Function processBlock

src/OpenFOAM/primitives/hashes/SHA1/SHA1.C:181–314

// Most of this code comes from GnuPG's cipher/sha1.c

void Foam::SHA1::processBlock(const void *data, size_t len)
{
    const uint32_t *words = reinterpret_cast<const uint32_t*>(data);
    size_t nwords = len / sizeof(uint32_t);
    const uint32_t *endp = words + nwords;

    // calculate with sixteen words of 32-bits
    uint32_t x[16];
    uint32_t a = hashsumA_;
    uint32_t b = hashsumB_;
    uint32_t c = hashsumC_;
    uint32_t d = hashsumD_;
    uint32_t e = hashsumE_;

    // First increment the byte count.
    // RFC 1321 specifies the possible length of the file up to 2^64 bits.
    // Here we only compute the number of bytes.  Do a double word increment.
    bufTotal_[0] += len;
    if (bufTotal_[0] < len)
    {
        ++bufTotal_[1];
    }

    // rotate left uint32_t by n bits
    #define rol_uint32(x, nbits)  (((x) << (nbits)) | ((x) >> (32 - (nbits))))

    #define M(I) ( tm = x[I & 0x0F] ^ x[(I-14) & 0x0F]                         \
               ^ x[(I-8) & 0x0F] ^ x[(I-3) & 0x0F]                             \
               , (x[I & 0x0F] = rol_uint32(tm, 1)) )

    #define R(A,B,C,D,E,F,K,M)                                                 \
        do                                                                     \
        {                                                                      \
            E += rol_uint32(A, 5) + F(B, C, D) + K + M;                        \
            B = rol_uint32(B, 30);                                             \
        } while (0)

    while (words < endp)
    {
        uint32_t tm;
        for (int t = 0; t < 16; ++t)
        {
            x[t] = swapBytes(*words);
            ++words;
        }

        R( a, b, c, d, e, F1, K1, x[ 0] );
        R( e, a, b, c, d, F1, K1, x[ 1] );
        R( d, e, a, b, c, F1, K1, x[ 2] );
        R( c, d, e, a, b, F1, K1, x[ 3] );
        R( b, c, d, e, a, F1, K1, x[ 4] );
        R( a, b, c, d, e, F1, K1, x[ 5] );
        R( e, a, b, c, d, F1, K1, x[ 6] );
        R( d, e, a, b, c, F1, K1, x[ 7] );
        R( c, d, e, a, b, F1, K1, x[ 8] );
        R( b, c, d, e, a, F1, K1, x[ 9] );
        R( a, b, c, d, e, F1, K1, x[10] );
        R( e, a, b, c, d, F1, K1, x[11] );