usbloadergx/source/libwbfs/wiidisc.c

// Copyright 2009 Kwiirk based on negentig.c:
// Copyright 2007,2008  Segher Boessenkool  <segher@kernel.crashing.org>
// Licensed under the terms of the GNU GPL, version 2
// http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt

#include "wiidisc.h"

void aes_set_key(u8 *key);
void aes_decrypt(u8 *iv, u8 *inbuf, u8 *outbuf, unsigned long long len);
static u8 get_fst = 0;

static void _decrypt_title_key(u8 *tik, u8 *title_key)
{
    u8 common_key[16] = { 0xeb, 0xe4, 0x2a, 0x22, 0x5e, 0x85, 0x93, 0xe4, 0x48, 0xd9, 0xc5, 0x45, 0x73, 0x81, 0xaa,
            0xf7 };
    ;
    u8 iv[16];

    wbfs_memset( iv, 0, sizeof iv );
    wbfs_memcpy( iv, tik + 0x01dc, 8 );
    aes_set_key(common_key);
    //_aes_cbc_dec(common_key, iv, tik + 0x01bf, 16, title_key);
    aes_decrypt(iv, tik + 0x01bf, title_key, 16);
}
static u32 _be32(const u8 *p)
{
    return (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
}

static void disc_read(wiidisc_t *d, u32 offset, u8 *data, u32 len)
{
    if (data)
    {
        int ret = 0;
        if (len == 0) return;
        ret = d->read(d->fp, offset, len, data);
        if (ret)
        wbfs_fatal( "error reading disc" );
    }
    if (d->sector_usage_table)
    {
        u32 blockno = offset >> 13;
        do
        {
            d->sector_usage_table[blockno] = 1;
            blockno += 1;
            if (len > 0x8000) len -= 0x8000;
        } while (len > 0x8000);
    }
}

static void partition_raw_read(wiidisc_t *d, u32 offset, u8 *data, u32 len)
{
    disc_read(d, d->partition_raw_offset + offset, data, len);
}

static void partition_read_block(wiidisc_t *d, u32 blockno, u8 *block)
{
    u8*raw = d->tmp_buffer;
    u8 iv[16];
    u32 offset;
    if (d->sector_usage_table) d->sector_usage_table[d->partition_block + blockno] = 1;
    offset = d->partition_data_offset + ((0x8000 >> 2) * blockno);
    partition_raw_read(d, offset, raw, 0x8000);

    // decrypt data
    memcpy(iv, raw + 0x3d0, 16);
    aes_set_key(d->disc_key);
    aes_decrypt(iv, raw + 0x400, block, 0x7c00);
}

static void partition_read(wiidisc_t *d, u32 offset, u8 *data, u32 len, int fake)
{
    u8 *block = d->tmp_buffer2;
    u32 offset_in_block;
    u32 len_in_block;
    if (fake && d->sector_usage_table == 0) return;

    while (len)
    {
        offset_in_block = offset % (0x7c00 >> 2);
        len_in_block = 0x7c00 - (offset_in_block << 2);
        if (len_in_block > len) len_in_block = len;
        if (!fake)
        {
            partition_read_block(d, offset / (0x7c00 >> 2), block);
            wbfs_memcpy( data, block + ( offset_in_block << 2 ), len_in_block );
        }
        else d->sector_usage_table[d->partition_block + (offset / (0x7c00 >> 2))] = 1;
        data += len_in_block;
        offset += len_in_block >> 2;
        len -= len_in_block;
    }
}

static u32 do_fst(wiidisc_t *d, u8 *fst, const char *names, u32 i)
{
    u32 offset;
    u32 size;
    const char *name;
    u32 j;

    name = names + (_be32(fst + 12 * i) & 0x00ffffff);
    size = _be32(fst + 12 * i + 8);

    if (i == 0)
    {
        for (j = 1; j < size && !d->extracted_buffer;)
        {
            j = do_fst(d, fst, names, j);
        }
        return size;
    }
    //printf("name    %s\n",name);

    if (fst[12 * i])
    {

        for (j = i + 1; j < size && !d->extracted_buffer;)
            j = do_fst(d, fst, names, j);

