mkxp/src/rgssad.cpp

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/*
** rgssad.cpp
**
** This file is part of mkxp.
**
** Copyright (C) 2014 Jonas Kulla <Nyocurio@gmail.com>
**
** mkxp is free software: you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation, either version 2 of the License, or
** (at your option) any later version.
**
** mkxp is distributed in the hope that 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 mkxp. If not, see <http://www.gnu.org/licenses/>.
*/
#include "rgssad.h"
#include "boost-hash.h"
#include <stdint.h>
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#include <string.h>
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struct RGSS_entryData
{
int64_t offset;
uint64_t size;
uint32_t startMagic;
};
struct RGSS_entryHandle
{
RGSS_entryData data;
uint32_t currentMagic;
uint64_t currentOffset;
PHYSFS_Io *io;
RGSS_entryHandle(const RGSS_entryData &data, PHYSFS_Io *archIo)
: data(data),
currentMagic(data.startMagic),
currentOffset(0)
{
io = archIo->duplicate(archIo);
}
~RGSS_entryHandle()
{
io->destroy(io);
}
};
struct RGSS_archiveData
{
PHYSFS_Io *archiveIo;
/* Maps: file path
* to: entry data */
BoostHash<std::string, RGSS_entryData> entryHash;
/* Maps: directory path,
* to: list of contained entries */
BoostHash<std::string, BoostSet<std::string> > dirHash;
};
static bool
readUint32(PHYSFS_Io *io, uint32_t &result)
{
char buff[4];
PHYSFS_sint64 count = io->read(io, buff, 4);
result = ((buff[0] << 0x00) & 0x000000FF) |
((buff[1] << 0x08) & 0x0000FF00) |
((buff[2] << 0x10) & 0x00FF0000) |
((buff[3] << 0x18) & 0xFF000000) ;
return (count == 4);
}
#define RGSS_HEADER "RGSSAD"
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#define RGSS_MAGIC 0xDEADCAFE
#define PHYSFS_ALLOC(type) \
static_cast<type*>(PHYSFS_getAllocator()->Malloc(sizeof(type)))
#define IO_READ(io, dest, size) (io->read(io, dest, size) == size)
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static inline uint32_t
advanceMagic(uint32_t &magic)
{
uint32_t old = magic;
magic = magic * 7 + 3;
return old;
}
static PHYSFS_sint64
RGSS_ioRead(PHYSFS_Io *self, void *buffer, PHYSFS_uint64 len)
{
RGSS_entryHandle *entry = static_cast<RGSS_entryHandle*>(self->opaque);
PHYSFS_Io *io = entry->io;
uint64_t toRead = std::min<uint64_t>(entry->data.size - entry->currentOffset, len);
uint64_t offs = entry->currentOffset;
io->seek(io, entry->data.offset + offs);
/* We divide up the bytes to be read in 3 categories:
*
* preAlign: If the current read address is not dword
* aligned, this is the number of bytes to read til
* we reach alignment again (therefore can only be
* 3 or less).
*
* align: The number of aligned dwords we can read
* times 4 (= number of bytes).
*
* postAlign: The number of bytes to read after the
* last aligned dword. Always 3 or less.
