server/token.c

/*
 * Tokens
 *
 * Copyright (C) 1998 Alexandre Julliard
 * Copyright (C) 2003 Mike McCormack
 *
 * This library 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) any later version.
 *
 * This library 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 Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "config.h"

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>

#include "windef.h"

#include "handle.h"
#include "thread.h"
#include "process.h"
#include "request.h"

struct token
{
    struct object  obj;             /* object header */
    struct list    privileges;      /* privileges available to the token */
};

struct privilege
{
    struct list entry;
    LUID        luid;
    int         enabled  : 1; /* is the privilege currently enabled? */
    int         def      : 1; /* is the privilege enabled by default? */
};

static void token_dump( struct object *obj, int verbose );
static void token_destroy( struct object *obj );

static const struct object_ops token_ops =
{
    sizeof(struct token),      /* size */
    token_dump,                /* dump */
    no_add_queue,              /* add_queue */
    NULL,                      /* remove_queue */
    NULL,                      /* signaled */
    NULL,                      /* satified */
    no_get_fd,                 /* get_fd */
    token_destroy              /* destroy */
};


static void token_dump( struct object *obj, int verbose )
{
    fprintf( stderr, "Security token\n" );
}

static inline int is_equal_luid( const LUID *luid1, const LUID *luid2 )
{
    return (luid1->LowPart == luid2->LowPart && luid1->HighPart == luid2->HighPart);
}

static inline void luid_and_attr_from_privilege( LUID_AND_ATTRIBUTES *out, const struct privilege *in)
{
    out->Luid = in->luid;
    out->Attributes =
        (in->enabled ? SE_PRIVILEGE_ENABLED : 0) |
        (in->def ? SE_PRIVILEGE_ENABLED_BY_DEFAULT : 0);
}

static struct privilege *privilege_add( struct token *token, const LUID *luid, int enabled )
{
    struct privilege *privilege = mem_alloc( sizeof(*privilege) );
    if (privilege)
    {
        privilege->luid = *luid;
        privilege->def = privilege->enabled = (enabled != 0);
        list_add_tail( &token->privileges, &privilege->entry );
    }
    return privilege;
}

static void privilege_remove( struct privilege *privilege )
{
    list_remove( &privilege->entry );
    free( privilege );
}

static void token_destroy( struct object *obj )
{
    struct token* token;
    struct list *cursor, *cursor_next;

    assert( obj->ops == &token_ops );
    token = (struct token *)obj;

    LIST_FOR_EACH_SAFE( cursor, cursor_next, &token->privileges )
    {
        struct privilege *privilege = LIST_ENTRY( cursor, struct privilege, entry );
        privilege_remove( privilege );
    }
}

static struct token *create_token( const LUID_AND_ATTRIBUTES *privs, unsigned int priv_count )
{
    struct token *token = alloc_object( &token_ops );
    if (token)
    {
        int i;
        list_init( &token->privileges );
        for (i = 0; i < priv_count; i++)
        {
            /* note: we don't check uniqueness: the caller must make sure
             * privs doesn't contain any duplicate luids */
            if (!privilege_add( token, &privs[i].Luid,
                                privs[i].Attributes & SE_PRIVILEGE_ENABLED ))
            {
                release_object( token );
                return NULL;
            }
        }
    }
    return token;
}

struct token *create_admin_token( void )
{
    static const LUID_AND_ATTRIBUTES admin_privs[] =
    {
        { { 23, 0 }, SE_PRIVILEGE_ENABLED }, /* SeChangeNotifyPrivilege */
        { {  8, 0 }, 0                    }, /* SeSecurityPrivilege */
        { { 17, 0 }, 0                    }, /* SeBackupPrivilege */
        { { 18, 0 }, 0                    }, /* SeRestorePrivilege */
        { { 12, 0 }, 0                    }, /* SeSystemtimePrivilege */
        { { 19, 0 }, 0                    }, /* SeShutdownPrivilege */
        { { 24, 0 }, 0                    }, /* SeRemoteShutdownPrivilege */
        { {  9, 0 }, 0                    }, /* SeTakeOwnershipPrivilege */
        { { 20, 0 }, 0                    }, /* SeDebugPrivilege */
        { { 22, 0 }, 0                    }, /* SeSystemEnvironmentPrivilege */
        { { 11, 0 }, 0                    }, /* SeSystemProfilePrivilege */
        { { 13, 0 }, 0                    }, /* SeProfileSingleProcessPrivilege */
        { { 14, 0 }, 0                    }, /* SeIncreaseBasePriorityPrivilege */
        { { 10, 0 }, 0                    }, /* SeLoadDriverPrivilege */
        { { 15, 0 }, 0                    }, /* SeCreatePagefilePrivilege */
        { {  5, 0 }, 0                    }, /* SeIncreaseQuotaPrivilege */
        { { 25, 0 }, 0                    }, /* SeUndockPrivilege */
        { { 28, 0 }, 0                    }, /* SeManageVolumePrivilege */
        { { 29, 0 }, SE_PRIVILEGE_ENABLED }, /* SeImpersonatePrivilege */
        { { 30, 0 }, SE_PRIVILEGE_ENABLED }, /* SeCreateGlobalPrivilege */
    };
    return create_token( admin_privs, sizeof(admin_privs)/sizeof(admin_privs[0]) );
}

static struct privilege *token_find_privilege( struct token *token, const LUID *luid, int enabled_only)
{
    struct privilege *privilege;
    LIST_FOR_EACH_ENTRY( privilege, &token->privileges, struct privilege, entry )
    {
        if (is_equal_luid( luid, &privilege->luid ))
        {
            if (enabled_only && !privilege->enabled)
                return NULL;
            return privilege;
        }
    }
    return NULL;
}

