static zip_cdir_t *
_zip_read_eocd(zip_buffer_t *buffer, zip_uint64_t buf_offset, unsigned int flags, zip_error_t *error)
{
zip_cdir_t *cd;
zip_uint64_t i, nentry, size, offset, eocd_offset;
if (_zip_buffer_left(buffer) < EOCDLEN) {
zip_error_set(error, ZIP_ER_INCONS, 0);
return NULL;
}
eocd_offset = _zip_buffer_offset(buffer);
_zip_buffer_get(buffer, 4); /* magic already verified */
if (_zip_buffer_get_32(buffer) != 0) {
zip_error_set(error, ZIP_ER_MULTIDISK, 0);
return NULL;
}
/* number of cdir-entries on this disk */
i = _zip_buffer_get_16(buffer);
/* number of cdir-entries */
nentry = _zip_buffer_get_16(buffer);
if (nentry != i) {
zip_error_set(error, ZIP_ER_NOZIP, 0);
return NULL;
}
size = _zip_buffer_get_32(buffer);
offset = _zip_buffer_get_32(buffer);
if (offset+size < offset) {
zip_error_set(error, ZIP_ER_SEEK, EFBIG);
return NULL;
}
if (offset+size > buf_offset + eocd_offset) {
/* cdir spans past EOCD record */
zip_error_set(error, ZIP_ER_INCONS, 0);
return NULL;
}
if ((flags & ZIP_CHECKCONS) && offset+size != buf_offset + eocd_offset) {
zip_error_set(error, ZIP_ER_INCONS, 0);
return NULL;
}
if ((cd=_zip_cdir_new(nentry, error)) == NULL)
return NULL;
cd->is_zip64 = false;
cd->size = size;
cd->offset = offset;
return cd;
}
static zip_cdir_t *
_zip_read_eocd64(zip_source_t *src, zip_buffer_t *buffer, zip_uint64_t buf_offset, unsigned int flags, zip_error_t *error)
{
zip_cdir_t *cd;
zip_uint64_t offset;
zip_uint8_t eocd[EOCD64LEN];
zip_uint64_t eocd_offset;
zip_uint64_t size, nentry, i, eocdloc_offset;
bool free_buffer;
zip_uint32_t num_disks, num_disks64, eocd_disk, eocd_disk64;
eocdloc_offset = _zip_buffer_offset(buffer);
_zip_buffer_get(buffer, 4); /* magic already verified */
num_disks = _zip_buffer_get_16(buffer);
eocd_disk = _zip_buffer_get_16(buffer);
eocd_offset = _zip_buffer_get_64(buffer);
if (eocd_offset > ZIP_INT64_MAX || eocd_offset + EOCD64LEN < eocd_offset) {
zip_error_set(error, ZIP_ER_SEEK, EFBIG);
return NULL;
}
if (eocd_offset + EOCD64LEN > eocdloc_offset + buf_offset) {
zip_error_set(error, ZIP_ER_INCONS, 0);
return NULL;
}
if (eocd_offset >= buf_offset && eocd_offset + EOCD64LEN <= buf_offset + _zip_buffer_size(buffer)) {
_zip_buffer_set_offset(buffer, eocd_offset - buf_offset);
free_buffer = false;
}
else {
if (zip_source_seek(src, (zip_int64_t)eocd_offset, SEEK_SET) < 0) {
_zip_error_set_from_source(error, src);
return NULL;
}
if ((buffer = _zip_buffer_new_from_source(src, EOCD64LEN, eocd, error)) == NULL) {
return NULL;
}
free_buffer = true;
}
if (memcmp(_zip_buffer_get(buffer, 4), EOCD64_MAGIC, 4) != 0) {
zip_error_set(error, ZIP_ER_INCONS, 0);
if (free_buffer) {
_zip_buffer_free(buffer);
}
return NULL;
}
size = _zip_buffer_get_64(buffer);
if ((flags & ZIP_CHECKCONS) && size + eocd_offset + 12 != buf_offset + eocdloc_offset) {
zip_error_set(error, ZIP_ER_INCONS, 0);
if (free_buffer) {
_zip_buffer_free(buffer);
}
return NULL;
}
_zip_buffer_get(buffer, 4); /* skip version made by/needed */
num_disks64 = _zip_buffer_get_32(buffer);
eocd_disk64 = _zip_buffer_get_32(buffer);
/* if eocd values are 0xffff, we have to use eocd64 values.