        return size;
    }
    else
    {
        offset = _be32(fst + 12 * i + 4);
        if (d->extract_pathname && strcasecmp(name, d->extract_pathname) == 0)
        {
            d->extracted_buffer = wbfs_ioalloc( size );
            d->extracted_size = size;
            partition_read(d, offset, d->extracted_buffer, size, 0);
        }
        else partition_read(d, offset, 0, size, 1);
        return i + 1;
    }
}

static void do_files(wiidisc_t*d)
{
    u8 *b = wbfs_ioalloc( 0x480 ); // XXX: determine actual header size
    u32 dol_offset;
    u32 fst_offset;
    u32 fst_size;
    u32 apl_offset;
    u32 apl_size;
    u8 *apl_header = wbfs_ioalloc( 0x20 );
    u8 *fst;
    u32 n_files;
    partition_read(d, 0, b, 0x480, 0);

    dol_offset = _be32(b + 0x0420);
    fst_offset = _be32(b + 0x0424);
    fst_size = _be32(b + 0x0428) << 2;

    apl_offset = 0x2440 >> 2;
    partition_read(d, apl_offset, apl_header, 0x20, 0);
    apl_size = 0x20 + _be32(apl_header + 0x14) + _be32(apl_header + 0x18);
    // fake read dol and partition
    if (apl_size) partition_read(d, apl_offset, 0, apl_size, 1);
    partition_read(d, dol_offset, 0, (fst_offset - dol_offset) << 2, 1);

    if (fst_size)
    {
        fst = wbfs_ioalloc( fst_size );
        if (fst == 0)
        wbfs_fatal( "malloc fst" );
        partition_read(d, fst_offset, fst, fst_size, 0);
        n_files = _be32(fst + 8);

        if(get_fst && !d->extracted_buffer)
        {
            d->extracted_buffer = malloc(fst_size);
            memcpy(d->extracted_buffer, fst, fst_size);
        }

        if (d->extract_pathname && *d->extract_pathname == 0)
        {
            // if empty pathname requested return fst
            d->extracted_buffer = fst;
            d->extracted_size = fst_size;
            d->extract_pathname = NULL;
            // skip do_fst if only fst requested
            n_files = 0;
        }

        if (12 * n_files <= fst_size)
        {
            if (n_files > 1) do_fst(d, fst, (char *) fst + 12 * n_files, 0);
        }

        if (fst != d->extracted_buffer) wbfs_iofree( fst );
    }
    wbfs_iofree( b );
    wbfs_iofree( apl_header );
}

static void do_partition(wiidisc_t*d)
{
    u8 *tik = wbfs_ioalloc( 0x2a4 );
    u8 *b = wbfs_ioalloc( 0x1c );
    u64 tmd_offset;
    u32 tmd_size;
    u8 *tmd;
    u64 cert_offset;
    u32 cert_size;
    u8 *cert;
    u64 h3_offset;

    // read ticket, and read some offsets and sizes
    partition_raw_read(d, 0, tik, 0x2a4);
    partition_raw_read(d, 0x2a4 >> 2, b, 0x1c);

    tmd_size = _be32(b);
    tmd_offset = _be32(b + 4);
    cert_size = _be32(b + 8);
    cert_offset = _be32(b + 0x0c);
    h3_offset = _be32(b + 0x10);
    d->partition_data_offset = _be32(b + 0x14);
    d->partition_block = (d->partition_raw_offset + d->partition_data_offset) >> 13;
    tmd = wbfs_ioalloc( tmd_size );
    if (tmd == 0)
    wbfs_fatal( "malloc tmd" );
    partition_raw_read(d, tmd_offset, tmd, tmd_size);

    cert = wbfs_ioalloc( cert_size );
    if (cert == 0)
    wbfs_fatal( "malloc cert" );
    partition_raw_read(d, cert_offset, cert, cert_size);

    _decrypt_title_key(tik, d->disc_key);

    partition_raw_read(d, h3_offset, 0, 0x18000);
    wbfs_iofree( b );
    wbfs_iofree( tik );
    wbfs_iofree( cert );
    wbfs_iofree( tmd );

    do_files(d);

