/*
* security.c
*
- * 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.
+ * Read and write the per-WIM-image table of security descriptors.
*/
/*
- * Copyright (C) 2012 Eric Biggers
+ * Copyright (C) 2012, 2013 Eric Biggers
*
* This file is part of wimlib, a library for working with WIM files.
*
*/
#include "wimlib_internal.h"
-#include "io.h"
+#include "buffer_io.h"
#include "security.h"
+
+#define SECURITY_DESCRIPTOR_REVISION 1
+#define SECURITY_DESCRIPTOR_REVISION1 1
+
+/* inherit AceFlags */
+#define OBJECT_INHERIT_ACE 0x01
+#define CONTAINER_INHERIT_ACE 0x02
+#define NO_PROPAGATE_INHERIT_ACE 0x04
+#define INHERIT_ONLY_ACE 0x08
+#define INHERITED_ACE 0x10
+#define VALID_INHERIT_FLAGS 0x1F
+
+#define SE_OWNER_DEFAULTED 0x00000001
+#define SE_GROUP_DEFAULTED 0x00000002
+#define SE_DACL_PRESENT 0x00000004
+#define SE_DACL_DEFAULTED 0x00000008
+#define SE_SACL_PRESENT 0x00000010
+#define SE_SACL_DEFAULTED 0x00000020
+#define SE_DACL_AUTO_INHERIT_REQ 0x00000100
+#define SE_SACL_AUTO_INHERIT_REQ 0x00000200
+#define SE_DACL_AUTO_INHERITED 0x00000400
+#define SE_SACL_AUTO_INHERITED 0x00000800
+#define SE_DACL_PROTECTED 0x00001000
+#define SE_SACL_PROTECTED 0x00002000
+#define SE_RM_CONTROL_VALID 0x00004000
+#define SE_SELF_RELATIVE 0x00008000
+
+/* Flags in access control entries */
+#define DELETE 0x00010000
+#define READ_CONTROL 0x00020000
+#define WRITE_DAC 0x00040000
+#define WRITE_OWNER 0x00080000
+#define SYNCHRONIZE 0x00100000
+#define STANDARD_RIGHTS_REQUIRED 0x000f0000
+
+#define STANDARD_RIGHTS_READ READ_CONTROL
+#define STANDARD_RIGHTS_WRITE READ_CONTROL
+#define STANDARD_RIGHTS_EXECUTE READ_CONTROL
+
+#define STANDARD_RIGHTS_ALL 0x001f0000
+
+#define SPECIFIC_RIGHTS_ALL 0x0000ffff
+
+#define GENERIC_READ 0x80000000
+#define GENERIC_WRITE 0x40000000
+#define GENERIC_EXECUTE 0x20000000
+#define GENERIC_ALL 0x10000000
+
+#define MAXIMUM_ALLOWED 0x02000000
+#define ACCESS_SYSTEM_SECURITY 0x01000000
+
+#define EVENT_QUERY_STATE 0x0001
+#define EVENT_MODIFY_STATE 0x0002
+#define EVENT_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x3)
+
+#define SEMAPHORE_MODIFY_STATE 0x0002
+#define SEMAPHORE_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x3)
+
+#define MUTEX_MODIFY_STATE 0x0001
+#define MUTEX_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x1)
+
+#define JOB_OBJECT_ASSIGN_PROCESS 0x0001
+#define JOB_OBJECT_SET_ATTRIBUTES 0x0002
+#define JOB_OBJECT_QUERY 0x0004
+#define JOB_OBJECT_TERMINATE 0x0008
+#define JOB_OBJECT_SET_SECURITY_ATTRIBUTES 0x0010
+#define JOB_OBJECT_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x1f)
+
+#define TIMER_QUERY_STATE 0x0001
+#define TIMER_MODIFY_STATE 0x0002
+#define TIMER_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x3)
+
+#define PROCESS_TERMINATE 0x0001
+#define PROCESS_CREATE_THREAD 0x0002
+#define PROCESS_VM_OPERATION 0x0008
+#define PROCESS_VM_READ 0x0010
+#define PROCESS_VM_WRITE 0x0020
+#define PROCESS_DUP_HANDLE 0x0040
+#define PROCESS_CREATE_PROCESS 0x0080
+#define PROCESS_SET_QUOTA 0x0100
+#define PROCESS_SET_INFORMATION 0x0200
+#define PROCESS_QUERY_INFORMATION 0x0400
+#define PROCESS_SUSPEND_RESUME 0x0800
+#define PROCESS_QUERY_LIMITED_INFORMATION 0x1000
+#define PROCESS_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0xfff)
+
+#define THREAD_TERMINATE 0x0001
