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mdfour.c

/* 
   a implementation of MD4 designed for use in the SMB authentication protocol
   Copyright (C) Andrew Tridgell 1997-1998.
   
   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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "ccache.h"

/* NOTE: This code makes no attempt to be fast! 

   It assumes that a int is at least 32 bits long
*/

static struct mdfour *m;

#define MASK32 (0xffffffff)

#define F(X,Y,Z) ((((X)&(Y)) | ((~(X))&(Z))))
#define G(X,Y,Z) ((((X)&(Y)) | ((X)&(Z)) | ((Y)&(Z))))
#define H(X,Y,Z) (((X)^(Y)^(Z)))
#define lshift(x,s) (((((x)<<(s))&MASK32) | (((x)>>(32-(s)))&MASK32)))

#define ROUND1(a,b,c,d,k,s) a = lshift((a + F(b,c,d) + M[k])&MASK32, s)
#define ROUND2(a,b,c,d,k,s) a = lshift((a + G(b,c,d) + M[k] + 0x5A827999)&MASK32,s)
#define ROUND3(a,b,c,d,k,s) a = lshift((a + H(b,c,d) + M[k] + 0x6ED9EBA1)&MASK32,s)

/* this applies md4 to 64 byte chunks */
static void mdfour64(uint32 *M)
{
      uint32 AA, BB, CC, DD;
      uint32 A,B,C,D;

      A = m->A; B = m->B; C = m->C; D = m->D; 
      AA = A; BB = B; CC = C; DD = D;

        ROUND1(A,B,C,D,  0,  3);  ROUND1(D,A,B,C,  1,  7);  
      ROUND1(C,D,A,B,  2, 11);  ROUND1(B,C,D,A,  3, 19);
        ROUND1(A,B,C,D,  4,  3);  ROUND1(D,A,B,C,  5,  7);  
      ROUND1(C,D,A,B,  6, 11);  ROUND1(B,C,D,A,  7, 19);
        ROUND1(A,B,C,D,  8,  3);  ROUND1(D,A,B,C,  9,  7);  
      ROUND1(C,D,A,B, 10, 11);  ROUND1(B,C,D,A, 11, 19);
        ROUND1(A,B,C,D, 12,  3);  ROUND1(D,A,B,C, 13,  7);  
      ROUND1(C,D,A,B, 14, 11);  ROUND1(B,C,D,A, 15, 19);    


        ROUND2(A,B,C,D,  0,  3);  ROUND2(D,A,B,C,  4,  5);  
      ROUND2(C,D,A,B,  8,  9);  ROUND2(B,C,D,A, 12, 13);
        ROUND2(A,B,C,D,  1,  3);  ROUND2(D,A,B,C,  5,  5);  
      ROUND2(C,D,A,B,  9,  9);  ROUND2(B,C,D,A, 13, 13);
        ROUND2(A,B,C,D,  2,  3);  ROUND2(D,A,B,C,  6,  5);  
      ROUND2(C,D,A,B, 10,  9);  ROUND2(B,C,D,A, 14, 13);
        ROUND2(A,B,C,D,  3,  3);  ROUND2(D,A,B,C,  7,  5);  
      ROUND2(C,D,A,B, 11,  9);  ROUND2(B,C,D,A, 15, 13);

      ROUND3(A,B,C,D,  0,  3);  ROUND3(D,A,B,C,  8,  9);  
      ROUND3(C,D,A,B,  4, 11);  ROUND3(B,C,D,A, 12, 15);
        ROUND3(A,B,C,D,  2,  3);  ROUND3(D,A,B,C, 10,  9);  
      ROUND3(C,D,A,B,  6, 11);  ROUND3(B,C,D,A, 14, 15);
        ROUND3(A,B,C,D,  1,  3);  ROUND3(D,A,B,C,  9,  9);  
      ROUND3(C,D,A,B,  5, 11);  ROUND3(B,C,D,A, 13, 15);
        ROUND3(A,B,C,D,  3,  3);  ROUND3(D,A,B,C, 11,  9);  
      ROUND3(C,D,A,B,  7, 11);  ROUND3(B,C,D,A, 15, 15);

      A += AA; B += BB; 
      C += CC; D += DD;
      
