大家都知道,MD5是一种摘要运算算法,关于更多的摘要算法,可以参考我之前的一篇文章:摘要算法汇总
今天要给大家带来的是MD5摘要运算的源码实现,废话不多说,直接上源码:
先看头文件,什么了一些结构体定义和操作宏定义,以及导出的3个API接口:
#ifndef __MD5_H__
#define __MD5_H__
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
#include
typedef struct _md5_ctx_t {
uint32_t count[2];
uint32_t state[4];
uint8_t buffer[64];
} md5_ctx_t;
#define F(x,y,z) ((x & y) | (~x & z))
#define G(x,y,z) ((x & z) | (y & ~z))
#define H(x,y,z) (x^y^z)
#define I(x,y,z) (y ^ (x | ~z))
#define ROTATE_LEFT(x,n) ((x << n) | (x >> (32-n)))
#define MD5_DIGEST_LEN 16
#define FF(a,b,c,d,x,s,ac) \
{ \
a += F(b,c,d) + x + ac; \
a = ROTATE_LEFT(a,s); \
a += b; \
}
#define GG(a,b,c,d,x,s,ac) \
{ \
a += G(b,c,d) + x + ac; \
a = ROTATE_LEFT(a,s); \
a += b; \
}
#define HH(a,b,c,d,x,s,ac) \
{ \
a += H(b,c,d) + x + ac; \
a = ROTATE_LEFT(a,s); \
a += b; \
}
#define II(a,b,c,d,x,s,ac) \
{ \
a += I(b,c,d) + x + ac; \
a = ROTATE_LEFT(a,s); \
a += b; \
}
extern void crypto_md5_init(md5_ctx_t *ctx);
extern void crypto_md5_update(md5_ctx_t *ctx, uint8_t *in, uint32_t in_len);
extern void crypto_md5_final(md5_ctx_t *ctx, uint8_t digest[MD5_DIGEST_LEN]);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /*__MD5_H__*/
接下来,上实现源码:
#include
#include
#include "md5.h"
static const unsigned char PADDING[] =
{
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 crypto_md5_init(md5_ctx_t *context)
{
context->count[0] = 0;
context->count[1] = 0;
context->state[0] = 0x67452301;
context->state[1] = 0xEFCDAB89;
context->state[2] = 0x98BADCFE;
context->state[3] = 0x10325476;
}
static void crypto_md5_decode(unsigned int *output, unsigned char *input, unsigned int len)
{
unsigned int i = 0;
unsigned int j = 0;
while (j < len) {
output[i] = (input[j]) |
(input[j+1] << 8) |
(input[j+2] << 16) |
(input[j+3] << 24);
i++;
j += 4;
}
}
static void crypto_md5_transform(unsigned int state[4], unsigned char block[64])
{
unsigned int a = state[0];
unsigned int b = state[1];
unsigned int c = state[2];
unsigned int d = state[3];
unsigned int x[64];
crypto_md5_decode(x,block,64);
FF(a, b, c, d, x[ 0], 7, 0xd76aa478); /* 1 */
FF(d, a, b, c, x[ 1], 12, 0xe8c7b756); /* 2 */
FF(c, d, a, b, x[ 2], 17, 0x242070db); /* 3 */
FF(b, c, d, a, x[ 3], 22, 0xc1bdceee); /* 4 */
FF(a, b, c, d, x[ 4], 7, 0xf57c0faf); /* 5 */
FF(d, a, b, c, x[ 5], 12, 0x4787c62a); /* 6 */
FF(c, d, a, b, x[ 6], 17, 0xa8304613); /* 7 */
FF(b, c, d, a, x[ 7], 22, 0xfd469501); /* 8 */
FF(a, b, c, d, x[ 8], 7, 0x698098d8); /* 9 */
FF(d, a, b, c, x[ 9], 12, 0x8b44f7af); /* 10 */
FF(c, d, a, b, x[10], 17, 0xffff5bb1); /* 11 */
FF(b, c, d, a, x[11], 22, 0x895cd7be); /* 12 */
FF(a, b, c, d, x[12], 7, 0x6b901122); /* 13 */
