif

}

Bignum::Bignum(Datasource& ds) :

    ds(ds) {

    mp = (mp_int*)util::malloc(sizeof(mp_int));

    if ( init_mp_int(mp, ds) != MP_OKAY ) {

        util::free(mp);

        throw std::exception();

    }

}

Bignum::Bignum(mp_int* mp, Datasource& ds) :

    mp(mp),

    ds(ds),

    noFree(true)

{ }

Bignum::Bignum(const Bignum& other) :

    ds(other.ds) {

    mp = (mp_int*)util::malloc(sizeof(mp_int));

    if ( init_mp_int(mp, ds) != MP_OKAY ) {

        util::free(mp);

        throw std::exception();

    }

    if ( mp_copy(other.mp, mp) != MP_OKAY ) {

        util::free(mp);

        throw std::exception();

    }

}

Bignum::Bignum(const Bignum&& other) :

    ds(other.ds) {

    mp = (mp_int*)util::malloc(sizeof(mp_int));

    if ( init_mp_int(mp, ds) != MP_OKAY ) {

        util::free(mp);

        throw std::exception();

    }

    if ( mp_copy(other.mp, mp) != MP_OKAY ) {

        util::free(mp);

        throw std::exception();

    }

}

Bignum::~Bignum() {

    invariants();

    if ( noFree == false ) {

        CF_NORET(mp_clear(mp));

        util::free(mp);

    }

}

void Bignum::SetNoFree(void) {

    noFree = true;

}

bool Bignum::Set(const std::string s) {

    bool ret = false;

    bool hex = false;

    try {

        hex = ds.Get<bool>();

    } catch ( ... ) { }

#if defined(WOLFSSL_SP_MATH)

    hex = true;

#endif

    if ( hex == true ) {

        CF_CHECK_EQ(read_radix(mp, util::DecToHex(s), 16), READ_RADIX_OK);

    } else {

        CF_CHECK_EQ(read_radix(mp, s, 10), READ_RADIX_OK);

    }

    ret = true;

end:

    return ret;

}

bool Bignum::Set(const component::Bignum i) {

    bool ret = false;

    CF_CHECK_EQ(Set(i.ToString()), true);

    ret = true;

end:

    return ret;

}

mp_int* Bignum::GetPtr(void) const {

    invariants();

    {

        /* Optionally clamp the bignum. This should not affect its value. */

        bool clamp = false;

        try { clamp = ds.Get<bool>(); } catch ( fuzzing::datasource::Datasource::OutOfData ) { }

        if ( clamp ) {

            /* Implemented as a macro so CF_NORET cannot be used here */

            /* noret */ mp_clamp(mp);

        }

    }

    {

        /* Optionally convert to a random base and back */

        bool convert = false;

        try { convert = ds.Get<bool>(); } catch ( fuzzing::datasource::Datasource::OutOfData ) { }

        if ( convert ) {

            baseConversion();

        }

    }

    {

        /* Optionally convert to bytes and back */

        bool convert = false;

        try { convert = ds.Get<bool>(); } catch ( fuzzing::datasource::Datasource::OutOfData ) { }

        if ( convert ) {

            binaryConversion();

        }

    }

    return mp;

}

mp_int* Bignum::GetPtrDirect(void) const {

    return mp;

}

std::optional<uint64_t> Bignum::AsUint64(void) const {

    std::optional<uint64_t> ret = std::nullopt;

    uint64_t v = 0;

#if !defined(WOLFSSL_SP_MATH)

    CF_CHECK_EQ(mp_isneg(mp), 0);

#endif

    CF_CHECK_LTE(mp_count_bits(mp), (int)(sizeof(v) * 8));

    CF_CHECK_EQ(mp_to_unsigned_bin_len(mp, (uint8_t*)&v, sizeof(v)), MP_OKAY);

    v =

        ((v & 0xFF00000000000000) >> 56) |

        ((v & 0x00FF000000000000) >> 40) |

        ((v & 0x0000FF0000000000) >> 24) |

        ((v & 0x000000FF00000000) >>  8) |

        ((v & 0x00000000FF000000) <<  8) |

        ((v & 0x0000000000FF0000) << 24) |

        ((v & 0x000000000000FF00) << 40) |

        ((v & 0x00000000000000FF) << 56);

    ret = v;

end:

    return ret;

}

std::optional<std::string> Bignum::ToDecString(void) {

    std::optional<std::string> ret = std::nullopt;

    char* str = nullptr;

#if defined(WOLFSSL_SP_MATH)

    str = (char*)util::malloc(8192);

    CF_CHECK_EQ(mp_tohex(mp, str), MP_OKAY);

    ret = { util::HexToDec(str) };

