sudo/plugins/sudoers/testsudoers.c

781 lines
20 KiB
C

/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 1996, 1998-2005, 2007-2023
* Todd C. Miller <Todd.Miller@sudo.ws>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Sponsored in part by the Defense Advanced Research Projects
* Agency (DARPA) and Air Force Research Laboratory, Air Force
* Materiel Command, USAF, under agreement number F39502-99-1-0512.
*/
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
#include <config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_STDBOOL_H
# include <stdbool.h>
#else
# include <compat/stdbool.h>
#endif /* HAVE_STDBOOL_H */
#include <string.h>
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#include <unistd.h>
#include <errno.h>
#include <testsudoers_pwutil.h>
#include <toke.h>
#include <tsgetgrpw.h>
#include <sudoers.h>
#include <interfaces.h>
#include <sudo_conf.h>
#include <sudo_lbuf.h>
#include <gram.h>
#ifndef YYDEBUG
# define YYDEBUG 0
#endif
enum sudoers_formats {
format_ldif,
format_sudoers
};
/*
* Function Prototypes
*/
static void dump_sudoers(void);
static void set_runaspw(struct sudoers_context *ctx, const char *);
static void set_runasgr(struct sudoers_context *ctx, const char *);
static int testsudoers_error(const char * restrict buf);
static int testsudoers_output(const char * restrict buf);
sudo_noreturn static void usage(void);
static void cb_lookup(const struct sudoers_parse_tree *parse_tree, const struct userspec *us, int user_match, const struct privilege *priv, int host_match, const struct cmndspec *cs, int date_match, int runas_match, int cmnd_match, void *closure);
static int testsudoers_query(struct sudoers_context *ctx, const struct sudo_nss *nss, struct passwd *pw);
/*
* Globals
*/
static const char *orig_cmnd;
static char *runas_group, *runas_user;
#if defined(SUDO_DEVEL) && defined(__OpenBSD__)
extern char *malloc_options;
#endif
sudo_dso_public int main(int argc, char *argv[]);
int
main(int argc, char *argv[])
{
struct sudoers_context test_ctx = SUDOERS_CONTEXT_INITIALIZER;
struct sudo_nss_list snl = TAILQ_HEAD_INITIALIZER(snl);
enum sudoers_formats input_format = format_sudoers;
struct sudo_nss testsudoers_nss;
char *p, *grfile, *pwfile, *shells;
const char *host = NULL;
const char *errstr;
int ch, dflag, exitcode = EXIT_FAILURE;
unsigned int validated;
int status = FOUND;
int pwflag = 0;
char cwdbuf[PATH_MAX];
time_t now;
id_t id;
debug_decl(main, SUDOERS_DEBUG_MAIN);
#if defined(SUDO_DEVEL) && defined(__OpenBSD__)
malloc_options = "S";
#endif
#if YYDEBUG
sudoersdebug = 1;
#endif
initprogname(argc > 0 ? argv[0] : "testsudoers");
if (!sudoers_initlocale(setlocale(LC_ALL, ""), def_sudoers_locale))
sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
sudo_warn_set_locale_func(sudoers_warn_setlocale);
bindtextdomain("sudoers", LOCALEDIR); /* XXX - should have own domain */
textdomain("sudoers");
time(&now);
/* Initialize the debug subsystem. */
if (sudo_conf_read(NULL, SUDO_CONF_DEBUG) == -1)
goto done;
if (!sudoers_debug_register(getprogname(), sudo_conf_debug_files(getprogname())))
goto done;
dflag = 0;
grfile = pwfile = shells = NULL;
test_ctx.mode = MODE_RUN;
while ((ch = getopt(argc, argv, "+D:dg:G:h:i:L:lP:p:R:S:T:tu:U:v")) != -1) {
switch (ch) {
case 'D':
test_ctx.runas.cwd = optarg;
break;
case 'd':
dflag = 1;
break;
case 'G':
id = sudo_strtoid(optarg, &errstr);
if (errstr != NULL)
sudo_fatalx("group-ID %s: %s", optarg, errstr);
