static zip_cdir_t *
_zip_find_central_dir(zip_t *za, zip_uint64_t len)
{
zip_cdir_t *cdir, *cdirnew;
zip_uint8_t *match;
zip_int64_t buf_offset;
zip_uint64_t buflen;
zip_int64_t a;
zip_int64_t best;
zip_error_t error;
zip_buffer_t *buffer;
if (len < EOCDLEN) {
zip_error_set(&za->error, ZIP_ER_NOZIP, 0);
return NULL;
}
buflen = (len < CDBUFSIZE ? len : CDBUFSIZE);
if (zip_source_seek(za->src, -(zip_int64_t)buflen, SEEK_END) < 0) {
zip_error_t *src_error = zip_source_error(za->src);
if (zip_error_code_zip(src_error) != ZIP_ER_SEEK || zip_error_code_system(src_error) != EFBIG) {
/* seek before start of file on my machine */
_zip_error_copy(&za->error, src_error);
return NULL;
}
}
if ((buf_offset = zip_source_tell(za->src)) < 0) {
_zip_error_set_from_source(&za->error, za->src);
return NULL;
}
if ((buffer = _zip_buffer_new_from_source(za->src, buflen, NULL, &za->error)) == NULL) {
return NULL;
}
best = -1;
cdir = NULL;
if (buflen >= CDBUFSIZE) {
/* EOCD64 locator is before EOCD, so leave place for it */
_zip_buffer_set_offset(buffer, EOCD64LOCLEN);
}
zip_error_set(&error, ZIP_ER_NOZIP, 0);
match = _zip_buffer_get(buffer, 0);
while ((match=_zip_memmem(match, _zip_buffer_left(buffer)-(EOCDLEN-4), (const unsigned char *)EOCD_MAGIC, 4)) != NULL) {
_zip_buffer_set_offset(buffer, (zip_uint64_t)(match - _zip_buffer_data(buffer)));
if ((cdirnew = _zip_read_cdir(za, buffer, (zip_uint64_t)buf_offset, &error)) != NULL) {
if (cdir) {
if (best <= 0) {
best = _zip_checkcons(za, cdir, &error);
}
a = _zip_checkcons(za, cdirnew, &error);
if (best < a) {
_zip_cdir_free(cdir);
cdir = cdirnew;
best = a;
}
else {
_zip_cdir_free(cdirnew);
}
}
else {
cdir = cdirnew;
if (za->open_flags & ZIP_CHECKCONS)
best = _zip_checkcons(za, cdir, &error);
else {
best = 0;
}
}
cdirnew = NULL;
}
match++;
_zip_buffer_set_offset(buffer, (zip_uint64_t)(match - _zip_buffer_data(buffer)));
}
_zip_buffer_free(buffer);
if (best < 0) {
_zip_error_copy(&za->error, &error);
_zip_cdir_free(cdir);
return NULL;
}
return cdir;
}
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;
}
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 (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 (left > 0) {
bool grown = false;
zip_int64_t entry_size;
if (i == cd->nentry) {
/* InfoZIP has a hack to avoid using Zip64: it stores nentries % 0x10000 */
/* This hack isn't applicable if we're using Zip64, or if there is no central directory entry following. */
if (cd->is_zip64 || left < CDENTRYSIZE) {
break;
}
if (!_zip_cdir_grow(cd, 0x10000, error)) {
_zip_cdir_free(cd);
_zip_buffer_free(cd_buffer);
return NULL;
}
grown = true;
}
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) {
if (grown && zip_error_code_zip(error) == ZIP_ER_NOZIP) {
zip_error_set(error, ZIP_ER_INCONS, 0);
}
_zip_cdir_free(cd);
_zip_buffer_free(cd_buffer);
return NULL;
}
i++;
