File content as of revision 3:85c6ee25cf3e:

#include "SHA2_32.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

static const uint32_t K[] =
{
    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
    0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
    0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
    0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
    0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
    0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
    0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
    0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
    0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
    0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
    0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
    0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
    0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
};

#define ROTL(W,N) (((W) << (N)) | ((W) >> (32-(N))))
#define ROTR(W,N) (((W) >> (N)) | ((W) << (32-(N))))
#define CH(X,Y,Z) (((X) & (Y)) ^ ((~(X)) & (Z)))
#define MAJ(X,Y,Z) (((X) & (Y)) ^ ((X) & (Z)) ^ ((Y) & (Z)))
#define BSIG0(X) (ROTR(X,2) ^ ROTR(X,13) ^ ROTR(X,22))
#define BSIG1(X) (ROTR(X,6) ^ ROTR(X,11) ^ ROTR(X,25))
#define SSIG0(X) (ROTR((X),7) ^ ROTR((X),18) ^ ((X) >> 3))
#define SSIG1(X) (ROTR((X),17) ^ ROTR((X),19) ^ ((X) >> 10))
#define R(A,B,C,D,E,F,G,H,T)  T1 = H + BSIG1(E) + CH(E,F,G) + K[T] + w[T]; \
                              T2 = BSIG0(A) + MAJ(A,B,C); \
                              D += T1; \
                              H = T1 + T2;
        
static const uint32_t H[] =
{
    // SHA-224
    0xc1059ed8, 0x367cd507, 0x3070dd17, 0xf70e5939,
    0xffc00b31, 0x68581511, 0x64f98fa7, 0xbefa4fa4,
    
    // SHA-256      
    0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
    0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
};

SHA2_32::SHA2_32(SHA_32_TYPE t):
type(t),
totalBufferLength(0),
bufferLength(0)
{
    switch(type)
    {
        case SHA_224:
            h0 = H[0];
            h1 = H[1];
            h2 = H[2];
            h3 = H[3];
            h4 = H[4];
            h5 = H[5];
            h6 = H[6];
            h7 = H[7];
        break;
        
        case SHA_256:
            h0 = H[8];
            h1 = H[9];
            h2 = H[10];
            h3 = H[11];
            h4 = H[12];
            h5 = H[13];
            h6 = H[14];
            h7 = H[15];     
        break;
    }
}

void SHA2_32::add(uint8_t *in, uint32_t length)
{
    if(length < 64-bufferLength)
    {
        memcpy(&buffer[bufferLength], in, length);
        bufferLength += length;
        totalBufferLength += length;
        return;
    }
    int offset = 64-bufferLength;
    memcpy(&buffer[bufferLength], in, offset);
    computeBlock(&h0,&h1,&h2,&h3,&h4,&h5,&h6,&h7,buffer);
    while(length-offset > 64)
    {
        memcpy(buffer, &in[offset], 64);
        computeBlock(&h0,&h1,&h2,&h3,&h4,&h5,&h6,&h7,buffer);
        offset += 64;
    }
    if(offset > length)
        offset -= 64;
    bufferLength = length - offset;
    memcpy(buffer, &in[offset], bufferLength);
    totalBufferLength += length;
}

void SHA2_32::computeDigest(uint8_t *digest)
{
    uint16_t padding;
    if(totalBufferLength % 64 < 56)
        padding = 56 - (totalBufferLength % 64);
    else
        padding = 56 + (64 - (totalBufferLength % 64));

    buffer[bufferLength++] = 0x80;
    padding--;
    if(padding+bufferLength == 56)
        memset(&buffer[bufferLength], 0, padding);
    else
    {
        memset(&buffer[bufferLength], 0, 64-bufferLength);
        computeBlock(&h0, &h1, &h2, &h3, &h4, &h5, &h6, &h7, buffer);
        memset(buffer, 0, bufferLength);
    }
    
    uint64_t lengthBit = totalBufferLength << 3;
    uint32_t lengthBitLow = lengthBit;
    uint32_t lengthBitHigh = lengthBit >> 32;
    lengthBitLow = __rev(lengthBitLow);
    lengthBitHigh = __rev(lengthBitHigh);
    memcpy(&buffer[60], &lengthBitLow, 4);    
    memcpy(&buffer[56], &lengthBitHigh, 4);    
    computeBlock(&h0, &h1, &h2, &h3, &h4, &h5, &h6, &h7, buffer);

    h0 = __rev(h0);
    h1 = __rev(h1);
    h2 = __rev(h2);
    h3 = __rev(h3);
    h4 = __rev(h4);
    h5 = __rev(h5);
    h6 = __rev(h6);
    memcpy(digest, &h0, 4);
    memcpy(&digest[4], &h1, 4);
    memcpy(&digest[8], &h2, 4);
    memcpy(&digest[12], &h3, 4);
    memcpy(&digest[16], &h4, 4);
    memcpy(&digest[20], &h5, 4);
    memcpy(&digest[24], &h6, 4);
    
    if(type == SHA_256)
    {
        h7 = __rev(h7);
        memcpy(&digest[28], &h7, 4);
    }
    
