/* Copyright (C) Nadezhda Ivanova 2009 This program 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. This program 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 details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ /* * Name: create_descriptor * * Component: routines for calculating and creating security descriptors * as described in MS-DTYP 2.5.3.x * * Description: * * * Author: Nadezhda Ivanova */ #include "includes.h" #include "libcli/security/security.h" #include "librpc/gen_ndr/ndr_security.h" /* Todos: * build the security token dacl as follows: * SYSTEM: GA, OWNER: GA, LOGIN_SID:GW|GE * Need session id information for the login SID. Probably * the best place for this is during token creation * * Implement SD Invariants * ACE sorting rules * LDAP_SERVER_SD_FLAGS_OID control * ADTS 7.1.3.3 needs to be clarified */ /* the mapping function for generic rights for DS.(GA,GR,GW,GX) * The mapping function is passed as an argument to the * descriptor calculating routine and depends on the security * manager that calls the calculating routine. * TODO: need similar mappings for the file system and * registry security managers in order to make this code * generic for all security managers */ uint32_t map_generic_rights_ds(uint32_t access_mask) { if (access_mask & SEC_GENERIC_ALL) { access_mask |= SEC_ADS_GENERIC_ALL; access_mask &= ~SEC_GENERIC_ALL; } if (access_mask & SEC_GENERIC_EXECUTE) { access_mask |= SEC_ADS_GENERIC_EXECUTE; access_mask &= ~SEC_GENERIC_EXECUTE; } if (access_mask & SEC_GENERIC_WRITE) { access_mask |= SEC_ADS_GENERIC_WRITE; access_mask &= ~SEC_GENERIC_WRITE; } if (access_mask & SEC_GENERIC_READ) { access_mask |= SEC_ADS_GENERIC_READ; access_mask &= ~SEC_GENERIC_READ; } return access_mask; } /* Not sure what this has to be, * and it does not seem to have any influence */ static bool object_in_list(const struct GUID *object_list, const struct GUID *object) { size_t i; if (object_list == NULL) { return true; } if (GUID_all_zero(object)) { return true; } for (i=0; ; i++) { if (GUID_all_zero(&object_list[i])) { return false; } if (!GUID_equal(&object_list[i], object)) { continue; } return true; } return false; } /* returns true if the ACE gontains generic information * that needs to be processed additionally */ static bool desc_ace_has_generic(const struct security_ace *ace) { if (ace->access_mask & SEC_GENERIC_ALL || ace->access_mask & SEC_GENERIC_READ || ace->access_mask & SEC_GENERIC_WRITE || ace->access_mask & SEC_GENERIC_EXECUTE) { return true; } if (dom_sid_equal(&ace->trustee, &global_sid_Creator_Owner) || dom_sid_equal(&ace->trustee, &global_sid_Creator_Group)) { return true; } return false; } /* creates an ace in which the generic information is expanded */ static void desc_expand_generic(struct security_ace *new_ace, struct dom_sid *owner, struct dom_sid *group) { new_ace->access_mask = map_generic_rights_ds(new_ace->access_mask); if (dom_sid_equal(&new_ace->trustee, &global_sid_Creator_Owner)) { new_ace->trustee = *owner; } if (dom_sid_equal(&new_ace->trustee, &global_sid_Creator_Group)) { new_ace->trustee = *group; } new_ace->flags = 0x0; } static struct security_acl *calculate_inherited_from_parent(TALLOC_CTX *mem_ctx, struct security_acl *acl, bool is_container, struct dom_sid *owner, struct dom_sid *group, struct GUID *object_list) { uint32_t i; TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx); struct security_acl *tmp_acl = talloc_zero(mem_ctx, struct security_acl); if (!tmp_acl) { return NULL; } if (!acl) { return NULL; } for (i=0; i < acl->num_aces; i++) { const struct security_ace *ace = &acl->aces[i]; const struct GUID *inherited_object = NULL; const struct GUID *inherited_property = NULL; struct security_ace *tmp_ace = NULL; bool applies = false; bool inherited_only = false; bool expand_ace = false; bool expand_only = false; if (is_container && (ace->flags & SEC_ACE_FLAG_CONTAINER_INHERIT)) { applies = true; } else if (!is_container && (ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT)) { applies = true; } if (!applies) { /* * If the ace doesn't apply to the * current node, we should only keep * it as SEC_ACE_FLAG_OBJECT_INHERIT * on a container. We'll add * SEC_ACE_FLAG_INHERITED_ACE * and SEC_ACE_FLAG_INHERIT_ONLY below. * * Otherwise we should completely ignore it. */ if (!(ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT)) { continue; } } switch (ace->type) { case SEC_ACE_TYPE_ACCESS_ALLOWED: case SEC_ACE_TYPE_ACCESS_DENIED: case SEC_ACE_TYPE_SYSTEM_AUDIT: case SEC_ACE_TYPE_SYSTEM_ALARM: case SEC_ACE_TYPE_ALLOWED_COMPOUND: break; case SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT: case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT: case SEC_ACE_TYPE_SYSTEM_ALARM_OBJECT: case SEC_ACE_TYPE_SYSTEM_AUDIT_OBJECT: if (ace->object.object.flags & SEC_ACE_OBJECT_TYPE_PRESENT) { inherited_property = &ace->object.object.type.type; } if (ace->object.object.flags & SEC_ACE_INHERITED_OBJECT_TYPE_PRESENT) { inherited_object = &ace->object.object.inherited_type.inherited_type; } if (inherited_object != NULL && !object_in_list(object_list, inherited_object)) { /* * An explicit object class schemaId is given, * but doesn't belong to the current object. */ applies = false; } break; } if (ace->flags & SEC_ACE_FLAG_NO_PROPAGATE_INHERIT) { if (!applies) { /* * If the ACE doesn't apply to * the current object, we should * ignore it as it should not be * inherited any further */ continue; } /* * We should only keep the expanded version * of the ACE on the current object. */ expand_ace = true; expand_only = true; } else if (applies) { /* * We check if should also add * the expanded version of the ACE * in addition, in case we should * expand generic access bits or * special sids. * * In that case we need to * keep the original ACE with * SEC_ACE_FLAG_INHERIT_ONLY. */ expand_ace = desc_ace_has_generic(ace); if (expand_ace) { inherited_only = true; } } else { /* * If the ACE doesn't apply * to the current object, * we need to keep it with * SEC_ACE_FLAG_INHERIT_ONLY * in order to apply them to * grandchildren */ inherited_only = true; } if (expand_ace) { tmp_acl->aces = talloc_realloc(tmp_acl, tmp_acl->aces, struct security_ace, tmp_acl->num_aces+1); if (tmp_acl->aces == NULL) { talloc_free(tmp_ctx); return NULL; } tmp_ace = &tmp_acl->aces[tmp_acl->num_aces]; tmp_acl->num_aces++; *tmp_ace = *ace; /* * Expand generic access bits as well as special * sids. */ desc_expand_generic(tmp_ace, owner, group); /* * Expanded ACEs are marked as inherited, * but never inherited any further to * grandchildren. */ tmp_ace->flags |= SEC_ACE_FLAG_INHERITED_ACE; tmp_ace->flags &= ~SEC_ACE_FLAG_CONTAINER_INHERIT; tmp_ace->flags &= ~SEC_ACE_FLAG_OBJECT_INHERIT; tmp_ace->flags &= ~SEC_ACE_FLAG_NO_PROPAGATE_INHERIT; /* * Expanded ACEs never have an explicit * object class schemaId, so clear it * if present. */ if (inherited_object != NULL) { tmp_ace->object.object.flags &= ~SEC_ACE_INHERITED_OBJECT_TYPE_PRESENT; } /* * If the ACE had an explicit object class * schemaId, but no attribute/propertySet * we need to downgrate the _OBJECT variants * to the normal ones. */ if (inherited_property == NULL) { switch (tmp_ace->type) { case SEC_ACE_TYPE_ACCESS_ALLOWED: case SEC_ACE_TYPE_ACCESS_DENIED: case SEC_ACE_TYPE_SYSTEM_AUDIT: case SEC_ACE_TYPE_SYSTEM_ALARM: case SEC_ACE_TYPE_ALLOWED_COMPOUND: break; case SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT: tmp_ace->type = SEC_ACE_TYPE_ACCESS_ALLOWED; break; case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT: tmp_ace->type = SEC_ACE_TYPE_ACCESS_DENIED; break; case SEC_ACE_TYPE_SYSTEM_ALARM_OBJECT: tmp_ace->type = SEC_ACE_TYPE_SYSTEM_ALARM; break; case