Atmosphere-libs/libvapours/include/vapours/crypto/impl/crypto_cbc_mac_impl.hpp
2022-03-23 09:15:55 -07:00

104 lines
3.5 KiB
C++

/*
* Copyright (c) Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <vapours/common.hpp>
#include <vapours/assert.hpp>
#include <vapours/util.hpp>
#include <vapours/crypto/crypto_memory_clear.hpp>
#include <vapours/crypto/crypto_aes_encryptor.hpp>
namespace ams::crypto::impl {
class CbcMacImpl {
NON_COPYABLE(CbcMacImpl);
NON_MOVEABLE(CbcMacImpl);
public:
static constexpr size_t BlockSize = 0x10;
private:
enum State {
State_None,
State_Initialized,
State_Done,
};
private:
u8 m_mac[BlockSize];
u8 m_buffer[BlockSize];
size_t m_buffered_bytes;
const void *m_cipher_context;
void (*m_cipher_function)(void *dst, const void *src, const void *ctx);
State m_state;
public:
CbcMacImpl() : m_buffered_bytes(0), m_state(State_None) { /* ... */ }
~CbcMacImpl() {
ClearMemory(this, sizeof(*this));
}
template<typename BlockCipher>
void Initialize(const BlockCipher *block_cipher) {
static_assert(BlockCipher::BlockSize == BlockSize);
/* Set our context. */
m_cipher_context = block_cipher;
m_cipher_function = &EncryptBlockCallback<BlockCipher>;
m_buffered_bytes = 0;
std::memset(m_mac, 0, sizeof(m_mac));
m_state = State_Initialized;
}
template<typename BlockCipher>
void Update(const void *data, size_t size) {
this->UpdateGeneric(data, size);
}
template<typename BlockCipher>
void ProcessBlocks(const void *data, size_t size) {
this->ProcessBlocksGeneric(data, size);
}
size_t GetBlockSize() const {
return BlockSize;
}
size_t GetBufferedDataSize() const {
return m_buffered_bytes;
}
void UpdateGeneric(const void *data, size_t size);
void ProcessBlocksGeneric(const void *data, size_t num_blocks);
void ProcessPartialData(const void *data, size_t size);
void ProcessRemainingData(const void *data, size_t size);
void GetMac(void *mac, size_t mac_size);
void MaskBufferedData(const void *data, size_t size);
private:
void ProcessBlock(const void *data);
template<typename BlockCipher>
static void EncryptBlockCallback(void *dst, const void *src, const void *cipher) {
static_assert(BlockCipher::BlockSize == BlockSize);
static_cast<const BlockCipher *>(cipher)->EncryptBlock(dst, BlockCipher::BlockSize, src, BlockCipher::BlockSize);
}
};
template<>
void CbcMacImpl::Update<AesEncryptor128>(const void *data, size_t size);
}