السلام عليكم
اريد احد من المتمكنين في البرمجة بلغة C من كتابة شرح مفصل تفصيلا دقيقا
عن كيفية عمل شفرة MD5 ..
لو وضعنا حرف واحد وشفرناه بـMD5 لظهر لنا 33 خانة....
ولو وضعنا كلمة .. نفس الشئ
ولو شفرنا المصحف كاملاً فإنه لن يتجاوز الثلاثة والثلاثون حرفا...
كييف
خذ مثال:-
abc
900150983cd24fb0d6963f7d28e17f72
config
2245023265ae4cf87d02c8b6ba991139
منتديات الفريق العربي للبرمجة
84140831002f31dca071ee20833b57a5
ولو شفرنا بأي لغة -اليابانية مثلاً- فإن النتيجة ثابتة
تفضلوا الشفرة المصدرية لـ MD5 بلغة سي .. واشرحوها لي.. ولو كان الشرح ببرنامج
Microsoft Visio يكون افضل
md5.h
#ifndef _MD5_H
#define _MD5_H
#ifndef uint8
#define uint8 unsigned char
#endif
#ifndef uint32
#define uint32 unsigned long int
#endif
typedef struct
{
uint32 total[2];
uint32 state[4];
uint8 buffer[64];
}
md5_context;
void md5_starts( md5_context *ctx );
void md5_update( md5_context *ctx, uint8 *input, uint32 length );
void md5_finish( md5_context *ctx, uint8 digest[16] );
#endif /* md5.h */md5.c
/*
* RFC 1321 compliant MD5 implementation
*
* Copyright (C) 2001-2003 Christophe Devine
*
* 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 <string.h>
#include "md5.h"
#define GET_UINT32(n,b,i) \
{ \
(n) = ( (uint32) (b)[(i) ] ) \
| ( (uint32) (b)[(i) + 1] << 8 ) \
| ( (uint32) (b)[(i) + 2] << 16 ) \
| ( (uint32) (b)[(i) + 3] << 24 ); \
}
#define PUT_UINT32(n,b,i) \
{ \
(b)[(i) ] = (uint8) ( (n) ); \
(b)[(i) + 1] = (uint8) ( (n) >> 8 ); \
(b)[(i) + 2] = (uint8) ( (n) >> 16 ); \
(b)[(i) + 3] = (uint8) ( (n) >> 24 ); \
}
void md5_starts( md5_context *ctx )
{
ctx->total[0] = 0;
ctx->total[1] = 0;
ctx->state[0] = 0x67452301;
ctx->state[1] = 0xEFCDAB89;
ctx->state[2] = 0x98BADCFE;
ctx->state[3] = 0x10325476;
}
void md5_process( md5_context *ctx, uint8 data[64] )
{
uint32 X[16], A, B, C, D;
GET_UINT32( X[0], data, 0 );
GET_UINT32( X[1], data, 4 );
GET_UINT32( X[2], data, 8 );
GET_UINT32( X[3], data, 12 );
GET_UINT32( X[4], data, 16 );
GET_UINT32( X[5], data, 20 );
GET_UINT32( X[6], data, 24 );
GET_UINT32( X[7], data, 28 );
GET_UINT32( X[8], data, 32 );
GET_UINT32( X[9], data, 36 );
GET_UINT32( X[10], data, 40 );
GET_UINT32( X[11], data, 44 );
GET_UINT32( X[12], data, 48 );
GET_UINT32( X[13], data, 52 );
GET_UINT32( X[14], data, 56 );
GET_UINT32( X[15], data, 60 );
#define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))
#define P(a,b,c,d,k,s,t) \
{ \
a += F(b,c,d) + X[k] + t; a = S(a,s) + b; \
}
A = ctx->state[0];
B = ctx->state[1];
C = ctx->state[2];
D = ctx->state[3];
#define F(x,y,z) (z ^ (x & (y ^ z)))
P( A, B, C, D, 0, 7, 0xD76AA478 );
P( D, A, B, C, 1, 12, 0xE8C7B756 );