FF(d, a, b, c, x[13], 12, 0xfd987193); /* 14 */
FF(c, d, a, b, x[14], 17, 0xa679438e); /* 15 */
FF(b, c, d, a, x[15], 22, 0x49b40821); /* 16 */
/* Round 2 */
GG(a, b, c, d, x[ 1], 5, 0xf61e2562); /* 17 */
GG(d, a, b, c, x[ 6], 9, 0xc040b340); /* 18 */
GG(c, d, a, b, x[11], 14, 0x265e5a51); /* 19 */
GG(b, c, d, a, x[ 0], 20, 0xe9b6c7aa); /* 20 */
GG(a, b, c, d, x[ 5], 5, 0xd62f105d); /* 21 */
GG(d, a, b, c, x[10], 9, 0x2441453); /* 22 */
GG(c, d, a, b, x[15], 14, 0xd8a1e681); /* 23 */
GG(b, c, d, a, x[ 4], 20, 0xe7d3fbc8); /* 24 */
GG(a, b, c, d, x[ 9], 5, 0x21e1cde6); /* 25 */
GG(d, a, b, c, x[14], 9, 0xc33707d6); /* 26 */
GG(c, d, a, b, x[ 3], 14, 0xf4d50d87); /* 27 */
GG(b, c, d, a, x[ 8], 20, 0x455a14ed); /* 28 */
GG(a, b, c, d, x[13], 5, 0xa9e3e905); /* 29 */
GG(d, a, b, c, x[ 2], 9, 0xfcefa3f8); /* 30 */
GG(c, d, a, b, x[ 7], 14, 0x676f02d9); /* 31 */
GG(b, c, d, a, x[12], 20, 0x8d2a4c8a); /* 32 */
/* Round 3 */
HH(a, b, c, d, x[ 5], 4, 0xfffa3942); /* 33 */
HH(d, a, b, c, x[ 8], 11, 0x8771f681); /* 34 */
HH(c, d, a, b, x[11], 16, 0x6d9d6122); /* 35 */
HH(b, c, d, a, x[14], 23, 0xfde5380c); /* 36 */
HH(a, b, c, d, x[ 1], 4, 0xa4beea44); /* 37 */
HH(d, a, b, c, x[ 4], 11, 0x4bdecfa9); /* 38 */
HH(c, d, a, b, x[ 7], 16, 0xf6bb4b60); /* 39 */
HH(b, c, d, a, x[10], 23, 0xbebfbc70); /* 40 */
HH(a, b, c, d, x[13], 4, 0x289b7ec6); /* 41 */
HH(d, a, b, c, x[ 0], 11, 0xeaa127fa); /* 42 */
HH(c, d, a, b, x[ 3], 16, 0xd4ef3085); /* 43 */
HH(b, c, d, a, x[ 6], 23, 0x4881d05); /* 44 */
HH(a, b, c, d, x[ 9], 4, 0xd9d4d039); /* 45 */
HH(d, a, b, c, x[12], 11, 0xe6db99e5); /* 46 */
HH(c, d, a, b, x[15], 16, 0x1fa27cf8); /* 47 */
HH(b, c, d, a, x[ 2], 23, 0xc4ac5665); /* 48 */
/* Round 4 */
II(a, b, c, d, x[ 0], 6, 0xf4292244); /* 49 */
II(d, a, b, c, x[ 7], 10, 0x432aff97); /* 50 */
II(c, d, a, b, x[14], 15, 0xab9423a7); /* 51 */
II(b, c, d, a, x[ 5], 21, 0xfc93a039); /* 52 */
II(a, b, c, d, x[12], 6, 0x655b59c3); /* 53 */
II(d, a, b, c, x[ 3], 10, 0x8f0ccc92); /* 54 */
II(c, d, a, b, x[10], 15, 0xffeff47d); /* 55 */
II(b, c, d, a, x[ 1], 21, 0x85845dd1); /* 56 */
II(a, b, c, d, x[ 8], 6, 0x6fa87e4f); /* 57 */
II(d, a, b, c, x[15], 10, 0xfe2ce6e0); /* 58 */
II(c, d, a, b, x[ 6], 15, 0xa3014314); /* 59 */
II(b, c, d, a, x[13], 21, 0x4e0811a1); /* 60 */
II(a, b, c, d, x[ 4], 6, 0xf7537e82); /* 61 */
II(d, a, b, c, x[11], 10, 0xbd3af235); /* 62 */
II(c, d, a, b, x[ 2], 15, 0x2ad7d2bb); /* 63 */
II(b, c, d, a, x[ 9], 21, 0xeb86d391); /* 64 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
}
void crypto_md5_update(md5_ctx_t *context, unsigned char *input, unsigned int inputlen)
{
unsigned int i = 0;
unsigned int index = 0;
unsigned int partlen = 0;
