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Adds PCK encryption support (using script encryption key for export).

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Change default encryption mode from ECB to CFB.
This commit is contained in:
bruvzg
2020-04-28 20:51:29 +03:00
parent 52f6ac81be
commit f043eabdd8
18 changed files with 692 additions and 151 deletions
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197
core/io/pck_packer.cpp
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@ -30,36 +30,58 @@
#include "pck_packer.h"
#include "core/crypto/crypto_core.h"
#include "core/io/file_access_encrypted.h"
#include "core/io/file_access_pack.h" // PACK_HEADER_MAGIC, PACK_FORMAT_VERSION
#include "core/os/file_access.h"
#include "core/version.h"
static uint64_t _align(uint64_t p_n, int p_alignment) {
if (p_alignment == 0) {
return p_n;
static int _get_pad(int p_alignment, int p_n) {
int rest = p_n % p_alignment;
int pad = 0;
if (rest > 0) {
pad = p_alignment - rest;
}
uint64_t rest = p_n % p_alignment;
if (rest == 0) {
return p_n;
} else {
return p_n + (p_alignment - rest);
}
}
static void _pad(FileAccess *p_file, int p_bytes) {
for (int i = 0; i < p_bytes; i++) {
p_file->store_8(0);
}
return pad;
}
void PCKPacker::_bind_methods() {
ClassDB::bind_method(D_METHOD("pck_start", "pck_name", "alignment"), &PCKPacker::pck_start, DEFVAL(0));
ClassDB::bind_method(D_METHOD("add_file", "pck_path", "source_path"), &PCKPacker::add_file);
ClassDB::bind_method(D_METHOD("pck_start", "pck_name", "alignment", "key", "encrypt_directory"), &PCKPacker::pck_start, DEFVAL(0), DEFVAL(String()), DEFVAL(false));
ClassDB::bind_method(D_METHOD("add_file", "pck_path", "source_path", "encrypt"), &PCKPacker::add_file, DEFVAL(false));
ClassDB::bind_method(D_METHOD("flush", "verbose"), &PCKPacker::flush, DEFVAL(false));
}
Error PCKPacker::pck_start(const String &p_file, int p_alignment) {
Error PCKPacker::pck_start(const String &p_file, int p_alignment, const String &p_key, bool p_encrypt_directory) {
ERR_FAIL_COND_V_MSG((p_key.empty() || !p_key.is_valid_hex_number(false) || p_key.length() != 64), ERR_CANT_CREATE, "Invalid Encryption Key (must be 64 characters long).");
String _key = p_key.to_lower();
key.resize(32);
for (int i = 0; i < 32; i++) {
int v = 0;
if (i * 2 < _key.length()) {
char32_t ct = _key[i * 2];
if (ct >= '0' && ct <= '9') {
ct = ct - '0';
} else if (ct >= 'a' && ct <= 'f') {
ct = 10 + ct - 'a';
}
v |= ct << 4;
}
if (i * 2 + 1 < _key.length()) {
char32_t ct = _key[i * 2 + 1];
if (ct >= '0' && ct <= '9') {
ct = ct - '0';
} else if (ct >= 'a' && ct <= 'f') {
ct = 10 + ct - 'a';
}
v |= ct;
}
key.write[i] = v;
}
enc_dir = p_encrypt_directory;
if (file != nullptr) {
memdelete(file);
}
@ -76,16 +98,19 @@ Error PCKPacker::pck_start(const String &p_file, int p_alignment) {
file->store_32(VERSION_MINOR);
file->store_32(VERSION_PATCH);
for (int i = 0; i < 16; i++) {
file->store_32(0); // reserved
uint32_t pack_flags = 0;
if (enc_dir) {
pack_flags |= PACK_DIR_ENCRYPTED;
}
file->store_32(pack_flags); // flags
files.clear();
ofs = 0;
return OK;
}
Error PCKPacker::add_file(const String &p_file, const String &p_src) {
Error PCKPacker::add_file(const String &p_file, const String &p_src, bool p_encrypt) {
FileAccess *f = FileAccess::open(p_src, FileAccess::READ);
if (!f) {
return ERR_FILE_CANT_OPEN;
@ -94,8 +119,32 @@ Error PCKPacker::add_file(const String &p_file, const String &p_src) {
File pf;
pf.path = p_file;
pf.src_path = p_src;
pf.ofs = ofs;
pf.size = f->get_len();
pf.offset_offset = 0;
Vector<uint8_t> data = FileAccess::get_file_as_array(p_src);
{
unsigned char hash[16];
CryptoCore::md5(data.ptr(), data.size(), hash);
pf.md5.resize(16);
for (int i = 0; i < 16; i++) {
pf.md5.write[i] = hash[i];
}
}
pf.encrypted = p_encrypt;
uint64_t _size = pf.size;
if (p_encrypt) { // Add encryption overhead.
if (_size % 16) { // Pad to encryption block size.