+#define THREAD_SUSPEND_RESUME 0x0002
+#define THREAD_GET_CONTEXT 0x0008
+#define THREAD_SET_CONTEXT 0x0010
+#define THREAD_SET_INFORMATION 0x0020
+#define THREAD_QUERY_INFORMATION 0x0040
+#define THREAD_SET_THREAD_TOKEN 0x0080
+#define THREAD_IMPERSONATE 0x0100
+#define THREAD_DIRECT_IMPERSONATION 0x0200
+#define THREAD_ALL_ACCESS (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x3ff)
+
+#define THREAD_BASE_PRIORITY_LOWRT 15
+#define THREAD_BASE_PRIORITY_MAX 2
+#define THREAD_BASE_PRIORITY_MIN -2
+#define THREAD_BASE_PRIORITY_IDLE -15
+
+/* predefined authority values for SID's (security identifiers) */
+enum sid_authority_value {
+ SECURITY_NULL_SID_AUTHORITY = 0,
+ SECURITY_WORLD_SID_AUTHORITY = 1,
+ SECURITY_LOCAL_SID_AUTHORITY = 2,
+ SECURITY_CREATOR_SID_AUTHORITY = 3,
+ SECURITY_NON_UNIQUE_AUTHORITY = 4,
+ SECURITY_NT_AUTHORITY = 5,
+};
+
+/* local administrators group */
+#define SECURITY_BUILTIN_DOMAIN_RID 32
+#define DOMAIN_ALIAS_RID_ADMINS 544
+
+/* See ACEHeader. */
+enum ace_type {
+ ACCESS_ALLOWED_ACE_TYPE = 0,
+ ACCESS_DENIED_ACE_TYPE = 1,
+ SYSTEM_AUDIT_ACE_TYPE = 2,
+};
+
+/* At the start of each type of access control entry. */
+typedef struct {
+ /* enum ace_type, specifies what type of ACE this is. */
+ u8 type;
+
+ /* bitwise OR of the inherit ACE flags #defined above */
+ u8 flags;
+
+ /* Size of the access control entry. */
+ u8 size;
+} ACEHeader;
+
+/* Grants rights to a user or group */
+typedef struct {
+ ACEHeader hdr;
+ u32 mask;
+ u32 sid_start;
+} AccessAllowedACE;
+
+/* Denies rights to a user or group */
+typedef struct {
+ ACEHeader hdr;
+ u32 mask;
+ u32 sid_start;
+} AccessDeniedACE;
+
+typedef struct {
+ ACEHeader hdr;
+ u32 mask;
+ u32 sid_start;
+} SystemAuditACE;
+
+
+/* Header of an access control list. */
+typedef struct {
+ /* ACL_REVISION or ACL_REVISION_DS */
+ u8 revision;
+
+ /* padding */
+ u8 sbz1;
+
+ /* Total size of the ACL, including all access control entries */
+ u16 acl_size;
+
+ /* Number of access control entry structures that follow the ACL
+ * structure. */
+ u16 ace_count;
+
+ /* padding */
+ u16 sbz2;
+} ACL;
+
+/* A structure used to identify users or groups. */
+typedef struct {
+
+ /* example: 0x1 */
+ u8 revision;
+ u8 sub_authority_count;
+
+ /* Identifies the authority that issued the SID. Can be, but does not
+ * have to be, one of enum sid_authority_value */
+ u8 identifier_authority[6];
+
+ u32 sub_authority[0];
+} SID;
+
+
+typedef struct {
+ /* Example: 0x1 */
+ u8 revision;
+ /* Example: 0x0 */
+ u8 sbz1;
+ /* Example: 0x4149 */
+ u16 security_descriptor_control;
+
+ /* Offset of a SID structure in the security descriptor. */
+ /* Example: 0x14 */
+ u32 owner_offset;
+
+ /* Offset of a SID structure in the security descriptor. */
+ /* Example: 0x24 */
+ u32 group_offset;
+
+ /* Offset of an ACL structure in the security descriptor. */
+ /* System ACL. */
+ /* Example: 0x00 */
+ u32 sacl_offset;
+
+ /* Offset of an ACL structure in the security descriptor. */
+ /* Discretionary ACL. */
+ /* Example: 0x34 */
+ u32 dacl_offset;
+} SecurityDescriptor;
+
/*
* This is a hack to work around a problem in libntfs-3g. libntfs-3g validates
* security descriptors with a function named ntfs_valid_descr().
* 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
