sha256.cpp

/*
 * Copyright 2012 Rui Araújo, Luís Fonseca
 *
 * This file is part of Router Keygen.
 *
 * Router Keygen is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * Router Keygen is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Router Keygen.  If not, see <http://www.gnu.org/licenses/>.
 */
/*
 * sha256.c - Implementation of the Secure Hash Algorithm-256 (SHA-256).
 *
 * Implemented from the description on the NIST Web site:
 *		http://csrc.nist.gov/cryptval/shs.html
 *
 * Copyright (C) 2002  Southern Storm Software, Pty Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include <stdint.h>
#include <cstring>
#include "sha256.h"



/*
 * Some helper macros for processing 32-bit values, while
 * being careful about 32-bit vs 64-bit system differences.
 */
#if SIZEOF_LONG > 4
        #define	TRUNCLONG(x)	((x) & 0xFFFFFFFF)
        #define	ROTATE(x,n)		(TRUNCLONG(((x) >> (n))) | ((x) << (32 - (n))))
        #define	SHIFT(x,n)		(TRUNCLONG(((x) >> (n))))
#else
        #define	TRUNCLONG(x)	(x)
        #define	ROTATE(x,n)		(((x) >> (n)) | ((x) << (32 - (n))))
        #define	SHIFT(x,n)		((x) >> (n))
#endif

/*
 * Helper macros used by the SHA-256 computation.
 */
#define	CH(x,y,z)		(((x) & (y)) ^ (TRUNCLONG(~(x)) & (z)))
#define	MAJ(x,y,z)		(((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
#define	SUM0(x)			(ROTATE((x), 2) ^ ROTATE((x), 13) ^ ROTATE((x), 22))
#define	SUM1(x)			(ROTATE((x), 6) ^ ROTATE((x), 11) ^ ROTATE((x), 25))
#define	RHO0(x)			(ROTATE((x), 7) ^ ROTATE((x), 18) ^ SHIFT((x), 3))
#define	RHO1(x)			(ROTATE((x), 17) ^ ROTATE((x), 19) ^ SHIFT((x), 10))

/*
 * Constants used in each of the SHA-256 rounds.
 */
static uint32_t const K[64] = {
        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
};

SHA256::SHA256(){
        this->reset();
}

void SHA256::reset()
{
        this->inputLen = 0;
        this->A = 0x6a09e667;
        this->B = 0xbb67ae85;
        this->C = 0x3c6ef372;
        this->D = 0xa54ff53a;
        this->E = 0x510e527f;
        this->F = 0x9b05688c;
        this->G = 0x1f83d9ab;
        this->H = 0x5be0cd19;
        this->totalLen = 0;
}

/*
 * Process a single block of input using the hash algorithm.
 */
void SHA256::ProcessBlock(const unsigned char *block)
{
        uint32_t W[64];
        uint32_t a, b, c, d, e, f, g, h;
        uint32_t temp, temp2;
        int t;

        /* Unpack the block into 64 32-bit words */
        for(t = 0; t < 16; ++t)
        {
                W[t] = (((uint32_t)(block[t * 4 + 0])) << 24) |
                       (((uint32_t)(block[t * 4 + 1])) << 16) |
                       (((uint32_t)(block[t * 4 + 2])) <<  8) |
                        ((uint32_t)(block[t * 4 + 3]));
        }
        for(t = 16; t < 64; ++t)
        {
                W[t] = TRUNCLONG(RHO1(W[t - 2]) + W[t - 7] +
                                                 RHO0(W[t - 15]) + W[t - 16]);
        }

        /* Load the SHA-256 state into local variables */
        a = this->A;
        b = this->B;
        c = this->C;
        d = this->D;
        e = this->E;
        f = this->F;
        g = this->G;
        h = this->H;

        /* Perform 64 rounds of hash computations */
        for(t = 0; t < 64; ++t)
        {
                temp = TRUNCLONG(h + SUM1(e) + CH(e, f, g) + K[t] + W[t]);
                temp2 = TRUNCLONG(SUM0(a) + MAJ(a, b, c));
                h = g;
                g = f;
                f = e;
                e = TRUNCLONG(d + temp);
                d = c;
                c = b;
                b = a;
                a = TRUNCLONG(temp + temp2);
        }

        /* Combine the previous SHA-256 state with the new state */
        this->A = TRUNCLONG(this->A + a);
        this->B = TRUNCLONG(this->B + b);
        this->C = TRUNCLONG(this->C + c);
        this->D = TRUNCLONG(this->D + d);
        this->E = TRUNCLONG(this->E + e);
        this->F = TRUNCLONG(this->F + f);
        this->G = TRUNCLONG(this->G + g);
        this->H = TRUNCLONG(this->H + h);

        /* Clear the temporary state */
        memset(W, 0 , sizeof(uint32_t) * 64);
        a = b = c = d = e = f = g = h = temp = temp2 = 0;
}

void SHA256::addData(const void *buffer, unsigned long len)
{
        unsigned long templen;

        /* Add to the total length of the input stream */
        this->totalLen += (uint64_t)len;

