4 * Read and write the per-WIM-image table of security descriptors.
8 * Copyright (C) 2012, 2013 Eric Biggers
10 * This file is part of wimlib, a library for working with WIM files.
12 * wimlib is free software; you can redistribute it and/or modify it under the
13 * terms of the GNU General Public License as published by the Free
14 * Software Foundation; either version 3 of the License, or (at your option)
17 * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
18 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
19 * A PARTICULAR PURPOSE. See the GNU General Public License for more
22 * You should have received a copy of the GNU General Public License
23 * along with wimlib; if not, see http://www.gnu.org/licenses/.
26 #include "wimlib_internal.h"
27 #include "buffer_io.h"
31 #define SECURITY_DESCRIPTOR_REVISION 1
32 #define SECURITY_DESCRIPTOR_REVISION1 1
34 /* inherit AceFlags */
35 #define OBJECT_INHERIT_ACE 0x01
36 #define CONTAINER_INHERIT_ACE 0x02
37 #define NO_PROPAGATE_INHERIT_ACE 0x04
38 #define INHERIT_ONLY_ACE 0x08
39 #define INHERITED_ACE 0x10
40 #define VALID_INHERIT_FLAGS 0x1F
42 #define SE_OWNER_DEFAULTED 0x00000001
43 #define SE_GROUP_DEFAULTED 0x00000002
44 #define SE_DACL_PRESENT 0x00000004
45 #define SE_DACL_DEFAULTED 0x00000008
46 #define SE_SACL_PRESENT 0x00000010
47 #define SE_SACL_DEFAULTED 0x00000020
48 #define SE_DACL_AUTO_INHERIT_REQ 0x00000100
49 #define SE_SACL_AUTO_INHERIT_REQ 0x00000200
50 #define SE_DACL_AUTO_INHERITED 0x00000400
51 #define SE_SACL_AUTO_INHERITED 0x00000800
52 #define SE_DACL_PROTECTED 0x00001000
53 #define SE_SACL_PROTECTED 0x00002000
54 #define SE_RM_CONTROL_VALID 0x00004000
55 #define SE_SELF_RELATIVE 0x00008000
57 /* Flags in access control entries */
58 #define DELETE 0x00010000
59 #define READ_CONTROL 0x00020000
60 #define WRITE_DAC 0x00040000
61 #define WRITE_OWNER 0x00080000
62 #define SYNCHRONIZE 0x00100000
63 #define STANDARD_RIGHTS_REQUIRED 0x000f0000
65 #define STANDARD_RIGHTS_READ READ_CONTROL
66 #define STANDARD_RIGHTS_WRITE READ_CONTROL
67 #define STANDARD_RIGHTS_EXECUTE READ_CONTROL
69 #define STANDARD_RIGHTS_ALL 0x001f0000
71 #define SPECIFIC_RIGHTS_ALL 0x0000ffff
73 #define GENERIC_READ 0x80000000
74 #define GENERIC_WRITE 0x40000000
75 #define GENERIC_EXECUTE 0x20000000
76 #define GENERIC_ALL 0x10000000
78 #define MAXIMUM_ALLOWED 0x02000000
79 #define ACCESS_SYSTEM_SECURITY 0x01000000
81 #define EVENT_QUERY_STATE 0x0001
82 #define EVENT_MODIFY_STATE 0x0002
83 #define EVENT_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x3)
85 #define SEMAPHORE_MODIFY_STATE 0x0002
86 #define SEMAPHORE_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x3)
88 #define MUTEX_MODIFY_STATE 0x0001
89 #define MUTEX_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x1)
91 #define JOB_OBJECT_ASSIGN_PROCESS 0x0001
92 #define JOB_OBJECT_SET_ATTRIBUTES 0x0002
93 #define JOB_OBJECT_QUERY 0x0004
94 #define JOB_OBJECT_TERMINATE 0x0008
95 #define JOB_OBJECT_SET_SECURITY_ATTRIBUTES 0x0010
96 #define JOB_OBJECT_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x1f)
98 #define TIMER_QUERY_STATE 0x0001
99 #define TIMER_MODIFY_STATE 0x0002
100 #define TIMER_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x3)
102 #define PROCESS_TERMINATE 0x0001
103 #define PROCESS_CREATE_THREAD 0x0002
104 #define PROCESS_VM_OPERATION 0x0008
105 #define PROCESS_VM_READ 0x0010
106 #define PROCESS_VM_WRITE 0x0020
107 #define PROCESS_DUP_HANDLE 0x0040
108 #define PROCESS_CREATE_PROCESS 0x0080
109 #define PROCESS_SET_QUOTA 0x0100
110 #define PROCESS_SET_INFORMATION 0x0200
111 #define PROCESS_QUERY_INFORMATION 0x0400
112 #define PROCESS_SUSPEND_RESUME 0x0800
