X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fsecurity.c;h=ca75ac0bf442ffb490ad8c9912a131e7fcf088d2;hp=8fda950c6261f26e99832723921ff0272e969cd3;hb=2a36f3ccb3773c33f0be7e8bc1e9e552ecf9fae0;hpb=ed828dc4cbf4eabc9f8b32cb4c6a86a04e087f7a

diff --git a/src/security.c b/src/security.c
index 8fda950c..ca75ac0b 100644
--- a/src/security.c
+++ b/src/security.c
@@ -1,8 +1,9 @@
 /*
  * 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.
  */
 
 /*
@@ -11,16 +12,16 @@
  * 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/.
  */
 
@@ -28,6 +29,29 @@
 #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.
  *
@@ -150,6 +174,7 @@ int read_security_data(const u8 metadata_resource[], u64 metadata_resource_len,
 			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;
@@ -189,22 +214,23 @@ u8 *write_security_data(const struct wim_security_data *sd, u8 *p)
 
 static void print_acl(const u8 *p, const char *type)
 {
-	ACL *acl = (ACL*)p;
-	TO_LE16(acl->acl_size);
-	TO_LE16(acl->acl_count);
+	const ACL *acl = (const ACL*)p;
+	u8 revision = acl->revision;
+	u16 acl_size = to_le16(acl->acl_size);
+	u16 ace_count = to_le16(acl->ace_count);
 	printf("    [%s ACL]\n", type);
-	printf("    Revision = %u\n", acl->revision);
-	printf("    ACL Size = %u\n", acl->acl_size);
-	printf("    ACE Count = %u\n", acl->ace_count);
+	printf("    Revision = %u\n", revision);
+	printf("    ACL Size = %u\n", acl_size);
+	printf("    ACE Count = %u\n", ace_count);
 
 	p += sizeof(ACL);
 	for (uint i = 0; i < acl->ace_count; i++) {
-		ACEHeader *hdr = (ACEHeader*)p;
+		const ACEHeader *hdr = (const ACEHeader*)p;
 		printf("        [ACE]\n");
 		printf("        ACE type  = %d\n", hdr->type);
 		printf("        ACE flags = 0x%x\n", hdr->flags);
 		printf("        ACE size  = %u\n", hdr->size);
-		AccessAllowedACE *aaa = (AccessAllowedACE*)hdr;
+		const AccessAllowedACE *aaa = (const AccessAllowedACE*)hdr;
 		printf("        ACE mask = %x\n", to_le32(aaa->mask));
 		printf("        SID start = %u\n", to_le32(aaa->sid_start));
 		p += hdr->size;
@@ -214,7 +240,7 @@ static void print_acl(const u8 *p, const char *type)
 
 static void print_sid(const u8 *p, const char *type)
 {
-	SID *sid = (SID*)p;
+	const SID *sid = (const SID*)p;
 	printf("    [%s SID]\n", type);
 	printf("    Revision = %u\n", sid->revision);
 	printf("    Subauthority count = %u\n", sid->sub_authority_count);
@@ -228,27 +254,28 @@ static void print_sid(const u8 *p, const char *type)
 
 static void print_security_descriptor(const u8 *p, u64 size)
 {
-	SecurityDescriptor *sd = (SecurityDescriptor*)p;
-	TO_LE16(sd->security_descriptor_control);
-	TO_LE32(sd->owner_offset);
-	TO_LE32(sd->group_offset);
-	TO_LE32(sd->sacl_offset);
-	TO_LE32(sd->dacl_offset);
-	printf("Revision = %u\n", sd->revision);
-	printf("Security Descriptor Control = %#x\n", sd->security_descriptor_control);
-	printf("Owner offset = %u\n", sd->owner_offset);
-	printf("Group offset = %u\n", sd->group_offset);
-	printf("System ACL offset = %u\n", sd->sacl_offset);
-	printf("Discretionary ACL offset = %u\n", sd->dacl_offset);
+	const SecurityDescriptor *sd = (const SecurityDescriptor*)p;
+	u8 revision      = sd->revision;
+	u16 control      = to_le16(sd->security_descriptor_control);
+	u32 owner_offset = to_le32(sd->owner_offset);
+	u32 group_offset = to_le32(sd->group_offset);
+	u32 sacl_offset  = to_le32(sd->sacl_offset);
+	u32 dacl_offset  = to_le32(sd->dacl_offset);
+	printf("Revision = %u\n", revision);
+	printf("Security Descriptor Control = %#x\n", control);
+	printf("Owner offset = %u\n", owner_offset);
+	printf("Group offset = %u\n", group_offset);
+	printf("System ACL offset = %u\n", sacl_offset);
+	printf("Discretionary ACL offset = %u\n", dacl_offset);
 
 	if (sd->owner_offset != 0)
-		print_sid(p + sd->owner_offset, "Owner");
+		print_sid(p + owner_offset, "Owner");
 	if (sd->group_offset != 0)
-		print_sid(p + sd->group_offset, "Group");
+		print_sid(p + group_offset, "Group");
 	if (sd->sacl_offset != 0)
-		print_acl(p + sd->sacl_offset, "System");
+		print_acl(p + sacl_offset, "System");
 	if (sd->dacl_offset != 0)
-		print_acl(p + sd->dacl_offset, "Discretionary");
+		print_acl(p + dacl_offset, "Discretionary");
 }
 
 /*