left -= (zip_uint64_t)entry_size;
}
if (i != cd->nentry || left > 0) {
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_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;
}
static zip_int64_t
crc_read(zip_source_t *src, void *_ctx, void *data, zip_uint64_t len, zip_source_cmd_t cmd)
{
struct crc_context *ctx;
zip_int64_t n;
ctx = (struct crc_context *)_ctx;
switch (cmd) {
case ZIP_SOURCE_OPEN:
ctx->position = 0;
return 0;
case ZIP_SOURCE_READ:
if ((n = zip_source_read(src, data, len)) < 0) {
_zip_error_set_from_source(&ctx->error, src);
return -1;
}
if (n == 0) {
if (ctx->crc_position == ctx->position) {
ctx->crc_complete = 1;
ctx->size = ctx->position;
if (ctx->validate) {
struct zip_stat st;
if (zip_source_stat(src, &st) < 0) {
_zip_error_set_from_source(&ctx->error, src);
return -1;
}
if ((st.valid & ZIP_STAT_CRC) && st.crc != ctx->crc) {
zip_error_set(&ctx->error, ZIP_ER_CRC, 0);
return -1;
}
if ((st.valid & ZIP_STAT_SIZE) && st.size != ctx->size) {
zip_error_set(&ctx->error, ZIP_ER_INCONS, 0);
return -1;
}
}
}
}
else if (!ctx->crc_complete && ctx->position <= ctx->crc_position) {
zip_uint64_t i, nn;
for (i = ctx->crc_position - ctx->position; i < (zip_uint64_t)n; i += nn) {
nn = ZIP_MIN(UINT_MAX, (zip_uint64_t)n-i);
ctx->crc = (zip_uint32_t)crc32(ctx->crc, (const Bytef *)data+i, (uInt)nn);
ctx->crc_position += nn;
}
}
ctx->position += (zip_uint64_t)n;
return n;
case ZIP_SOURCE_CLOSE:
return 0;
case ZIP_SOURCE_STAT:
{
zip_stat_t *st;
st = (zip_stat_t *)data;
if (ctx->crc_complete) {
/* TODO: Set comp_size, comp_method, encryption_method?
After all, this only works for uncompressed data. */
st->size = ctx->size;
st->crc = ctx->crc;
st->comp_size = ctx->size;
st->comp_method = ZIP_CM_STORE;
st->encryption_method = ZIP_EM_NONE;
st->valid |= ZIP_STAT_SIZE|ZIP_STAT_CRC|ZIP_STAT_COMP_SIZE|ZIP_STAT_COMP_METHOD|ZIP_STAT_ENCRYPTION_METHOD;;
}
return 0;
}
case ZIP_SOURCE_ERROR:
return zip_error_to_data(&ctx->error, data, len);
case ZIP_SOURCE_FREE:
free(ctx);
return 0;
case ZIP_SOURCE_SUPPORTS:
{
zip_int64_t mask = zip_source_supports(src);
if (mask < 0) {
_zip_error_set_from_source(&ctx->error, src);
return -1;
}
return mask & ~zip_source_make_command_bitmap(ZIP_SOURCE_BEGIN_WRITE, ZIP_SOURCE_COMMIT_WRITE, ZIP_SOURCE_ROLLBACK_WRITE, ZIP_SOURCE_SEEK_WRITE, ZIP_SOURCE_TELL_WRITE, ZIP_SOURCE_REMOVE, -1);
}
case ZIP_SOURCE_SEEK:
{
zip_int64_t new_position;
zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, len, &ctx->error);
if (args == NULL) {
return -1;
}
if (zip_source_seek(src, args->offset, args->whence) < 0 || (new_position = zip_source_tell(src)) < 0) {
_zip_error_set_from_source(&ctx->error, src);
return -1;
}
ctx->position = (zip_uint64_t)new_position;
return 0;
}
case ZIP_SOURCE_TELL:
return (zip_int64_t)ctx->position;
default:
zip_error_set(&ctx->error, ZIP_ER_OPNOTSUPP, 0);
return -1;
}
}
