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simple-crypto/md5.c
2022-04-18 14:57:58 +08:00

265 lines
6.4 KiB
C

// https://github.com/pod32g/MD5
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
// Constants are the integer part of the sines of integers (in radians) * 2^32.
const static uint32_t k[64] = {
0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee ,
0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501 ,
0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be ,
0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821 ,
0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa ,
0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8 ,
0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed ,
0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a ,
0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c ,
0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70 ,
0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05 ,
0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665 ,
0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039 ,
0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1 ,
0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1 ,
0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391 };
// r specifies the per-round shift amounts
const static uint32_t r[] = {7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20,
4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23,
6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21};
// leftrotate function definition
#define LEFTROTATE(x, c) (((x) << (c)) | ((x) >> (32 - (c))))
static void to_bytes(uint32_t val, uint8_t *bytes) {
#ifdef WORDS_BIGENDIAN
*(uint32_t*)bytes = __builtin_bswap32(val);
#else
*(uint32_t*)bytes = val;
#endif
}
static uint32_t to_uint32(const uint8_t *bytes) {
#ifdef WORDS_BIGENDIAN
return __builtin_bswap32(*(uint32_t*)bytes);
#else
return *(uint32_t*)bytes;
#endif
}
#ifdef WORDS_BIGENDIAN
/* break chunk into sixteen 32-bit words w[j], 0 ≤ j ≤ 15 */
#define break_chunk_into_w(trunk)\
(for(i = 0; i < 16; i++) w[i] = to_uint32((trunk) + i*4))
#else
/* break chunk into sixteen 32-bit words w[j], 0 ≤ j ≤ 15 */
#define break_chunk_into_w(trunk) (w = (uint32_t*)(trunk))
#endif
//for each 512-bit chunk of message:
#define sum(trunk) {\
/* break chunk into sixteen 32-bit words w[j], 0 ≤ j ≤ 15 */\
break_chunk_into_w(trunk);\
\
/* Initialize hash value for this chunk: */\
a = h0;\
b = h1;\
c = h2;\
d = h3;\
\
/* Main loop: */\
for(i = 0; i < 16; i++) {\
f = (b & c) | ((~b) & d);\
g = i;\
temp = d;\
d = c;\
c = b;\
b += LEFTROTATE((a + f + k[i] + w[g]), r[i]);\
a = temp;\
}\
for(i = 16; i < 32; i++) {\
f = (d & b) | ((~d) & c);\
g = (5*i + 1) % 16;\
temp = d;\
d = c;\
c = b;\
b += LEFTROTATE((a + f + k[i] + w[g]), r[i]);\
a = temp;\
}\
for(i = 32; i < 48; i++) {\
f = b ^ c ^ d;\
g = (3*i + 5) % 16;\
temp = d;\
d = c;\
c = b;\
b += LEFTROTATE((a + f + k[i] + w[g]), r[i]);\
a = temp;\
}\
for(i = 48; i < 64; i++) {\
f = c ^ (b | (~d));\
g = (7*i) % 16;\
temp = d;\
d = c;\
c = b;\
b += LEFTROTATE((a + f + k[i] + w[g]), r[i]);\
a = temp;\
}\
\
/* Add this chunk's hash to result so far: */\
h0 += a;\
h1 += b;\
h2 += c;\
h3 += d;\
}
uint8_t* md5(const uint8_t *data, size_t data_len, uint8_t digest[16]) {
// buffer of last trunk
uint8_t trunk[64];
#ifdef WORDS_BIGENDIAN
uint32_t w[16];
#else
uint32_t* w;
#endif
// These vars will contain the hash
// Initialize variables - simple count in nibbles:
uint32_t h0 = 0x67452301;
uint32_t h1 = 0xefcdab89;
uint32_t h2 = 0x98badcfe;
uint32_t h3 = 0x10325476;
size_t offset = 0;
uint32_t a, b, c, d, i, f, g, temp;
// Process the message in successive 512-bit chunks:
if(data_len >= 64)
for(offset=0; offset<(data_len&(~0x3f)); offset += 64)
sum(data+offset);
// Process the last trunk of message:
//append "1" bit to message
//append "0" bits until message length in bits ≡ 448 (mod 512)
//append length mod (2^64) to message
i = data_len-offset;
if(i) memcpy(trunk, data+offset, i);
trunk[i++] = 0x80; // append the "1" bit; most significant bit is "first"
temp = 64-i;
if(temp) memset(&trunk[i], 0, temp); // append "0" bits
//no enough space to fill the len in bits
//we need to process one more trunk
if(i > 56) {
sum(trunk);
memset(trunk, 0, 64);
}
// append the len in bits at the end of the buffer.
to_bytes(data_len * 8, &trunk[56]);
// initial_len>>29 == initial_len*8>>32, but avoids overflow.
to_bytes(data_len>>29, &trunk[60]);
//sum the last trunk
sum(trunk);
//var char digest[16] := h0 append h1 append h2 append h3
//(Output is in little-endian)
to_bytes(h0, &digest[0]);
to_bytes(h1, &digest[4]);
to_bytes(h2, &digest[8]);
to_bytes(h3, &digest[12]);
return (uint8_t*)digest;
}
#ifdef TEST_SIMPLE_CRYPTO
#include <stdio.h>
#include <sys/stat.h>
#include <time.h>
unsigned long get_start_ms() {
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return (ts.tv_sec * 1000 + ts.tv_nsec / 1000000);
}
int main(int argc, char **argv) {
char *msg;
size_t len;
int i;
FILE* fp;
uint8_t* buf;
unsigned long t1, t2;
uint8_t result[16];
struct stat statbuf;
if (argc < 3) {
printf("usage: %s [options]\n\toptions:\n\t-s string: encode a string\n\t-f file: encode a file\n\t-b file: benchmark using the file\n", argv[0]);
return 1;
}
msg = argv[2];
switch(argv[1][1]) {
case 's':
len = strlen(msg);
md5((uint8_t*)msg, len, result);
// display result
for (i = 0; i < 16; i++)
printf("%2.2x", result[i]);
putchar('\n');
break;
case 'f':
if(stat(msg, &statbuf)) {
perror("stat: ");
return 1;
}
fp = fopen(msg, "rb");
if(!fp) {
perror("fopen: ");
return 2;
}
buf = malloc(statbuf.st_size);
if(!buf) {
perror("malloc: ");
return 3;
}
if(fread(buf, statbuf.st_size, 1, fp) != 1) {
perror("fread: ");
return 4;
}
md5(buf, statbuf.st_size, result);
// display result
for (i = 0; i < 16; i++)
printf("%2.2x", result[i]);
putchar('\n');
break;
case 'b':
if(stat(msg, &statbuf)) {
perror("stat: ");
return 1;
}
fp = fopen(msg, "rb");
if(!fp) {
perror("fopen: ");
return 2;
}
buf = malloc(statbuf.st_size);
if(!buf) {
perror("malloc: ");
return 3;
}
if(fread(buf, statbuf.st_size, 1, fp) != 1) {
perror("fread: ");
return 4;
}
t1 = get_start_ms();
for(int i = 0; i < 4; i++) {
md5(buf, statbuf.st_size, result);
buf[0] = result[0];
}
t2 = get_start_ms();
printf("benchmark: %lu ms.\n", t2-t1);
break;
}
return 0;
}
#endif