text: 
  #ifndef MD5_H
  #define MD5_H
   
  typedef struct
  {
      unsigned int count[2];
      unsigned int state[4];
      unsigned char buffer[64];   
  }MD5_CTX;
                            
  #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 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);
   
  #endif
  