+ * entries anyway; however this ensures that that the security descriptors pass
* the validation in libntfs-3g.
*/
-static void empty_sacl_fixup(char *descr, u64 *size_p)
+static void empty_sacl_fixup(u8 *descr, u64 *size_p)
{
if (*size_p >= sizeof(SecurityDescriptor)) {
SecurityDescriptor *sd = (SecurityDescriptor*)descr;
*
* @metadata_resource: An array that contains the uncompressed metadata
* resource for the WIM file.
- * @metadata_resource_len: The length of @metadata_resource. It MUST be at
+ * @metadata_resource_len: The length of @metadata_resource. It must be at
* least 8 bytes.
* @sd_p: A pointer to a pointer to a wim_security_data structure that
* will be filled in with a pointer to a new wim_security_data
int ret;
u64 total_len;
+ wimlib_assert(metadata_resource_len >= 8);
+
+ /*
+ * Sorry this function is excessively complicated--- I'm just being
+ * extremely careful about integer overflows.
+ */
+
sd = MALLOC(sizeof(struct wim_security_data));
if (!sd) {
ERROR("Out of memory");
p = get_u32(p, &sd->total_length);
p = get_u32(p, (u32*)&sd->num_entries);
- if (sd->num_entries > 0x7fffffff) {
+ /* The security_id field of each dentry is a signed 32-bit integer, so
+ * the possible indices into the security descriptors table are 0
+ * through 0x7fffffff. Which means 0x80000000 security descriptors
+ * maximum. Not like you should ever have anywhere close to that many
+ * security descriptors! */
+ if (sd->num_entries > 0x80000000) {
ERROR("Security data has too many entries!");
- ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
- goto out_free_sd;
+ goto out_invalid_sd;
}
/* Verify the listed total length of the security 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_SECURITY_DATA;
- goto out_free_sd;
+ goto out_invalid_sd;
}
DEBUG("Reading security data: %u entries, length = %u",
sd->num_entries, sd->total_length);
if (sd->num_entries == 0) {
- /* No security data. */
- total_len = 8;
- goto out;
+ /* No security descriptors. We allow the total_length field to
+ * be either 8 (which is correct, since there are always 2
+ * 32-bit integers) or 0. */
+ if (sd->total_length != 0 && sd->total_length != 8) {
+ ERROR("Invalid security data length (%u): expected 0 or 8",
+ sd->total_length);
+ goto out_invalid_sd;
+ }
+ sd->total_length = 8;
+ goto out_return_sd;
}
u64 sizes_size = (u64)sd->num_entries * sizeof(u64);
u64 size_no_descriptors = 8 + sizes_size;
if (size_no_descriptors > (u64)sd->total_length) {
ERROR("Security data total length of %u is too short because "
- "there must be at least %"PRIu64" bytes of security data",
+ "there seem to be at least %"PRIu64" bytes of security data",
sd->total_length, 8 + sizes_size);
- ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
- goto out_free_sd;
+ goto out_invalid_sd;
}
+
sd->sizes = MALLOC(sizes_size);
if (!sd->sizes) {
ret = WIMLIB_ERR_NOMEM;
"(current total length = %"PRIu64", security "
"descriptor size = %"PRIu64")",
total_len, sd->sizes[i]);
- ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
- goto out_free_sd;
+ goto out_invalid_sd;
}
total_len += sd->sizes[i];
+ /* This check ensures that the descriptor size fits in a 32 bit
+ * integer. Because if it didn't, the total length would come
+ * out bigger than sd->total_length, which is a 32 bit integer.