      A &= MASK32; B &= MASK32; 
      C &= MASK32; D &= MASK32;

      m->A = A; m->B = B; m->C = C; m->D = D;
}

static void copy64(uint32 *M, const unsigned char *in)
{
      int i;

      for (i=0;i<16;i++)
            M[i] = (in[i*4+3]<<24) | (in[i*4+2]<<16) |
                  (in[i*4+1]<<8) | (in[i*4+0]<<0);
}

static void copy4(unsigned char *out,uint32 x)
{
      out[0] = x&0xFF;
      out[1] = (x>>8)&0xFF;
      out[2] = (x>>16)&0xFF;
      out[3] = (x>>24)&0xFF;
}

void mdfour_begin(struct mdfour *md)
{
      md->A = 0x67452301;
      md->B = 0xefcdab89;
      md->C = 0x98badcfe;
      md->D = 0x10325476;
      md->totalN = 0;
      md->tail_len = 0;
}


static void mdfour_tail(const unsigned char *in, int n)
{
      unsigned char buf[128];
      uint32 M[16];
      uint32 b;

      m->totalN += n;

      b = m->totalN * 8;

      memset(buf, 0, 128);
      if (n) memcpy(buf, in, n);
      buf[n] = 0x80;

      if (n <= 55) {
            copy4(buf+56, b);
            copy64(M, buf);
            mdfour64(M);
      } else {
            copy4(buf+120, b); 
            copy64(M, buf);
            mdfour64(M);
            copy64(M, buf+64);
            mdfour64(M);
      }
}

void mdfour_update(struct mdfour *md, const unsigned char *in, int n)
{
      uint32 M[16];

      m = md;

      if (in == NULL) {
            mdfour_tail(md->tail, md->tail_len);
            return;
      }

      if (md->tail_len) {
            int len = 64 - md->tail_len;
            if (len > n) len = n;
            memcpy(md->tail+md->tail_len, in, len);
            md->tail_len += len;
            n -= len;
            in += len;
            if (md->tail_len == 64) {
                  copy64(M, md->tail);
                  mdfour64(M);
                  m->totalN += 64;
                  md->tail_len = 0;
            }
      }

      while (n >= 64) {
            copy64(M, in);
            mdfour64(M);
            in += 64;
            n -= 64;
            m->totalN += 64;
      }

      if (n) {
            memcpy(md->tail, in, n);
            md->tail_len = n;
      }
}


void mdfour_result(struct mdfour *md, unsigned char *out)
{
      m = md;

      copy4(out, m->A);
      copy4(out+4, m->B);
      copy4(out+8, m->C);
      copy4(out+12, m->D);
}


void mdfour(unsigned char *out, const unsigned char *in, int n)
{
      struct mdfour md;
      mdfour_begin(&md);
      mdfour_update(&md, in, n);
      mdfour_update(&md, NULL, 0);
      mdfour_result(&md, out);
}

#ifdef TEST_MDFOUR
static void file_checksum1(char *fname)
{
      int fd, i;
      struct mdfour md;
      unsigned char buf[1024], sum[16];
      unsigned chunk;
      
      fd = open(fname,O_RDONLY);
      if (fd == -1) {
            perror("fname");
            exit(1);
      }

      chunk = 1 + random() % (sizeof(buf) - 1);
      
      mdfour_begin(&md);

      while (1) {
            int n = read(fd, buf, chunk);
            if (n >= 0) {
                  mdfour_update(&md, buf, n);
            }
            if (n < chunk) break;
      }

      close(fd);

      mdfour_update(&md, NULL, 0);

      mdfour_result(&md, sum);

      for (i=0;i<16;i++)
            printf("%02x", sum[i]);
      printf("\n");
}

#if 0
#include "../md4.h"

static void file_checksum2(char *fname)
{
      int fd, i;
      MDstruct md;
      unsigned char buf[64], sum[16];

      fd = open(fname,O_RDONLY);
      if (fd == -1) {
            perror("fname");
            exit(1);
      }
      
      MDbegin(&md);

      while (1) {
            int n = read(fd, buf, sizeof(buf));
            if (n <= 0) break;
            MDupdate(&md, buf, n*8);
      }

      if (!md.done) {
            MDupdate(&md, buf, 0);
      }

      close(fd);

      memcpy(sum, md.buffer, 16);

      for (i=0;i<16;i++)
            printf("%02x", sum[i]);
      printf("\n");
}
#endif

 int main(int argc, char *argv[])
{
      file_checksum1(argv[1]);
#if 0
      file_checksum2(argv[1]);
#endif
      return 0;
}
#endif

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