sha512.cpp

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#include "sha512.hpp"

using namespace cryptoTools;


// =========================== Standard functions of the specification

// Macros are used instead of functions for better performances

#define ROTR(n,x) ( ((x)>>(n)) | ((x)<<(64-(n))) )
#define SHR(n,x)  ((x)>>(n))
#define CH(x,y,z)   ( ((x)&(y)) ^ ((~x)&(z)) )
#define MAJ(x,y,z) ( ((x)&(y)) ^ ((x)&(z)) ^ ((y)&(z)) )
#define BIGSIGMA0(x) ( ROTR(28,(x)) ^ ROTR(34,(x)) ^ ROTR(39,(x)) )
#define BIGSIGMA1(x) ( ROTR(14,(x)) ^ ROTR(18,(x)) ^ ROTR(41,(x)) )
#define SMALLSIGMA0(x) ( ROTR(1,(x)) ^ ROTR(8,(x)) ^ SHR(7,(x)) )
#define SMALLSIGMA1(x) ( ROTR(19,(x)) ^ ROTR(61,(x)) ^ SHR(6,(x)) )


// ================================================= Constants

// The constants to which the internal state  must be initialised.
uint64_t init512[8] =
{
        0x6a09e667f3bcc908, 0xbb67ae8584caa73b, 0x3c6ef372fe94f82b,
        0xa54ff53a5f1d36f1, 0x510e527fade682d1, 0x9b05688c2b3e6c1f,
        0x1f83d9abfb41bd6b, 0x5be0cd19137e2179
};


// The constants to use in each step of the main loop of a round.
uint64_t K512[80] =
{
        0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f,
        0xe9b5dba58189dbbc, 0x3956c25bf348b538, 0x59f111f1b605d019,
        0x923f82a4af194f9b, 0xab1c5ed5da6d8118, 0xd807aa98a3030242,
        0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2,
        0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235,
        0xc19bf174cf692694, 0xe49b69c19ef14ad2, 0xefbe4786384f25e3,
        0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65, 0x2de92c6f592b0275,
        0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
        0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f,
        0xbf597fc7beef0ee4, 0xc6e00bf33da88fc2, 0xd5a79147930aa725,
        0x06ca6351e003826f, 0x142929670a0e6e70, 0x27b70a8546d22ffc,
        0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df,
        0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6,
        0x92722c851482353b, 0xa2bfe8a14cf10364, 0xa81a664bbc423001,
        0xc24b8b70d0f89791, 0xc76c51a30654be30, 0xd192e819d6ef5218,
        0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8,
        0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99,
        0x34b0bcb5e19b48a8, 0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb,
        0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3, 0x748f82ee5defb2fc,
        0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
        0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915,
        0xc67178f2e372532b, 0xca273eceea26619c, 0xd186b8c721c0c207,
        0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178, 0x06f067aa72176fba,
        0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b,
        0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc,
        0x431d67c49c100d4c, 0x4cc5d4becb3e42b6, 0x597f299cfc657e2a,
        0x5fcb6fab3ad6faec, 0x6c44198c4a475817
};
                                                                           


// ================================================== public functions


void SHA512::preprocess(std::vector<unsigned char> initialMessage)
{
        // padding the initial message by...
        l = initialMessage.size()*8;
        // ... adding 10000000
        initialMessage.push_back(0x80);
        // ... adding the correct amount of zeroes 
        unsigned int k = ( (896-(l+8))%1024 >= 0) ?  (896-(l+8))%1024 :1024+(960-(l+8))%1024;
        k += 64; // Adding 64 bits to zero: we don't treat cases where l>2^64
        for (unsigned int i=0; i<k; i+=8)
                initialMessage.push_back(0x00);
        // ... and appending the length of the input.
        initialMessage.push_back((l>>56)%0x100);
        initialMessage.push_back((l>>48)%0x100);
        initialMessage.push_back((l>>40)%0x100);
        initialMessage.push_back((l>>32)%0x100);
        initialMessage.push_back((l>>24)%0x100);
        initialMessage.push_back((l>>16)%0x100);
        initialMessage.push_back((l>>8 )%0x100);
        initialMessage.push_back(l%0x100);
        // Turning the initial byte message into a 32words one
        M.clear();
        for (unsigned int i=0; i<initialMessage.size() ; i+=8)
                M.push_back(    ((uint64_t)initialMessage[i]   << 56)
                              | ((uint64_t)initialMessage[i+1] << 48)
                              | ((uint64_t)initialMessage[i+2] << 40)
                              | ((uint64_t)initialMessage[i+3] << 32)
                              | ((uint64_t)initialMessage[i+4] << 24)
                              | ((uint64_t)initialMessage[i+5] << 16)
                              | ((uint64_t)initialMessage[i+6] << 8)
                              |  (uint64_t)initialMessage[i+7] );
        // initialising the hash values H_i
        for (unsigned int i=0; i<8; i++)
                H[i] = init512[i];
}



void SHA512::round(unsigned int counter)
{
        uint64_t W[80], T1, T2;
        // initializing the working variables
        a = H[0]; b = H[1];
        c = H[2]; d = H[3];
        e = H[4]; f = H[5];
        g = H[6]; h = H[7];
        // loop over the currently processed hash
        for (unsigned int t=0; t<80; t++)
        {
                // preparing the message schedule
                W[t] = (t<=15) ? M[counter+t] : SMALLSIGMA1(W[t-2]) + W[t-7] + SMALLSIGMA0(W[t-15]) + W[t-16];
                // Re-assigning the temporary variables
                T1 = h + BIGSIGMA1(e) + CH(e,f,g) + K512[t] + W[t];
                T2 = BIGSIGMA0(a) + MAJ(a,b,c) ;
                h = g; g = f; f = e;
                e = d + T1;
                d = c; c = b; b = a;
                a = T1 + T2;
        }
        // computing the ith hash value H[8] 
        H[0] += a; H[1] += b;
        H[2] += c; H[3] += d;
        H[4] += e; H[5] += f;
        H[6] += g; H[7] += h;
}


void SHA512::hash(std::vector<unsigned char> initialMessage)
{
        preprocess(initialMessage);
        for (unsigned int counter=0; counter<M.size(); counter+=16)
                round(counter);
}


std::vector<uint8_t> SHA512::getHash()
{                
        std::vector<uint8_t> digest;
        for (unsigned int i=0; i<8; i++)
        {
                digest.push_back( (H[i]>>56) % 0x100);
                digest.push_back( (H[i]>>48) % 0x100);
                digest.push_back( (H[i]>>40) % 0x100);
                digest.push_back( (H[i]>>32) % 0x100);
                digest.push_back( (H[i]>>24) % 0x100);
                digest.push_back( (H[i]>>16) % 0x100);
                digest.push_back( (H[i]>>8)  % 0x100);
                digest.push_back(  H[i]      % 0x100);
        }
        return digest;
}


std::string SHA512::getType()
{
        return "SHA-512";
}


uint32_t SHA512::getHashLength()
{
        return 512;
}

#undef ROTR
#undef SHR
#undef CH
#undef MAJ
#undef BIGSIGMA0
#undef BIGSIGMA1
#undef SMALLSIGMA0
#undef SMALLSIGMA1