/*
* 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 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.
*
* 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 "wimlib_internal.h"
-#include "io.h"
-#include "security.h"
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "wimlib/assert.h"
+#include "wimlib/endianness.h"
+#include "wimlib/error.h"
+#include "wimlib/security.h"
+#include "wimlib/sha1.h"
+#include "wimlib/util.h"
+
+/* At the start of each type of access control entry. */
+typedef struct _ACE_HEADER {
+ /* 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. */
+ le16 size;
+} _packed_attribute ACE_HEADER;
+
+/* Grants rights to a user or group */
+typedef struct _ACCESS_ALLOWED_ACE {
+ ACE_HEADER hdr;
+ le32 mask;
+ le32 sid_start;
+} _packed_attribute ACCESS_ALLOWED_ACE;
+
+/* Denies rights to a user or group */
+typedef struct _ACCESS_DENIED_ACE {
+ ACE_HEADER hdr;
+ le32 mask;
+ le32 sid_start;
+} _packed_attribute ACCESS_DENIED_ACE;
+
+typedef struct _SYSTEM_AUDIT_ACE {
+ ACE_HEADER hdr;
+ le32 mask;
+ le32 sid_start;
+} _packed_attribute SYSTEM_AUDIT_ACE;
+
+
+/* Header of an access control list. */
+typedef struct _ACL {
+ /* ACL_REVISION or ACL_REVISION_DS */
+ u8 revision;
+
+ /* padding */
+ u8 sbz1;
+
+ /* Total size of the ACL, including all access control entries */
+ le16 acl_size;
+
+ /* Number of access control entry structures that follow the ACL
+ * structure. */
+ le16 ace_count;
+
+ /* padding */
+ le16 sbz2;
+} _packed_attribute ACL;
+
+/* A structure used to identify users or groups. */
+typedef struct _SID {
+
+ /* 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];
+
+ le32 sub_authority[];
+} _packed_attribute SID;
+
+typedef struct _SECURITY_DESCRIPTOR_RELATIVE {
+ /* Example: 0x1 */
+ u8 revision;
+ /* Example: 0x0 */
+ u8 sbz1;
+
+ /* Example: 0x4149 */
+ le16 security_descriptor_control;
+
+ /* Offset of a SID structure in the security descriptor. */
+ /* Example: 0x14 */
+ le32 owner_offset;
+
+ /* Offset of a SID structure in the security descriptor. */
+ /* Example: 0x24 */
+ le32 group_offset;
+
+ /* Offset of an ACL structure in the security descriptor. */
+ /* System ACL. */
+ /* Example: 0x00 */
+ le32 sacl_offset;
+
+ /* Offset of an ACL structure in the security descriptor. */
+ /* Discretionary ACL. */
+ /* Example: 0x34 */
+ le32 dacl_offset;
+} _packed_attribute SECURITY_DESCRIPTOR_RELATIVE;
+
+struct wim_security_data_disk {
+ le32 total_length;
+ le32 num_entries;
+ le64 sizes[];
+} _packed_attribute;
+
+/*
+ * 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 this ensures that that the security descriptors pass
+ * the validation in libntfs-3g.
+ */
+static void
+empty_sacl_fixup(SECURITY_DESCRIPTOR_RELATIVE *descr, size_t *size_p)
+{
+ /* No-op if no NTFS-3g support, or if NTFS-3g is version 2013 or later
+ * */
+#if defined(WITH_NTFS_3G) && !defined(HAVE_NTFS_MNT_RDONLY)
+ if (*size_p >= sizeof(SECURITY_DESCRIPTOR_RELATIVE)) {
+ u32 sacl_offset = le32_to_cpu(descr->sacl_offset);
+ if (sacl_offset == *size_p - sizeof(ACL)) {
+ descr->sacl_offset = cpu_to_le32(0);
+ *size_p -= sizeof(ACL);
+ }
+ }
+#endif
+}
-#ifdef ENABLE_SECURITY_DATA
+struct wim_security_data *
+new_wim_security_data(void)
+{
+ return CALLOC(1, sizeof(struct wim_security_data));
+}
-/*
- * Reads the security data from the metadata resource.
+/*
+ * Reads the security data from the metadata resource of a WIM image.
*
* @metadata_resource: An array that contains the uncompressed metadata
- * resource for the WIM file.