_size += 16 - (_size % 16);
}
_size += 16; // hash
_size += 8; // data size
_size += 16; // iv
}
int pad = _get_pad(alignment, ofs + _size);
ofs = ofs + _size + pad;
files.push_back(pf);
@ -108,27 +157,64 @@ Error PCKPacker::add_file(const String &p_file, const String &p_src) {
Error PCKPacker::flush(bool p_verbose) {
ERR_FAIL_COND_V_MSG(!file, ERR_INVALID_PARAMETER, "File must be opened before use.");
// write the index
int64_t file_base_ofs = file->get_position();
file->store_64(0); // files base
file->store_32(files.size());
for (int i = 0; i < files.size(); i++) {
file->store_pascal_string(files[i].path);
files.write[i].offset_offset = file->get_position();
file->store_64(0); // offset
file->store_64(files[i].size); // size
// # empty md5
file->store_32(0);
file->store_32(0);
file->store_32(0);
file->store_32(0);
for (int i = 0; i < 16; i++) {
file->store_32(0); // reserved
}
uint64_t ofs = file->get_position();
ofs = _align(ofs, alignment);
// write the index
file->store_32(files.size());
_pad(file, ofs - file->get_position());
FileAccessEncrypted *fae = nullptr;
FileAccess *fhead = file;
if (enc_dir) {
fae = memnew(FileAccessEncrypted);
ERR_FAIL_COND_V(!fae, ERR_CANT_CREATE);
Error err = fae->open_and_parse(file, key, FileAccessEncrypted::MODE_WRITE_AES256, false);
ERR_FAIL_COND_V(err != OK, ERR_CANT_CREATE);
fhead = fae;
}
for (int i = 0; i < files.size(); i++) {
int string_len = files[i].path.utf8().length();
int pad = _get_pad(4, string_len);
fhead->store_32(string_len + pad);
fhead->store_buffer((const uint8_t *)files[i].path.utf8().get_data(), string_len);
for (int j = 0; j < pad; j++) {
fhead->store_8(0);
}
fhead->store_64(files[i].ofs);
fhead->store_64(files[i].size); // pay attention here, this is where file is
fhead->store_buffer(files[i].md5.ptr(), 16); //also save md5 for file
uint32_t flags = 0;
if (files[i].encrypted) {
flags |= PACK_FILE_ENCRYPTED;
}
fhead->store_32(flags);
}
if (fae) {
fae->release();
memdelete(fae);
}
int header_padding = _get_pad(alignment, file->get_position());
for (int i = 0; i < header_padding; i++) {
file->store_8(Math::rand() % 256);
}
int64_t file_base = file->get_position();
file->seek(file_base_ofs);
file->store_64(file_base); // update files base
file->seek(file_base);
const uint32_t buf_max = 65536;
uint8_t *buf = memnew_arr(uint8_t, buf_max);
@ -137,26 +223,41 @@ Error PCKPacker::flush(bool p_verbose) {
for (int i = 0; i < files.size(); i++) {
FileAccess *src = FileAccess::open(files[i].src_path, FileAccess::READ);
uint64_t to_write = files[i].size;
fae = nullptr;
FileAccess *ftmp = file;
if (files[i].encrypted) {
fae = memnew(FileAccessEncrypted);
ERR_FAIL_COND_V(!fae, ERR_CANT_CREATE);
Error err = fae->open_and_parse(file, key, FileAccessEncrypted::MODE_WRITE_AES256, false);
ERR_FAIL_COND_V(err != OK, ERR_CANT_CREATE);
ftmp = fae;
}
while (to_write > 0) {
int read = src->get_buffer(buf, MIN(to_write, buf_max));
file->store_buffer(buf, read);
ftmp->store_buffer(buf, read);
to_write -= read;
}
uint64_t pos = file->get_position();
file->seek(files[i].offset_offset); // go back to store the file's offset
file->store_64(ofs);
file->seek(pos);
if (fae) {
fae->release();
memdelete(fae);
}
ofs = _align(ofs + files[i].size, alignment);
_pad(file, ofs - pos);
int pad = _get_pad(alignment, file->get_position());
for (int j = 0; j < pad; j++) {
file->store_8(Math::rand() % 256);
}
src->close();
memdelete(src);
count += 1;
if (p_verbose && files.size() > 0) {
const int file_num = files.size();
if (p_verbose && (file_num > 0)) {
if (count % 100 == 0) {
printf("%i/%i (%.2f)\r", count, files.size(), float(count) / files.size() * 100);
printf("%i/%i (%.2f)\r", count, file_num, float(count) / file_num * 100);
fflush(stdout);
}
}