/* md5.c - MD5 Message-Digest Algorithm
 *	Copyright (C) 1995, 1996, 1998, 1999 Free Software Foundation, Inc.
 *
 * according to the definition of MD5 in RFC 1321 from April 1992.
 * NOTE: This is *not* the same file as the one from glibc.
 *
 * 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, 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.
 */
/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.  */
/* heavily modified for GnuPG by <werner.koch@guug.de> */
/* Modified for inclusion in Loki setup by Stéphane Peter <megastep@lokigames.com> */

/* Test values:
 * ""                  D4 1D 8C D9 8F 00 B2 04  E9 80 09 98 EC F8 42 7E
 * "a"                 0C C1 75 B9 C0 F1 B6 A8  31 C3 99 E2 69 77 26 61
 * "abc                90 01 50 98 3C D2 4F B0  D6 96 3F 7D 28 E1 7F 72
 * "message digest"    F9 6B 69 7D 7C B7 93 8D  52 5A 2F 31 AA F1 61 D0
 */

#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>
#include <fcntl.h>
#include <sys/stat.h>
#ifndef NO_ZLIB
#include <zlib.h>
#endif

#include "arch.h"
#include "md5.h"


void md5_init( MD5_CONTEXT *ctx )
{
    ctx->A = 0x67452301;
    ctx->B = 0xefcdab89;
    ctx->C = 0x98badcfe;
    ctx->D = 0x10325476;

    ctx->nblocks = 0;
    ctx->count = 0;
}

/****************
 * Rotate a 32 bit integer by n bytes
 */
#if defined(__GNUC__) && defined(__i386__)
static inline unsigned int rol( unsigned int x, int n)
{
        __asm__("roll %%cl,%0"
                :"=r" (x)
                :"0" (x),"c" (n));
        return x;
}
#else
  #define rol(x,n) ( ((x) << (n)) | ((x) >> (32-(n))) )
#endif


/* These are the four functions used in the four steps of the MD5 algorithm
   and defined in the RFC 1321.  The first function is a little bit optimized
   (as found in Colin Plumbs public domain implementation).  */
/* #define FF(b, c, d) ((b & c) | (~b & d)) */
#define FF(b, c, d) (d ^ (b & (c ^ d)))
#define FG(b, c, d) FF (d, b, c)
#define FH(b, c, d) (b ^ c ^ d)
#define FI(b, c, d) (c ^ (b | ~d))


/****************
 * transform n*64 bytes
 */
static void transform( MD5_CONTEXT *ctx, unsigned char *data )
{
    unsigned int correct_words[16];
    unsigned int A = ctx->A;
    unsigned int B = ctx->B;
    unsigned int C = ctx->C;
    unsigned int D = ctx->D;
    unsigned int *cwp = correct_words;

#if BYTE_ORDER == BIG_ENDIAN
    { int i;
      unsigned char *p2, *p1;
      for(i=0, p1=data, p2=(unsigned char*)correct_words; i < 16; i++, p2 += 4 ) {
		  p2[3] = *p1++;
		  p2[2] = *p1++;
		  p2[1] = *p1++;
		  p2[0] = *p1++;
      }
    }
#else
    memcpy( correct_words, data, 64 );
#endif


#define OP(a, b, c, d, s, T)					    \
  do								    \
    {								    \
      a += FF (b, c, d) + (*cwp++) + T; 	    \
      a = rol(a, s);						    \
      a += b;							    \
    }								    \
  while (0)

    /* Before we start, one word about the strange constants.
       They are defined in RFC 1321 as

       T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
     */

    /* Round 1.  */
    OP (A, B, C, D,  7, 0xd76aa478);
    OP (D, A, B, C, 12, 0xe8c7b756);
    OP (C, D, A, B, 17, 0x242070db);
    OP (B, C, D, A, 22, 0xc1bdceee);
    OP (A, B, C, D,  7, 0xf57c0faf);
    OP (D, A, B, C, 12, 0x4787c62a);
    OP (C, D, A, B, 17, 0xa8304613);
    OP (B, C, D, A, 22, 0xfd469501);
    OP (A, B, C, D,  7, 0x698098d8);
    OP (D, A, B, C, 12, 0x8b44f7af);
    OP (C, D, A, B, 17, 0xffff5bb1);
    OP (B, C, D, A, 22, 0x895cd7be);
    OP (A, B, C, D,  7, 0x6b901122);
    OP (D, A, B, C, 12, 0xfd987193);
    OP (C, D, A, B, 17, 0xa679438e);
    OP (B, C, D, A, 22, 0x49b40821);