#else

    bool hex = false;

    int size;

    try {

        hex = ds.Get<bool>();

    } catch ( ... ) { }

    if ( hex == true ) {

        CF_CHECK_EQ(mp_radix_size(mp, 16, &size), MP_OKAY);

        CF_ASSERT(size > 0, "Output of mp_radix_size is 0 or less");

        str = (char*)util::malloc(size+1);

        CF_CHECK_EQ(mp_tohex(mp, str), MP_OKAY);

        ret = { util::HexToDec(str) };

    } else {

        CF_CHECK_EQ(mp_radix_size(mp, 10, &size), MP_OKAY);

        CF_ASSERT(size > 0, "Output of mp_radix_size is 0 or less");

        str = (char*)util::malloc(size);

        CF_CHECK_EQ(mp_toradix(mp, str, 10), MP_OKAY);

        ret = std::string(str);

    }

#endif

end:

    free(str);

    return ret;

}

std::optional<component::Bignum> Bignum::ToComponentBignum(void) {

    std::optional<component::Bignum> ret = std::nullopt;

    auto str = ToDecString();

    CF_CHECK_NE(str, std::nullopt);

    ret = { str };

end:

    return ret;

}

bool Bignum::ToBin(uint8_t* dest, const size_t size) {

    bool ret = false;

    const auto required = mp_unsigned_bin_size(GetPtr());

    CF_ASSERT(required >= 0, "mp_unsigned_bin_size returned negative value");

    CF_CHECK_GTE(size, static_cast<size_t>(required));

    CF_CHECK_EQ(mp_to_unsigned_bin_len(GetPtr(), dest, size), MP_OKAY);

    ret = true;

end:

    return ret;

}

std::optional<std::vector<uint8_t>> Bignum::ToBin(Datasource& ds, const component::Bignum b, std::optional<size_t> size) {

    std::optional<std::vector<uint8_t>> ret = std::nullopt;

    std::vector<uint8_t> v;

    Bignum bn(ds);

    uint16_t padding = 0;

    CF_CHECK_EQ(bn.Set(b), true);

    if ( size != std::nullopt ) {

        v.resize(*size);

    } else {

        try {

            padding = ds.Get<uint16_t>();

        } catch ( fuzzing::datasource::Datasource::OutOfData ) { }

        v.resize( mp_unsigned_bin_size(bn.GetPtr()) + padding );

    }

    CF_CHECK_EQ(bn.ToBin(v.data(), v.size()), true);

    ret = v;

end:

    return ret;

}

bool Bignum::ToBin(

        Datasource& ds,

        const component::Bignum b,

        uint8_t* dest,

        const size_t size,

        const bool mustSucceed) {

    bool ret = false;

    if ( mustSucceed == true ) {

        std::optional<std::vector<uint8_t>> bytes;

        CF_CHECK_NE(bytes = util::DecToBin(b.ToTrimmedString(), size), std::nullopt);

        memcpy(dest, bytes->data(), bytes->size());

        ret = true;

    } else {

        Bignum bn(ds);

        CF_CHECK_EQ(bn.Set(b), true);

        CF_CHECK_EQ(bn.ToBin(dest, size), true);

        ret = true;

    }

end:

    return ret;

}

bool Bignum::ToBin(

        Datasource& ds,

        const component::BignumPair b,

        uint8_t* dest,

        const size_t size,

        const bool mustSucceed) {

    CF_ASSERT((size % 2) == 0, "Input size is not multiple of 2 in Bignum::ToBin");

    bool ret = false;

    const auto halfSize = size / 2;

    CF_CHECK_EQ(ToBin(ds, b.first, dest, halfSize, mustSucceed), true);

    CF_CHECK_EQ(ToBin(ds, b.second, dest + halfSize, halfSize, mustSucceed), true);

    ret = true;

end:

    return ret;

}

std::optional<component::Bignum> Bignum::BinToBignum(Datasource& ds, const uint8_t* src, const size_t size) {

    std::optional<component::Bignum> ret = std::nullopt;

    wolfCrypt_bignum::Bignum bn(ds);

    CF_CHECK_EQ(mp_read_unsigned_bin(bn.GetPtr(), src, size), MP_OKAY);

    ret = bn.ToComponentBignum();

end:

    return ret;

}

std::optional<component::BignumPair> Bignum::BinToBignumPair(Datasource& ds, const uint8_t* src, const size_t size) {

    CF_ASSERT((size % 2) == 0, "Input size is not multiple of 2 in Bignum::BinToBignumPair");

    std::optional<component::BignumPair> ret = std::nullopt;

    std::optional<component::Bignum> A, B;

    const auto halfSize = size / 2;

    {

        wolfCrypt_bignum::Bignum bn(ds);

