#include <stdio.h>
#include <string.h>
#include <stdint.h>
/* ref:
http://www.ietf.org/rfc/rfc1321.txt
http://oss.org.cn/man/develop/rfc/RFC1321.txt
http://www.codeforge.cn/read/240035/md5sum.c__html
*/
static inline void convert_endian_32(uint32_t * in_out)
{
uint32_t old = *in_out;
uint8_t * a = (uint8_t *)in_out;
uint8_t * b = (uint8_t *)&old;
# define do4(N) a[N] = b[3-N]
do4(0); do4(1); do4(2); do4(3);
}
static inline void convert_endian_64(uint64_t * in_out)
{
uint64_t old = *in_out;
uint8_t * a = (uint8_t *)in_out;
uint8_t * b = (uint8_t *)&old;
# define do8(N) a[N] = b[7-N]
do8(0); do8(1); do8(2); do8(3);
do8(4); do8(5); do8(6); do8(7);
}
static inline void convert_endian_32_array(uint32_t in_out[], uint32_t num)
{
uint32_t i;
for(i = 0; i < num; i++) {
convert_endian_32(in_out + i);
}
}
static int judge_endian(void)
{
union {
uint32_t i;
uint8_t c;
} u;
u.i = 1;
return u.c == 0; // return 1 if big endian
}
#define FF(b,c,d) ( d ^ (b & (c ^ d)) ) // ( (b & c) | (~b & d) )
#define FG(b,c,d) FF(d, b, c) // ( (b & d) | (c & ~d) )
#define FH(b,c,d) ( b ^ c ^ d )
#define FI(b,c,d) ( c ^ (b | ~d) )
#define ROLL(a,s) ( (a<<s) | (a>>(32-s)) )
#define OP(func, a,b,c,d, k,s,t) a+=func(b,c,d)+in[k]+t; a=b+ROLL(a,s)
static void md5_transform(uint32_t abcd[4], const uint32_t in[16])
{
uint32_t A = abcd[0];
uint32_t B = abcd[1];
uint32_t C = abcd[2];
uint32_t D = abcd[3];
OP(FF, A, B, C, D, 0, 7, 0xd76aa478);
OP(FF, D, A, B, C, 1, 12, 0xe8c7b756);
OP(FF, C, D, A, B, 2, 17, 0x242070db);
OP(FF, B, C, D, A, 3, 22, 0xc1bdceee);
OP(FF, A, B, C, D, 4, 7, 0xf57c0faf);
OP(FF, D, A, B, C, 5, 12, 0x4787c62a);
OP(FF, C, D, A, B, 6, 17, 0xa8304613);
OP(FF, B, C, D, A, 7, 22, 0xfd469501);
OP(FF, A, B, C, D, 8, 7, 0x698098d8);
OP(FF, D, A, B, C, 9, 12, 0x8b44f7af);
OP(FF, C, D, A, B, 10, 17, 0xffff5bb1);
OP(FF, B, C, D, A, 11, 22, 0x895cd7be);
OP(FF, A, B, C, D, 12, 7, 0x6b901122);
OP(FF, D, A, B, C, 13, 12, 0xfd987193);
OP(FF, C, D, A, B, 14, 17, 0xa679438e);
OP(FF, B, C, D, A, 15, 22, 0x49b40821);
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);
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);
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);
abcd[0] += A;
abcd[1] += B;
abcd[2] += C;
abcd[3] += D;
}
int main(int argc, char * argv[])
{
if(argc != 2) {
return 1;
}
FILE * f = fopen(argv[1], "rb");
if(!f) {
return 2;
}
int is_big_endian = judge_endian();
uint32_t abcd[4] = { 0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476 };
uint64_t bit_sum = 0;
for(;;) {
uint32_t in[32]; //128 bytes
size_t n = fread(in, 1, 64, f);
bit_sum += n * 8;
if(n == 64) {
if(is_big_endian) {
convert_endian_32_array(in, 16);
}
md5_transform(abcd, in);
} else {
uint8_t * buf = (uint8_t *)in;
memset(buf + n, 0, 128 - n);
buf[n] = 0x80;
uint64_t * p_len = (uint64_t *)(n < 56 ? &buf[64-8] : &buf[128-8]);
*p_len = bit_sum;
if(is_big_endian) {
convert_endian_64(p_len);
convert_endian_32_array(in, 32);
}
md5_transform(abcd, in);
if(n >= 56) {
md5_transform(abcd, in + 16);
}
break;
}
}
fclose(f);
int i;
for(i = 0; i < 4; i++) {
convert_endian_32(abcd + i);
printf("%08x", abcd[i]);
}
printf("\n");
return 0;
}