SEC_ACE_TYPE_SYSTEM_AUDIT_OBJECT: tmp_ace->type = SEC_ACE_TYPE_SYSTEM_AUDIT; break; } } if (expand_only) { continue; } } tmp_acl->aces = talloc_realloc(tmp_acl, tmp_acl->aces, struct security_ace, tmp_acl->num_aces+1); if (tmp_acl->aces == NULL) { talloc_free(tmp_ctx); return NULL; } tmp_ace = &tmp_acl->aces[tmp_acl->num_aces]; tmp_acl->num_aces++; *tmp_ace = *ace; tmp_ace->flags |= SEC_ACE_FLAG_INHERITED_ACE; if (inherited_only) { tmp_ace->flags |= SEC_ACE_FLAG_INHERIT_ONLY; } else { tmp_ace->flags &= ~SEC_ACE_FLAG_INHERIT_ONLY; } if (ace->flags & SEC_ACE_FLAG_NO_PROPAGATE_INHERIT) { tmp_ace->flags &= ~SEC_ACE_FLAG_CONTAINER_INHERIT; tmp_ace->flags &= ~SEC_ACE_FLAG_OBJECT_INHERIT; tmp_ace->flags &= ~SEC_ACE_FLAG_NO_PROPAGATE_INHERIT; } } if (tmp_acl->num_aces == 0) { return NULL; } if (acl) { tmp_acl->revision = acl->revision; } return tmp_acl; } static struct security_acl *process_user_acl(TALLOC_CTX *mem_ctx, struct security_acl *acl, bool is_container, struct dom_sid *owner, struct dom_sid *group, struct GUID *object_list, bool is_protected) { uint32_t i; TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx); struct security_acl *tmp_acl = talloc_zero(tmp_ctx, struct security_acl); struct security_acl *new_acl; if (!acl) return NULL; if (!tmp_acl) return NULL; tmp_acl->revision = acl->revision; DBG_DEBUG("acl revision %d\n", acl->revision); for (i=0; i < acl->num_aces; i++){ struct security_ace *ace = &acl->aces[i]; /* Remove ID flags from user-provided ACEs * if we break inheritance, ignore them otherwise */ if (ace->flags & SEC_ACE_FLAG_INHERITED_ACE) { if (is_protected) { ace->flags &= ~SEC_ACE_FLAG_INHERITED_ACE; } else { continue; } } if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY && !(ace->flags & SEC_ACE_FLAG_CONTAINER_INHERIT || ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT)) continue; tmp_acl->aces = talloc_realloc(tmp_acl, tmp_acl->aces, struct security_ace, tmp_acl->num_aces+1); tmp_acl->aces[tmp_acl->num_aces] = *ace; tmp_acl->num_aces++; if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY) { continue; } /* if the ACE contains CO, CG, GA, GE, GR or GW, and is inheritable * it has to be expanded to two aces, the original as IO, * and another one where these are translated */ if (desc_ace_has_generic(ace)) { if (!(ace->flags & SEC_ACE_FLAG_CONTAINER_INHERIT)) { desc_expand_generic(&tmp_acl->aces[tmp_acl->num_aces-1], owner, group); } else { /*The original ACE becomes read only */ tmp_acl->aces[tmp_acl->num_aces-1].flags |= SEC_ACE_FLAG_INHERIT_ONLY; tmp_acl->aces = talloc_realloc(tmp_acl, tmp_acl->aces, struct security_ace, tmp_acl->num_aces+1); /* add a new ACE with expanded generic info */ tmp_acl->aces[tmp_acl->num_aces] = *ace; desc_expand_generic(&tmp_acl->aces[tmp_acl->num_aces], owner, group); tmp_acl->num_aces++; } } } new_acl = security_acl_dup(mem_ctx,tmp_acl); if (new_acl) new_acl->revision = acl->revision; talloc_free(tmp_ctx); return new_acl; } static void cr_descr_log_descriptor(struct security_descriptor *sd, const char *message, int level) { if (sd) { DEBUG(level,("%s: %s\n", message, ndr_print_struct_string(0,(ndr_print_fn_t)ndr_print_security_descriptor, "", sd))); } else { DEBUG(level,("%s: NULL\n", message)); } } #if 0 static void cr_descr_log_acl(struct security_acl *acl, const char *message, int level) { if (acl) { DEBUG(level,("%s: %s\n", message, ndr_print_struct_string(0,(ndr_print_fn_t)ndr_print_security_acl, "", acl))); } else { DEBUG(level,("%s: NULL\n", message)); } } #endif static bool compute_acl(struct security_descriptor *parent_sd, struct security_descriptor *creator_sd, bool is_container, uint32_t inherit_flags, struct GUID *object_list, uint32_t (*generic_map)(uint32_t access_mask), struct security_token *token, struct security_descriptor *new_sd) /* INOUT argument */ { struct security_acl *user_dacl, *user_sacl, *inherited_dacl, *inherited_sacl; int level = 10; if (!parent_sd || !