*
* Treating the pre- and post aligned reads specially,
* we can read all aligned dwords in one syscall directly
* into the write buffer and then run the xor chain on
* it afterwards. */
uint8_t preAlign = 4 - (offs % 4);
if (preAlign == 4)
preAlign = 0;
else
preAlign = std::min<uint64_t>(preAlign, len);
uint8_t postAlign = (len > preAlign) ? (offs + len) % 4 : 0;
uint64_t align = len - (preAlign + postAlign);
/* Byte buffer pointer */
uint8_t *bBufferP = static_cast<uint8_t*>(buffer);
if (preAlign > 0)
{
uint32_t dword;
io->read(io, &dword, preAlign);
/* Need to align the bytes with the
* magic before xoring */
dword <<= 8 * (offs % 4);
dword ^= entry->currentMagic;
/* Shift them back to normal */
dword >>= 8 * (offs % 4);
memcpy(bBufferP, &dword, preAlign);
bBufferP += preAlign;
/* Only advance the magic if we actually
* reached the next alignment */
if ((offs+preAlign) % 4 == 0)
advanceMagic(entry->currentMagic);
}
if (align > 0)
{
/* Double word buffer pointer */
uint32_t *dwBufferP = reinterpret_cast<uint32_t*>(bBufferP);
/* Read aligned dwords in one go */
io->read(io, bBufferP, align);
/* Then xor them */
for (uint64_t i = 0; i < (align / 4); ++i)
dwBufferP[i] ^= advanceMagic(entry->currentMagic);
bBufferP += align;
}
if (postAlign > 0)
{
uint32_t dword;
io->read(io, &dword, postAlign);
/* Bytes are already aligned with magic */
dword ^= entry->currentMagic;
memcpy(bBufferP, &dword, postAlign);
}
entry->currentOffset += toRead;
return toRead;
}
static int
RGSS_ioSeek(PHYSFS_Io *self, PHYSFS_uint64 offset)
{
RGSS_entryHandle *entry = static_cast<RGSS_entryHandle*>(self->opaque);
if (offset == entry->currentOffset)
return 1;
if (offset > entry->data.size-1)
return 0;
/* If rewinding, we need to rewind to begining */
if (offset < entry->currentOffset)
{
entry->currentOffset = 0;
entry->currentMagic = entry->data.startMagic;
}
/* For each overstepped alignment, advance magic */
uint64_t currentDword = entry->currentOffset / 4;
uint64_t targetDword = offset / 4;
uint64_t dwordsSought = targetDword - currentDword;
for (uint64_t i = 0; i < dwordsSought; ++i)
advanceMagic(entry->currentMagic);
entry->currentOffset = offset;
entry->io->seek(entry->io, entry->data.offset + entry->currentOffset);
return 1;
}
static PHYSFS_sint64
RGSS_ioTell(PHYSFS_Io *self)
{
RGSS_entryHandle *entry = static_cast<RGSS_entryHandle*>(self->opaque);
return entry->currentOffset;
}
static PHYSFS_sint64
RGSS_ioLength(PHYSFS_Io *self)
{
RGSS_entryHandle *entry = static_cast<RGSS_entryHandle*>(self->opaque);
return entry->data.size;
}
static PHYSFS_Io*
RGSS_ioDuplicate(PHYSFS_Io *self)
{
RGSS_entryHandle *entry = static_cast<RGSS_entryHandle*>(self->opaque);
RGSS_entryHandle *entryDup = new RGSS_entryHandle(*entry);
PHYSFS_Io *dup = PHYSFS_ALLOC(PHYSFS_Io);
*dup = *self;
dup->opaque = entryDup;
return dup;
}
static void
RGSS_ioDestroy(PHYSFS_Io *self)
{
RGSS_entryHandle *entry = static_cast<RGSS_entryHandle*>(self->opaque);
delete entry;
PHYSFS_getAllocator()->Free(self);
}
static const PHYSFS_Io RGSS_IoTemplate =
{
0, /* version */
0, /* opaque */
RGSS_ioRead,
0, /* write */
RGSS_ioSeek,
RGSS_ioTell,
RGSS_ioLength,
RGSS_ioDuplicate,
0, /* flush */
RGSS_ioDestroy
};
static void
processDirectories(RGSS_archiveData *data, BoostSet<std::string> &topLevel,
char *nameBuf, uint32_t nameLen)
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{
