// $Id: md5calc.c,v 1.1.1.1 2004/09/10 17:26:54 MagicalTux Exp $
/***********************************************************
* md5 calculation algorithm
*
* The source code referred to the following URL.
* http://www.geocities.co.jp/SiliconValley-Oakland/8878/lab17/lab17.html
*
***********************************************************/
#include "md5calc.h"
#include <string.h>
#include <stdio.h>
#ifndef UINT_MAX
#define UINT_MAX 4294967295U
#endif
// Global variable
static unsigned int *pX;
// Stirng Table
static const unsigned int T[] = {
0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, //0
0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501, //4
0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be, //8
0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821, //12
0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa, //16
0xd62f105d, 0x2441453, 0xd8a1e681, 0xe7d3fbc8, //20
0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed, //24
0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a, //28
0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c, //32
0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70, //36
0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05, //40
0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665, //44
0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039, //48
0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1, //52
0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1, //56
0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391 //60
};
// ROTATE_LEFT The left is made to rotate x [ n-bit ]. This is diverted as it is from RFC.
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
// The function used for other calculation
static unsigned int F (unsigned int X, unsigned int Y, unsigned int Z)
{
return (X & Y) | (~X & Z);
}
static unsigned int G (unsigned int X, unsigned int Y, unsigned int Z)
{
return (X & Z) | (Y & ~Z);
}
static unsigned int H (unsigned int X, unsigned int Y, unsigned int Z)
{
return X ^ Y ^ Z;
}
static unsigned int I (unsigned int X, unsigned int Y, unsigned int Z)
{
return Y ^ (X | ~Z);
}
static unsigned int Round (unsigned int a, unsigned int b, unsigned int FGHI,
unsigned int k, unsigned int s, unsigned int i)
{
return b + ROTATE_LEFT (a + FGHI + pX[k] + T[i], s);
}
static void Round1 (unsigned int *a, unsigned int b, unsigned int c,
unsigned int d, unsigned int k, unsigned int s,
unsigned int i)
{
*a = Round (*a, b, F (b, c, d), k, s, i);
}
static void Round2 (unsigned int *a, unsigned int b, unsigned int c,
unsigned int d, unsigned int k, unsigned int s,
unsigned int i)
{
*a = Round (*a, b, G (b, c, d), k, s, i);
}
static void Round3 (unsigned int *a, unsigned int b, unsigned int c,
unsigned int d, unsigned int k, unsigned int s,
unsigned int i)
{
*a = Round (*a, b, H (b, c, d), k, s, i);
}
static void Round4 (unsigned int *a, unsigned int b, unsigned int c,
unsigned int d, unsigned int k, unsigned int s,
unsigned int i)
{
*a = Round (*a, b, I (b, c, d), k, s, i);
}
static void MD5_Round_Calculate (const unsigned char *block,
unsigned int *A2, unsigned int *B2,
unsigned int *C2, unsigned int *D2)
{
//create X It is since it is required.
