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 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
    partition_read(d,apl_offset, 0, apl_size,1);
    partition_read(d,dol_offset, 0,  (fst_offset - dol_offset)<<2,1);


    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 (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 (n_files > 1)
        do_fst(d,fst, (char *)fst + 12*n_files, 0);
    wbfs_iofree(b);
    wbfs_iofree(apl_header);
    if (fst != d->extracted_buffer)
        wbfs_iofree(fst);
}

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;
}

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);
}