X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fsecurity.c;h=85cfb5bc6ce968f85671672577bd0c3984a69e41;hp=628b93584d1dfff77727ecc9f845c85c2b6a6152;hb=d31b2fee211b1c31420bafe1c2379f6f89bd92fe;hpb=5caa3dfded8e0f590112b59feeb3b55e4fa28420 diff --git a/src/security.c b/src/security.c index 628b9358..85cfb5bc 100644 --- a/src/security.c +++ b/src/security.c @@ -5,22 +5,20 @@ */ /* - * Copyright (C) 2012, 2013 Eric Biggers + * Copyright (C) 2012, 2013, 2014 Eric Biggers * - * This file is part of wimlib, a library for working with WIM files. + * This file 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 3 of the License, or (at your option) any + * later version. * - * wimlib is free software; you can redistribute it and/or modify it under the - * 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 General Public License for more + * This file 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 * details. * - * You should have received a copy of the GNU General Public License - * along with wimlib; if not, see http://www.gnu.org/licenses/. + * You should have received a copy of the GNU Lesser General Public License + * along with this file; if not, see http://www.gnu.org/licenses/. */ #ifdef HAVE_CONFIG_H @@ -28,139 +26,19 @@ #endif #include "wimlib/assert.h" +#include "wimlib/avl_tree.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 -} - struct wim_security_data * new_wim_security_data(void) { @@ -170,23 +48,24 @@ new_wim_security_data(void) /* * 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 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. + * @buf + * Buffer containing an uncompressed WIM metadata resource. + * @buf_len + * Length of the uncompressed metadata resource, in bytes. + * @sd_ret + * On success, a pointer to the resulting security data structure will be + * returned here. * * 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 + * Return values: + * WIMLIB_ERR_SUCCESS (0) + * WIMLIB_ERR_INVALID_METADATA_RESOURCE + * WIMLIB_ERR_NOMEM */ int -read_wim_security_data(const u8 metadata_resource[], size_t metadata_resource_len, +read_wim_security_data(const u8 *buf, size_t buf_len, struct wim_security_data **sd_ret) { struct wim_security_data *sd; @@ -197,19 +76,17 @@ read_wim_security_data(const u8 metadata_resource[], size_t metadata_resource_le const struct wim_security_data_disk *sd_disk; const u8 *p; - wimlib_assert(metadata_resource_len >= 8); + if (buf_len < 8) + return WIMLIB_ERR_INVALID_METADATA_RESOURCE; sd = new_wim_security_data(); if (!sd) 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_disk = (const struct wim_security_data_disk *)buf; + sd->total_length = ALIGN(le32_to_cpu(sd_disk->total_length), 8); 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) @@ -231,7 +108,7 @@ read_wim_security_data(const u8 metadata_resource[], size_t metadata_resource_le * 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) + if (sd->total_length > buf_len) goto out_invalid_sd; sizes_size = (u64)sd->num_entries * sizeof(u64); @@ -243,7 +120,7 @@ read_wim_security_data(const u8 metadata_resource[], size_t metadata_resource_le /* Return immediately if no security descriptors. */ if (sd->num_entries == 0) - goto out_align_total_length; + goto out_descriptors_ready; /* Allocate a new buffer for the sizes array */ sd->sizes = MALLOC(sizes_size); @@ -275,23 +152,19 @@ read_wim_security_data(const u8 metadata_resource[], size_t metadata_resource_le if (!sd->descriptors[i]) goto out_of_memory; p += sd->sizes[i]; - empty_sacl_fixup((SECURITY_DESCRIPTOR_RELATIVE*)sd->descriptors[i], - &sd->sizes[i]); } -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); +out_descriptors_ready: + if (ALIGN(total_len, 8) != sd->total_length) { + WARNING("Stored WIM security data total length was " + "%"PRIu32" bytes, but calculated %"PRIu32" bytes", + sd->total_length, (u32)total_len); } *sd_ret = sd; ret = 0; goto out; out_invalid_sd: ERROR("WIM security data is invalid!"); - ret = WIMLIB_ERR_INVALID_SECURITY_DATA; + ret = WIMLIB_ERR_INVALID_METADATA_RESOURCE; goto out_free_sd; out_of_memory: ERROR("Out of memory while reading WIM security data!"); @@ -309,9 +182,6 @@ u8 * write_wim_security_data(const struct wim_security_data * restrict sd, u8 * restrict p) { - DEBUG("Writing security data (total_length = %"PRIu32", num_entries " - "= %"PRIu32")", sd->total_length, sd->num_entries); - u8 *orig_p = p; struct wim_security_data_disk *sd_disk = (struct wim_security_data_disk*)p; u32 num_entries = sd->num_entries; @@ -331,121 +201,9 @@ write_wim_security_data(const struct wim_security_data * restrict sd, *p++ = 0; wimlib_assert(p - orig_p == sd->total_length); - - DEBUG("Successfully wrote security data."); return p; } -static void -print_acl(const ACL *acl, const tchar *type, size_t max_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 SID *sid, const tchar *type, size_t max_size) -{ - 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 SECURITY_DESCRIPTOR_RELATIVE *descr, - size_t size) -{ - 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_wim_security_data(const struct wim_security_data *sd) -{ - 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')); - } - tputchar(T('\n')); -} - void free_wim_security_data(struct wim_security_data *sd) { @@ -462,79 +220,72 @@ free_wim_security_data(struct wim_security_data *sd) } struct sd_node { - int security_id; + s32 security_id; u8 hash[SHA1_HASH_SIZE]; - struct rb_node rb_node; + struct avl_tree_node index_node; }; +#define SD_NODE(avl_node) \ + avl_tree_entry(avl_node, struct sd_node, index_node) + static void -free_sd_tree(struct rb_node *node) +free_sd_tree(struct avl_tree_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)); + free_sd_tree(node->left); + free_sd_tree(node->right); + FREE(SD_NODE(node)); } } +void +rollback_new_security_descriptors(struct wim_sd_set *sd_set) +{ + 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; +} + /* Frees a security descriptor index set. */ void -destroy_sd_set(struct wim_sd_set *sd_set, bool rollback) +destroy_sd_set(struct wim_sd_set *sd_set) { - 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); + free_sd_tree(sd_set->root); } -/* Inserts a a new node into the security descriptor index tree. */ +static int +_avl_cmp_nodes_by_hash(const struct avl_tree_node *n1, + const struct avl_tree_node *n2) +{ + return hashes_cmp(SD_NODE(n1)->hash, SD_NODE(n2)->hash); +} + +/* Inserts a new node into the security descriptor index tree. Returns true + * if successful (not a duplicate). */ 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; + return NULL == avl_tree_insert(&set->root, &new->index_node, + _avl_cmp_nodes_by_hash); } /* Returns the index of the security descriptor having a SHA1 message digest of * @hash. If not found, return -1. */ -int +static s32 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; + struct avl_tree_node *res; + struct sd_node dummy; + + copy_hash(dummy.hash, hash); + res = avl_tree_lookup_node(set->root, &dummy.index_node, + _avl_cmp_nodes_by_hash); + if (!res) + return -1; + return SD_NODE(res)->security_id; } /* @@ -544,11 +295,11 @@ lookup_sd(struct wim_sd_set *set, const u8 hash[SHA1_HASH_SIZE]) * the security ID for it. If a new security descriptor cannot be allocated, * return -1. */ -int +s32 sd_set_add_sd(struct wim_sd_set *sd_set, const char *descriptor, size_t size) { u8 hash[SHA1_HASH_SIZE]; - int security_id; + s32 security_id; struct sd_node *new; u8 **descriptors; u64 *sizes; @@ -568,13 +319,12 @@ sd_set_add_sd(struct wim_sd_set *sd_set, const char *descriptor, size_t size) new = MALLOC(sizeof(*new)); if (!new) goto out; - descr_copy = MALLOC(size); + + descr_copy = memdup(descriptor, 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); @@ -594,7 +344,6 @@ sd_set_add_sd(struct wim_sd_set *sd_set, const char *descriptor, size_t size) 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; @@ -616,7 +365,7 @@ 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; + sd_set->root = NULL; /* Remember the original number of security descriptors so that newly * added ones can be rolled back if needed. */ @@ -637,7 +386,7 @@ init_sd_set(struct wim_sd_set *sd_set, struct wim_security_data *sd) ret = 0; goto out; out_destroy_sd_set: - destroy_sd_set(sd_set, false); + destroy_sd_set(sd_set); out: return ret; }