P( C, D, A, B, 2, 17, 0x242070DB );
P( B, C, D, A, 3, 22, 0xC1BDCEEE );
P( A, B, C, D, 4, 7, 0xF57C0FAF );
P( D, A, B, C, 5, 12, 0x4787C62A );
P( C, D, A, B, 6, 17, 0xA8304613 );
P( B, C, D, A, 7, 22, 0xFD469501 );
P( A, B, C, D, 8, 7, 0x698098D8 );
P( D, A, B, C, 9, 12, 0x8B44F7AF );
P( C, D, A, B, 10, 17, 0xFFFF5BB1 );
P( B, C, D, A, 11, 22, 0x895CD7BE );
P( A, B, C, D, 12, 7, 0x6B901122 );
P( D, A, B, C, 13, 12, 0xFD987193 );
P( C, D, A, B, 14, 17, 0xA679438E );
P( B, C, D, A, 15, 22, 0x49B40821 );
#undef F
#define F(x,y,z) (y ^ (z & (x ^ y)))
P( A, B, C, D, 1, 5, 0xF61E2562 );
P( D, A, B, C, 6, 9, 0xC040B340 );
P( C, D, A, B, 11, 14, 0x265E5A51 );
P( B, C, D, A, 0, 20, 0xE9B6C7AA );
P( A, B, C, D, 5, 5, 0xD62F105D );
P( D, A, B, C, 10, 9, 0x02441453 );
P( C, D, A, B, 15, 14, 0xD8A1E681 );
P( B, C, D, A, 4, 20, 0xE7D3FBC8 );
P( A, B, C, D, 9, 5, 0x21E1CDE6 );
P( D, A, B, C, 14, 9, 0xC33707D6 );
P( C, D, A, B, 3, 14, 0xF4D50D87 );
P( B, C, D, A, 8, 20, 0x455A14ED );
P( A, B, C, D, 13, 5, 0xA9E3E905 );
P( D, A, B, C, 2, 9, 0xFCEFA3F8 );
P( C, D, A, B, 7, 14, 0x676F02D9 );
P( B, C, D, A, 12, 20, 0x8D2A4C8A );
#undef F
#define F(x,y,z) (x ^ y ^ z)
P( A, B, C, D, 5, 4, 0xFFFA3942 );
P( D, A, B, C, 8, 11, 0x8771F681 );
P( C, D, A, B, 11, 16, 0x6D9D6122 );
P( B, C, D, A, 14, 23, 0xFDE5380C );
P( A, B, C, D, 1, 4, 0xA4BEEA44 );
P( D, A, B, C, 4, 11, 0x4BDECFA9 );
P( C, D, A, B, 7, 16, 0xF6BB4B60 );
P( B, C, D, A, 10, 23, 0xBEBFBC70 );
P( A, B, C, D, 13, 4, 0x289B7EC6 );
P( D, A, B, C, 0, 11, 0xEAA127FA );
P( C, D, A, B, 3, 16, 0xD4EF3085 );
P( B, C, D, A, 6, 23, 0x04881D05 );
P( A, B, C, D, 9, 4, 0xD9D4D039 );
P( D, A, B, C, 12, 11, 0xE6DB99E5 );
P( C, D, A, B, 15, 16, 0x1FA27CF8 );
P( B, C, D, A, 2, 23, 0xC4AC5665 );
#undef F
#define F(x,y,z) (y ^ (x | ~z))
P( A, B, C, D, 0, 6, 0xF4292244 );
P( D, A, B, C, 7, 10, 0x432AFF97 );
P( C, D, A, B, 14, 15, 0xAB9423A7 );
P( B, C, D, A, 5, 21, 0xFC93A039 );
P( A, B, C, D, 12, 6, 0x655B59C3 );
P( D, A, B, C, 3, 10, 0x8F0CCC92 );
P( C, D, A, B, 10, 15, 0xFFEFF47D );
P( B, C, D, A, 1, 21, 0x85845DD1 );
P( A, B, C, D, 8, 6, 0x6FA87E4F );
P( D, A, B, C, 15, 10, 0xFE2CE6E0 );
P( C, D, A, B, 6, 15, 0xA3014314 );
P( B, C, D, A, 13, 21, 0x4E0811A1 );
P( A, B, C, D, 4, 6, 0xF7537E82 );
P( D, A, B, C, 11, 10, 0xBD3AF235 );
P( C, D, A, B, 2, 15, 0x2AD7D2BB );
P( B, C, D, A, 9, 21, 0xEB86D391 );
#undef F
ctx->state[0] += A;
ctx->state[1] += B;
ctx->state[2] += C;
ctx->state[3] += D;
}
void md5_update( md5_context *ctx, uint8 *input, uint32 length )
{
uint32 left, fill;
if( ! length ) return;
left = ctx->total[0] & 0x3F;
fill = 64 - left;