index = (context->count[0] >> 3) & 0x3F;
partlen = 64 - index;
context->count[0] += inputlen << 3;
if(context->count[0] < (inputlen << 3))
context->count[1]++;
context->count[1] += inputlen >> 29;
if (inputlen >= partlen) {
memcpy(&context->buffer[index], input,partlen);
crypto_md5_transform(context->state, context->buffer);
for (i = partlen; i+64 <= inputlen; i+=64) {
crypto_md5_transform(context->state, &input[i]);
}
index = 0;
} else {
i = 0;
}
memcpy(&context->buffer[index], &input[i], inputlen-i);
}
static void crypto_md5_encode(unsigned char *output,unsigned int *input,unsigned int len)
{
unsigned int i = 0;
unsigned int j = 0;
while (j < len) {
output[j] = input[i] & 0xFF;
output[j+1] = (input[i] >> 8) & 0xFF;
output[j+2] = (input[i] >> 16) & 0xFF;
output[j+3] = (input[i] >> 24) & 0xFF;
i++;
j += 4;
}
}
void crypto_md5_final(md5_ctx_t *context, unsigned char digest[16])
{
unsigned int index = 0,padlen = 0;
unsigned char bits[8];
index = (context->count[0] >> 3) & 0x3F;
padlen = (index < 56)?(56-index):(120-index);
crypto_md5_encode(bits, context->count, 8);
crypto_md5_update(context, (unsigned char *)PADDING, padlen);
crypto_md5_update(context, bits, 8);
crypto_md5_encode(digest, context->state, 16);
}
我们先写一段测试代码测试一下看看:
#include
#include
#include "md5.h"
int main(int argc, const char *argv[])
{
const char *data = "C1D0F8FB4958670DBA40AB1F3752EF0D";
uint8_t digest_calc[MD5_DIGEST_LEN];
uint8_t digest_exp[MD5_DIGEST_LEN] = "\x4C\x61\x8F\xD1\x4C\x14\x88\x1E\xFB\x13\x35\x2E\x40\x04\x73\xB1";
md5_ctx_t ctx;
const char *p_calc = data;
uint8_t data_bytes[128];
uint16_t len_bytes;
char data_str[128];
if (argc > 1) {
p_calc = argv[1];
}
crypto_md5_init(&ctx);
crypto_md5_update(&ctx, (uint8_t *)p_calc, strlen(p_calc));
crypto_md5_final(&ctx, digest_calc);
if (!memcmp(digest_calc, digest_exp, sizeof(digest_calc))) {
printf("MD5 digest test OK\n");
} else {
//log_hexdump("digest_calc", digest_calc, sizeof(digest_calc));
//log_hexdump("digest_exp", digest_exp, sizeof(digest_exp));
printf("MD5 digest test FAIL\n");
}
return 0;
}
这个测试案例,是计算一段字符串:"C1D0F8FB4958670DBA40AB1F3752EF0D"的MD5摘要,然后期往的MD5摘要是下面的32字节数据:
"\x4C\x61\x8F\xD1\x4C\x14\x88\x1E\xFB\x13\x35\x2E\x40\x04\x73\xB1"
通过取得计算的结果与期望值进行比对,进而得出运算结果正确与否。
通过运行测试程序,可以发现,运算结果正常。
也可以跟一些算法小工具的结果做下对比,发现,结果也是没有问题的。
以上就是本次对MD5源码的测试,本案例的所有源代码,均可以在我的github上面找到,对你有帮助的话,请帮忙点个star呦,先谢谢了。
更多参考链接
[1] 【安全算法的github仓库】
[2] 【安全算法之概述】一文带你简要了解常见常用的安全算法
[3] 【安全算法之base64】base64加解密的C语言源码实现
[4] 【安全算法之MD5】MD5摘要运算的C语言源码实现
[5] 【安全算法之SHA1】SHA1摘要运算的C语言源码实现
[6] 【安全算法之SHA224】SHA224摘要运算的C语言源码实现
[7] 【安全算法之SHA256】SHA256摘要运算的C语言源码实现
[8] 【安全算法之SHA384】SHA384摘要运算的C语言源码实现
[9] 【安全算法之SHA512】SHA512摘要运算的C语言源码实现