otherwise, if the values are not the same, it's inconsistent;
in any case, if the value is not 0, we don't support it */
if (num_disks == 0xffff) {
num_disks = num_disks64;
}
if (eocd_disk == 0xffff) {
eocd_disk = eocd_disk64;
}
if ((flags & ZIP_CHECKCONS) && (eocd_disk != eocd_disk64 || num_disks != num_disks64)) {
zip_error_set(error, ZIP_ER_INCONS, 0);
if (free_buffer) {
_zip_buffer_free(buffer);
}
return NULL;
}
if (num_disks != 0 || eocd_disk != 0) {
zip_error_set(error, ZIP_ER_MULTIDISK, 0);
if (free_buffer) {
_zip_buffer_free(buffer);
}
return NULL;
}
nentry = _zip_buffer_get_64(buffer);
i = _zip_buffer_get_64(buffer);
if (nentry != i) {
zip_error_set(error, ZIP_ER_MULTIDISK, 0);
if (free_buffer) {
_zip_buffer_free(buffer);
}
return NULL;
}
size = _zip_buffer_get_64(buffer);
offset = _zip_buffer_get_64(buffer);
if (!_zip_buffer_ok(buffer)) {
zip_error_set(error, ZIP_ER_INTERNAL, 0);
if (free_buffer) {
_zip_buffer_free(buffer);
}
return NULL;
}
if (free_buffer) {
_zip_buffer_free(buffer);
}
if (offset > ZIP_INT64_MAX || offset+size < offset) {
zip_error_set(error, ZIP_ER_SEEK, EFBIG);
return NULL;
}
if (offset+size > buf_offset + eocd_offset) {
/* cdir spans past EOCD record */
zip_error_set(error, ZIP_ER_INCONS, 0);
return NULL;
}
if ((flags & ZIP_CHECKCONS) && offset+size != buf_offset + eocd_offset) {
zip_error_set(error, ZIP_ER_INCONS, 0);
return NULL;
}
if ((cd=_zip_cdir_new(nentry, error)) == NULL)
return NULL;
cd->is_zip64 = true;
cd->size = size;
cd->offset = offset;
return cd;
}
static zip_cdir_t *
_zip_read_cdir(zip_t *za, zip_buffer_t *buffer, zip_uint64_t buf_offset, zip_error_t *error)
{
zip_cdir_t *cd;
zip_uint16_t comment_len;
zip_uint64_t i, left;
zip_uint64_t eocd_offset = _zip_buffer_offset(buffer);
zip_buffer_t *cd_buffer;
if (_zip_buffer_left(buffer) < EOCDLEN) {
/* not enough bytes left for comment */
zip_error_set(error, ZIP_ER_NOZIP, 0);
return NULL;
}
/* check for end-of-central-dir magic */
if (memcmp(_zip_buffer_get(buffer, 4), EOCD_MAGIC, 4) != 0) {
zip_error_set(error, ZIP_ER_NOZIP, 0);
return NULL;
}
if (_zip_buffer_get_32(buffer) != 0) {
zip_error_set(error, ZIP_ER_MULTIDISK, 0);
return NULL;
}
if (eocd_offset >= EOCD64LOCLEN && memcmp(_zip_buffer_data(buffer) + eocd_offset - EOCD64LOCLEN, EOCD64LOC_MAGIC, 4) == 0) {
_zip_buffer_set_offset(buffer, eocd_offset - EOCD64LOCLEN);
cd = _zip_read_eocd64(za->src, buffer, buf_offset, za->flags, error);
}
else {
_zip_buffer_set_offset(buffer, eocd_offset);
cd = _zip_read_eocd(buffer, buf_offset, za->flags, error);
}
if (cd == NULL)
return NULL;
