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

static void rk_crypto_cbc128_encrypt(const unsigned char *in,
                                     unsigned char *out, int len,
                                     const void *key, unsigned char *ivec) {
  int n;
  const unsigned char *iv = ivec;

  while (len) {
    for (n = 0; n < 16 && n < len; ++n)
      out[n] = in[n] ^ iv[n];
    for (; n < 16; ++n)
      out[n] = iv[n];
    rk_aes_encrypt(out, out, key);
    iv = out;
    if (len <= 16)
      break;
    len -= 16;
    in += 16;
    out += 16;
  }
  memcpy(ivec, iv, 16);
}

static void rk_crypto_cbc128_decrypt(const unsigned char *in,
                                     unsigned char *out, int len,
                                     const void *key, unsigned char *ivec) {
  int n;
  unsigned char c;
  unsigned char tmp_buf[AES_BLOCK_SIZE];

  memset(tmp_buf, 0x00, sizeof(tmp_buf));

  while (len) {
    rk_aes_decrypt(in, tmp_buf, key);
    for (n = 0; n < 16 && n < len; ++n) {
      c = in[n];
      out[n] = tmp_buf[n] ^ ivec[n];
      ivec[n] = c;
    }
    if (len <= 16) {
      for (; n < 16; ++n)
        ivec[n] = in[n];
      break;
    }
    len -= 16;
    in += 16;
    out += 16;
  }
}

int rk_aes_cbc_encrypt(const unsigned char *in, unsigned char *out,
                       unsigned long length, const unsigned char *key,
                       const int key_len, unsigned char *ivec, const int enc) {
  RK_AES_KEY ks;

  if (key_len != 16 && key_len != 24 && key_len != 32)
    return -1;

  if (length % AES_BLOCK_SIZE)
    return -1;

  if (enc) {
    rk_aes_set_encrypt_key(key, key_len * 8, &ks);
    rk_crypto_cbc128_encrypt(in, out, length, &ks, ivec);
  } else {
    rk_aes_set_decrypt_key(key, key_len * 8, &ks);
    rk_crypto_cbc128_decrypt(in, out, length, &ks, ivec);
  }
  return 0;
}