- * @metadata_resource_len: The length of @metadata_resource.
- * @sd_p: A pointer to a pointer wim_security_data structure that will be filled
- * in with a pointer to a new wim_security_data structure on success.
+ * resource for the WIM image.
+ * @metadata_resource_len: The length of @metadata_resource. It must be at
+ * least 8 bytes.
+ * @sd_ret: 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
+ * structure containing the security data on success.
*
* Note: There is no `offset' argument because the security data is located at
* the beginning of the metadata resource.
+ *
+ * Possible errors include:
+ * WIMLIB_ERR_NOMEM
+ * WIMLIB_ERR_INVALID_SECURITY_DATA
*/
-int read_security_data(const u8 metadata_resource[],
- u64 metadata_resource_len, struct wim_security_data **sd_p)
+int
+read_wim_security_data(const u8 metadata_resource[], size_t metadata_resource_len,
+ struct wim_security_data **sd_ret)
{
struct wim_security_data *sd;
- const u8 *p;
+ int ret;
+ u64 total_len;
u64 sizes_size;
+ u64 size_no_descriptors;
+ const struct wim_security_data_disk *sd_disk;
+ const u8 *p;
- if (metadata_resource_len < 8) {
- ERROR("Not enough space in %"PRIu64"-byte file resource for "
- "security data!\n", metadata_resource_len);
- return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
- }
- sd = MALLOC(sizeof(struct wim_security_data));
+ wimlib_assert(metadata_resource_len >= 8);
+
+ sd = new_wim_security_data();
if (!sd)
- return WIMLIB_ERR_NOMEM;
- p = get_u32(metadata_resource, &sd->total_length);
- p = get_u32(p, &sd->num_entries);
+ goto out_of_memory;
+
+ sd_disk = (const struct wim_security_data_disk*)metadata_resource;
+ sd->total_length = le32_to_cpu(sd_disk->total_length);
+ sd->num_entries = le32_to_cpu(sd_disk->num_entries);
+
+ DEBUG("Reading security data: num_entries=%u, total_length=%u",
+ sd->num_entries, sd->total_length);
+
+ /* Length field of 0 is a special case that really means length
+ * of 8. */
+ if (sd->total_length == 0)
+ sd->total_length = 8;
+
+ /* 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)
+ goto out_invalid_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
- * include it as well, then allocate the array of sizes. */
- sizes_size = sd->num_entries * sizeof(u64);
+ * include it as well, then allocate the array of sizes.
+ *
+ * Note: The total length of the security data must fit in a 32-bit
+ * integer, even though each security descriptor size is a 64-bit
+ * integer. This is stupid, and we need to be careful not to actually
+ * let the security descriptor sizes be over 0xffffffff. */
+ if (sd->total_length > metadata_resource_len)
+ goto out_invalid_sd;
- DEBUG("Reading security data with %u entries\n", sd->num_entries);
+ sizes_size = (u64)sd->num_entries * sizeof(u64);
+ size_no_descriptors = 8 + sizes_size;
+ if (size_no_descriptors > sd->total_length)
+ goto out_invalid_sd;
- if (sd->num_entries == 0) {
- FREE(sd);
- return 0;
- }
+ total_len = size_no_descriptors;
- u64 size_no_descriptors = 8 + sizes_size;
- if (size_no_descriptors > sd->total_length) {
- ERROR("Security data total length of %"PRIu64" is too short because\n"
- "there must be at least %"PRIu64" bytes of security "
- "data!\n", sd->total_length,
- 8 + sizes_size);
- FREE(sd);
- return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
- }
- if (size_no_descriptors > metadata_resource_len) {
