Cppcheck report - LibreOffice 2020-06-13 19:58:00 41c465b5ee443ec04441077b5eb80f263336ea8a, CppCheck 2020-06-13 18:19:47 6d5d12f283cf568d2dfe09aa77cb41f34b322d62: comphelper/source/misc/hash.cxx

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#include <sal/config.h>

#include <com/sun/star/uno/Reference.hxx>
#include <comphelper/hash.hxx>
#include <rtl/ustring.hxx>
#include <rtl/alloc.h>
#include <osl/endian.h>
#include <config_oox.h>

#if USE_TLS_NSS
#include <nss.h>
#include <sechash.h>
#elif USE_TLS_OPENSSL
#include <openssl/evp.h>
#include <openssl/sha.h>
#endif // USE_TLS_OPENSSL

namespace comphelper {

struct HashImpl
{

#if USE_TLS_NSS
    HASHContext* mpContext;

    HASH_HashType getNSSType() const
    {
        switch (meType)
        {
            case HashType::MD5:
                return HASH_AlgMD5;
            case HashType::SHA1:
                return HASH_AlgSHA1;
            case HashType::SHA256:
                return HASH_AlgSHA256;
            case HashType::SHA512:
                return HASH_AlgSHA512;
        }

        return HASH_AlgNULL;
    }
#elif USE_TLS_OPENSSL
    EVP_MD_CTX* mpContext;

    const EVP_MD* getOpenSSLType() const
    {
        switch (meType)
        {
            case HashType::MD5:
                return EVP_md5();
            case HashType::SHA1:
                return EVP_sha1();
            case HashType::SHA256:
                return EVP_sha256();
            case HashType::SHA512:
                return EVP_sha512();
        }

        return nullptr;
    }
#endif

    HashType const meType;

    HashImpl(HashType eType):
<--- Struct 'HashImpl' has a constructor with 1 argument that is not explicit. [+]
Struct 'HashImpl' has a constructor with 1 argument that is not explicit. Such constructors should in general be explicit for type safety reasons. Using the explicit keyword in the constructor means some mistakes when using the class can be avoided.
        meType(eType)
    {

#if USE_TLS_NSS
        auto const e = NSS_NoDB_Init(nullptr);
        if (e != SECSuccess) {
            throw css::uno::RuntimeException("NSS_NoDB_Init failed with " + OUString::number(e));
        }
        mpContext = HASH_Create(getNSSType());
        HASH_Begin(mpContext);
#elif USE_TLS_OPENSSL
        mpContext = EVP_MD_CTX_create();
        EVP_DigestInit_ex(mpContext, getOpenSSLType(), NULL);
#endif
    }

    ~HashImpl()
    {
#if USE_TLS_NSS
        HASH_Destroy(mpContext);
#elif USE_TLS_OPENSSL
        EVP_MD_CTX_destroy(mpContext);
#endif
    }
};

Hash::Hash(HashType eType):
    mpImpl(new HashImpl(eType))
{
}

Hash::~Hash()
{
}

void Hash::update(const unsigned char* pInput, size_t length)
{
#if USE_TLS_NSS
    HASH_Update(mpImpl->mpContext, pInput, length);
#elif USE_TLS_OPENSSL
    EVP_DigestUpdate(mpImpl->mpContext, pInput, length);
#else
    (void)pInput;
    (void)length;
#endif
}

std::vector<unsigned char> Hash::finalize()
{
    std::vector<unsigned char> hash(getLength(), 0);
    unsigned int digestWrittenLength;<--- Variable 'digestWrittenLength' is not assigned a value.
#if USE_TLS_NSS
    HASH_End(mpImpl->mpContext, hash.data(), &digestWrittenLength, getLength());
#elif USE_TLS_OPENSSL
    EVP_DigestFinal_ex(mpImpl->mpContext, hash.data(), &digestWrittenLength);
#else
    (void)digestWrittenLength;
#endif

    return hash;
}

size_t Hash::getLength() const
{
    switch (mpImpl->meType)
    {
        case HashType::MD5:
            return 16;
        case HashType::SHA1:
            return 20;
        case HashType::SHA256:
            return 32;
        case HashType::SHA512:
            return 64;
    }

