/*
* security.c
*
- * Read the security data from the WIM. Doing anything with the security data
- * is not yet implemented other than printing some information about it.
+ * Read and write the WIM security data. The security data is a table of
+ * security descriptors. Each WIM image has its own security data, but it's
+ * possible that an image's security data have no security descriptors.
*/
/*
* This file is part of wimlib, a library for working with WIM files.
*
* wimlib is free software; you can redistribute it and/or modify it under the
- * terms of the GNU Lesser General Public License as published by the Free
- * Software Foundation; either version 2.1 of the License, or (at your option)
+ * terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your option)
* any later version.
*
* wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
- * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+ * A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
- * You should have received a copy of the GNU Lesser General Public License
+ * You should have received a copy of the GNU General Public License
* along with wimlib; if not, see http://www.gnu.org/licenses/.
*/
#include "io.h"
#include "security.h"
+/*
+ * This is a hack to work around a problem in libntfs-3g. libntfs-3g validates
+ * security descriptors with a function named ntfs_valid_descr().
+ * ntfs_valid_descr() considers a security descriptor that ends in a SACL
+ * (Sysetm Access Control List) with no ACE's (Access Control Entries) to be
+ * invalid. However, a security descriptor like this exists in the Windows 7
+ * install.wim. Here, security descriptors matching this pattern are modified
+ * to have no SACL. This should make no difference since the SACL had no
+ * entries anyway; however his ensures that that the security descriptors pass
+ * the validation in libntfs-3g.
+ */
+static void empty_sacl_fixup(char *descr, u64 *size_p)
+{
+ if (*size_p >= sizeof(SecurityDescriptor)) {
+ SecurityDescriptor *sd = (SecurityDescriptor*)descr;
+ u32 sacl_offset = le32_to_cpu(sd->sacl_offset);
+ if (sacl_offset == *size_p - sizeof(ACL)) {
+ sd->sacl_offset = to_le32(0);
+ *size_p -= sizeof(ACL);
+ }
+ }
+}
+
/*
* Reads the security data from the metadata resource.
*
p = metadata_resource;
p = get_u32(p, &sd->total_length);
- p = get_u32(p, &sd->num_entries);
+ p = get_u32(p, (u32*)&sd->num_entries);
+
+ if (sd->num_entries > 0x7fffffff) {
+ ERROR("Security data has too many entries!");
+ ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
+ goto out_free_sd;
+ }
/* Verify the listed total length of the security data is big enough to
* include the sizes array, verify that the file data is big enough to
ERROR("Security data total length (%u) is bigger than the "
"metadata resource length (%"PRIu64")",
sd->total_length, metadata_resource_len);
- ret = WIMLIB_ERR_INVALID_RESOURCE_SIZE;
+ ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
goto out_free_sd;
}
ERROR("Security data total length of %u is too short because "
"there must be at least %"PRIu64" bytes of security data",
sd->total_length, 8 + sizes_size);
- ret = WIMLIB_ERR_INVALID_RESOURCE_SIZE;
+ ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
goto out_free_sd;
}
sd->sizes = MALLOC(sizes_size);
ERROR("Security data total length of %u is too short "
"because there are at least %"PRIu64" bytes of "
"security data", sd->total_length, total_len);
- ret = WIMLIB_ERR_INVALID_RESOURCE_SIZE;
+ ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
goto out_free_sd;
}
sd->descriptors[i] = MALLOC(sd->sizes[i]);
goto out_free_sd;
}
p = get_bytes(p, sd->sizes[i], sd->descriptors[i]);
+ empty_sacl_fixup(sd->descriptors[i], &sd->sizes[i]);
}
out:
sd->total_length = (u32)total_len;
DEBUG("Writing security data (total_length = %"PRIu32", num_entries "
"= %"PRIu32")", sd->total_length, sd->num_entries);
+ u32 aligned_length = (sd->total_length + 7) & ~7;
+
u8 *orig_p = p;
- p = put_u32(p, sd->total_length);
+ p = put_u32(p, aligned_length);
p = put_u32(p, sd->num_entries);
for (u32 i = 0; i < sd->num_entries; i++)
p = put_bytes(p, sd->sizes[i], sd->descriptors[i]);
wimlib_assert(p - orig_p == sd->total_length);
+ p = put_zeroes(p, aligned_length - sd->total_length);
DEBUG("Successfully wrote security data.");
return p;
git://wimlib.net / wimlib / blobdiff