md5_example.c

#include <stdio.h> 

/*
Output should be:
d41d8cd98f00b204e9800998ecf8427e
900150983cd24fb0d6963f7d28e17f72
d174ab98d277d9f5a5611c2c9f419d9f
*/

void print_hash(char hash[]) 
{
   int idx; 
   for (idx=0; idx < 16; idx++) 
      printf("%02x",hash[idx]); 
   printf("\n"); 
}   

int main() 
{  
   char hash[16],
        in1[]={""},
        in2[]={"abc"},
        in3_1[]={"ABCDEFGHIJKLMNOPQRSTUVWXYZabcde"},
        in3_2[]={"fghijklmnopqrstuvwxyz0123456789"}; 
   unsigned int len; 
   MD5_CTX ctx; 
   
   // First hash 
   md5_init(&ctx); 
   md5_update(&ctx,in1,strlen(in1)); 
   md5_final(&ctx,hash); 
   print_hash(hash); 
   
   // Second hash (note the MD5 object can be reused) 
   md5_init(&ctx); 
   md5_update(&ctx,in2,strlen(in2)); 
   md5_final(&ctx,hash); 
   print_hash(hash); 
   
   // Third hash (note the data is being added in two chunks) 
   md5_init(&ctx); 
   md5_update(&ctx,in3_1,strlen(in3_1)); 
   md5_update(&ctx,in3_2,strlen(in3_2)); 
   md5_final(&ctx,hash); 
   print_hash(hash); 
   
   getchar(); 
   return 0; 
}