test_ctx.parser_conf.sudoers_gid = (gid_t)id;
break;
case 'g':
runas_group = optarg;
SET(test_ctx.settings.flags, RUNAS_GROUP_SPECIFIED);
break;
case 'h':
host = optarg;
break;
case 'i':
if (strcasecmp(optarg, "ldif") == 0) {
input_format = format_ldif;
} else if (strcasecmp(optarg, "sudoers") == 0) {
input_format = format_sudoers;
} else {
sudo_warnx(U_("unsupported input format %s"), optarg);
usage();
}
break;
case 'L':
test_ctx.runas.list_pw = sudo_getpwnam(optarg);
if (test_ctx.runas.list_pw == NULL) {
sudo_warnx(U_("unknown user %s"), optarg);
usage();
}
FALLTHROUGH;
case 'l':
if (test_ctx.mode != MODE_RUN) {
sudo_warnx(
"only one of the -l or -v flags may be specified");
usage();
}
test_ctx.mode = MODE_LIST;
pwflag = I_LISTPW;
orig_cmnd = "list";
break;
case 'p':
pwfile = optarg;
break;
case 'P':
grfile = optarg;
break;
case 'S':
shells = optarg;
break;
case 'T':
now = parse_gentime(optarg);
if (now == -1)
sudo_fatalx("invalid time: %s", optarg);
break;
case 'R':
test_ctx.runas.chroot = optarg;
break;
case 't':
trace_print = testsudoers_error;
break;
case 'U':
id = sudo_strtoid(optarg, &errstr);
if (errstr != NULL)
sudo_fatalx("user-ID %s: %s", optarg, errstr);
test_ctx.parser_conf.sudoers_uid = (uid_t)id;
break;
case 'u':
runas_user = optarg;
SET(test_ctx.settings.flags, RUNAS_USER_SPECIFIED);
break;
case 'v':
if (test_ctx.mode != MODE_RUN) {
sudo_warnx(
"only one of the -l or -v flags may be specified");
usage();
}
test_ctx.mode = MODE_VALIDATE;
pwflag = I_VERIFYPW;
orig_cmnd = "validate";
break;
default:
usage();
/* NOTREACHED */
}
}
argc -= optind;
argv += optind;
if (grfile != NULL || pwfile != NULL || shells != NULL) {
/* Set group/passwd/shells file and init the cache. */
if (grfile)
testsudoers_setgrfile(grfile);
if (pwfile)
testsudoers_setpwfile(pwfile);
if (shells)
testsudoers_setshellfile(shells);
/* Use custom passwd/group backend. */
sudo_pwutil_set_backend(testsudoers_make_pwitem,
testsudoers_make_gritem, testsudoers_make_gidlist_item,
testsudoers_make_grlist_item, testsudoers_valid_shell);
}
if (argc < 2) {
/* No command or user specified. */
if (dflag) {
orig_cmnd = "true";
} else if (pwflag == 0) {
usage();
}
test_ctx.user.name = strdup(argc ? *argv++ : "root");
if (test_ctx.user.name == NULL) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
argc = 0;
} else {
if (argc > 2 && test_ctx.mode == MODE_LIST)
test_ctx.mode = MODE_CHECK;
test_ctx.user.name = strdup(*argv++);
if (test_ctx.user.name == NULL) {
sudo_fatalx(U_("%s: %s"), __func__,
U_("unable to allocate memory"));
}
argc--;
if (orig_cmnd == NULL) {
orig_cmnd = *argv++;
argc--;
}
}
test_ctx.user.cmnd = strdup(orig_cmnd);
if (test_ctx.user.cmnd == NULL)
sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
test_ctx.user.cmnd_base = sudo_basename(test_ctx.user.cmnd);
if (getcwd(cwdbuf, sizeof(cwdbuf)) == NULL)
strlcpy(cwdbuf, "/", sizeof(cwdbuf));
test_ctx.user.cwd = strdup(cwdbuf);
if (test_ctx.user.cwd == NULL)
sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
if ((test_ctx.user.pw = sudo_getpwnam(test_ctx.user.name)) == NULL)
sudo_fatalx(U_("unknown user %s"), test_ctx.user.name);
test_ctx.user.uid = test_ctx.user.pw->pw_uid;
test_ctx.user.gid = test_ctx.user.pw->pw_gid;
if (!sudoers_sethost(&test_ctx, host, NULL))
goto done;
/* Fill in test_ctx.user.cmnd_args from argv. */
if (argc > 0) {
size_t n, size = 0;
char *cp;
int i;
for (i = 0; i < argc; i++)
size += strlen(argv[i]) + 1;