- ERROR("File resource of %"PRIu64" bytes is not big enough\n"
- "to hold security data of at least %"PRIu64" "
- "bytes!\n", metadata_resource_len, size_no_descriptors);
- FREE(sd);
- return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
- }
+ /* Return immediately if no security descriptors. */
+ if (sd->num_entries == 0)
+ goto out_align_total_length;
+
+ /* Allocate a new buffer for the sizes array */
sd->sizes = MALLOC(sizes_size);
- if (!sd->sizes) {
- FREE(sd);
- return WIMLIB_ERR_NOMEM;
+ if (!sd->sizes)
+ goto out_of_memory;
+
+ /* Copy the sizes array into the new buffer */
+ for (u32 i = 0; i < sd->num_entries; i++) {
+ sd->sizes[i] = le64_to_cpu(sd_disk->sizes[i]);
+ if (sd->sizes[i] > 0xffffffff)
+ goto out_invalid_sd;
}
- /* Copy the sizes array in from the file data. */
- p = get_bytes(p, sizes_size, sd->sizes);
- array_to_le64(sd->sizes, sd->num_entries);
+ p = (const u8*)sd_disk + size_no_descriptors;
- /* Allocate the array of pointers to descriptors, and read them in. */
- sd->descriptors = CALLOC(sd->num_entries, sizeof(u8*));
- if (!sd->descriptors) {
- FREE(sd);
- FREE(sd->sizes);
- return WIMLIB_ERR_NOMEM;
- }
- u64 total_len = size_no_descriptors;
+ /* Allocate the array of pointers to the security descriptors, then read
+ * them into separate buffers. */
+ sd->descriptors = CALLOC(sd->num_entries, sizeof(sd->descriptors[0]));
+ if (!sd->descriptors)
+ goto out_of_memory;
- for (uint i = 0; i < sd->num_entries; i++) {
+ for (u32 i = 0; i < sd->num_entries; i++) {
+ if (sd->sizes[i] == 0)
+ continue;
total_len += sd->sizes[i];
- if (total_len > sd->total_length) {
- ERROR("Security data total length of %"PRIu64" is too "
- "short because there are at least %"PRIu64" "
- "bytes of security data!\n",
- sd->total_length, total_len);
- free_security_data(sd);
- return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
- }
- if (total_len > metadata_resource_len) {
- ERROR("File resource of %"PRIu64" bytes is not big enough "
- "to hold security data of at least %"PRIu64" "
- "bytes!\n", metadata_resource_len, total_len);
- free_security_data(sd);
- return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
- }
- sd->descriptors[i] = MALLOC(sd->sizes[i]);
- if (!sd->descriptors[i]) {
- free_security_data(sd);
- return WIMLIB_ERR_NOMEM;
- }
- p = get_bytes(p, sd->sizes[i], sd->descriptors[i]);
+ if (total_len > (u64)sd->total_length)
+ goto out_invalid_sd;
+ sd->descriptors[i] = memdup(p, sd->sizes[i]);
+ if (!sd->descriptors[i])
+ goto out_of_memory;
+ p += sd->sizes[i];
+ empty_sacl_fixup((SECURITY_DESCRIPTOR_RELATIVE*)sd->descriptors[i],
+ &sd->sizes[i]);
}
- sd->refcnt = 1;
- *sd_p = sd;
- return 0;
+out_align_total_length:
+ total_len = (total_len + 7) & ~7;
+ sd->total_length = (sd->total_length + 7) & ~7;
+ if (total_len != sd->total_length) {
+ WARNING("Expected WIM security data total length of "
+ "%u bytes, but calculated %u bytes",
+ sd->total_length, (unsigned)total_len);
+ }
+ *sd_ret = sd;
+ ret = 0;
+ goto out;
+out_invalid_sd:
+ ERROR("WIM security data is invalid!");
+ ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
+ goto out_free_sd;
+out_of_memory:
+ ERROR("Out of memory while reading WIM security data!");
+ ret = WIMLIB_ERR_NOMEM;
+out_free_sd:
+ free_wim_security_data(sd);
+out:
+ return ret;
}
-/*
- * Writes security data to an in-memory buffer.
+/*
+ * Writes the security data for a WIM image to an in-memory buffer.