unsigned int X[16]; //512bit 64byte
int j, k;
//Save A as AA, B as BB, C as CC, and and D as DD (saving of A, B, C, and D)
unsigned int A = *A2, B = *B2, C = *C2, D = *D2;
unsigned int AA = A, BB = B, CC = C, DD = D;
//It is a large region variable reluctantly because of calculation of a round. . . for Round1...4
pX = X;
//Copy block(padding_message) i into X
for (j = 0, k = 0; j < 64; j += 4, k++)
X[k] = ((unsigned int) block[j]) // 8byte*4 -> 32byte conversion
| (((unsigned int) block[j + 1]) << 8) // A function called Decode as used in the field of RFC
| (((unsigned int) block[j + 2]) << 16)
| (((unsigned int) block[j + 3]) << 24);
//Round 1
Round1 (&A, B, C, D, 0, 7, 0);
Round1 (&D, A, B, C, 1, 12, 1);
Round1 (&C, D, A, B, 2, 17, 2);
Round1 (&B, C, D, A, 3, 22, 3);
Round1 (&A, B, C, D, 4, 7, 4);
Round1 (&D, A, B, C, 5, 12, 5);
Round1 (&C, D, A, B, 6, 17, 6);
Round1 (&B, C, D, A, 7, 22, 7);
Round1 (&A, B, C, D, 8, 7, 8);
Round1 (&D, A, B, C, 9, 12, 9);
Round1 (&C, D, A, B, 10, 17, 10);
Round1 (&B, C, D, A, 11, 22, 11);
Round1 (&A, B, C, D, 12, 7, 12);
Round1 (&D, A, B, C, 13, 12, 13);
Round1 (&C, D, A, B, 14, 17, 14);
Round1 (&B, C, D, A, 15, 22, 15);
//Round 2
Round2 (&A, B, C, D, 1, 5, 16);
Round2 (&D, A, B, C, 6, 9, 17);
Round2 (&C, D, A, B, 11, 14, 18);
Round2 (&B, C, D, A, 0, 20, 19);
Round2 (&A, B, C, D, 5, 5, 20);
Round2 (&D, A, B, C, 10, 9, 21);
Round2 (&C, D, A, B, 15, 14, 22);
Round2 (&B, C, D, A, 4, 20, 23);
Round2 (&A, B, C, D, 9, 5, 24);
Round2 (&D, A, B, C, 14, 9, 25);
Round2 (&C, D, A, B, 3, 14, 26);
Round2 (&B, C, D, A, 8, 20, 27);
Round2 (&A, B, C, D, 13, 5, 28);
Round2 (&D, A, B, C, 2, 9, 29);
Round2 (&C, D, A, B, 7, 14, 30);
Round2 (&B, C, D, A, 12, 20, 31);
//Round 3
Round3 (&A, B, C, D, 5, 4, 32);
Round3 (&D, A, B, C, 8, 11, 33);
Round3 (&C, D, A, B, 11, 16, 34);
Round3 (&B, C, D, A, 14, 23, 35);
Round3 (&A, B, C, D, 1, 4, 36);
Round3 (&D, A, B, C, 4, 11, 37);
Round3 (&C, D, A, B, 7, 16, 38);
Round3 (&B, C, D, A, 10, 23, 39);
Round3 (&A, B, C, D, 13, 4, 40);
Round3 (&D, A, B, C, 0, 11, 41);
Round3 (&C, D, A, B, 3, 16, 42);
Round3 (&B, C, D, A, 6, 23, 43);
Round3 (&A, B, C, D, 9, 4, 44);
Round3 (&D, A, B, C, 12, 11, 45);
Round3 (&C, D, A, B, 15, 16, 46);
Round3 (&B, C, D, A, 2, 23, 47);
//Round 4
Round4 (&A, B, C, D, 0, 6, 48);
Round4 (&D, A, B, C, 7, 10, 49);
Round4 (&C, D, A, B, 14, 15, 50);
Round4 (&B, C, D, A, 5, 21, 51);
Round4 (&A, B, C, D, 12, 6, 52);
Round4 (&D, A, B, C, 3, 10, 53);
Round4 (&C, D, A, B, 10, 15, 54);
Round4 (&B, C, D, A, 1, 21, 55);
Round4 (&A, B, C, D, 8, 6, 56);
Round4 (&D, A, B, C, 15, 10, 57);
Round4 (&C, D, A, B, 6, 15, 58);
Round4 (&B, C, D, A, 13, 21, 59);
Round4 (&A, B, C, D, 4, 6, 60);
Round4 (&D, A, B, C, 11, 10, 61);
Round4 (&C, D, A, B, 2, 15, 62);
Round4 (&B, C, D, A, 9, 21, 63);
// Then perform the following additions. (let's add)
*A2 = A + AA;
*B2 = B + BB;
*C2 = C + CC;
*D2 = D + DD;
//The clearance of confidential information
memset (pX, 0, sizeof (X));
}
//-------------------------------------------------------------------
// The function for the exteriors
/** output is the coded binary in the character sequence which wants to code string. */
void MD5_String2binary (const char *string, char *output)
{
//var
/*8bit */
unsigned char padding_message[64]; //Extended message 512bit 64byte
unsigned char *pstring; //The position of string in the present scanning notes is held.
