C++ (Cpp) setint64の例

コード例 #1

ファイル: cryptopp.cpp プロジェクト: meganz/sdk

// encryption: data must be NUL-padded to BLOCKSIZE
// decryption: data must be padded to BLOCKSIZE
// len must be < 2^31
void SymmCipher::ctr_crypt(byte* data, unsigned len, m_off_t pos, ctr_iv ctriv, byte* mac, bool encrypt, bool initmac)
{
    assert(!(pos & (KEYLENGTH - 1)));

    byte ctr[BLOCKSIZE], tmp[BLOCKSIZE];

    MemAccess::set<int64_t>(ctr,ctriv);
    setint64(pos / BLOCKSIZE, ctr + sizeof ctriv);

    if (mac && initmac)
    {
        memcpy(mac, ctr, sizeof ctriv);
        memcpy(mac + sizeof ctriv, ctr, sizeof ctriv);
    }

    while ((int)len > 0)
    {
        if (encrypt)
        {
            if(mac)
            {
                xorblock(data, mac);
                ecb_encrypt(mac);
            }

            ecb_encrypt(ctr, tmp);
            xorblock(tmp, data);
        }
        else
        {
            ecb_encrypt(ctr, tmp);
            xorblock(tmp, data);

            if (mac)
            {
                if (len >= (unsigned)BLOCKSIZE)
                {
                    xorblock(data, mac);
                }
                else
                {
                    xorblock(data, mac, len);
                }

                ecb_encrypt(mac);
            }
        }

        len -= BLOCKSIZE;
        data += BLOCKSIZE;

        incblock(ctr);
    }
}

コード例 #2

ファイル: megacrypto.cpp プロジェクト: falkbizz/MegaFuse

// encryption: data must be NUL-padded to BLOCKSIZE
// decryption: data must be padded to BLOCKSIZE
// len must be < 2^31
void SymmCipher::ctr_crypt(byte* data, unsigned len, m_off_t pos, ctr_iv ctriv, byte* mac, int encrypt)
{
    assert(!(pos&(KEYLENGTH-1)));

    byte ctr[BLOCKSIZE], tmp[BLOCKSIZE];

    *(uint64_t*)ctr = ctriv;
    setint64(pos/BLOCKSIZE,ctr+sizeof ctriv);

    memcpy(mac,ctr,sizeof ctriv);
    memcpy(mac+sizeof ctriv,ctr,sizeof ctriv);

    while ((int)len > 0)
    {
        if (encrypt)
        {
            xorblock(data,mac);
            ecb_encrypt(mac);
            ecb_encrypt(ctr,tmp);
            xorblock(tmp,data);
        }
        else
        {
            ecb_encrypt(ctr,tmp);
            xorblock(tmp,data);
            if (len >= (unsigned)BLOCKSIZE) xorblock(data,mac);
            else xorblock(data,mac,len);
            ecb_encrypt(mac);
        }

        len -= BLOCKSIZE;
        data += BLOCKSIZE;

        incblock(ctr);
    }
}