*/
-u8 *write_security_data(const struct wim_security_data *sd, u8 *p)
+u8 *
+write_wim_security_data(const struct wim_security_data * restrict sd,
+ u8 * restrict p)
{
- if (sd) {
- DEBUG("Writing security data (total_length = %u, "
- "num_entries = %u)\n", sd->total_length,
- sd->num_entries);
- u8 *orig_p = p;
- p = put_u32(p, sd->total_length);
- p = put_u32(p, sd->num_entries);
+ DEBUG("Writing security data (total_length = %"PRIu32", num_entries "
+ "= %"PRIu32")", sd->total_length, sd->num_entries);
- for (uint i = 0; i < sd->num_entries; i++)
- p = put_u64(p, sd->sizes[i]);
+ u8 *orig_p = p;
+ struct wim_security_data_disk *sd_disk = (struct wim_security_data_disk*)p;
+ u32 num_entries = sd->num_entries;
- for (uint i = 0; i < sd->num_entries; i++)
- p = put_bytes(p, sd->sizes[i], sd->descriptors[i]);
+ sd_disk->total_length = cpu_to_le32(sd->total_length);
+ sd_disk->num_entries = cpu_to_le32(num_entries);
- wimlib_assert(p - orig_p <= sd->total_length);
+ for (u32 i = 0; i < num_entries; i++)
+ sd_disk->sizes[i] = cpu_to_le64(sd->sizes[i]);
- DEBUG("Successfully wrote security data.\n");
- return orig_p + sd->total_length;
- } else {
- DEBUG("Writing security data (total_length = 8, "
- "num_entries = 0)\n");
- p = put_u32(p, 8);
- return put_u32(p, 0);
+ p = (u8*)&sd_disk->sizes[num_entries];
- }
-}
+ for (u32 i = 0; i < num_entries; i++)
+ p = mempcpy(p, sd->descriptors[i], sd->sizes[i]);
+
+ while ((uintptr_t)p & 7)
+ *p++ = 0;
-/* XXX We don't actually do anything with the ACL's yet besides being able to
- * print a few things. It seems it would be a lot of work to have comprehensive
- * support for all the weird flags and stuff, and Windows PE seems to be okay
- * running from a WIM file that doesn't have any security data at all... */
+ wimlib_assert(p - orig_p == sd->total_length);
-static void print_acl(const u8 *p)
+ DEBUG("Successfully wrote security data.");
+ return p;
+}
+
+static void
+print_acl(const ACL *acl, const tchar *type, size_t max_size)
{
- ACL *acl = (ACL*)p;
- TO_LE16(acl->acl_size);
- TO_LE16(acl->acl_count);
- printf(" [ACL]\n");
- printf(" Revision = %u\n", acl->revision);
- printf(" ACL Size = %u\n", acl->acl_size);
- printf(" ACE Count = %u\n", acl->ace_count);
-
- p += sizeof(ACL);
- for (uint i = 0; i < acl->ace_count; i++) {
- ACEHeader *hdr = (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;
- printf(" ACE mask = %x\n", to_le32(aaa->mask));
- printf(" SID start = %u\n", to_le32(aaa->sid_start));
- p += hdr->size;
+ const u8 *p;
+
+ if (max_size < sizeof(ACL))
+ return;
+
+ u8 revision = acl->revision;
+ u16 acl_size = le16_to_cpu(acl->acl_size);
+ u16 ace_count = le16_to_cpu(acl->ace_count);
+
+ tprintf(T(" [%"TS" ACL]\n"), type);
+ tprintf(T(" Revision = %u\n"), revision);
+ tprintf(T(" ACL Size = %u\n"), acl_size);
+ tprintf(T(" ACE Count = %u\n"), ace_count);
+
+ p = (const u8*)acl + sizeof(ACL);
+ for (u16 i = 0; i < ace_count; i++) {
+ if (max_size < p + sizeof(ACCESS_ALLOWED_ACE) - (const u8*)acl)
+ break;
+ const ACCESS_ALLOWED_ACE *aaa = (const ACCESS_ALLOWED_ACE*)p;
+ tprintf(T(" [ACE]\n"));
+ tprintf(T(" ACE type = %d\n"), aaa->hdr.type);
+ tprintf(T(" ACE flags = 0x%x\n"), aaa->hdr.flags);