// unsigned char digest[16];
/*32bit */
unsigned int string_byte_len, //The byte chief of string is held.
string_bit_len, //The bit length of string is held.
copy_len, //The number of bytes which is used by 1-3 and which remained
msg_digest[4]; //Message digest 128bit 4byte
unsigned int *A = &msg_digest[0], //The message digest in accordance with RFC (reference)
*B = &msg_digest[1], *C = &msg_digest[2], *D = &msg_digest[3];
int i;
//prog
//Step 3.Initialize MD Buffer (although it is the initialization; step 3 of A, B, C, and D -- unavoidable -- a head)
*A = 0x67452301;
*B = 0xefcdab89;
*C = 0x98badcfe;
*D = 0x10325476;
//Step 1.Append Padding Bits (extension of a mark bit)
//1-1
string_byte_len = strlen (string); //The byte chief of a character sequence is acquired.
pstring = (unsigned char *) string; //The position of the present character sequence is set.
//1-2 Repeat calculation until length becomes less than 64 bytes.
for (i = string_byte_len; 64 <= i; i -= 64, pstring += 64)
MD5_Round_Calculate (pstring, A, B, C, D);
//1-3
copy_len = string_byte_len % 64; //The number of bytes which remained is computed.
strncpy ((char *) padding_message, (char *) pstring, copy_len); //A message is copied to an extended bit sequence.
memset (padding_message + copy_len, 0, 64 - copy_len); //It buries by 0 until it becomes extended bit length.
padding_message[copy_len] |= 0x80; //The next of a message is 1.
//1-4
//If 56 bytes or more (less than 64 bytes) of remainder becomes, it will calculate by extending to 64 bytes.
if (56 <= copy_len)
{
MD5_Round_Calculate (padding_message, A, B, C, D);
memset (padding_message, 0, 56); //56 bytes is newly fill uped with 0.
}
//Step 2.Append Length (the information on length is added)
string_bit_len = string_byte_len * 8; //From the byte chief to bit length (32 bytes of low rank)
memcpy (&padding_message[56], &string_bit_len, 4); //32 bytes of low rank is set.
//When bit length cannot be expressed in 32 bytes of low rank, it is a beam raising to a higher rank.
if (UINT_MAX / 8 < string_byte_len)
{
unsigned int high = (string_byte_len - UINT_MAX / 8) * 8;
memcpy (&padding_message[60], &high, 4);
}
else
memset (&padding_message[60], 0, 4); //In this case, it is good for a higher rank at 0.
//Step 4.Process Message in 16-Word Blocks (calculation of MD5)
MD5_Round_Calculate (padding_message, A, B, C, D);
//Step 5.Output (output)
memcpy (output, msg_digest, 16);
// memcpy (digest, msg_digest, and 16); //8 byte*4 < - 32byte conversion A function called Encode as used in the field of RFC
/* sprintf(output,
"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
digest[ 0], digest[ 1], digest[ 2], digest[ 3],
digest[ 4], digest[ 5], digest[ 6], digest[ 7],
digest[ 8], digest[ 9], digest[10], digest[11],
digest[12], digest[13], digest[14], digest[15]);*/
}
/** output is the coded character sequence in the character sequence which wants to code string. */
void MD5_String (const char *string, char *output)
{
unsigned char digest[16];
MD5_String2binary (string, digest);
sprintf (output,
"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
digest[0], digest[1], digest[2], digest[3],
digest[4], digest[5], digest[6], digest[7],
digest[8], digest[9], digest[10], digest[11],
digest[12], digest[13], digest[14], digest[15]);
}
