MD5 hash check implemented in C/C++

MD5 hash check implemented in C/C++

I don’t know which blogger’s code I found online, collect and use it, and delete it if it infringes.

#ifndef MD5_H
#define MD5_H

#ifdef __cplusplus
extern "C" {<!-- -->
#endif

typedef struct
{<!-- -->
        unsigned int count[2];
        unsigned int state[4];
        unsigned char buffer[64];
} MD5_CTX;

#define F(x,y,z) ((x & amp; y) | (~x & amp; z))
#define G(x,y,z) ((x & amp; z) | (y & amp; ~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 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; \
          }
void MD5Init(MD5_CTX *context);
void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputlen);
void MD5Final(MD5_CTX *context, unsigned char digest[16]);
void MD5Transform(unsigned int state[4], unsigned char block[64]);
void MD5Encode(unsigned char *output, unsigned int *input, unsigned int len);
void MD5Decode(unsigned int *output, unsigned char *input, unsigned int len);

#ifdef __cplusplus
extern }
#endif

#endif


#include <memory.h>
#include "md5.h"

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 MD5Init(MD5_CTX *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;
}

void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputlen)
{<!-- -->
        unsigned int i = 0, index = 0, partlen = 0;
        index = (context->count[0] >> 3) & amp; 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( & amp;context->buffer[index], input, partlen);
                MD5Transform(context->state, context->buffer);
                for (i = partlen; i + 64 <= inputlen; i + = 64)
                        MD5Transform(context->state, & amp;input[i]);
                index = 0;
        }
        else
        {<!-- -->
                i = 0;
        }
        memcpy( & amp;context->buffer[index], & amp;input[i], inputlen - i);
}

void MD5Final(MD5_CTX *context, unsigned char digest[16])
{<!-- -->
        unsigned int index = 0, padlen = 0;
        unsigned char bits[8];
        index = (context->count[0] >> 3) & amp; 0x3F;
        padlen = (index < 56) ? (56 - index) : (120 - index);
        MD5Encode(bits, context->count, 8);
        MD5Update(context, PADDING, padlen);
        MD5Update(context, bits, 8);
        MD5Encode(digest, context->state, 16);
}

void MD5Encode(unsigned char *output, unsigned int *input, unsigned int len)
{<!-- -->
        unsigned int i = 0, j = 0;
        while (j < len)
        {<!-- -->
                output[j] = input[i] & amp; 0xFF;
                output[j + 1] = (input[i] >> 8) & amp; 0xFF;
                output[j + 2] = (input[i] >> 16) & amp; 0xFF;
                output[j + 3] = (input[i] >> 24) & amp; 0xFF;
                i + + ;
                j + = 4;
        }
}

void MD5Decode(unsigned int *output, unsigned char *input, unsigned int len)
{<!-- -->
        unsigned int i = 0, j = 0;
        while (j < len)
        {<!-- -->
                output[i] = (input[j]) | (input[j + 1] << 8) | (input[j + 2] << 16) | (input[j + 3] << 24);
                i + + ;
                j + = 4;
        }
}
void MD5Transform(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];
        MD5Decode(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;
}

/*

#include "md5.h"
#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[])
{
        int i;
        unsigned char encrypt[] = "1234567890";
        unsigned char decrypt[16] = {0};

        MD5_CTX md5;
        MD5Init( & amp;md5);
        MD5Update( & amp;md5, encrypt, strlen((char*)encrypt));
        MD5Final( & amp;md5, decrypt);
        printf("encrypt: \r\
%s\r\
", encrypt);

        printf("decrypt: \r\
");

        for (i = 0; i < sizeof(decrypt); i + + )
        {
                printf("X", decrypt[i]);
        }

        printf("\r\
");

        return 0;
}

 */