if ((test_ctx.user.cmnd_args = malloc(size)) == NULL)
sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
for (cp = test_ctx.user.cmnd_args, i = 0; i < argc; i++) {
n = strlcpy(cp, argv[i], size - (size_t)(cp - test_ctx.user.cmnd_args));
if (n >= size - (size_t)(cp - test_ctx.user.cmnd_args))
sudo_fatalx(U_("internal error, %s overflow"), getprogname());
cp += n;
*cp++ = ' ';
}
*--cp = '\0';
}
/* Initialize default values. */
if (!init_defaults())
sudo_fatalx("%s", U_("unable to initialize sudoers default values"));
/* Set group_plugin callback. */
sudo_defs_table[I_GROUP_PLUGIN].callback = cb_group_plugin;
/* Set runas callback. */
sudo_defs_table[I_RUNAS_DEFAULT].callback = cb_runas_default;
/* Set locale callback. */
sudo_defs_table[I_SUDOERS_LOCALE].callback = sudoers_locale_callback;
/* Load ip addr/mask for each interface. */
if (get_net_ifs(&p) > 0) {
if (!set_interfaces(p))
sudo_fatal("%s", U_("unable to parse network address list"));
free(p);
}
/* Initialize the parser and set sudoers filename to "sudoers". */
test_ctx.parser_conf.strict = true;
test_ctx.parser_conf.verbose = 2;
init_parser(&test_ctx, "sudoers");
/*
* Set runas passwd/group entries based on command line or sudoers.
* Note that if runas_group was specified without runas_user we
* run the command as the invoking user.
*/
if (runas_group != NULL) {
set_runasgr(&test_ctx, runas_group);
set_runaspw(&test_ctx, runas_user ? runas_user : test_ctx.user.name);
} else
set_runaspw(&test_ctx, runas_user ? runas_user : def_runas_default);
/* Parse the policy file. */
sudoers_setlocale(SUDOERS_LOCALE_SUDOERS, NULL);
switch (input_format) {
case format_ldif:
if (!sudoers_parse_ldif(&parsed_policy, stdin, NULL, true)) {
(void) puts("Parse error in LDIF");
parse_error = true;
}
break;
case format_sudoers:
if (sudoersparse() != 0)
parse_error = true;
break;
default:
sudo_fatalx("error: unhandled input %d", input_format);
}
if (!update_defaults(&test_ctx, &parsed_policy, NULL, SETDEF_ALL, false))
parse_error = true;
if (!parse_error)
(void) puts("Parses OK");
if (dflag) {
(void) putchar('\n');
dump_sudoers();
if (argc < 2) {
exitcode = parse_error ? 1 : 0;
goto done;
}
}
/* Fake up a minimal sudo nss list with the parsed policy. */
TAILQ_INSERT_TAIL(&snl, &testsudoers_nss, entries);
testsudoers_nss.query = testsudoers_query;
testsudoers_nss.parse_tree = &parsed_policy;
printf("\nEntries for user %s:\n", test_ctx.user.name);
validated = sudoers_lookup(&snl, &test_ctx, now, cb_lookup, NULL,
&status, pwflag);
/* Validate user-specified chroot or cwd (if any) and runas user shell. */
if (ISSET(validated, VALIDATE_SUCCESS)) {
if (!user_shell_valid(test_ctx.runas.pw)) {
printf(U_("\nInvalid shell for user %s: %s\n"),
test_ctx.runas.pw->pw_name, test_ctx.runas.pw->pw_shell);
CLR(validated, VALIDATE_SUCCESS);
SET(validated, VALIDATE_FAILURE);
}
if (check_user_runchroot(test_ctx.runas.chroot) != true) {
printf("\nUser %s is not allowed to change root directory to %s\n",
test_ctx.user.name, test_ctx.runas.chroot);
CLR(validated, VALIDATE_SUCCESS);
SET(validated, VALIDATE_FAILURE);
}
if (check_user_runcwd(test_ctx.runas.cwd) != true) {
printf("\nUser %s is not allowed to change directory to %s\n",
test_ctx.user.name, test_ctx.runas.cwd);
CLR(validated, VALIDATE_SUCCESS);
SET(validated, VALIDATE_FAILURE);
}
}
if (def_authenticate) {
puts(U_("\nPassword required"));
}
/*
* Exit codes:
* 0 - parsed OK and command matched.