+ * */
if (total_len > (u64)sd->total_length) {
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_SECURITY_DATA;
- goto out_free_sd;
+ "because there seem to be at least %"PRIu64" "
+ "bytes of security data",
+ sd->total_length, total_len);
+ goto out_invalid_sd;
}
sd->descriptors[i] = MALLOC(sd->sizes[i]);
if (!sd->descriptors[i]) {
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;
+ wimlib_assert(total_len <= 0xffffffff);
+ if (((total_len + 7) & ~7) != ((sd->total_length + 7) & ~7)) {
+ ERROR("Expected security data total length = %u, but "
+ "calculated %u", sd->total_length, (unsigned)total_len);
+ goto out_invalid_sd;
+ }
+ sd->total_length = total_len;
+out_return_sd:
*sd_p = sd;
return 0;
+out_invalid_sd:
+ ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
out_free_sd:
free_security_data(sd);
return ret;
printf(" ACE Count = %u\n", ace_count);
p += sizeof(ACL);
- for (uint i = 0; i < acl->ace_count; i++) {
+ for (u16 i = 0; i < ace_count; i++) {
const ACEHeader *hdr = (const ACEHeader*)p;
printf(" [ACE]\n");
printf(" ACE type = %d\n", hdr->type);
print_byte_field(sid->identifier_authority,
sizeof(sid->identifier_authority));
putchar('\n');
- for (uint i = 0; i < sid->sub_authority_count; i++)
+ for (u8 i = 0; i < sid->sub_authority_count; i++)
printf(" Subauthority %u = %u\n",
i, le32_to_cpu(sid->sub_authority[i]));
putchar('\n');
void free_security_data(struct wim_security_data *sd)
{
- if (!sd)
- return;
- wimlib_assert(sd->refcnt != 0);
- if (--sd->refcnt == 0) {
- u8 **descriptors = sd->descriptors;
- u32 num_entries = sd->num_entries;
- if (descriptors)
- while (num_entries--)
- FREE(*descriptors++);
- FREE(sd->sizes);
- FREE(sd->descriptors);
- FREE(sd);
+ if (sd) {
+ wimlib_assert(sd->refcnt != 0);
+ if (--sd->refcnt == 0) {
+ u8 **descriptors = sd->descriptors;
+ u32 num_entries = sd->num_entries;
+ if (descriptors)
+ while (num_entries--)
+ FREE(*descriptors++);
+ FREE(sd->sizes);
+ FREE(sd->descriptors);
+ FREE(sd);
+ }
+ }
+}
+
+#if defined(WITH_NTFS_3G) || defined(__CYGWIN__) || defined(__WIN32__)
+struct sd_node {
+ int security_id;
+ u8 hash[SHA1_HASH_SIZE];
+ struct rb_node rb_node;
+};
+
+static void free_sd_tree(struct rb_node *node)
+{
+ if (node) {
+ free_sd_tree(node->rb_left);
+ free_sd_tree(node->rb_right);
+ FREE(container_of(node, struct sd_node, rb_node));
+ }
+}
+
+/* Frees a security descriptor index set. */
+void destroy_sd_set(struct sd_set *sd_set)
+{
+ free_sd_tree(sd_set->rb_root.rb_node);
+}
+
+/* Inserts a a new node into the security descriptor index tree. */
+static void insert_sd_node(struct sd_set *set, struct sd_node *new)
+{
+ struct rb_root *root = &set->rb_root;
+ struct rb_node **p = &(root->rb_node);
+ struct rb_node *rb_parent = NULL;
