// $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 #include #include "mt_rand.h" #include #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]); } // Hash a password with a salt. char *MD5_saltcrypt(const char *key, const char *salt) { char buf[66], *sbuf = buf+32; static char obuf[33]; // hash the key then the salt // buf ends up as a 64char null terminated string MD5_String(key, buf); MD5_String(salt, sbuf); // Hash the buffer back into sbuf MD5_String(buf, sbuf); snprintf(obuf, 32, "!%s$%s", salt, sbuf); return(obuf); } char *make_salt() { static char salt[6]; int i; for (i=0; i<5; i++) salt[i] = (char)((mt_rand() % 78) + 48); salt[5] = '\0'; return(salt); } int pass_ok(const char *password, const char *crypted) { char buf[40], *salt=buf+1; strncpy(buf, crypted, 40); *strchr(buf, '$') = '\0'; if (!strcmp(crypted, MD5_saltcrypt(password, salt))) return(1); return(0); }