(inherit_flags & SEC_DACL_AUTO_INHERIT)) { inherited_dacl = NULL; } else if (creator_sd && (creator_sd->type & SEC_DESC_DACL_PROTECTED)) { inherited_dacl = NULL; } else { inherited_dacl = calculate_inherited_from_parent(new_sd, parent_sd->dacl, is_container, new_sd->owner_sid, new_sd->group_sid, object_list); } if (!parent_sd || !(inherit_flags & SEC_SACL_AUTO_INHERIT)) { inherited_sacl = NULL; } else if (creator_sd && (creator_sd->type & SEC_DESC_SACL_PROTECTED)) { inherited_sacl = NULL; } else { inherited_sacl = calculate_inherited_from_parent(new_sd, parent_sd->sacl, is_container, new_sd->owner_sid, new_sd->group_sid, object_list); } if (!creator_sd || (inherit_flags & SEC_DEFAULT_DESCRIPTOR)) { user_dacl = NULL; user_sacl = NULL; } else { user_dacl = process_user_acl(new_sd, creator_sd->dacl, is_container, new_sd->owner_sid, new_sd->group_sid, object_list, creator_sd->type & SEC_DESC_DACL_PROTECTED); user_sacl = process_user_acl(new_sd, creator_sd->sacl, is_container, new_sd->owner_sid, new_sd->group_sid, object_list, creator_sd->type & SEC_DESC_SACL_PROTECTED); } cr_descr_log_descriptor(parent_sd, __location__"parent_sd", level); cr_descr_log_descriptor(creator_sd,__location__ "creator_sd", level); new_sd->dacl = security_acl_concatenate(new_sd, user_dacl, inherited_dacl); if (new_sd->dacl) { new_sd->type |= SEC_DESC_DACL_PRESENT; } if (inherited_dacl) { new_sd->type |= SEC_DESC_DACL_AUTO_INHERITED; } new_sd->sacl = security_acl_concatenate(new_sd, user_sacl, inherited_sacl); if (new_sd->sacl) { new_sd->type |= SEC_DESC_SACL_PRESENT; } if (inherited_sacl) { new_sd->type |= SEC_DESC_SACL_AUTO_INHERITED; } /* This is a hack to handle the fact that * apprantly any AI flag provided by the user is preserved */ if (creator_sd) new_sd->type |= creator_sd->type; cr_descr_log_descriptor(new_sd, __location__"final sd", level); return true; } struct security_descriptor *create_security_descriptor(TALLOC_CTX *mem_ctx, struct security_descriptor *parent_sd, struct security_descriptor *creator_sd, bool is_container, struct GUID *object_list, uint32_t inherit_flags, struct security_token *token, struct dom_sid *default_owner, /* valid only for DS, NULL for the other RSs */ struct dom_sid *default_group, /* valid only for DS, NULL for the other RSs */ uint32_t (*generic_map)(uint32_t access_mask)) { struct security_descriptor *new_sd; struct dom_sid *new_owner = NULL; struct dom_sid *new_group = NULL; new_sd = security_descriptor_initialise(mem_ctx); if (!new_sd) { return NULL; } if (!creator_sd || !creator_sd->owner_sid) { if ((inherit_flags & SEC_OWNER_FROM_PARENT) && parent_sd) { new_owner = parent_sd->owner_sid; } else if (!default_owner) { new_owner = &token->sids[PRIMARY_USER_SID_INDEX]; } else { new_owner = default_owner; new_sd->type |= SEC_DESC_OWNER_DEFAULTED; } } else { new_owner = creator_sd->owner_sid; } if (!creator_sd || !creator_sd->group_sid){ if ((inherit_flags & SEC_GROUP_FROM_PARENT) && parent_sd) { new_group = parent_sd->group_sid; } else if (!default_group && token->num_sids > PRIMARY_GROUP_SID_INDEX) { new_group = &token->sids[PRIMARY_GROUP_SID_INDEX]; } else if (!default_group) { /* This will happen only for anonymous, which has no other groups */ new_group = &token->sids[PRIMARY_USER_SID_INDEX]; } else { new_group = default_group; new_sd->type |= SEC_DESC_GROUP_DEFAULTED; } } else { new_group = creator_sd->group_sid; } new_sd->owner_sid = talloc_memdup(new_sd, new_owner, sizeof(struct dom_sid)); new_sd->group_sid = talloc_memdup(new_sd, new_group, sizeof(struct dom_sid)); if (!new_sd->owner_sid || !new_sd->group_sid){ talloc_free(new_sd); return NULL; } if (!compute_acl(parent_sd, creator_sd, is_container, inherit_flags, object_list, generic_map,token,new_sd)){ talloc_free(new_sd); return NULL; } return new_sd; }