#undef OP
#define OP(f, a, b, c, d, k, s, T)  \
    do								      \
      { 							      \
	a += f (b, c, d) + correct_words[k] + T;		      \
	a = rol(a, s);						      \
	a += b; 						      \
      } 							      \
    while (0)

    /* Round 2.  */
    OP (FG, A, B, C, D,  1,  5, 0xf61e2562);
    OP (FG, D, A, B, C,  6,  9, 0xc040b340);
    OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
    OP (FG, B, C, D, A,  0, 20, 0xe9b6c7aa);
    OP (FG, A, B, C, D,  5,  5, 0xd62f105d);
    OP (FG, D, A, B, C, 10,  9, 0x02441453);
    OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
    OP (FG, B, C, D, A,  4, 20, 0xe7d3fbc8);
    OP (FG, A, B, C, D,  9,  5, 0x21e1cde6);
    OP (FG, D, A, B, C, 14,  9, 0xc33707d6);
    OP (FG, C, D, A, B,  3, 14, 0xf4d50d87);
    OP (FG, B, C, D, A,  8, 20, 0x455a14ed);
    OP (FG, A, B, C, D, 13,  5, 0xa9e3e905);
    OP (FG, D, A, B, C,  2,  9, 0xfcefa3f8);
    OP (FG, C, D, A, B,  7, 14, 0x676f02d9);
    OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);

    /* Round 3.  */
    OP (FH, A, B, C, D,  5,  4, 0xfffa3942);
    OP (FH, D, A, B, C,  8, 11, 0x8771f681);
    OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
    OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
    OP (FH, A, B, C, D,  1,  4, 0xa4beea44);
    OP (FH, D, A, B, C,  4, 11, 0x4bdecfa9);
    OP (FH, C, D, A, B,  7, 16, 0xf6bb4b60);
    OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
    OP (FH, A, B, C, D, 13,  4, 0x289b7ec6);
    OP (FH, D, A, B, C,  0, 11, 0xeaa127fa);
    OP (FH, C, D, A, B,  3, 16, 0xd4ef3085);
    OP (FH, B, C, D, A,  6, 23, 0x04881d05);
    OP (FH, A, B, C, D,  9,  4, 0xd9d4d039);
    OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
    OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
    OP (FH, B, C, D, A,  2, 23, 0xc4ac5665);

    /* Round 4.  */
    OP (FI, A, B, C, D,  0,  6, 0xf4292244);
    OP (FI, D, A, B, C,  7, 10, 0x432aff97);
    OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
    OP (FI, B, C, D, A,  5, 21, 0xfc93a039);
    OP (FI, A, B, C, D, 12,  6, 0x655b59c3);
    OP (FI, D, A, B, C,  3, 10, 0x8f0ccc92);
    OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
    OP (FI, B, C, D, A,  1, 21, 0x85845dd1);
    OP (FI, A, B, C, D,  8,  6, 0x6fa87e4f);
    OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
    OP (FI, C, D, A, B,  6, 15, 0xa3014314);
    OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
    OP (FI, A, B, C, D,  4,  6, 0xf7537e82);
    OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
    OP (FI, C, D, A, B,  2, 15, 0x2ad7d2bb);
    OP (FI, B, C, D, A,  9, 21, 0xeb86d391);

    /* Put checksum in context given as argument.  */
    ctx->A += A;
    ctx->B += B;
    ctx->C += C;
    ctx->D += D;
}



/* The routine updates the message-digest context to
 * account for the presence of each of the characters inBuf[0..inLen-1]
 * in the message whose digest is being computed.
 */
void md5_write( MD5_CONTEXT *hd, unsigned char *inbuf, size_t inlen)
{
    if( hd->count == 64 ) { /* flush the buffer */
		transform( hd, hd->buf );
		hd->count = 0;
		hd->nblocks++;
    }
    if( !inbuf )
		return;
    if( hd->count ) {
		for( ; inlen && hd->count < 64; inlen-- )
			hd->buf[hd->count++] = *inbuf++;
		md5_write( hd, NULL, 0 );
		if( !inlen )
			return;
    }

    while( inlen >= 64 ) {
		transform( hd, inbuf );
		hd->count = 0;
		hd->nblocks++;
		inlen -= 64;
		inbuf += 64;
    }
    for( ; inlen && hd->count < 64; inlen-- )
		hd->buf[hd->count++] = *inbuf++;
}