113 #define PROCESS_QUERY_LIMITED_INFORMATION 0x1000
114 #define PROCESS_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0xfff)
116 #define THREAD_TERMINATE 0x0001
117 #define THREAD_SUSPEND_RESUME 0x0002
118 #define THREAD_GET_CONTEXT 0x0008
119 #define THREAD_SET_CONTEXT 0x0010
120 #define THREAD_SET_INFORMATION 0x0020
121 #define THREAD_QUERY_INFORMATION 0x0040
122 #define THREAD_SET_THREAD_TOKEN 0x0080
123 #define THREAD_IMPERSONATE 0x0100
124 #define THREAD_DIRECT_IMPERSONATION 0x0200
125 #define THREAD_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x3ff)
127 #define THREAD_BASE_PRIORITY_LOWRT 15
128 #define THREAD_BASE_PRIORITY_MAX 2
129 #define THREAD_BASE_PRIORITY_MIN -2
130 #define THREAD_BASE_PRIORITY_IDLE -15
132 /* predefined authority values for SID's (security identifiers) */
133 enum sid_authority_value {
134 SECURITY_NULL_SID_AUTHORITY = 0,
135 SECURITY_WORLD_SID_AUTHORITY = 1,
136 SECURITY_LOCAL_SID_AUTHORITY = 2,
137 SECURITY_CREATOR_SID_AUTHORITY = 3,
138 SECURITY_NON_UNIQUE_AUTHORITY = 4,
139 SECURITY_NT_AUTHORITY = 5,
142 /* local administrators group */
143 #define SECURITY_BUILTIN_DOMAIN_RID 32
144 #define DOMAIN_ALIAS_RID_ADMINS 544
148 ACCESS_ALLOWED_ACE_TYPE = 0,
149 ACCESS_DENIED_ACE_TYPE = 1,
150 SYSTEM_AUDIT_ACE_TYPE = 2,
153 /* At the start of each type of access control entry. */
155 /* enum ace_type, specifies what type of ACE this is. */
158 /* bitwise OR of the inherit ACE flags #defined above */
161 /* Size of the access control entry. */
165 /* Grants rights to a user or group */
172 /* Denies rights to a user or group */
186 /* Header of an access control list. */
188 /* ACL_REVISION or ACL_REVISION_DS */
194 /* Total size of the ACL, including all access control entries */
197 /* Number of access control entry structures that follow the ACL
205 /* A structure used to identify users or groups. */
210 u8 sub_authority_count;
212 /* Identifies the authority that issued the SID. Can be, but does not
213 * have to be, one of enum sid_authority_value */
214 u8 identifier_authority[6];
216 u32 sub_authority[0];
225 /* Example: 0x4149 */
226 u16 security_descriptor_control;
228 /* Offset of a SID structure in the security descriptor. */
232 /* Offset of a SID structure in the security descriptor. */
236 /* Offset of an ACL structure in the security descriptor. */
241 /* Offset of an ACL structure in the security descriptor. */
242 /* Discretionary ACL. */
245 } SecurityDescriptor;
248 * This is a hack to work around a problem in libntfs-3g. libntfs-3g validates
249 * security descriptors with a function named ntfs_valid_descr().
250 * ntfs_valid_descr() considers a security descriptor that ends in a SACL
251 * (Sysetm Access Control List) with no ACE's (Access Control Entries) to be
252 * invalid. However, a security descriptor like this exists in the Windows 7
253 * install.wim. Here, security descriptors matching this pattern are modified
254 * to have no SACL. This should make no difference since the SACL had no
255 * entries anyway; however this ensures that that the security descriptors pass
256 * the validation in libntfs-3g.
259 empty_sacl_fixup(u8 *descr, u64 *size_p)
261 /* No-op if no NTFS-3g support, or if NTFS-3g is version 2013 or later
263 #if defined(WITH_NTFS_3G) && !defined(HAVE_NTFS_MNT_RDONLY)
264 if (*size_p >= sizeof(SecurityDescriptor)) {
265 SecurityDescriptor *sd = (SecurityDescriptor*)descr;
266 u32 sacl_offset = le32_to_cpu(sd->sacl_offset);
267 if (sacl_offset == *size_p - sizeof(ACL)) {
268 sd->sacl_offset = cpu_to_le32(0);
269 *size_p -= sizeof(ACL);
276 * Reads the security data from the metadata resource.
