#pragma once

#include <cstdint>

namespace AES {

constexpr size_t kKeyLen = 16;  // Key length in bytes
constexpr size_t kKeyExpansionSize = 176;
constexpr size_t kBlockLen = 16;  // Block length in bytes - AES is 128b block only

struct AES_ctx {
    uint8_t RoundKey[kKeyExpansionSize];
    uint8_t Iv[16];
};

void AES_init_ctx_iv(AES_ctx* ctx, const uint8_t* key, const uint8_t* iv);

// buffer size MUST be mutile of AES_BLOCKLEN;
// Suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
// NOTES: you need to set IV in ctx via AES_init_ctx_iv() or AES_ctx_set_iv()
//        no IV should ever be reused with the same key
void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);

}  // namespace AES