/* The routine final terminates the message-digest computation and
 * ends with the desired message digest in mdContext->digest[0...15].
 * The handle is prepared for a new MD5 cycle.
 * Returns 16 unsigned chars representing the digest.
 */

void md5_final( MD5_CONTEXT *hd )
{
    unsigned int t, msb, lsb;
    unsigned char *p;

    md5_write(hd, NULL, 0); /* flush */;
	
    msb = 0;
    t = hd->nblocks;
    if( (lsb = t << 6) < t ) /* multiply by 64 to make a byte count */
		msb++;
    msb += t >> 26;
    t = lsb;
    if( (lsb = t + hd->count) < t ) /* add the count */
		msb++;
    t = lsb;
    if( (lsb = t << 3) < t ) /* multiply by 8 to make a bit count */
		msb++;
    msb += t >> 29;
	
    if( hd->count < 56 ) { /* enough room */
		hd->buf[hd->count++] = 0x80; /* pad */
		while( hd->count < 56 )
			hd->buf[hd->count++] = 0;  /* pad */
    }
    else { /* need one extra block */
		hd->buf[hd->count++] = 0x80; /* pad character */
		while( hd->count < 64 )
			hd->buf[hd->count++] = 0;
		md5_write(hd, NULL, 0);  /* flush */;
		memset(hd->buf, 0, 56 ); /* fill next block with zeroes */
    }
    /* append the 64 bit count */
    hd->buf[56] = lsb	   ;
    hd->buf[57] = lsb >>  8;
    hd->buf[58] = lsb >> 16;
    hd->buf[59] = lsb >> 24;
    hd->buf[60] = msb	   ;
    hd->buf[61] = msb >>  8;
    hd->buf[62] = msb >> 16;
    hd->buf[63] = msb >> 24;
    transform( hd, hd->buf );
	
    p = hd->buf;
#if BYTE_ORDER == BIG_ENDIAN
/*#define X(a) do { *p++ = hd->##a; *p++ = hd->##a >> 8; *p++ = hd->##a >> 16; *p++ = hd->##a >> 24; } while(0)*/
    /* MacOS X cpp doesn't like the above construct so we do it like below. ( Jon Champoux )*/
#define X(a) do { *p++ = (*hd).a; *p++ = (*hd).a >> 8; *p++ = (*hd).a >> 16; *p++=(*hd).a>>24; } while(0)                      
#else /* little endian */
    /*#define X(a) do { *(unsigned int*)p = hd->##a ; p += 4; } while(0)*/
    /* Unixware's cpp doesn't like the above construct so we do it his way:
     * (reported by Allan Clark) */
#define X(a) do { *(unsigned int*)p = (*hd).a ; p += 4; } while(0)
#endif
    X(A);
    X(B);
    X(C);
    X(D);
#undef X
}


const char *get_md5(unsigned char *binsum)
{
	static char buf[33];
	static const char *trans = "0123456789abcdef";
	int i, j;

	for( i = 0, j = 0; i < 16; ++i ) {
		buf[j++] = trans[binsum[i] >> 4];
		buf[j++] = trans[binsum[i] & 0xF];
	}
	buf[j] = '\0';

	return buf;
}

unsigned char *get_md5_bin(const char *asciisum)
{
    static unsigned char buf[16];
    char str[3] = "xx";

    int i, j;
	for( i = 0, j = 0; i < 16; ++i ) {
        str[0] = asciisum[j++];
        str[1] = asciisum[j++];
        buf[i] = (unsigned char)strtol(str, NULL, 16);
    }
    return buf;
}

int md5_compute(const char *path, char md5sum[], int unpack)
{
    char buf[4096];
    size_t count;
    MD5_CONTEXT ctx;