278 * @metadata_resource: An array that contains the uncompressed metadata
279 * resource for the WIM file.
280 * @metadata_resource_len: The length of @metadata_resource. It must be at
282 * @sd_p: A pointer to a pointer to a wim_security_data structure that
283 * will be filled in with a pointer to a new wim_security_data
284 * structure on success.
286 * Note: There is no `offset' argument because the security data is located at
287 * the beginning of the metadata resource.
290 read_security_data(const u8 metadata_resource[], u64 metadata_resource_len,
291 struct wim_security_data **sd_p)
293 struct wim_security_data *sd;
298 wimlib_assert(metadata_resource_len >= 8);
301 * Sorry this function is excessively complicated--- I'm just being
302 * extremely careful about integer overflows.
305 sd = MALLOC(sizeof(struct wim_security_data));
307 ERROR("Out of memory");
308 return WIMLIB_ERR_NOMEM;
311 sd->descriptors = NULL;
314 p = metadata_resource;
315 p = get_u32(p, &sd->total_length);
316 p = get_u32(p, (u32*)&sd->num_entries);
318 /* The security_id field of each dentry is a signed 32-bit integer, so
319 * the possible indices into the security descriptors table are 0
320 * through 0x7fffffff. Which means 0x80000000 security descriptors
321 * maximum. Not like you should ever have anywhere close to that many
322 * security descriptors! */
323 if (sd->num_entries > 0x80000000) {
324 ERROR("Security data has too many entries!");
328 /* Verify the listed total length of the security data is big enough to
329 * include the sizes array, verify that the file data is big enough to
330 * include it as well, then allocate the array of sizes.
332 * Note: The total length of the security data must fit in a 32-bit
333 * integer, even though each security descriptor size is a 64-bit
334 * integer. This is stupid, and we need to be careful not to actually
335 * let the security descriptor sizes be over 0xffffffff. */
336 if ((u64)sd->total_length > metadata_resource_len) {
337 ERROR("Security data total length (%u) is bigger than the "
338 "metadata resource length (%"PRIu64")",
339 sd->total_length, metadata_resource_len);
343 DEBUG("Reading security data: %u entries, length = %u",
344 sd->num_entries, sd->total_length);
346 if (sd->num_entries == 0) {
347 /* No security descriptors. We allow the total_length field to
348 * be either 8 (which is correct, since there are always 2
349 * 32-bit integers) or 0. */
350 if (sd->total_length != 0 && sd->total_length != 8) {
351 ERROR("Invalid security data length (%u): expected 0 or 8",
355 sd->total_length = 8;
359 u64 sizes_size = (u64)sd->num_entries * sizeof(u64);
360 u64 size_no_descriptors = 8 + sizes_size;
361 if (size_no_descriptors > (u64)sd->total_length) {
362 ERROR("Security data total length of %u is too short because "
363 "there seem to be at least %"PRIu64" bytes of security data",
364 sd->total_length, 8 + sizes_size);
368 sd->sizes = MALLOC(sizes_size);
370 ret = WIMLIB_ERR_NOMEM;
374 /* Copy the sizes array in from the file data. */
375 p = get_bytes(p, sizes_size, sd->sizes);
376 array_le64_to_cpu(sd->sizes, sd->num_entries);
378 /* Allocate the array of pointers to descriptors, and read them in. */
379 sd->descriptors = CALLOC(sd->num_entries, sizeof(u8*));
380 if (!sd->descriptors) {
381 ERROR("Out of memory while allocating security "
383 ret = WIMLIB_ERR_NOMEM;
386 total_len = size_no_descriptors;
388 for (u32 i = 0; i < sd->num_entries; i++) {
389 /* Watch out for huge security descriptor sizes that could
390 * overflow the total length and wrap it around. */
391 if (total_len + sd->sizes[i] < total_len) {
392 ERROR("Caught overflow in security descriptor lengths "
393 "(current total length = %"PRIu64", security "
394 "descriptor size = %"PRIu64")",
395 total_len, sd->sizes[i]);
398 total_len += sd->sizes[i];
399 /* This check ensures that the descriptor size fits in a 32 bit
400 * integer. Because if it didn't, the total length would come
401 * out bigger than sd->total_length, which is a 32 bit integer.