+
+ while (*p) {
+ struct sd_node *this = container_of(*p, struct sd_node, rb_node);
+ int cmp = hashes_cmp(new->hash, this->hash);
+
+ rb_parent = *p;
+ if (cmp < 0)
+ p = &((*p)->rb_left);
+ else if (cmp > 0)
+ p = &((*p)->rb_right);
+ else
+ wimlib_assert(0); /* Duplicate SHA1 message digest */
}
+ rb_link_node(&new->rb_node, rb_parent, p);
+ rb_insert_color(&new->rb_node, root);
+}
+
+/* Returns the index of the security descriptor having a SHA1 message digest of
+ * @hash. If not found, return -1. */
+int lookup_sd(struct sd_set *set, const u8 hash[SHA1_HASH_SIZE])
+{
+ struct rb_node *node = set->rb_root.rb_node;
+
+ while (node) {
+ struct sd_node *sd_node = container_of(node, struct sd_node, rb_node);
+ int cmp = hashes_cmp(hash, sd_node->hash);
+ if (cmp < 0)
+ node = node->rb_left;
+ else if (cmp > 0)
+ node = node->rb_right;
+ else
+ return sd_node->security_id;
+ }
+ return -1;
+}
+
+/*
+ * Adds a security descriptor to the indexed security descriptor set as well as
+ * the corresponding `struct wim_security_data', and returns the new security
+ * ID; or, if there is an existing security descriptor that is the same, return
+ * the security ID for it. If a new security descriptor cannot be allocated,
+ * return -1.
+ */
+int sd_set_add_sd(struct sd_set *sd_set, const char descriptor[],
+ size_t size)
+{
+ u8 hash[SHA1_HASH_SIZE];
+ int security_id;
+ struct sd_node *new;
+ u8 **descriptors;
+ u64 *sizes;
+ u8 *descr_copy;
+ struct wim_security_data *sd;
+
+ sha1_buffer((const u8*)descriptor, size, hash);
+
+ security_id = lookup_sd(sd_set, hash);
+ if (security_id >= 0) /* Identical descriptor already exists */
+ return security_id;
+
+ /* Need to add a new security descriptor */
+ new = MALLOC(sizeof(*new));
+ if (!new)
+ goto out;
+ descr_copy = MALLOC(size);
+ if (!descr_copy)
+ goto out_free_node;
+
+ sd = sd_set->sd;
+
+ memcpy(descr_copy, descriptor, size);
+ new->security_id = sd->num_entries;
+ copy_hash(new->hash, hash);
+
+ descriptors = REALLOC(sd->descriptors,
+ (sd->num_entries + 1) * sizeof(sd->descriptors[0]));
+ if (!descriptors)
+ goto out_free_descr;
+ sd->descriptors = descriptors;
+ sizes = REALLOC(sd->sizes,
+ (sd->num_entries + 1) * sizeof(sd->sizes[0]));
+ if (!sizes)
+ goto out_free_descr;
+ sd->sizes = sizes;
+ sd->descriptors[sd->num_entries] = descr_copy;
+ sd->sizes[sd->num_entries] = size;
+ sd->num_entries++;
+ DEBUG("There are now %d security descriptors", sd->num_entries);
+ sd->total_length += size + sizeof(sd->sizes[0]);
+ insert_sd_node(sd_set, new);
+ return new->security_id;
+out_free_descr:
+ FREE(descr_copy);
+out_free_node:
+ FREE(new);
+out:
+ return -1;
}
+#endif /* WITH_NTFS_3G || __CYGWIN__ || __WIN32__ */
git://wimlib.net / wimlib / blobdiff