mirror of
https://github.com/vgmstream/vgmstream.git
synced 2024-12-24 04:14:50 +01:00
67 lines
2.3 KiB
C
67 lines
2.3 KiB
C
#ifndef _BGW_STREAMFILE_H_
|
|
#define _BGW_STREAMFILE_H_
|
|
#include "../streamfile.h"
|
|
|
|
|
|
#define BGW_KEY_MAX (0xC0*2)
|
|
|
|
typedef struct {
|
|
uint8_t key[BGW_KEY_MAX];
|
|
size_t key_size;
|
|
} bgw_decryption_data;
|
|
|
|
/* Encrypted ATRAC3 info from Moogle Toolbox (https://sourceforge.net/projects/mogbox/) */
|
|
static size_t bgw_decryption_read(STREAMFILE *streamfile, uint8_t *dest, off_t offset, size_t length, bgw_decryption_data* data) {
|
|
size_t bytes_read;
|
|
int i;
|
|
|
|
bytes_read = streamfile->read(streamfile, dest, offset, length);
|
|
|
|
/* decrypt data (xor) */
|
|
for (i = 0; i < bytes_read; i++) {
|
|
dest[i] ^= data->key[(offset + i) % data->key_size];
|
|
}
|
|
|
|
//todo: a few files (music069.bgw, music071.bgw, music900.bgw) have the last frames unencrypted,
|
|
// though they are blank and encoder ignores wrongly decrypted frames and outputs blank samples as well
|
|
|
|
return bytes_read;
|
|
}
|
|
|
|
static STREAMFILE* setup_bgw_atrac3_streamfile(STREAMFILE *streamFile, off_t subfile_offset, size_t subfile_size, size_t frame_size, int channels) {
|
|
STREAMFILE *temp_streamFile = NULL, *new_streamFile = NULL;
|
|
bgw_decryption_data io_data = {0};
|
|
size_t io_data_size = sizeof(bgw_decryption_data);
|
|
int ch;
|
|
|
|
/* setup decryption with key (first frame + modified channel header) */
|
|
if (frame_size*channels == 0 || frame_size*channels > BGW_KEY_MAX) goto fail;
|
|
|
|
io_data.key_size = read_streamfile(io_data.key, subfile_offset, frame_size*channels, streamFile);
|
|
for (ch = 0; ch < channels; ch++) {
|
|
uint32_t xor = get_32bitBE(io_data.key + frame_size*ch);
|
|
put_32bitBE(io_data.key + frame_size*ch, xor ^ 0xA0024E9F);
|
|
}
|
|
|
|
/* setup subfile */
|
|
new_streamFile = open_wrap_streamfile(streamFile);
|
|
if (!new_streamFile) goto fail;
|
|
temp_streamFile = new_streamFile;
|
|
|
|
new_streamFile = open_clamp_streamfile(temp_streamFile, subfile_offset,subfile_size);
|
|
if (!new_streamFile) goto fail;
|
|
temp_streamFile = new_streamFile;
|
|
|
|
new_streamFile = open_io_streamfile(temp_streamFile, &io_data,io_data_size, bgw_decryption_read,NULL);
|
|
if (!new_streamFile) goto fail;
|
|
temp_streamFile = new_streamFile;
|
|
|
|
return temp_streamFile;
|
|
|
|
fail:
|
|
close_streamfile(temp_streamFile);
|
|
return NULL;
|
|
}
|
|
|
|
#endif /* _BGW_STREAMFILE_H_ */
|