+ tprintf(T(" ACE size = %u\n"), le16_to_cpu(aaa->hdr.size));
+ tprintf(T(" ACE mask = %x\n"), le32_to_cpu(aaa->mask));
+ tprintf(T(" SID start = %u\n"), le32_to_cpu(aaa->sid_start));
+ p += le16_to_cpu(aaa->hdr.size);
}
+ tputchar(T('\n'));
}
-static void print_sid(const u8 *p)
+static void
+print_sid(const SID *sid, const tchar *type, size_t max_size)
{
- SID *sid = (SID*)p;
- printf(" [SID]\n");
- printf(" Revision = %u\n", sid->revision);
- printf(" Subauthority count = %u\n", sid->sub_authority_count);
- printf(" Identifier authority = ");
- print_byte_field(sid->identifier_authority, sizeof(sid->identifier_authority));
- putchar('\n');
- for (uint i = 0; i < sid->sub_authority_count; i++)
- printf(" Subauthority %u = %u\n", i, to_le32(sid->sub_authority[i]));
+ if (max_size < sizeof(SID))
+ return;
+
+ tprintf(T(" [%"TS" SID]\n"), type);
+ tprintf(T(" Revision = %u\n"), sid->revision);
+ tprintf(T(" Subauthority count = %u\n"), sid->sub_authority_count);
+ tprintf(T(" Identifier authority = "));
+ print_byte_field(sid->identifier_authority,
+ sizeof(sid->identifier_authority), stdout);
+ tputchar(T('\n'));
+ if (max_size < sizeof(SID) + (size_t)sid->sub_authority_count * sizeof(u32))
+ return;
+ for (u8 i = 0; i < sid->sub_authority_count; i++) {
+ tprintf(T(" Subauthority %u = %u\n"),
+ i, le32_to_cpu(sid->sub_authority[i]));
+ }
+ tputchar(T('\n'));
}
-static void print_security_descriptor(const u8 *p, u64 size)
+static void
+print_security_descriptor(const SECURITY_DESCRIPTOR_RELATIVE *descr,
+ size_t 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 = %u\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);
-
- if (sd->owner_offset != 0)
- print_sid(p + sd->owner_offset);
- if (sd->group_offset != 0)
- print_sid(p + sd->group_offset);
- if (sd->sacl_offset != 0)
- print_acl(p + sd->sacl_offset);
- if (sd->dacl_offset != 0)
- print_acl(p + sd->dacl_offset);
+ u8 revision = descr->revision;
+ u16 control = le16_to_cpu(descr->security_descriptor_control);
+ u32 owner_offset = le32_to_cpu(descr->owner_offset);
+ u32 group_offset = le32_to_cpu(descr->group_offset);
+ u32 dacl_offset = le32_to_cpu(descr->dacl_offset);
+ u32 sacl_offset = le32_to_cpu(descr->sacl_offset);
+
+ tprintf(T("Revision = %u\n"), revision);
+ tprintf(T("Security Descriptor Control = %#x\n"), control);
+ tprintf(T("Owner offset = %u\n"), owner_offset);
+ tprintf(T("Group offset = %u\n"), group_offset);
+ tprintf(T("Discretionary ACL offset = %u\n"), dacl_offset);
+ tprintf(T("System ACL offset = %u\n"), sacl_offset);
+
+ if (owner_offset != 0 && owner_offset <= size)
+ print_sid((const SID*)((const u8*)descr + owner_offset),
+ T("Owner"), size - owner_offset);
+
+ if (group_offset != 0 && group_offset <= size)
+ print_sid((const SID*)((const u8*)descr + group_offset),
+ T("Group"), size - group_offset);
+
+ if (dacl_offset != 0 && dacl_offset <= size)
+ print_acl((const ACL*)((const u8*)descr + dacl_offset),
+ T("Discretionary"), size - dacl_offset);
+
+ if (sacl_offset != 0 && sacl_offset <= size)
+ print_acl((const ACL*)((const u8*)descr + sacl_offset),
+ T("System"), size - sacl_offset);
}
-/*
+/*
* Prints the security data for a WIM file.