        CF_CHECK_EQ(mp_read_unsigned_bin(bn.GetPtr(), src, halfSize), MP_OKAY);

        CF_CHECK_NE(A = bn.ToComponentBignum(), std::nullopt);

    }

    {

        wolfCrypt_bignum::Bignum bn(ds);

        CF_CHECK_EQ(mp_read_unsigned_bin(bn.GetPtr(), src + halfSize, halfSize), MP_OKAY);

        CF_CHECK_NE(B = bn.ToComponentBignum(), std::nullopt);

    }

    ret = {A->ToTrimmedString(), B->ToTrimmedString()};

end:

    return ret;

}

void Bignum::Randomize(void) {

    std::vector<uint8_t> data;

    try {

        data = ds.GetData(0, 1, 1024);

    } catch ( fuzzing::datasource::Datasource::OutOfData ) { }

    if ( !data.empty() ) {

        /* ignore return value */ mp_read_unsigned_bin(GetPtrDirect(), data.data(), data.size());

    }

}

bool Bignum::operator==(const Bignum& rhs) const {

    return mp_cmp(GetPtr(), rhs.GetPtr()) == MP_EQ;

}

BignumCluster::BignumCluster(Datasource& ds, Bignum bn0, Bignum bn1, Bignum bn2, Bignum bn3) :

    ds(ds),

    bn({bn0, bn1, bn2, bn3})

{ }

BignumCluster::~BignumCluster() {

    for (size_t i = 0; i < 4; i++) {

        if ( cache.bn[i] == nullptr ) {

            continue;

        }

        mp_clear(cache.bn[i]);

        util::free(cache.bn[i]);

    }

}

Bignum& BignumCluster::operator[](const size_t index) {

    CF_ASSERT(index < bn.size(), "Invalid index requested in BignumCluster::operator[]");

    try {

        /* Rewire? */

        if ( ds.Get<bool>() == true ) {

            /* Pick a random bignum */

            const auto newIndex = ds.Get<uint8_t>() % 4;

            /* Same value? */

            if ( bn[newIndex] == bn[index] ) {

                /* Then return reference to other bignum */

                return bn[newIndex];

            }

            /* Fall through */

        }

    } catch ( fuzzing::datasource::Datasource::OutOfData ) { }

    return bn[index];

}

bool BignumCluster::Set(const size_t index, const std::string s) {

    CF_ASSERT(index < bn.size(), "Invalid index requested in BignumCluster::Set");

    return bn[index].Set(s);

}

mp_int* BignumCluster::GetDestPtr(const size_t index) {

    /* Because it is requested as a destination pointer,

     * this bignum will be altered, hence invalidate

     * the cache

     */

    InvalidateCache();

    return bn[index].GetPtr();

}

void BignumCluster::Save(void) {

    for (size_t i = 0; i < 4; i++) {

        mp_int* cached_mp = (mp_int*)util::malloc(sizeof(mp_int));

        wolfCrypt_detail::disableAllocationFailures = true;

        CF_ASSERT(mp_init(cached_mp) == MP_OKAY, "mp_init failed unexpectedly");

        CF_ASSERT(mp_copy(bn[i].GetPtrDirect(), cached_mp) == MP_OKAY, "mp_copy failed unexpectedly");

        wolfCrypt_detail::disableAllocationFailures = false;

        cache.bn[i] = cached_mp;

    }

}

void BignumCluster::InvalidateCache(void) {

    cache.invalid = true;

}

bool BignumCluster::EqualsCache(void) const {

    if ( cache.invalid == true ) {

        return true;

    }

    for (size_t i = 0; i < 4; i++) {

        if ( cache.bn[i] == nullptr ) {

            continue;

        }

        wolfCrypt_detail::disableAllocationFailures = true;

        if ( mp_cmp(bn[i].GetPtrDirect(), cache.bn[i]) != MP_EQ ) {

#if defined(CRYPTOFUZZ_WOLFCRYPT_DEBUG)

            char str[8192];

            std::cout << "Bignum with index " << std::to_string(i) << " was changed" << std::endl;

            wolfCrypt_detail::disableAllocationFailures = true;

            CF_ASSERT(mp_tohex(cache.bn[i], str) == MP_OKAY, "mp_tohex failed unexpectedly");

            printf("it was: %s\n", str);

            CF_ASSERT(mp_tohex(bn[i].GetPtrDirect(), str) == MP_OKAY, "mp_tohex failed unexpectedly");

            printf("it is now %s\n", str);

#endif

            wolfCrypt_detail::disableAllocationFailures = false;

            return false;

        }

        wolfCrypt_detail::disableAllocationFailures = false;

    }

    return true;

}

} /* namespace wolfCrypt_bignum */

} /* namespace module */

} /* namespace cryptofuzz */