crypto.h

// encoding: UTF-8
#ifndef __CRYPTO_H__
#define __CRYPTO_H__

#include <stdbool.h>
#ifdef _DEBUG
#define BUG1(a,b) { perror("a"); }
#define BUG(a) { perror("a"); }
#else
#define BUG1(a,b) ((void)0);
#define BUG(a) ((void)0);
#endif

#define PREAMBLE_SIZE 8			  // 4 byte signature + 4 byte subfile type
#define PAD_SLOP 16           // padding for block chain
#define KEY_BYTES 32			    // 32 bytes = 256 bits of key
#define PREAMBLE 0x01020304		// first 4 bytes of the file
#define FILEKEY_FORMAT 1		  // next 4 bytes determine version/format
#define MASTERKEY_FORMAT 2		// format with master key
#define MASTER_KEY_OFFSET (PREAMBLE_SIZE+AES_MAX_IV_SIZE)
#define UNUSED(expr) (void)(expr)

#define DECRYPT_SUCCESS 0x00
#define DECRYPT_FREAD_FAILED 0x01
#define DECRYPT_WRONG_PASS 0x02
#define DECRYPT_NO_ENCRYPTION 0x04
#define DECRYPT_CANCELED_NO_PASS 0x08
#define DECRYPT_FATAL_ERROR 0x10

bool IsEncryptionRequired();

int ReadAndDecryptFile(HWND hwnd, HANDLE hFile, size_t fileSize, void** result, size_t *resultlen);
bool EncryptAndWriteFile(HWND hwnd, HANDLE hFile, BYTE *data, size_t size, size_t*written);

bool GetFileKey(HWND hwnd);
void ResetEncryption();

#endif