_zip_buffer_set_offset(buffer, eocd_offset + 20);
comment_len = _zip_buffer_get_16(buffer);
if (cd->offset + cd->size > buf_offset + eocd_offset) {
/* cdir spans past EOCD record */
zip_error_set(error, ZIP_ER_INCONS, 0);
_zip_cdir_free(cd);
return NULL;
}
if (comment_len || (za->open_flags & ZIP_CHECKCONS)) {
zip_uint64_t tail_len;
_zip_buffer_set_offset(buffer, eocd_offset + EOCDLEN);
tail_len = _zip_buffer_left(buffer);
if (tail_len < comment_len || ((za->open_flags & ZIP_CHECKCONS) && tail_len != comment_len)) {
zip_error_set(error, ZIP_ER_INCONS, 0);
_zip_cdir_free(cd);
return NULL;
}
if (comment_len) {
if ((cd->comment=_zip_string_new(_zip_buffer_get(buffer, comment_len), comment_len, ZIP_FL_ENC_GUESS, error)) == NULL) {
_zip_cdir_free(cd);
return NULL;
}
}
}
if (cd->offset >= buf_offset) {
zip_uint8_t *data;
/* if buffer already read in, use it */
_zip_buffer_set_offset(buffer, cd->offset - buf_offset);
if ((data = _zip_buffer_get(buffer, cd->size)) == NULL) {
zip_error_set(error, ZIP_ER_INCONS, 0);
_zip_cdir_free(cd);
return NULL;
}
if ((cd_buffer = _zip_buffer_new(data, cd->size)) == NULL) {
zip_error_set(error, ZIP_ER_MEMORY, 0);
_zip_cdir_free(cd);
return NULL;
}
}
else {
cd_buffer = NULL;
if (zip_source_seek(za->src, (zip_int64_t)cd->offset, SEEK_SET) < 0) {
_zip_error_set_from_source(error, za->src);
_zip_cdir_free(cd);
return NULL;
}
/* possible consistency check: cd->offset = len-(cd->size+cd->comment_len+EOCDLEN) ? */
if (zip_source_tell(za->src) != (zip_int64_t)cd->offset) {
zip_error_set(error, ZIP_ER_NOZIP, 0);
_zip_cdir_free(cd);
return NULL;
}
}
left = (zip_uint64_t)cd->size;
i=0;
while (i<cd->nentry && left > 0) {
zip_int64_t entry_size;
if ((cd->entry[i].orig=_zip_dirent_new()) == NULL || (entry_size = _zip_dirent_read(cd->entry[i].orig, za->src, cd_buffer, false, error)) < 0) {
_zip_cdir_free(cd);
_zip_buffer_free(cd_buffer);
return NULL;
}
i++;
left -= (zip_uint64_t)entry_size;
}
if (i != cd->nentry) {
zip_error_set(error, ZIP_ER_INCONS, 0);
_zip_buffer_free(cd_buffer);
_zip_cdir_free(cd);
return NULL;
}
if (za->open_flags & ZIP_CHECKCONS) {
bool ok;
if (cd_buffer) {
ok = _zip_buffer_eof(cd_buffer);
}
else {
zip_int64_t offset = zip_source_tell(za->src);
if (offset < 0) {
_zip_error_set_from_source(error, za->src);
_zip_buffer_free(cd_buffer);
_zip_cdir_free(cd);
return NULL;
}
ok = ((zip_uint64_t)offset == cd->offset + cd->size);
}
if (!ok) {
zip_error_set(error, ZIP_ER_INCONS, 0);
_zip_buffer_free(cd_buffer);
_zip_cdir_free(cd);
return NULL;
}
}
_zip_buffer_free(cd_buffer);
return cd;
}