*/
-void print_security_data(const struct wim_security_data *sd)
+void
+print_wim_security_data(const struct wim_security_data *sd)
{
- puts("[SECURITY DATA]");
- if (sd) {
- printf("Length = %u bytes\n", sd->total_length);
- printf("Number of Entries = %u\n", sd->num_entries);
-
- u64 num_entries = (u64)sd->num_entries;
- for (u64 i = 0; i < num_entries; i++) {
- printf("[SecurityDescriptor %"PRIu64", "
- "length = %"PRIu64"]\n",
- i, sd->sizes[i]);
- print_security_descriptor(sd->descriptors[i],
- sd->sizes[i]);
- putchar('\n');
- }
- } else {
- puts("Length = 8 bytes\n"
- "Number of Entries = 0");
+ tputs(T("[SECURITY DATA]"));
+ tprintf(T("Length = %"PRIu32" bytes\n"), sd->total_length);
+ tprintf(T("Number of Entries = %"PRIu32"\n"), sd->num_entries);
+
+ for (u32 i = 0; i < sd->num_entries; i++) {
+ tprintf(T("[SECURITY_DESCRIPTOR_RELATIVE %"PRIu32", length = %"PRIu64"]\n"),
+ i, sd->sizes[i]);
+ print_security_descriptor((const SECURITY_DESCRIPTOR_RELATIVE*)sd->descriptors[i],
+ sd->sizes[i]);
+ tputchar(T('\n'));
}
- putchar('\n');
+ tputchar(T('\n'));
}
-void free_security_data(struct wim_security_data *sd)
+void
+free_wim_security_data(struct wim_security_data *sd)
{
- if (!sd)
- return;
- wimlib_assert(sd->refcnt >= 1);
- if (sd->refcnt == 1) {
+ if (sd) {
u8 **descriptors = sd->descriptors;
- u32 num_entries = sd->num_entries;
-
+ u32 num_entries = sd->num_entries;
if (descriptors)
while (num_entries--)
FREE(*descriptors++);
FREE(sd->sizes);
FREE(sd->descriptors);
FREE(sd);
- } else {
- sd->refcnt--;
}
}
-#endif
+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 wim_sd_set *sd_set, bool rollback)
+{
+ if (rollback) {
+ struct wim_security_data *sd = sd_set->sd;
+ u8 **descriptors = sd->descriptors + sd_set->orig_num_entries;
+ u32 num_entries = sd->num_entries - sd_set->orig_num_entries;
+ while (num_entries--)
+ FREE(*descriptors++);
+ sd->num_entries = sd_set->orig_num_entries;
+ }
+ free_sd_tree(sd_set->rb_root.rb_node);
+}
+
+/* Inserts a a new node into the security descriptor index tree. */
+static bool
+insert_sd_node(struct wim_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
+ return false; /* Duplicate security descriptor */
+ }
+ rb_link_node(&new->rb_node, rb_parent, p);
+ rb_insert_color(&new->rb_node, root);
+ return true;
+}
+
+/* Returns the index of the security descriptor having a SHA1 message digest of
+ * @hash. If not found, return -1. */
+int
+lookup_sd(struct wim_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 wim_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;
+ bool bret;
+
+ sha1_buffer(descriptor, size, hash);
+
+ security_id = lookup_sd(sd_set, hash);
+ if (security_id >= 0) /* Identical descriptor already exists */
+ goto out;
+
+ /* Need to add a new security descriptor */
+ security_id = -1;
+
+ 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);
+
+ /* There typically are only a few dozen security descriptors in a
+ * directory tree, so expanding the array of security descriptors by
+ * only 1 extra space each time should not be a problem. */
+ 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 %u security descriptors", sd->num_entries);
+ bret = insert_sd_node(sd_set, new);
+ wimlib_assert(bret);
+ security_id = new->security_id;
+ goto out;
+out_free_descr:
+ FREE(descr_copy);
+out_free_node:
+ FREE(new);
+out:
+ return security_id;
+}
+
+/* Initialize a `struct sd_set' mapping from SHA1 message digests of security
+ * descriptors to indices into the security descriptors table of the WIM image
+ * (security IDs). */
+int
+init_sd_set(struct wim_sd_set *sd_set, struct wim_security_data *sd)
+{
+ int ret;
+
+ sd_set->sd = sd;
+ sd_set->rb_root.rb_node = NULL;
+
+ /* Remember the original number of security descriptors so that newly
+ * added ones can be rolled back if needed. */
+ sd_set->orig_num_entries = sd->num_entries;
+ for (u32 i = 0; i < sd->num_entries; i++) {
+ struct sd_node *new;
+
+ new = MALLOC(sizeof(struct sd_node));
+ if (!new) {
+ ret = WIMLIB_ERR_NOMEM;
+ goto out_destroy_sd_set;
+ }
+ sha1_buffer(sd->descriptors[i], sd->sizes[i], new->hash);
+ new->security_id = i;
+ if (!insert_sd_node(sd_set, new))
+ FREE(new); /* Ignore duplicate security descriptor */
+ }
+ ret = 0;
+ goto out;
+out_destroy_sd_set:
+ destroy_sd_set(sd_set, false);
+out:
+ return ret;
+}
git://wimlib.net / wimlib / blobdiff