#ifdef NO_ZLIB
    if ( 1 ) {
#else
    if ( unpack ) {
        gzFile fd = gzopen(path, "rb");
        if ( !fd ) {
            perror(path);
            return -1;
        }
        md5_init(&ctx);
        while ( (count = gzread(fd, buf, sizeof(buf))) > 0 ){        
            md5_write(&ctx, (unsigned char *)buf, count);
        }
        md5_final(&ctx);
        gzclose(fd);
    } else {
#endif
        FILE *fd = fopen(path, "rb");
        if ( !fd ) {
            perror(path);
            return -1;
        }
        md5_init(&ctx);
        while ( (count = fread(buf, 1, sizeof(buf), fd)) > 0 ){        
            md5_write(&ctx, (unsigned char *)buf, count);
        }
        md5_final(&ctx);
        fclose(fd);
    }
    strcpy(md5sum, get_md5(ctx.buf));
    return 0;
}

#ifdef MD5SUM_PROGRAM

#ifdef HAVE_FTW
#include <ftw.h>
#else
#define FTW_F   0
#endif
#ifndef isspace
#define isspace(X)	(((X) == ' ') || ((X) == '\t'))
#endif

static int unpack = 0;

static int ftw_func(const char *file, const struct stat *st, int flag)
{
    if ( flag == FTW_F ) {
        char sum[33] = "";
        md5_compute(file, sum, unpack);
        printf("%s  %s\n", sum, file);
    }
    return 0;
}

static int check_sums(const char *checksumfile)
{
    FILE *csumfp;
    int checked;
    int failed_open;
    int failed_csum;
    int status;

    status = -1;
    checked = 0;
    failed_open = 0;
    failed_csum = 0;
    csumfp = fopen(checksumfile, "r");
    if ( csumfp ) {
        char line[4096];
        char *csum, *file;
        char sum[33];

        while ( fgets(line, sizeof(line)-1, csumfp) ) {
            /* Trim trailing newline */
            line[strlen(line)-1] = '\0';

            /* Split the checksum and filename */
            csum = line;
            for ( file = csum; *file && !isspace(*file); ++file );
            if ( ! *file ) {
                fprintf(stderr, "Malformed line: %s\n", line);
                continue;
            }
            *file++ = '\0';
            while ( *file && isspace(*file) ) {
                ++file;
            }
            if ( ! *file ) {
                fprintf(stderr, "Malformed line: %s\n", line);
                continue;
            }
            if ( md5_compute(file, sum, unpack) == 0 ) {
                if ( strcmp(csum, sum) == 0 ) {
                    printf("%s: OK\n", file);
                } else {
                    printf("%s: FAILED\n", file);
                    ++failed_csum;
                }
            } else {
                printf("%s: FAILED open\n", file);
                ++failed_open;
            }
            ++checked;
        }
        fclose(csumfp);

        /* Print out totals */
        printf("%d files checked, ", checked);
	if ( failed_open ) {
            printf("%d files failed open, ", failed_open);
        }
        if ( failed_csum ) {
            printf("%d files failed checksum.\n", failed_csum);
            status = 2;
        } else {
            printf("all files okay.\n");
            status = 0;
        }
    } else {
        perror(checksumfile);
    }
    return status;
}

static void usage(const char *argv0)
{
    printf("Usage: %s [-z] <file | directory>\n", argv0);
    printf("or\n");
    printf("       %s [-z] -c <checksumfile>\n", argv0);
}

int main(int argc, char **argv)
{
    struct stat st;
    int i;
    int status;
    
    unpack = 0;
    if ( argv[1] && (strcmp(argv[1], "-z") == 0) ) {
        unpack = 1;
        --argc;
        ++argv;
    } else
    if ( argv[1] && (strcmp(argv[1], "-c") == 0) ) {
        if ( argc == 3 ) {
            return check_sums(argv[2]);
        } else {
            usage(argv[0]);
            return 1;
        }
    }
    if ( argc < 2 ) {
        usage(argv[0]);
        return 1;
    }

    status = 0;
    for( i = 1; i < argc; ++i ) {
        if( stat(argv[i], &st) == 0 ) {
#ifdef HAVE_FTW
            if ( S_ISREG(st.st_mode) ) {
                ftw_func(argv[i], &st, FTW_F);
            } else {
                ftw(argv[i], ftw_func, 3);
            }
#else
            ftw_func(argv[i], &st, FTW_F);
#endif
        } else {
            perror(argv[i]);
            status = 2;
        }
    }
    return status;
}

#endif


/* end of file */