    return 0;
}

std::vector<unsigned char> Hash::calculateHash(const unsigned char* pInput, size_t length, HashType eType)
{
    Hash aHash(eType);
    aHash.update(pInput, length);
    return aHash.finalize();
}

std::vector<unsigned char> Hash::calculateHash(
        const unsigned char* pInput, size_t nLength,
        const unsigned char* pSalt, size_t nSaltLen,
        sal_uInt32 nSpinCount,
        IterCount eIterCount,
        HashType eType)
{
    if (!pSalt)
        nSaltLen = 0;

    if (!nSaltLen && !nSpinCount)
        return calculateHash( pInput, nLength, eType);

    Hash aHash(eType);
    if (nSaltLen)
    {
        std::vector<unsigned char> initialData( nSaltLen + nLength);
        std::copy( pSalt, pSalt + nSaltLen, initialData.begin());
        std::copy( pInput, pInput + nLength, initialData.begin() + nSaltLen);
        aHash.update( initialData.data(), initialData.size());
        rtl_secureZeroMemory( initialData.data(), initialData.size());
    }
    else
    {
        aHash.update( pInput, nLength);
    }
    std::vector<unsigned char> hash( aHash.finalize());

    if (nSpinCount)
    {
        // https://msdn.microsoft.com/en-us/library/dd920692
        // says the iteration is concatenated after the hash.
        // https://msdn.microsoft.com/en-us/library/dd924776 and
        // https://msdn.microsoft.com/en-us/library/dd925430
        // say the iteration is prepended to the hash.
        const size_t nAddIter = (eIterCount == IterCount::NONE ? 0 : 4);
        const size_t nIterPos = (eIterCount == IterCount::APPEND ? hash.size() : 0);
        const size_t nHashPos = (eIterCount == IterCount::PREPEND ? nAddIter : 0);
        std::vector<unsigned char> data( hash.size() + nAddIter, 0);
        for (sal_uInt32 i = 0; i < nSpinCount; ++i)
        {
            std::copy( hash.begin(), hash.end(), data.begin() + nHashPos);
            if (nAddIter)
            {
#ifdef OSL_BIGENDIAN
                sal_uInt32 be = i;
                sal_uInt8* p = reinterpret_cast<sal_uInt8*>(&be);
                std::swap( p[0], p[3] );
                std::swap( p[1], p[2] );
                memcpy( data.data() + nIterPos, &be, nAddIter);
#else
                memcpy( data.data() + nIterPos, &i, nAddIter);
#endif
            }
            /* TODO: isn't there something better than
             * creating/finalizing/destroying on each iteration? */
            Hash aReHash(eType);
            aReHash.update( data.data(), data.size());
            hash = aReHash.finalize();
        }
    }

    return hash;
}

std::vector<unsigned char> Hash::calculateHash(
        const OUString& rPassword,
        const std::vector<unsigned char>& rSaltValue,
        sal_uInt32 nSpinCount,
        IterCount eIterCount,
        HashType eType)
{
    const unsigned char* pPassBytes = reinterpret_cast<const unsigned char*>(rPassword.getStr());
    const size_t nPassBytesLen = rPassword.getLength() * 2;
#ifdef OSL_BIGENDIAN
    // Swap UTF16-BE to UTF16-LE
    std::vector<unsigned char> vPass;
    if (nPassBytesLen)
    {
        vPass.resize( nPassBytesLen);
        std::copy( pPassBytes, pPassBytes + nPassBytesLen, vPass.begin());
        unsigned char* p = vPass.data();
        unsigned char const * const pEnd = p + nPassBytesLen;
        for ( ; p < pEnd; p += 2 )
        {
            std::swap( p[0], p[1] );
        }
        pPassBytes = vPass.data();
    }
#endif
    return calculateHash( pPassBytes, nPassBytesLen, rSaltValue.data(), rSaltValue.size(), nSpinCount,
            eIterCount, eType);
}

}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */