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 if (*size_p >= sizeof(SecurityDescriptor)) {
262 SecurityDescriptor *sd = (SecurityDescriptor*)descr;
263 u32 sacl_offset = le32_to_cpu(sd->sacl_offset);
264 if (sacl_offset == *size_p - sizeof(ACL)) {
265 sd->sacl_offset = cpu_to_le32(0);
266 *size_p -= sizeof(ACL);
272 * Reads the security data from the metadata resource.
274 * @metadata_resource: An array that contains the uncompressed metadata
275 * resource for the WIM file.
276 * @metadata_resource_len: The length of @metadata_resource. It must be at
278 * @sd_p: A pointer to a pointer to a wim_security_data structure that
279 * will be filled in with a pointer to a new wim_security_data
280 * structure on success.
282 * Note: There is no `offset' argument because the security data is located at
283 * the beginning of the metadata resource.
286 read_security_data(const u8 metadata_resource[], u64 metadata_resource_len,
287 struct wim_security_data **sd_p)
289 struct wim_security_data *sd;
294 wimlib_assert(metadata_resource_len >= 8);
297 * Sorry this function is excessively complicated--- I'm just being
298 * extremely careful about integer overflows.
301 sd = MALLOC(sizeof(struct wim_security_data));
303 ERROR("Out of memory");
304 return WIMLIB_ERR_NOMEM;
307 sd->descriptors = NULL;
310 p = metadata_resource;
311 p = get_u32(p, &sd->total_length);
312 p = get_u32(p, (u32*)&sd->num_entries);
314 /* The security_id field of each dentry is a signed 32-bit integer, so
315 * the possible indices into the security descriptors table are 0
316 * through 0x7fffffff. Which means 0x80000000 security descriptors
317 * maximum. Not like you should ever have anywhere close to that many
318 * security descriptors! */
319 if (sd->num_entries > 0x80000000) {
320 ERROR("Security data has too many entries!");
324 /* Verify the listed total length of the security data is big enough to
325 * include the sizes array, verify that the file data is big enough to
326 * include it as well, then allocate the array of sizes.
328 * Note: The total length of the security data must fit in a 32-bit
329 * integer, even though each security descriptor size is a 64-bit
330 * integer. This is stupid, and we need to be careful not to actually
331 * let the security descriptor sizes be over 0xffffffff. */
332 if ((u64)sd->total_length > metadata_resource_len) {
333 ERROR("Security data total length (%u) is bigger than the "
334 "metadata resource length (%"PRIu64")",
335 sd->total_length, metadata_resource_len);
339 DEBUG("Reading security data: %u entries, length = %u",
340 sd->num_entries, sd->total_length);
342 if (sd->num_entries == 0) {
343 /* No security descriptors. We allow the total_length field to
344 * be either 8 (which is correct, since there are always 2
345 * 32-bit integers) or 0. */
346 if (sd->total_length != 0 && sd->total_length != 8) {
347 ERROR("Invalid security data length (%u): expected 0 or 8",
351 sd->total_length = 8;
355 u64 sizes_size = (u64)sd->num_entries * sizeof(u64);
356 u64 size_no_descriptors = 8 + sizes_size;
357 if (size_no_descriptors > (u64)sd->total_length) {
358 ERROR("Security data total length of %u is too short because "
359 "there seem to be at least %"PRIu64" bytes of security data",
360 sd->total_length, 8 + sizes_size);
364 sd->sizes = MALLOC(sizes_size);
366 ret = WIMLIB_ERR_NOMEM;
370 /* Copy the sizes array in from the file data. */
371 p = get_bytes(p, sizes_size, sd->sizes);
372 array_le64_to_cpu(sd->sizes, sd->num_entries);
374 /* Allocate the array of pointers to descriptors, and read them in. */
375 sd->descriptors = CALLOC(sd->num_entries, sizeof(u8*));
376 if (!sd->descriptors) {
377 ERROR("Out of memory while allocating security "
379 ret = WIMLIB_ERR_NOMEM;
382 total_len = size_no_descriptors;
384 for (u32 i = 0; i < sd->num_entries; i++) {
385 /* Watch out for huge security descriptor sizes that could
386 * overflow the total length and wrap it around. */
387 if (total_len + sd->sizes[i] < total_len) {
388 ERROR("Caught overflow in security descriptor lengths "
389 "(current total length = %"PRIu64", security "
390 "descriptor size = %"PRIu64")",
391 total_len, sd->sizes[i]);
394 total_len += sd->sizes[i];
395 /* This check ensures that the descriptor size fits in a 32 bit
396 * integer. Because if it didn't, the total length would come
397 * out bigger than sd->total_length, which is a 32 bit integer.
399 if (total_len > (u64)sd->total_length) {
400 ERROR("Security data total length of %u is too short "
401 "because there seem to be at least %"PRIu64" "
402 "bytes of security data",
403 sd->total_length, total_len);
406 sd->descriptors[i] = MALLOC(sd->sizes[i]);
407 if (!sd->descriptors[i]) {
408 ERROR("Out of memory while allocating security "
410 ret = WIMLIB_ERR_NOMEM;
413 p = get_bytes(p, sd->sizes[i], sd->descriptors[i]);
414 empty_sacl_fixup(sd->descriptors[i], &sd->sizes[i]);
416 wimlib_assert(total_len <= 0xffffffff);
417 if (((total_len + 7) & ~7) != ((sd->total_length + 7) & ~7)) {
418 ERROR("Expected security data total length = %u, but "
419 "calculated %u", sd->total_length, (unsigned)total_len);
422 sd->total_length = total_len;
427 ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
429 free_security_data(sd);
434 * Writes security data to an in-memory buffer.
437 write_security_data(const struct wim_security_data *sd, u8 *p)
439 DEBUG("Writing security data (total_length = %"PRIu32", num_entries "
440 "= %"PRIu32")", sd->total_length, sd->num_entries);
442 u32 aligned_length = (sd->total_length + 7) & ~7;
445 p = put_u32(p, aligned_length);
446 p = put_u32(p, sd->num_entries);
448 for (u32 i = 0; i < sd->num_entries; i++)
449 p = put_u64(p, sd->sizes[i]);
451 for (u32 i = 0; i < sd->num_entries; i++)
452 p = put_bytes(p, sd->sizes[i], sd->descriptors[i]);
454 wimlib_assert(p - orig_p == sd->total_length);
455 p = put_zeroes(p, aligned_length - sd->total_length);
457 DEBUG("Successfully wrote security data.");
462 print_acl(const u8 *p, const char *type)
464 const ACL *acl = (const ACL*)p;
465 u8 revision = acl->revision;
466 u16 acl_size = le16_to_cpu(acl->acl_size);
467 u16 ace_count = le16_to_cpu(acl->ace_count);
468 printf(" [%s ACL]\n", type);
469 printf(" Revision = %u\n", revision);
470 printf(" ACL Size = %u\n", acl_size);
471 printf(" ACE Count = %u\n", ace_count);
474 for (u16 i = 0; i < ace_count; i++) {
475 const ACEHeader *hdr = (const ACEHeader*)p;
477 printf(" ACE type = %d\n", hdr->type);
478 printf(" ACE flags = 0x%x\n", hdr->flags);
479 printf(" ACE size = %u\n", hdr->size);
480 const AccessAllowedACE *aaa = (const AccessAllowedACE*)hdr;
481 printf(" ACE mask = %x\n", le32_to_cpu(aaa->mask));
482 printf(" SID start = %u\n", le32_to_cpu(aaa->sid_start));
489 print_sid(const u8 *p, const char *type)
491 const SID *sid = (const SID*)p;
492 printf(" [%s SID]\n", type);
493 printf(" Revision = %u\n", sid->revision);
494 printf(" Subauthority count = %u\n", sid->sub_authority_count);
495 printf(" Identifier authority = ");
496 print_byte_field(sid->identifier_authority,
497 sizeof(sid->identifier_authority));
499 for (u8 i = 0; i < sid->sub_authority_count; i++)
500 printf(" Subauthority %u = %u\n",
501 i, le32_to_cpu(sid->sub_authority[i]));
506 print_security_descriptor(const u8 *p, u64 size)
508 const SecurityDescriptor *sd = (const SecurityDescriptor*)p;
509 u8 revision = sd->revision;
510 u16 control = le16_to_cpu(sd->security_descriptor_control);
511 u32 owner_offset = le32_to_cpu(sd->owner_offset);
512 u32 group_offset = le32_to_cpu(sd->group_offset);
513 u32 sacl_offset = le32_to_cpu(sd->sacl_offset);
514 u32 dacl_offset = le32_to_cpu(sd->dacl_offset);
515 printf("Revision = %u\n", revision);
516 printf("Security Descriptor Control = %#x\n", control);
517 printf("Owner offset = %u\n", owner_offset);
518 printf("Group offset = %u\n", group_offset);
519 printf("System ACL offset = %u\n", sacl_offset);
520 printf("Discretionary ACL offset = %u\n", dacl_offset);
522 if (sd->owner_offset != 0)
523 print_sid(p + owner_offset, "Owner");
524 if (sd->group_offset != 0)
525 print_sid(p + group_offset, "Group");
526 if (sd->sacl_offset != 0)
527 print_acl(p + sacl_offset, "System");
528 if (sd->dacl_offset != 0)
529 print_acl(p + dacl_offset, "Discretionary");
533 * Prints the security data for a WIM file.
536 print_security_data(const struct wim_security_data *sd)
538 wimlib_assert(sd != NULL);
540 puts("[SECURITY DATA]");
541 printf("Length = %"PRIu32" bytes\n", sd->total_length);
542 printf("Number of Entries = %"PRIu32"\n", sd->num_entries);
544 for (u32 i = 0; i < sd->num_entries; i++) {
545 printf("[SecurityDescriptor %"PRIu32", length = %"PRIu64"]\n",
547 print_security_descriptor(sd->descriptors[i], sd->sizes[i]);
554 free_security_data(struct wim_security_data *sd)
557 wimlib_assert(sd->refcnt != 0);
558 if (--sd->refcnt == 0) {
559 u8 **descriptors = sd->descriptors;
560 u32 num_entries = sd->num_entries;
562 while (num_entries--)
563 FREE(*descriptors++);
565 FREE(sd->descriptors);
571 /* The security tree stuff is only needed when NTFS capture is supported, either
572 * through NTFS-3G or through a native Windows build. */
573 #if defined(WITH_NTFS_3G) || defined(__WIN32__)
576 u8 hash[SHA1_HASH_SIZE];
577 struct rb_node rb_node;
581 free_sd_tree(struct rb_node *node)
584 free_sd_tree(node->rb_left);
585 free_sd_tree(node->rb_right);
586 FREE(container_of(node, struct sd_node, rb_node));
590 /* Frees a security descriptor index set. */
592 destroy_sd_set(struct sd_set *sd_set)
594 free_sd_tree(sd_set->rb_root.rb_node);
597 /* Inserts a a new node into the security descriptor index tree. */
599 insert_sd_node(struct sd_set *set, struct sd_node *new)
601 struct rb_root *root = &set->rb_root;
602 struct rb_node **p = &(root->rb_node);
603 struct rb_node *rb_parent = NULL;
606 struct sd_node *this = container_of(*p, struct sd_node, rb_node);
607 int cmp = hashes_cmp(new->hash, this->hash);
611 p = &((*p)->rb_left);
613 p = &((*p)->rb_right);
615 wimlib_assert(0); /* Duplicate SHA1 message digest */
617 rb_link_node(&new->rb_node, rb_parent, p);
618 rb_insert_color(&new->rb_node, root);
621 /* Returns the index of the security descriptor having a SHA1 message digest of
622 * @hash. If not found, return -1. */
624 lookup_sd(struct sd_set *set, const u8 hash[SHA1_HASH_SIZE])
626 struct rb_node *node = set->rb_root.rb_node;
629 struct sd_node *sd_node = container_of(node, struct sd_node, rb_node);
630 int cmp = hashes_cmp(hash, sd_node->hash);
632 node = node->rb_left;
634 node = node->rb_right;
636 return sd_node->security_id;
642 * Adds a security descriptor to the indexed security descriptor set as well as
643 * the corresponding `struct wim_security_data', and returns the new security
644 * ID; or, if there is an existing security descriptor that is the same, return
645 * the security ID for it. If a new security descriptor cannot be allocated,
649 sd_set_add_sd(struct sd_set *sd_set, const char descriptor[], size_t size)
651 u8 hash[SHA1_HASH_SIZE];
657 struct wim_security_data *sd;
659 sha1_buffer((const u8*)descriptor, size, hash);
661 security_id = lookup_sd(sd_set, hash);
662 if (security_id >= 0) /* Identical descriptor already exists */
665 /* Need to add a new security descriptor */
666 new = MALLOC(sizeof(*new));
669 descr_copy = MALLOC(size);
675 memcpy(descr_copy, descriptor, size);
676 new->security_id = sd->num_entries;
677 copy_hash(new->hash, hash);
679 descriptors = REALLOC(sd->descriptors,
680 (sd->num_entries + 1) * sizeof(sd->descriptors[0]));
683 sd->descriptors = descriptors;
684 sizes = REALLOC(sd->sizes,
685 (sd->num_entries + 1) * sizeof(sd->sizes[0]));
689 sd->descriptors[sd->num_entries] = descr_copy;
690 sd->sizes[sd->num_entries] = size;
692 DEBUG("There are now %d security descriptors", sd->num_entries);
693 sd->total_length += size + sizeof(sd->sizes[0]);
694 insert_sd_node(sd_set, new);
695 return new->security_id;
703 #endif /* WITH_NTFS_3G || __WIN32__ */