    // reset state
    switch(type)
    {
        case SHA_224:
            h0 = H[0];
            h1 = H[1];
            h2 = H[2];
            h3 = H[3];
            h4 = H[4];
            h5 = H[5];
            h6 = H[6];
            h7 = H[7];
        break;
        
        case SHA_256:
            h0 = H[8];
            h1 = H[9];
            h2 = H[10];
            h3 = H[11];
            h4 = H[12];
            h5 = H[13];
            h6 = H[14];
            h7 = H[15];     
        break;
    }
    totalBufferLength = 0;
    bufferLength = 0;
}

void SHA2_32::computeBlock(uint32_t *h02, 
                        uint32_t *h12, 
                        uint32_t *h22, 
                        uint32_t *h32, 
                        uint32_t *h42, 
                        uint32_t *h52, 
                        uint32_t *h62,
                        uint32_t *h72,
                        uint8_t *buffer)
{
    uint32_t w[64];
    uint32_t *buffer2 = (uint32_t*)buffer;
    w[0] = __rev(buffer2[0]);
    w[1] = __rev(buffer2[1]);
    w[2] = __rev(buffer2[2]);
    w[3] = __rev(buffer2[3]);
    w[4] = __rev(buffer2[4]);
    w[5] = __rev(buffer2[5]);
    w[6] = __rev(buffer2[6]);
    w[7] = __rev(buffer2[7]);
    w[8] = __rev(buffer2[8]);
    w[9] = __rev(buffer2[9]);
    w[10] = __rev(buffer2[10]);
    w[11] = __rev(buffer2[11]);
    w[12] = __rev(buffer2[12]);
    w[13] = __rev(buffer2[13]);
    w[14] = __rev(buffer2[14]);
    w[15] = __rev(buffer2[15]);

    for(int t = 16; t < 64; ++t)
        w[t] = SSIG1(w[t-2]) + w[t-7] + SSIG0(w[t-15]) + w[t-16];
    
    uint32_t a = *h02, b = *h12, c = *h22, d = *h32, e = *h42, f = *h52, g = *h62, h = *h72;
    uint32_t T1, T2;
    
    R(a,b,c,d,e,f,g,h,0)
    R(h,a,b,c,d,e,f,g,1)
    R(g,h,a,b,c,d,e,f,2)
    R(f,g,h,a,b,c,d,e,3)
    R(e,f,g,h,a,b,c,d,4)
    R(d,e,f,g,h,a,b,c,5)
    R(c,d,e,f,g,h,a,b,6)
    R(b,c,d,e,f,g,h,a,7)

    R(a,b,c,d,e,f,g,h,8)
    R(h,a,b,c,d,e,f,g,9)
    R(g,h,a,b,c,d,e,f,10)
    R(f,g,h,a,b,c,d,e,11)
    R(e,f,g,h,a,b,c,d,12)
    R(d,e,f,g,h,a,b,c,13)
    R(c,d,e,f,g,h,a,b,14)
    R(b,c,d,e,f,g,h,a,15)
    
    R(a,b,c,d,e,f,g,h,16)
    R(h,a,b,c,d,e,f,g,17)
    R(g,h,a,b,c,d,e,f,18)
    R(f,g,h,a,b,c,d,e,19)
    R(e,f,g,h,a,b,c,d,20)
    R(d,e,f,g,h,a,b,c,21)
    R(c,d,e,f,g,h,a,b,22)
    R(b,c,d,e,f,g,h,a,23)
    
    R(a,b,c,d,e,f,g,h,24)
    R(h,a,b,c,d,e,f,g,25)
    R(g,h,a,b,c,d,e,f,26)
    R(f,g,h,a,b,c,d,e,27)
    R(e,f,g,h,a,b,c,d,28)
    R(d,e,f,g,h,a,b,c,29)
    R(c,d,e,f,g,h,a,b,30)
    R(b,c,d,e,f,g,h,a,31) 
    