403 if (total_len > (u64)sd->total_length) {
404 ERROR("Security data total length of %u is too short "
405 "because there seem to be at least %"PRIu64" "
406 "bytes of security data",
407 sd->total_length, total_len);
410 sd->descriptors[i] = MALLOC(sd->sizes[i]);
411 if (!sd->descriptors[i]) {
412 ERROR("Out of memory while allocating security "
414 ret = WIMLIB_ERR_NOMEM;
417 p = get_bytes(p, sd->sizes[i], sd->descriptors[i]);
418 empty_sacl_fixup(sd->descriptors[i], &sd->sizes[i]);
420 wimlib_assert(total_len <= 0xffffffff);
421 if (((total_len + 7) & ~7) != ((sd->total_length + 7) & ~7)) {
422 ERROR("Expected security data total length = %u, but "
423 "calculated %u", sd->total_length, (unsigned)total_len);
426 sd->total_length = total_len;
431 ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
433 free_security_data(sd);
438 * Writes security data to an in-memory buffer.
441 write_security_data(const struct wim_security_data *sd, u8 *p)
443 DEBUG("Writing security data (total_length = %"PRIu32", num_entries "
444 "= %"PRIu32")", sd->total_length, sd->num_entries);
446 u32 aligned_length = (sd->total_length + 7) & ~7;
449 p = put_u32(p, aligned_length);
450 p = put_u32(p, sd->num_entries);
452 for (u32 i = 0; i < sd->num_entries; i++)
453 p = put_u64(p, sd->sizes[i]);
455 for (u32 i = 0; i < sd->num_entries; i++)
456 p = put_bytes(p, sd->sizes[i], sd->descriptors[i]);
458 wimlib_assert(p - orig_p == sd->total_length);
459 p = put_zeroes(p, aligned_length - sd->total_length);
461 DEBUG("Successfully wrote security data.");
466 print_acl(const u8 *p, const char *type)
468 const ACL *acl = (const ACL*)p;
469 u8 revision = acl->revision;
470 u16 acl_size = le16_to_cpu(acl->acl_size);
471 u16 ace_count = le16_to_cpu(acl->ace_count);
472 printf(" [%s ACL]\n", type);
473 printf(" Revision = %u\n", revision);
474 printf(" ACL Size = %u\n", acl_size);
475 printf(" ACE Count = %u\n", ace_count);
478 for (u16 i = 0; i < ace_count; i++) {
479 const ACEHeader *hdr = (const ACEHeader*)p;
481 printf(" ACE type = %d\n", hdr->type);
482 printf(" ACE flags = 0x%x\n", hdr->flags);
483 printf(" ACE size = %u\n", hdr->size);
484 const AccessAllowedACE *aaa = (const AccessAllowedACE*)hdr;
485 printf(" ACE mask = %x\n", le32_to_cpu(aaa->mask));
486 printf(" SID start = %u\n", le32_to_cpu(aaa->sid_start));
493 print_sid(const u8 *p, const char *type)
495 const SID *sid = (const SID*)p;
496 printf(" [%s SID]\n", type);
497 printf(" Revision = %u\n", sid->revision);
498 printf(" Subauthority count = %u\n", sid->sub_authority_count);
499 printf(" Identifier authority = ");
500 print_byte_field(sid->identifier_authority,
501 sizeof(sid->identifier_authority));
503 for (u8 i = 0; i < sid->sub_authority_count; i++)
504 printf(" Subauthority %u = %u\n",
505 i, le32_to_cpu(sid->sub_authority[i]));
510 print_security_descriptor(const u8 *p, u64 size)
512 const SecurityDescriptor *sd = (const SecurityDescriptor*)p;
513 u8 revision = sd->revision;
514 u16 control = le16_to_cpu(sd->security_descriptor_control);
515 u32 owner_offset = le32_to_cpu(sd->owner_offset);
516 u32 group_offset = le32_to_cpu(sd->group_offset);
517 u32 sacl_offset = le32_to_cpu(sd->sacl_offset);
518 u32 dacl_offset = le32_to_cpu(sd->dacl_offset);
519 printf("Revision = %u\n", revision);
520 printf("Security Descriptor Control = %#x\n", control);
521 printf("Owner offset = %u\n", owner_offset);
522 printf("Group offset = %u\n", group_offset);
523 printf("System ACL offset = %u\n", sacl_offset);
524 printf("Discretionary ACL offset = %u\n", dacl_offset);
526 if (sd->owner_offset != 0)
527 print_sid(p + owner_offset, "Owner");
528 if (sd->group_offset != 0)
529 print_sid(p + group_offset, "Group");
530 if (sd->sacl_offset != 0)
531 print_acl(p + sacl_offset, "System");
532 if (sd->dacl_offset != 0)
533 print_acl(p + dacl_offset, "Discretionary");
537 * Prints the security data for a WIM file.