}
static int test_parition_skip(u32 partition_type, partition_selector_t part_sel)
{
    switch (part_sel)
    {
        case ALL_PARTITIONS:
            return 0;
        case REMOVE_UPDATE_PARTITION:
            return (partition_type == 1);
        case ONLY_GAME_PARTITION:
            return (partition_type != 0);
        default:
            return (partition_type != part_sel);
    }
}
static void do_disc(wiidisc_t*d)
{
    u8 *b = wbfs_ioalloc( 0x100 );
    u64 partition_offset[32]; // XXX: don't know the real maximum
    u64 partition_type[32]; // XXX: don't know the real maximum
    u32 n_partitions;
    u32 magic;
    u32 i;
    disc_read(d, 0, b, 0x100);
    magic = _be32(b + 24);
    if (magic != 0x5D1C9EA3)
    {
        wbfs_error( "not a wii disc" );
        return;
    }
    disc_read(d, 0x40000 >> 2, b, 0x100);
    n_partitions = _be32(b);
    disc_read(d, _be32(b + 4), b, 0x100);
    for (i = 0; i < n_partitions; i++)
    {
        partition_offset[i] = _be32(b + 8 * i);
        partition_type[i] = _be32(b + 8 * i + 4);
    }
    for (i = 0; i < n_partitions; i++)
    {
        d->partition_raw_offset = partition_offset[i];
        if (!test_parition_skip(partition_type[i], d->part_sel)) do_partition(d);
    }
    wbfs_iofree( b );
}

wiidisc_t *wd_open_disc(read_wiidisc_callback_t read, void*fp)
{
    wiidisc_t *d = wbfs_malloc( sizeof( wiidisc_t ) );
    if (!d) return 0;
    wbfs_memset( d, 0, sizeof( wiidisc_t ) );
    d->read = read;
    d->fp = fp;
    d->part_sel = ALL_PARTITIONS;
    d->tmp_buffer = wbfs_ioalloc( 0x8000 );
    d->tmp_buffer2 = wbfs_malloc( 0x8000 );

    return d;
}
void wd_close_disc(wiidisc_t *d)
{
    wbfs_iofree( d->tmp_buffer );
    wbfs_free( d->tmp_buffer2 );
    wbfs_free( d );
}
// returns a buffer allocated with wbfs_ioalloc() or NULL if not found of alloc error
// XXX pathname not implemented. files are extracted by their name.
// first file found with that name is returned.
u8 * wd_extract_file(wiidisc_t *d, partition_selector_t partition_type, char *pathname)
{
    u8 *retval = 0;
    d->extract_pathname = pathname;
    d->extracted_buffer = 0;
    d->part_sel = partition_type;
    do_disc(d);
    d->extract_pathname = 0;
    d->part_sel = ALL_PARTITIONS;
    retval = d->extracted_buffer;
    d->extracted_buffer = 0;
    return retval;
}

u8 * wd_get_fst(wiidisc_t *d, partition_selector_t partition_type)
{
    get_fst = 1;
    u8 *retval = 0;
    d->extract_pathname = 0;
    d->extracted_buffer = 0;
    d->part_sel = partition_type;
    do_disc(d);
    d->extract_pathname = 0;
    d->part_sel = ALL_PARTITIONS;
    retval = d->extracted_buffer;
    d->extracted_buffer = 0;
    return retval;
}

void wd_build_disc_usage(wiidisc_t *d, partition_selector_t selector, u8* usage_table)
{
    d->sector_usage_table = usage_table;
    wbfs_memset( usage_table, 0, 143432*2 );
    d->part_sel = selector;
    do_disc(d);
    d->part_sel = ALL_PARTITIONS;
    d->sector_usage_table = 0;
}

void wd_fix_partition_table(wiidisc_t *d, partition_selector_t selector, u8* partition_table)
{
    u8 *b = partition_table;
    u32 partition_offset;
    u32 partition_type;
    u32 n_partitions, i, j;
    u32 *b32;
    if (selector == ALL_PARTITIONS) return;
    n_partitions = _be32(b);
    if (_be32(b + 4) - (0x40000 >> 2) > 0x50)
    wbfs_fatal( "cannot modify this partition table. Please report the bug." );

    b += (_be32(b + 4) - (0x40000 >> 2)) * 4;
    j = 0;
    for (i = 0; i < n_partitions; i++)
    {
        partition_offset = _be32(b + 8 * i);
        partition_type = _be32(b + 8 * i + 4);
        if (!test_parition_skip(partition_type, selector))
        {
            b32 = (u32*) (b + 8 * j);
            b32[0] = wbfs_htonl( partition_offset );
            b32[1] = wbfs_htonl( partition_type );
            j++;
        }
    }
    b32 = (u32*) (partition_table);
    *b32 = wbfs_htonl( j );
}