    R(a,b,c,d,e,f,g,h,32)
    R(h,a,b,c,d,e,f,g,33)
    R(g,h,a,b,c,d,e,f,34)
    R(f,g,h,a,b,c,d,e,35)
    R(e,f,g,h,a,b,c,d,36)
    R(d,e,f,g,h,a,b,c,37)
    R(c,d,e,f,g,h,a,b,38)
    R(b,c,d,e,f,g,h,a,39)
    
    R(a,b,c,d,e,f,g,h,40)
    R(h,a,b,c,d,e,f,g,41)
    R(g,h,a,b,c,d,e,f,42)
    R(f,g,h,a,b,c,d,e,43)
    R(e,f,g,h,a,b,c,d,44)
    R(d,e,f,g,h,a,b,c,45)
    R(c,d,e,f,g,h,a,b,46)
    R(b,c,d,e,f,g,h,a,47)

    R(a,b,c,d,e,f,g,h,48)
    R(h,a,b,c,d,e,f,g,49)
    R(g,h,a,b,c,d,e,f,50)
    R(f,g,h,a,b,c,d,e,51)
    R(e,f,g,h,a,b,c,d,52)
    R(d,e,f,g,h,a,b,c,53)
    R(c,d,e,f,g,h,a,b,54)
    R(b,c,d,e,f,g,h,a,55)
    
    R(a,b,c,d,e,f,g,h,56)
    R(h,a,b,c,d,e,f,g,57)
    R(g,h,a,b,c,d,e,f,58)
    R(f,g,h,a,b,c,d,e,59)
    R(e,f,g,h,a,b,c,d,60)
    R(d,e,f,g,h,a,b,c,61)
    R(c,d,e,f,g,h,a,b,62)
    R(b,c,d,e,f,g,h,a,63)
    
    
    *h02 += a;
    *h12 += b;
    *h22 += c;
    *h32 += d;
    *h42 += e;
    *h52 += f;
    *h62 += g;
    *h72 += h;
}

void SHA2_32::computeDigest(SHA_32_TYPE type, uint8_t *digest, uint8_t *in, uint32_t length)
{
    uint32_t h0 = H[type*8], h1 = H[type*8+1], h2 = H[type*8+2], h3 = H[type*8+3];
    uint32_t h4 = H[type*8+4], h5 = H[type*8+5], h6 = H[type*8+6], h7 = H[type*8+7];
    uint64_t lengthBit = length << 3;
    uint16_t padding;
    if(length % 64 < 56)
        padding = 56 - (length % 64);
    else
        padding = 56 + (64 - (length % 64));
        
    while(length >= 64)
    {
        computeBlock(&h0, &h1, &h2, &h3, &h4, &h5, &h6, &h7, in);
        length -= 64;
        in += 64;
    }
    uint8_t buffer[64];
    memcpy(buffer, in,length); 
    buffer[length++] = 0x80;
    padding--;
    if(padding+length == 56)
        memset(&buffer[length], 0, padding);
    else
    {
        memset(&buffer[length], 0, 64-length);
        computeBlock(&h0, &h1, &h2, &h3, &h4, &h5, &h6, &h7, buffer);
        memset(buffer, 0, length);
    }
    
    uint32_t lengthBitLow = lengthBit;
    uint32_t lengthBitHigh = lengthBit >> 32;
    lengthBitLow = __rev(lengthBitLow);
    memcpy(&buffer[60], &lengthBitLow, 4);
    lengthBitHigh = __rev(lengthBitHigh);
    memcpy(&buffer[56], &lengthBitHigh, 4);    
    computeBlock(&h0, &h1, &h2, &h3, &h4, &h5, &h6, &h7, buffer);

    h0 = __rev(h0);
    h1 = __rev(h1);
    h2 = __rev(h2);
    h3 = __rev(h3);
    h4 = __rev(h4);
    h5 = __rev(h5);
    h6 = __rev(h6);

    memcpy(digest, &h0, 4);
    memcpy(&digest[4], &h1, 4);
    memcpy(&digest[8], &h2, 4);
    memcpy(&digest[12], &h3, 4);
    memcpy(&digest[16], &h4, 4);
    memcpy(&digest[20], &h5, 4);
    memcpy(&digest[24], &h6, 4);


    if(type == SHA_256)
    {
        h7 = __rev(h7);
        memcpy(&digest[28], &h7, 4);
    }
}