ctx->total[0] += length;
ctx->total[0] &= 0xFFFFFFFF;
if( ctx->total[0] < length )
ctx->total[1]++;
if( left && length >= fill )
{
memcpy( (void *) (ctx->buffer + left),
(void *) input, fill );
md5_process( ctx, ctx->buffer );
length -= fill;
input += fill;
left = 0;
}
while( length >= 64 )
{
md5_process( ctx, input );
length -= 64;
input += 64;
}
if( length )
{
memcpy( (void *) (ctx->buffer + left),
(void *) input, length );
}
}
static uint8 md5_padding[64] =
{
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
void md5_finish( md5_context *ctx, uint8 digest[16] )
{
uint32 last, padn;
uint32 high, low;
uint8 msglen[8];
high = ( ctx->total[0] >> 29 )
| ( ctx->total[1] << 3 );
low = ( ctx->total[0] << 3 );
PUT_UINT32( low, msglen, 0 );
PUT_UINT32( high, msglen, 4 );
last = ctx->total[0] & 0x3F;
padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );
md5_update( ctx, md5_padding, padn );
md5_update( ctx, msglen, 8 );
PUT_UINT32( ctx->state[0], digest, 0 );
PUT_UINT32( ctx->state[1], digest, 4 );
PUT_UINT32( ctx->state[2], digest, 8 );
PUT_UINT32( ctx->state[3], digest, 12 );
}
#ifdef TEST
#include <stdlib.h>
#include <stdio.h>
/*
* those are the standard RFC 1321 test vectors
*/
static char *msg[] =
{
"",
"a",
"abc",
"message digest",
"abcdefghijklmnopqrstuvwxyz",
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
"12345678901234567890123456789012345678901234567890123456789012" \
"345678901234567890"
};
static char *val[] =
{
"d41d8cd98f00b204e9800998ecf8427e",
"0cc175b9c0f1b6a831c399e269772661",
"900150983cd24fb0d6963f7d28e17f72",
"f96b697d7cb7938d525a2f31aaf161d0",
"c3fcd3d76192e4007dfb496cca67e13b",
"d174ab98d277d9f5a5611c2c9f419d9f",
"57edf4a22be3c955ac49da2e2107b67a"
};
int main( int argc, char *argv[] )
{
FILE *f;
int i, j;
char output[33];
md5_context ctx;
unsigned char buf[1000];
unsigned char md5sum[16];
if( argc < 2 )
{
printf( "\n MD5 Validation Tests:\n\n" );
for( i = 0; i < 7; i++ )
{
printf( " Test %d ", i + 1 );
md5_starts( &ctx );
md5_update( &ctx, (uint8 *) msg, strlen( msg ) );
md5_finish( &ctx, md5sum );
for( j = 0; j < 16; j++ )
{
sprintf( output + j * 2, "%02x", md5sum[j] );
}
if( memcmp( output, val, 32 ) )
{
printf( "failed!\n" );
return( 1 );
}
printf( "passed.\n" );
}
printf( "\n" );
}
else
{
if( ! ( f = fopen( argv[1], "rb" ) ) )
{
perror( "fopen" );
return( 1 );
}
md5_starts( &ctx );
while( ( i = fread( buf, 1, sizeof( buf ), f ) ) > 0 )
{
md5_update( &ctx, buf, i );
}
md5_finish( &ctx, md5sum );
for( j = 0; j < 16; j++ )
{
printf( "%02x", md5sum[j] );
}
printf( " %s\n", argv[1] );
}
return( 0 );
}
#endif