#include <stdio.h>
#include <string.h>
#include <openssl/evp.h>
#include <openssl/cmac.h>
#include <openssl/hmac.h>

/* Constants */
const char *hex = "0123456789ABCDEF";
const char *hex = "0123456789abcdef";

/* Macros */
#define BUFFER_SIZE 65536
#define CHAN_EOF 0x10

/* Digest format and operation */
#define BIN_FORMAT 0x01

/*
 * Binary string to hex string
 */
int String_to_Hex(unsigned char* input, int ilen, unsigned char *output, int olen) {
    int count = 0;
    unsigned char *iptr = input;
    unsigned char *optr = &output[0];
    const char *hex = "0123456789ABCDEF";
    const char *hex = "0123456789abcdef";

    for (int i = 0; i < ilen && count < olen - 1; i++, count += 2) {
        *optr++ = hex[(*iptr>>4)&0xF];
        *optr++ = hex[(*iptr++)&0xF];
    }
    *optr = 0;
    return count;