Question

所以这就是我的问题..我正在为一个库写出一个AES-NI实现，而我仍然坚持解释一个256位的块。这就是我所知道的...... 128位块完美运行。 256块的加密与经过验证的Rijndael实现一致。扩展密钥还与其他Rijndael实现（允许小端字节顺序）对齐。例程使用混合和移位掩码来补偿256位块的偏移列混洗，它是用于加密块的掩码的反转，这也经过测试并且似乎工作正常。这是加密功能：

    void Encrypt32(const std::vector<byte> &Input, const size_t InOffset, std::vector<byte> &Output, const size_t OutOffset)
{
    const size_t LRD = m_expKey.size() - 3;
    size_t keyCtr = 0;
    __m128i RIJNDAEL256_MASK = { 0,1,6,7,4,5,10,11,8,9,14,15,12,13,2,3 };
    __m128i BLEND_MASK = _mm_set_epi32(0x80000000, 0x80800000, 0x80800000, 0x80808000);
    __m128i block1 = _mm_loadu_si128((const __m128i*)(const void*)&Input[InOffset]);
    __m128i block2 = _mm_loadu_si128((const __m128i*)(const void*)&Input[InOffset + 16]);
    __m128i temp1, temp2;

    block1 = _mm_xor_si128(block1, m_expKey[keyCtr]);
    block2 = _mm_xor_si128(block2, m_expKey[++keyCtr]);

    while (keyCtr != LRD)
    {
        temp1 = _mm_blendv_epi8(block1, block2, BLEND_MASK);    // combine 2 blocks
        temp2 = _mm_blendv_epi8(block2, block1, BLEND_MASK);
        temp1 = _mm_shuffle_epi8(temp1, RIJNDAEL256_MASK);      // shuffle
        temp2 = _mm_shuffle_epi8(temp2, RIJNDAEL256_MASK);
        block1 = _mm_aesenc_si128(temp1, m_expKey[++keyCtr]);   // encrypt
        block2 = _mm_aesenc_si128(temp2, m_expKey[++keyCtr]);
    }

    temp1 = _mm_blendv_epi8(block1, block2, BLEND_MASK);
    temp2 = _mm_blendv_epi8(block2, block1, BLEND_MASK);
    temp1 = _mm_shuffle_epi8(temp1, RIJNDAEL256_MASK);
    temp2 = _mm_shuffle_epi8(temp2, RIJNDAEL256_MASK);
    block1 = _mm_aesenclast_si128(temp1, m_expKey[++keyCtr]);
    block2 = _mm_aesenclast_si128(temp2, m_expKey[++keyCtr]);

    _mm_storeu_si128((__m128i*)(void*)&Output[OutOffset], block1);
    _mm_storeu_si128((__m128i*)(void*)&Output[OutOffset + 16], block2);
}

这是逆变换：

    void Decrypt32(const std::vector<byte> &Input, const size_t InOffset, std::vector<byte> &Output, const size_t OutOffset)
{
    const size_t LRD = m_expKey.size() - 3;
    __m128i RIJNDAELINV_MASK = { 0,1,14,15,4,5,2,3,8,9,6,7,12,13,10,11 };
    __m128i BLEND_MASK = _mm_set_epi32(0x80000000, 0x80800000, 0x80800000, 0x80808000);
    __m128i block1 = _mm_loadu_si128((const __m128i*)(const void*)&Input[InOffset]);
    __m128i block2 = _mm_loadu_si128((const __m128i*)(const void*)&Input[InOffset + 16]);
    __m128i temp1, temp2;
    size_t keyCtr = 0;

    block1 = _mm_xor_si128(block1, m_expKey[keyCtr]);
    block2 = _mm_xor_si128(block2, m_expKey[++keyCtr]);

    while (keyCtr != LRD)
    {
        temp1 = _mm_aesdec_si128(block1, m_expKey[++keyCtr]);   // decrypt
        temp2 = _mm_aesdec_si128(block2, m_expKey[++keyCtr]);
        temp1 = _mm_shuffle_epi8(temp1, RIJNDAELINV_MASK);      // shuffle
        temp2 = _mm_shuffle_epi8(temp2, RIJNDAELINV_MASK);
        block1 = _mm_blendv_epi8(temp1, temp2, BLEND_MASK);     // combine
        block2 = _mm_blendv_epi8(temp2, temp1, BLEND_MASK);
    }

    temp1 = _mm_aesdeclast_si128(block1, m_expKey[++keyCtr]);
    temp2 = _mm_aesdeclast_si128(block2, m_expKey[++keyCtr]);
    temp1 = _mm_shuffle_epi8(temp1, RIJNDAELINV_MASK);
    temp2 = _mm_shuffle_epi8(temp2, RIJNDAELINV_MASK);
    block1 = _mm_blendv_epi8(temp1, temp2, BLEND_MASK);
    block2 = _mm_blendv_epi8(temp2, temp1, BLEND_MASK);

    _mm_storeu_si128((__m128i*)(void*)&Output[OutOffset], block1);
    _mm_storeu_si128((__m128i*)(void*)&Output[OutOffset + 16], block2);
}

我已经调试了好几个小时，而且无法发现问题，任何人都可以看到为什么这不起作用？我可以将代码发布到git，如果这会有所帮助。

C ++ AES-NI解密256位块

0 个答案: