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SCD Ogg Vorbis with obfuscated header triad (FFXIII-2)

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git-svn-id: https://vgmstream.svn.sourceforge.net/svnroot/vgmstream@970 51a99a44-fe44-0410-b1ba-c3e57ba2b86b
This commit is contained in:
halleyscometsw 2011-12-15 08:00:47 +00:00
parent 968b6afdf1
commit d8e13f6d29
4 changed files with 87 additions and 6 deletions
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4
src/meta/meta.h
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@ -97,6 +97,10 @@ typedef struct {
int32_t loop_end;
meta_t meta_type;
layout_t layout_type;
// XOR setup with a single byte (SCD)
unsigned char scd_xor;
off_t scd_xor_len;
} vgm_vorbis_info_t;
VGMSTREAM * init_vgmstream_ogg_vorbis_callbacks(STREAMFILE *streamFile, const char * filename, ov_callbacks *callbacks, off_t other_header_bytes, const vgm_vorbis_info_t *vgm_inf);

47
src/meta/ogg_vorbis_file.c
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@ -80,6 +80,32 @@ static size_t read_func_kovs(void *ptr, size_t size, size_t nmemb, void * dataso
return items_read;
}
static size_t read_func_scd(void *ptr, size_t size, size_t nmemb, void * datasource)
{
ogg_vorbis_streamfile * const ov_streamfile = datasource;
size_t items_read;
size_t bytes_read;
bytes_read = read_streamfile(ptr, ov_streamfile->offset + ov_streamfile->other_header_bytes, size * nmemb,
ov_streamfile->streamfile);
items_read = bytes_read / size;
/* first bytes are xor'd with a constant byte */
if (ov_streamfile->offset < ov_streamfile->scd_xor_len) {
int num_crypt = ov_streamfile->scd_xor_len-ov_streamfile->offset;
int i;
if (num_crypt > bytes_read) num_crypt=bytes_read;
for (i=0;i<num_crypt;i++)
((uint8_t*)ptr)[i] ^= ov_streamfile->scd_xor;
}
ov_streamfile->offset += items_read * size;
return items_read;
}
static int seek_func(void *datasource, ogg_int64_t offset, int whence) {
ogg_vorbis_streamfile * const ov_streamfile = datasource;
ogg_int64_t base_offset;
@ -130,7 +156,8 @@ VGMSTREAM * init_vgmstream_ogg_vorbis(STREAMFILE *streamFile) {
int um3_ogg = 0;
int kovs_ogg = 0;
vgm_vorbis_info_t inf = {0,0,0,0,0,0,0,0};
vgm_vorbis_info_t inf;
memset(&inf, 0, sizeof(inf));
/* check extension, case insensitive */
streamFile->get_name(streamFile,filename,sizeof(filename));
@ -214,12 +241,17 @@ VGMSTREAM * init_vgmstream_ogg_vorbis_callbacks(STREAMFILE *streamFile, const ch
int32_t loop_end = vgm_inf->loop_end;
ov_callbacks default_callbacks;
default_callbacks.read_func = read_func;
default_callbacks.seek_func = seek_func;
default_callbacks.close_func = close_func;
default_callbacks.tell_func = tell_func;
if (!callbacks_p) {
default_callbacks.read_func = read_func;
default_callbacks.seek_func = seek_func;
default_callbacks.close_func = close_func;
default_callbacks.tell_func = tell_func;
if (vgm_inf->scd_xor != 0) {
default_callbacks.read_func = read_func_scd;
}
callbacks_p = &default_callbacks;
}
@ -227,11 +259,14 @@ VGMSTREAM * init_vgmstream_ogg_vorbis_callbacks(STREAMFILE *streamFile, const ch
temp_streamfile.offset = 0;
temp_streamfile.size = get_streamfile_size(temp_streamfile.streamfile);
temp_streamfile.other_header_bytes = other_header_bytes;
temp_streamfile.scd_xor = vgm_inf->scd_xor;
temp_streamfile.scd_xor_len = vgm_inf->scd_xor_len;
/* can we open this as a proper ogg vorbis file? */
memset(&temp_ovf, 0, sizeof(temp_ovf));
if (ov_test_callbacks(&temp_streamfile, &temp_ovf, NULL,
0, *callbacks_p)) goto fail;
/* we have to close this as it has the init_vgmstream meta-reading
STREAMFILE */
ov_clear(&temp_ovf);
@ -246,6 +281,8 @@ VGMSTREAM * init_vgmstream_ogg_vorbis_callbacks(STREAMFILE *streamFile, const ch
data->ov_streamfile.offset = 0;
data->ov_streamfile.size = get_streamfile_size(data->ov_streamfile.streamfile);
data->ov_streamfile.other_header_bytes = other_header_bytes;
data->ov_streamfile.scd_xor = vgm_inf->scd_xor;
data->ov_streamfile.scd_xor_len = vgm_inf->scd_xor_len;
/* open the ogg vorbis file for real */
if (ov_open_callbacks(&data->ov_streamfile, &data->ogg_vorbis_file, NULL,

38
src/meta/sqex_scd.c
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@ -64,6 +64,10 @@ VGMSTREAM * init_vgmstream_sqex_scd(STREAMFILE *streamFile) {
if (codec_id == 0x6)
{
vgm_vorbis_info_t inf;
uint32_t seek_table_size = read_32bit(meta_offset+0x30, streamFile);
uint32_t vorb_header_size = read_32bit(meta_offset+0x34, streamFile);
memset(&inf, 0, sizeof(inf));
inf.loop_start = loop_start;
inf.loop_end = loop_end;
inf.loop_flag = loop_flag;
@ -72,7 +76,39 @@ VGMSTREAM * init_vgmstream_sqex_scd(STREAMFILE *streamFile) {
inf.layout_type = layout_ogg_vorbis;
inf.meta_type = meta_SQEX_SCD;
return init_vgmstream_ogg_vorbis_callbacks(streamFile, filename, NULL, start_offset, &inf);
VGMSTREAM * result = init_vgmstream_ogg_vorbis_callbacks(streamFile, filename, NULL, start_offset, &inf);
if (result != NULL) {
return result;
}
// try skipping seek table
{
if (0x20 + seek_table_size + vorb_header_size != read_32bit(meta_offset+0x18, streamFile)) {
return NULL;
}
start_offset = meta_offset + 0x40 + seek_table_size;
result = init_vgmstream_ogg_vorbis_callbacks(streamFile, filename, NULL, start_offset, &inf);
if (result != NULL) {
return result;
}
}
// try deobfuscating header (assume skipping seek table)
{
unsigned char xor_byte = read_8bit(meta_offset+0x22, streamFile);
if (xor_byte == 0) {
return NULL;
}
inf.scd_xor = xor_byte;
inf.scd_xor_len = vorb_header_size;
VGMSTREAM * result = init_vgmstream_ogg_vorbis_callbacks(streamFile, filename, NULL, start_offset, &inf);
return result;
}
}
#endif

4
src/vgmstream.h
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@ -659,6 +659,10 @@ typedef struct {
ogg_int64_t offset;
ogg_int64_t size;
ogg_int64_t other_header_bytes;
// XOR setup with a single byte (SCD)
unsigned char scd_xor;
ogg_int64_t scd_xor_len;
} ogg_vorbis_streamfile;
typedef struct {