#include "aes_core.h"
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static int xor
    (unsigned char *a, unsigned char *b, unsigned char *c) {
      int i = 0;

      if (a == NULL || b == NULL || c == NULL)
        return -1;

      for (i = 0; i < 16; i++) {
        *c = *a ^ *b;
        c++;
        b++;
        a++;
      }

      return 0;
    }

    static int rk_aes_cbc_mac_encrypt(const unsigned char *in,
                                      unsigned long length, unsigned char *out,
                                      const RK_AES_KEY *ks1, const int enc) {
  unsigned long i = 0;
  int ret = 0;
  unsigned char tmp[16];
  memset(out, 0x00, 16);
  memset(tmp, 0x00, 16);

  for (i = 0; i < (length / 16); i++) {
    xor((unsigned char *)in + 16 * i, out, out);
    rk_aes_encrypt(out, out, ks1);
  };

  if (length % 16) {
    memcpy(tmp, in + 16 * i, length % 16);
    xor(tmp, out, out);
    rk_aes_encrypt(out, out, ks1);
  }
  return ret;
}

static int compare_string(unsigned char *a, unsigned char *b,
                          unsigned int len) {
  unsigned int i;

  if ((a == NULL) || (b == NULL))
    return -1;

  for (i = 0; i < len; i++) {
    if (*a != *b)
      return -1;
    a++;
    b++;
  }
  return 0;
}
int rk_aes_cbc_mac_op(const unsigned char *in, unsigned char *out,
                      unsigned long length, const unsigned char *key,
                      const int key_len, const int enc) {
  RK_AES_KEY ks1;
  int ret = 0;
  unsigned char tmp_out[16] = {0};
  unsigned int out_len = 16;

  if (in == NULL || out == NULL || key == NULL)
    return -1;

  if (key_len != 128 / 8 && key_len != 192 / 8 && key_len != 256 / 8)
    return -2;

  if (length == 0)
    return -3;

  ret = rk_aes_set_encrypt_key(key, key_len * 8, &ks1);
  if (ret != 0)
    return ret;

  ret = rk_aes_cbc_mac_encrypt(in, length, tmp_out, &ks1, enc);
  if (ret != 0)
    return ret;

  if (enc)
    memcpy(out, tmp_out, out_len);
  else
    ret = compare_string(out, tmp_out, out_len);

  return ret;
}