godot/core/io/file_access_encrypted.cpp
Rémi Verschelde c7bc44d5ad Welcome in 2017, dear changelog reader!
That year should bring the long-awaited OpenGL ES 3.0 compatible renderer
with state-of-the-art rendering techniques tuned to work as low as middle
end handheld devices - without compromising with the possibilities given
for higher end desktop games of course. Great times ahead for the Godot
community and the gamers that will play our games!
2017-01-01 22:03:33 +01:00

324 lines
7 KiB
C++

/*************************************************************************/
/* file_access_encrypted.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "file_access_encrypted.h"
#include "aes256.h"
#include "md5.h"
#include "os/copymem.h"
#include "print_string.h"
#define COMP_MAGIC 0x43454447
#include "core/variant.h"
#include <stdio.h>
Error FileAccessEncrypted::open_and_parse(FileAccess *p_base,const Vector<uint8_t>& p_key,Mode p_mode) {
//print_line("open and parse!");
ERR_FAIL_COND_V(file!=NULL,ERR_ALREADY_IN_USE);
ERR_FAIL_COND_V(p_key.size()!=32,ERR_INVALID_PARAMETER);
pos=0;
eofed=false;
if (p_mode==MODE_WRITE_AES256) {
data.clear();
writing=true;
file=p_base;
mode=p_mode;
key=p_key;
} else if (p_mode==MODE_READ) {
writing=false;
key=p_key;
uint32_t magic = p_base->get_32();
print_line("MAGIC: "+itos(magic));
ERR_FAIL_COND_V(magic!=COMP_MAGIC,ERR_FILE_UNRECOGNIZED);
mode=Mode(p_base->get_32());
ERR_FAIL_INDEX_V(mode,MODE_MAX,ERR_FILE_CORRUPT);
ERR_FAIL_COND_V(mode==0,ERR_FILE_CORRUPT);
print_line("MODE: "+itos(mode));
unsigned char md5d[16];
p_base->get_buffer(md5d,16);
length=p_base->get_64();
base=p_base->get_pos();
ERR_FAIL_COND_V(p_base->get_len() < base+length, ERR_FILE_CORRUPT );
int ds = length;
if (ds % 16) {
ds+=16-(ds % 16);
}
data.resize(ds);
int blen = p_base->get_buffer(data.ptr(),ds);
ERR_FAIL_COND_V(blen!=ds,ERR_FILE_CORRUPT);
aes256_context ctx;
aes256_init(&ctx,key.ptr());
for(size_t i=0;i<ds;i+=16) {
aes256_decrypt_ecb(&ctx,&data[i]);
}
aes256_done(&ctx);
data.resize(length);
MD5_CTX md5;
MD5Init(&md5);
MD5Update(&md5,data.ptr(),data.size());
MD5Final(&md5);
ERR_FAIL_COND_V(String::md5(md5.digest)!=String::md5(md5d),ERR_FILE_CORRUPT) ;
file=p_base;
}
return OK;
}
Error FileAccessEncrypted::open_and_parse_password(FileAccess *p_base,const String& p_key,Mode p_mode){
String cs = p_key.md5_text();
ERR_FAIL_COND_V(cs.length()!=32,ERR_INVALID_PARAMETER);
Vector<uint8_t> key;
key.resize(32);
for(int i=0;i<32;i++) {
key[i]=cs[i];
}
return open_and_parse(p_base,key,p_mode);
}
Error FileAccessEncrypted::_open(const String& p_path, int p_mode_flags) {
return OK;
}
void FileAccessEncrypted::close() {
if (!file)
return;
if (writing) {
Vector<uint8_t> compressed;
size_t len = data.size();
if (len % 16) {
len+=16-(len % 16);
}
MD5_CTX md5;
MD5Init(&md5);
MD5Update(&md5,data.ptr(),data.size());
MD5Final(&md5);
compressed.resize(len);
zeromem( compressed.ptr(), len );
for(int i=0;i<data.size();i++) {
compressed[i]=data[i];
}
aes256_context ctx;
aes256_init(&ctx,key.ptr());
for(size_t i=0;i<len;i+=16) {
aes256_encrypt_ecb(&ctx,&compressed[i]);
}
aes256_done(&ctx);
file->store_32(COMP_MAGIC);
file->store_32(mode);
file->store_buffer(md5.digest,16);
file->store_64(data.size());
file->store_buffer(compressed.ptr(),compressed.size());
file->close();
memdelete(file);
file=NULL;
data.clear();
} else {
file->close();
memdelete(file);
data.clear();
file=NULL;
}
}
bool FileAccessEncrypted::is_open() const{
return file!=NULL;
}
void FileAccessEncrypted::seek(size_t p_position){
if (p_position > (size_t)data.size())
p_position=data.size();
pos=p_position;
eofed=false;
}
void FileAccessEncrypted::seek_end(int64_t p_position){
seek( data.size() + p_position );
}
size_t FileAccessEncrypted::get_pos() const{
return pos;
}
size_t FileAccessEncrypted::get_len() const{
return data.size();
}
bool FileAccessEncrypted::eof_reached() const{
return eofed;
}
uint8_t FileAccessEncrypted::get_8() const{
ERR_FAIL_COND_V(writing,0);
if (pos>=data.size()) {
eofed=true;
return 0;
}
uint8_t b = data[pos];
pos++;
return b;
}
int FileAccessEncrypted::get_buffer(uint8_t *p_dst, int p_length) const{
ERR_FAIL_COND_V(writing,0);
int to_copy=MIN(p_length,data.size()-pos);
for(int i=0;i<to_copy;i++) {
p_dst[i]=data[pos++];
}
if (to_copy<p_length) {
eofed=true;
}
return to_copy;
}
Error FileAccessEncrypted::get_error() const{
return eofed?ERR_FILE_EOF:OK;
}
void FileAccessEncrypted::store_buffer(const uint8_t *p_src,int p_length) {
ERR_FAIL_COND(!writing);
if (pos<data.size()) {
for(int i=0;i<p_length;i++) {
store_8(p_src[i]);
}
} else if (pos==data.size()) {
data.resize(pos+p_length);
for(int i=0;i<p_length;i++) {
data[pos+i]=p_src[i];
}
pos+=p_length;
}
}
void FileAccessEncrypted::store_8(uint8_t p_dest){
ERR_FAIL_COND(!writing);
if (pos<data.size()) {
data[pos]=p_dest;
pos++;
} else if (pos==data.size()){
data.push_back(p_dest);
pos++;
}
}
bool FileAccessEncrypted::file_exists(const String& p_name){
FileAccess *fa = FileAccess::open(p_name,FileAccess::READ);
if (!fa)
return false;
memdelete(fa);
return true;
}
uint64_t FileAccessEncrypted::_get_modified_time(const String& p_file){
return 0;
}
FileAccessEncrypted::FileAccessEncrypted() {
file=NULL;
pos=0;
eofed=false;
mode=MODE_MAX;
writing=false;
}
FileAccessEncrypted::~FileAccessEncrypted() {
if (file)
close();
}