/* Check for top level entries */
for (uint32_t i = 0; i < nameLen; ++i)
{
bool slash = nameBuf[i] == '/';
if (!slash && i+1 < nameLen)
continue;
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if (slash)
nameBuf[i] = '\0';
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topLevel.insert(nameBuf);
if (slash)
nameBuf[i] = '/';
}
/* Check for more entries */
for (uint32_t i = nameLen; i > 0; i--)
if (nameBuf[i] == '/')
{
nameBuf[i] = '\0';
const char *dir = nameBuf;
const char *entry = &nameBuf[i+1];
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BoostSet<std::string> &entryList = data->dirHash[dir];
entryList.insert(entry);
}
}
static bool
verifyHeader(PHYSFS_Io *io, char version)
{
char header[8];
if (!IO_READ(io, header, sizeof(header)))
return false;
if (strcmp(header, RGSS_HEADER))
return false;
if (header[7] != version)
return false;
return true;
}
static void*
RGSS_openArchive(PHYSFS_Io *io, const char *, int forWrite)
{
if (forWrite)
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return 0;
/* Version 1 */
if (!verifyHeader(io, 1))
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return 0;
RGSS_archiveData *data = new RGSS_archiveData;
data->archiveIo = io;
uint32_t magic = RGSS_MAGIC;
/* Top level entry list */
BoostSet<std::string> &topLevel = data->dirHash[""];
while (true)
{
/* Read filename length,
* if nothing was read, no files remain */
uint32_t nameLen;
if (!readUint32(io, nameLen))
break;
nameLen ^= advanceMagic(magic);
static char nameBuf[512];
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for (uint32_t i = 0; i < nameLen; ++i)
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{
char c;
io->read(io, &c, 1);
nameBuf[i] = c ^ (advanceMagic(magic) & 0xFF);
if (nameBuf[i] == '\\')
nameBuf[i] = '/';
}
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nameBuf[nameLen] = '\0';
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uint32_t entrySize;
readUint32(io, entrySize);
entrySize ^= advanceMagic(magic);
RGSS_entryData entry;
entry.offset = io->tell(io);
entry.size = entrySize;
entry.startMagic = magic;
data->entryHash.insert(nameBuf, entry);
processDirectories(data, topLevel, nameBuf, nameLen);
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io->seek(io, entry.offset + entry.size);
}
return data;
}
static void
RGSS_enumerateFiles(void *opaque, const char *dirname,
PHYSFS_EnumFilesCallback cb,
const char *origdir, void *callbackdata)
{
RGSS_archiveData *data = static_cast<RGSS_archiveData*>(opaque);
std::string _dirname(dirname);
if (!data->dirHash.contains(_dirname))
return;
const BoostSet<std::string> &entries = data->dirHash[_dirname];
BoostSet<std::string>::const_iterator iter;
for (iter = entries.cbegin(); iter != entries.cend(); ++iter)
cb(callbackdata, origdir, iter->c_str());
}
static PHYSFS_Io*
RGSS_openRead(void *opaque, const char *filename)
{
RGSS_archiveData *data = static_cast<RGSS_archiveData*>(opaque);
if (!data->entryHash.contains(filename))
return 0;
RGSS_entryHandle *entry =
new RGSS_entryHandle(data->entryHash[filename], data->archiveIo);
PHYSFS_Io *io = PHYSFS_ALLOC(PHYSFS_Io);
*io = RGSS_IoTemplate;
io->opaque = entry;
return io;
}
static int
RGSS_stat(void *opaque, const char *filename, PHYSFS_Stat *stat)
{
RGSS_archiveData *data = static_cast<RGSS_archiveData*>(opaque);
