utils.c

void get_random_string(char *random_str,int length)
{
   FILE *fp = fopen("/dev/urandom","r");
   if(!fp){
       perror("Unble to open urandom device");
       exit(EXIT_FAILURE);
   }
   fread(random_str,length,1,fp);
   fclose(fp);
}
 
char random_string[11];
  
  //get random string
   get_random_string(random_string,10);
  //convert random string to base64 coz input string is coming from /dev/urandom and may contain binary chars
   const int encoded_length = Base64encode_len(10);
   base64_string=(char *)malloc(encoded_length+1);
   Base64encode(base64_string,random_string,10);
   base64_string[encoded_length]='\0';