        /* Copy the blocks into the input buffer and process them */
        while(len > 0)
        {
                if(!(this->inputLen) && len >= 64)
                {
                        /* Short cut: no point copying the data twice */
                        ProcessBlock((const unsigned char *)buffer);
                        buffer = (const void *)(((const unsigned char *)buffer) + 64);
                        len -= 64;
                }
                else
                {
                        templen = len;
                        if(templen > (64 - this->inputLen))
                        {
                                templen = 64 - this->inputLen;
                        }
                        memcpy(this->input + this->inputLen, buffer, templen);
                        if((this->inputLen += templen) >= 64)
                        {
                                ProcessBlock(this->input);
                                this->inputLen = 0;
                        }
                        buffer = (const void *)(((const unsigned char *)buffer) + templen);
                        len -= templen;
                }
        }
}

/*
 * Write a 32-bit big-endian long value to a buffer.
 */
void SHA256::WriteLong(unsigned char *buf, uint32_t value)
{
        buf[0] = (unsigned char)(value >> 24);
        buf[1] = (unsigned char)(value >> 16);
        buf[2] = (unsigned char)(value >> 8);
        buf[3] = (unsigned char)value;
}

void SHA256::result( unsigned char hash[SHA256_HASH_SIZE])
{
        uint64_t totalBits;

        /* Compute the final hash if necessary */
        if(hash)
        {
                /* Pad the input data to a multiple of 512 bits */
                if(this->inputLen >= 56)
                {
                        /* Need two blocks worth of padding */
                        this->input[(this->inputLen)++] = (unsigned char)0x80;
                        while(this->inputLen < 64)
                        {
                                this->input[(this->inputLen)++] = (unsigned char)0x00;
                        }
                        ProcessBlock( this->input);
                        this->inputLen = 0;
                }
                else
                {
                        /* Need one block worth of padding */
                        this->input[(this->inputLen)++] = (unsigned char)0x80;
                }
                while(this->inputLen < 56)
                {
                        this->input[(this->inputLen)++] = (unsigned char)0x00;
                }
                totalBits = (this->totalLen << 3);
                WriteLong(this->input + 56, (uint32_t)(totalBits >> 32));
                WriteLong(this->input + 60, (uint32_t)totalBits);
                ProcessBlock( this->input);

                /* Write the final hash value to the supplied buffer */
                WriteLong(hash,      this->A);
                WriteLong(hash + 4,  this->B);
                WriteLong(hash + 8,  this->C);
                WriteLong(hash + 12, this->D);
                WriteLong(hash + 16, this->E);
                WriteLong(hash + 20, this->F);
                WriteLong(hash + 24, this->G);
                WriteLong(hash + 28, this->H);
        }

        /* Fill the entire context structure with zeros to blank it */
        memset(this,0, sizeof(SHA256));
}
//#define TEST_SHA256
#ifdef TEST_SHA256

#include <stdio.h>

/*
 * Define the test vectors and the expected answers.
 */
typedef struct
{
        const char *value;
        unsigned char expected[32];

} SHATestVector;
static SHATestVector vector1 = {
        "abc",
        {0xba, 0x78, 0x16, 0xbf, 0x8f, 0x01, 0xcf, 0xea,
         0x41, 0x41, 0x40, 0xde, 0x5d, 0xae, 0x22, 0x23,
         0xb0, 0x03, 0x61, 0xa3, 0x96, 0x17, 0x7a, 0x9c,
         0xb4, 0x10, 0xff, 0x61, 0xf2, 0x00, 0x15, 0xad}
};
static SHATestVector vector2 = {
        "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
        {0x24, 0x8d, 0x6a, 0x61, 0xd2, 0x06, 0x38, 0xb8,
         0xe5, 0xc0, 0x26, 0x93, 0x0c, 0x3e, 0x60, 0x39,
         0xa3, 0x3c, 0xe4, 0x59, 0x64, 0xff, 0x21, 0x67,
         0xf6, 0xec, 0xed, 0xd4, 0x19, 0xdb, 0x06, 0xc1}
};

/*
 * Print a 32-byte hash value.
 */
static void PrintHash(unsigned char *hash)
{
        printf("%02X%02X %02X%02X %02X%02X %02X%02X "
               "%02X%02X %02X%02X %02X%02X %02X%02X "
               "%02X%02X %02X%02X %02X%02X %02X%02X "
               "%02X%02X %02X%02X %02X%02X %02X%02X\n",
                   hash[0], hash[1], hash[2], hash[3],
                   hash[4], hash[5], hash[6], hash[7],
                   hash[8], hash[9], hash[10], hash[11],
                   hash[12], hash[13], hash[14], hash[15],
                   hash[16], hash[17], hash[18], hash[19],
                   hash[20], hash[21], hash[22], hash[23],
                   hash[24], hash[25], hash[26], hash[27],
                   hash[28], hash[29], hash[30], hash[31]);
}

/*
 * Process a test vector.
 */
static void ProcessVector(SHATestVector *vector)
{
        SHA256 sha;
        unsigned char hash[32];

        /* Compute the hash */

        sha.addData(vector->value, strlen(vector->value));
        sha.result(hash);

        /* Report the results */
        printf("Value    = %s\n", vector->value);
        printf("Expected = ");
        PrintHash(vector->expected);
        printf("Actual   = ");
        PrintHash(hash);
        if(memcmp(vector->expected, hash, 32) != 0)
        {
                printf("*** test failed ***\n");
        }
        printf("\n");
}

int main(int argc, char *argv[])
{
        printf("\n");
        ProcessVector(&vector1);
        ProcessVector(&vector2);
        return 0;
}

#endif /* TEST_SHA256 */