bool hasFile = data->entryHash.contains(filename);
bool hasDir = data->dirHash.contains(filename);
if (!hasFile && !hasDir)
{
PHYSFS_setErrorCode(PHYSFS_ERR_NOT_FOUND);
return 0;
}
stat->modtime =
stat->createtime =
stat->accesstime = 0;
stat->readonly = 1;
if (hasFile)
{
RGSS_entryData &entry = data->entryHash[filename];
stat->filesize = entry.size;
stat->filetype = PHYSFS_FILETYPE_REGULAR;
}
else
{
stat->filesize = 0;
stat->filetype = PHYSFS_FILETYPE_DIRECTORY;
}
return 1;
}
static void
RGSS_closeArchive(void *opaque)
{
RGSS_archiveData *data = static_cast<RGSS_archiveData*>(opaque);
delete data;
}
static PHYSFS_Io*
RGSS_noop1(void*, const char*)
{
return 0;
}
static int
RGSS_noop2(void*, const char*)
{
return 0;
}
const PHYSFS_Archiver RGSS1_Archiver =
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{
0,
{
"RGSSAD",
"RGSS encrypted archive format",
"", /* Author */
"", /* Website */
0 /* symlinks not supported */
},
RGSS_openArchive,
RGSS_enumerateFiles,
RGSS_openRead,
RGSS_noop1, /* openWrite */
RGSS_noop1, /* openAppend */
RGSS_noop2, /* remove */
RGSS_noop2, /* mkdir */
RGSS_stat,
RGSS_closeArchive
};
const PHYSFS_Archiver RGSS2_Archiver =
{
0,
{
"RGSS2A",
"RGSS2 encrypted archive format",
"", /* Author */
"", /* Website */
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0 /* symlinks not supported */
},
RGSS_openArchive,
RGSS_enumerateFiles,
RGSS_openRead,
RGSS_noop1, /* openWrite */
RGSS_noop1, /* openAppend */
RGSS_noop2, /* remove */
RGSS_noop2, /* mkdir */
RGSS_stat,
RGSS_closeArchive
};
static bool
readUint32AndXor(PHYSFS_Io *io, uint32_t &result, uint32_t key)
{
if (!readUint32(io, result))
return false;
result ^= key;
return true;
}
static void*
RGSS3_openArchive(PHYSFS_Io *io, const char *, int forWrite)
{
if (forWrite)
return 0;
/* Version 3 */
if (!verifyHeader(io, 3))
return 0;
uint32_t baseMagic;
if (!readUint32(io, baseMagic))
return 0;
baseMagic = (baseMagic * 9) + 3;
RGSS_archiveData *data = new RGSS_archiveData;
data->archiveIo = io;
/* Top level entry list */
BoostSet<std::string> &topLevel = data->dirHash[""];
while (true)
{
uint32_t offset, size, magic, nameLen;
if (!readUint32AndXor(io, offset, baseMagic))
goto error;
/* Zero offset means entry list has ended */
if (offset == 0)
break;
if (!readUint32AndXor(io, size, baseMagic))
goto error;
if (!readUint32AndXor(io, magic, baseMagic))
goto error;
if (!readUint32AndXor(io, nameLen, baseMagic))
goto error;
char nameBuf[512];
if (!IO_READ(io, nameBuf, nameLen))
goto error;
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for (uint32_t i = 0; i < nameLen; ++i)
{
nameBuf[i] ^= ((baseMagic >> 8*(i%4)) & 0xFF);
if (nameBuf[i] == '\\')
nameBuf[i] = '/';
}
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nameBuf[nameLen] = '\0';
RGSS_entryData entry;
entry.offset = offset;
entry.size = size;
entry.startMagic = magic;
data->entryHash.insert(nameBuf, entry);
processDirectories(data, topLevel, nameBuf, nameLen);
continue;
error:
delete data;
return 0;
}
return data;
}
const PHYSFS_Archiver RGSS3_Archiver =
{
0,
{
"RGSS3A",
"RGSS3 encrypted archive format",
"", /* Author */
"", /* Website */
0 /* symlinks not supported */
},
RGSS3_openArchive,
RGSS_enumerateFiles,
RGSS_openRead,
RGSS_noop1, /* openWrite */
RGSS_noop1, /* openAppend */
RGSS_noop2, /* remove */
RGSS_noop2, /* mkdir */
RGSS_stat,
RGSS_closeArchive
};