static unsigned int token_adjust_privileges( struct token *token, const LUID_AND_ATTRIBUTES *privs,
                                             unsigned int count, LUID_AND_ATTRIBUTES *mod_privs,
                                             unsigned int mod_privs_count)
{
    int i;
    unsigned int modified_count = 0;

    for (i = 0; i < count; i++)
    {
        struct privilege *privilege =
            token_find_privilege( token, &privs[i].Luid, FALSE );
        if (!privilege)
        {
            set_error( STATUS_NOT_ALL_ASSIGNED );
            continue;
        }

        if (privs[i].Attributes & SE_PRIVILEGE_REMOVE)
            privilege_remove( privilege );
        else
        {
            /* save previous state for caller */
            if (mod_privs_count)
            {
                luid_and_attr_from_privilege(mod_privs, privilege);
                mod_privs++;
                mod_privs_count--;
                modified_count++;
            }

            if (privs[i].Attributes & SE_PRIVILEGE_ENABLED)
                privilege->enabled = TRUE;
            else
                privilege->enabled = FALSE;
        }
    }
    return modified_count;
}

static void token_disable_privileges( struct token *token )
{
    struct privilege *privilege;
    LIST_FOR_EACH_ENTRY( privilege, &token->privileges, struct privilege, entry )
        privilege->enabled = FALSE;
}

/* open a security token */
DECL_HANDLER(open_token)
{
    if( req->flags & OPEN_TOKEN_THREAD )
    {
        struct thread *thread = get_thread_from_handle( req->handle, 0 );
        if (thread)
        {
            if (thread->token)
                reply->token = alloc_handle( current->process, thread->token, TOKEN_ALL_ACCESS, 0);
            else
                set_error(STATUS_NO_TOKEN);
            release_object( thread );
        }
    }
    else
    {
        struct process *process = get_process_from_handle( req->handle, 0 );
        if (process)
        {
            if (process->token)
                reply->token = alloc_handle( current->process, process->token, TOKEN_ALL_ACCESS, 0);
            else
                set_error(STATUS_NO_TOKEN);
            release_object( process );
        }
    }
}

/* adjust the privileges held by a token */
DECL_HANDLER(adjust_token_privileges)
{
    struct token *token;
    unsigned int access = TOKEN_ADJUST_PRIVILEGES;

    if (req->get_modified_state) access |= TOKEN_QUERY;

    if ((token = (struct token *)get_handle_obj( current->process, req->handle,
                                                 access, &token_ops )))
    {
        const LUID_AND_ATTRIBUTES *privs = get_req_data();
        LUID_AND_ATTRIBUTES *modified_privs = NULL;
        unsigned int priv_count = get_req_data_size() / sizeof(LUID_AND_ATTRIBUTES);
        unsigned int modified_priv_count = 0;

        if (req->get_modified_state && !req->disable_all)
        {
            int i;
            /* count modified privs */
            for (i = 0; i < priv_count; i++)
            {
                struct privilege *privilege =
                    token_find_privilege( token, &privs[i].Luid, FALSE );
                if (privilege && req->get_modified_state)
                    modified_priv_count++;
            }
            reply->len = modified_priv_count;
            modified_priv_count = min( modified_priv_count, get_reply_max_size() / sizeof(*modified_privs) );
            if (modified_priv_count)
                modified_privs = set_reply_data_size( modified_priv_count * sizeof(*modified_privs) );
        }
        reply->len = modified_priv_count * sizeof(*modified_privs);

        if (req->disable_all)
            token_disable_privileges( token );
        else
            modified_priv_count = token_adjust_privileges( token, privs,
                priv_count, modified_privs, modified_priv_count );

        release_object( token );
    }
}

/* retrieves the list of privileges that may be held be the token */
DECL_HANDLER(get_token_privileges)
{
    struct token *token;

    if ((token = (struct token *)get_handle_obj( current->process, req->handle,
                                                 TOKEN_QUERY,
                                                 &token_ops )))
    {
        int priv_count = 0;
        LUID_AND_ATTRIBUTES *privs;
        struct privilege *privilege;

        LIST_FOR_EACH_ENTRY( privilege, &token->privileges, struct privilege, entry )
            priv_count++;

        reply->len = priv_count * sizeof(*privs);
        if (reply->len <= get_reply_max_size())
        {
            privs = set_reply_data_size( priv_count * sizeof(*privs) );
            if (privs)
            {
                int i = 0;
                LIST_FOR_EACH_ENTRY( privilege, &token->privileges, struct privilege, entry )
                {
                    luid_and_attr_from_privilege( &privs[i], privilege );
                    i++;
                }
            }
        }
        else
            set_error(STATUS_BUFFER_TOO_SMALL);

        release_object( token );
    }
}

/* creates a duplicate of the token */
DECL_HANDLER(duplicate_token)
{
    struct token *src_token;
    if ((src_token = (struct token *)get_handle_obj( current->process, req->handle,
                                                     TOKEN_DUPLICATE,
                                                     &token_ops )))
    {
        /* FIXME: use req->primary and req->impersonation_level */
        struct token *token = create_token( NULL, 0 );
        if (token)
        {
            struct privilege *privilege;
            unsigned int access;

            LIST_FOR_EACH_ENTRY( privilege, &src_token->privileges, struct privilege, entry )
                privilege_add( token, &privilege->luid, privilege->enabled );

            access = req->access;
            if (access & MAXIMUM_ALLOWED) access = TOKEN_ALL_ACCESS; /* FIXME: needs general solution */
            reply->new_handle = alloc_handle( current->process, token, access, req->inherit);
            release_object( token );
        }
        release_object( src_token );
    }
}