540 print_security_data(const struct wim_security_data *sd)
542 wimlib_assert(sd != NULL);
544 puts("[SECURITY DATA]");
545 printf("Length = %"PRIu32" bytes\n", sd->total_length);
546 printf("Number of Entries = %"PRIu32"\n", sd->num_entries);
548 for (u32 i = 0; i < sd->num_entries; i++) {
549 printf("[SecurityDescriptor %"PRIu32", length = %"PRIu64"]\n",
551 print_security_descriptor(sd->descriptors[i], sd->sizes[i]);
558 free_security_data(struct wim_security_data *sd)
561 wimlib_assert(sd->refcnt != 0);
562 if (--sd->refcnt == 0) {
563 u8 **descriptors = sd->descriptors;
564 u32 num_entries = sd->num_entries;
566 while (num_entries--)
567 FREE(*descriptors++);
569 FREE(sd->descriptors);
577 u8 hash[SHA1_HASH_SIZE];
578 struct rb_node rb_node;
582 free_sd_tree(struct rb_node *node)
585 free_sd_tree(node->rb_left);
586 free_sd_tree(node->rb_right);
587 FREE(container_of(node, struct sd_node, rb_node));
591 /* Frees a security descriptor index set. */
593 destroy_sd_set(struct sd_set *sd_set)
595 free_sd_tree(sd_set->rb_root.rb_node);
598 /* Inserts a a new node into the security descriptor index tree. */
600 insert_sd_node(struct sd_set *set, struct sd_node *new)
602 struct rb_root *root = &set->rb_root;
603 struct rb_node **p = &(root->rb_node);
604 struct rb_node *rb_parent = NULL;
607 struct sd_node *this = container_of(*p, struct sd_node, rb_node);
608 int cmp = hashes_cmp(new->hash, this->hash);
612 p = &((*p)->rb_left);
614 p = &((*p)->rb_right);
616 wimlib_assert(0); /* Duplicate SHA1 message digest */
618 rb_link_node(&new->rb_node, rb_parent, p);
619 rb_insert_color(&new->rb_node, root);
622 /* Returns the index of the security descriptor having a SHA1 message digest of
623 * @hash. If not found, return -1. */
625 lookup_sd(struct sd_set *set, const u8 hash[SHA1_HASH_SIZE])
627 struct rb_node *node = set->rb_root.rb_node;
630 struct sd_node *sd_node = container_of(node, struct sd_node, rb_node);
631 int cmp = hashes_cmp(hash, sd_node->hash);
633 node = node->rb_left;
635 node = node->rb_right;
637 return sd_node->security_id;
643 * Adds a security descriptor to the indexed security descriptor set as well as
644 * the corresponding `struct wim_security_data', and returns the new security
645 * ID; or, if there is an existing security descriptor that is the same, return
646 * the security ID for it. If a new security descriptor cannot be allocated,
650 sd_set_add_sd(struct sd_set *sd_set, const char descriptor[], size_t size)
652 u8 hash[SHA1_HASH_SIZE];
658 struct wim_security_data *sd;
660 sha1_buffer((const u8*)descriptor, size, hash);
662 security_id = lookup_sd(sd_set, hash);
663 if (security_id >= 0) /* Identical descriptor already exists */
666 /* Need to add a new security descriptor */
667 new = MALLOC(sizeof(*new));
670 descr_copy = MALLOC(size);
676 memcpy(descr_copy, descriptor, size);
677 new->security_id = sd->num_entries;
678 copy_hash(new->hash, hash);
680 descriptors = REALLOC(sd->descriptors,
681 (sd->num_entries + 1) * sizeof(sd->descriptors[0]));
684 sd->descriptors = descriptors;
685 sizes = REALLOC(sd->sizes,
686 (sd->num_entries + 1) * sizeof(sd->sizes[0]));
690 sd->descriptors[sd->num_entries] = descr_copy;
691 sd->sizes[sd->num_entries] = size;
693 DEBUG("There are now %d security descriptors", sd->num_entries);
694 sd->total_length += size + sizeof(sd->sizes[0]);
695 insert_sd_node(sd_set, new);
696 return new->security_id;