* 1 - parse error
* 2 - command not matched
* 3 - command denied
*/
if (parse_error || ISSET(validated, VALIDATE_ERROR)) {
puts(U_("\nParse error"));
exitcode = 1;
} else if (ISSET(validated, VALIDATE_SUCCESS)) {
puts(U_("\nCommand allowed"));
exitcode = 0;
} else if (ISSET(validated, VALIDATE_FAILURE)) {
puts(U_("\nCommand denied"));
exitcode = 3;
} else {
puts(U_("\nCommand unmatched"));
exitcode = 2;
}
done:
sudoers_ctx_free(&test_ctx);
sudo_freepwcache();
sudo_freegrcache();
sudo_debug_exit_int(__func__, __FILE__, __LINE__, sudo_debug_subsys, exitcode);
return exitcode;
}
static void
set_runaspw(struct sudoers_context *ctx, const char *user)
{
struct passwd *pw = NULL;
debug_decl(set_runaspw, SUDOERS_DEBUG_UTIL);
if (*user == '#') {
const char *errstr;
uid_t uid = sudo_strtoid(user + 1, &errstr);
if (errstr == NULL) {
if ((pw = sudo_getpwuid(uid)) == NULL)
pw = sudo_fakepwnam(user, ctx->user.gid);
}
}
if (pw == NULL) {
if ((pw = sudo_getpwnam(user)) == NULL)
sudo_fatalx(U_("unknown user %s"), user);
}
if (ctx->runas.pw != NULL)
sudo_pw_delref(ctx->runas.pw);
ctx->runas.pw = pw;
debug_return;
}
static void
set_runasgr(struct sudoers_context *ctx, const char *group)
{
struct group *gr = NULL;
debug_decl(set_runasgr, SUDOERS_DEBUG_UTIL);
if (*group == '#') {
const char *errstr;
gid_t gid = sudo_strtoid(group + 1, &errstr);
if (errstr == NULL) {
if ((gr = sudo_getgrgid(gid)) == NULL)
gr = sudo_fakegrnam(group);
}
}
if (gr == NULL) {
if ((gr = sudo_getgrnam(group)) == NULL)
sudo_fatalx(U_("unknown group %s"), group);
}
if (ctx->runas.gr != NULL)
sudo_gr_delref(ctx->runas.gr);
ctx->runas.gr = gr;
debug_return;
}
bool
cb_log_input(struct sudoers_context *ctx, const char *file,
int line, int column, const union sudo_defs_val *sd_un, int op)
{
return true;
}
bool
cb_log_output(struct sudoers_context *ctx, const char *file,
int line, int column, const union sudo_defs_val *sd_un, int op)
{
return true;
}
/*
* Callback for runas_default sudoers setting.
*/
bool
cb_runas_default(struct sudoers_context *ctx, const char *file,
int line, int column, const union sudo_defs_val *sd_un, int op)
{
/* Only reset runaspw if user didn't specify one. */
if (!runas_user && !runas_group)
set_runaspw(ctx, sd_un->str);
return true;
}
bool
sudo_nss_can_continue(const struct sudo_nss *nss, int match)
{
return true;
}
void
sudo_setspent(void)
{
return;
}
void
sudo_endspent(void)
{
return;
}
FILE *
open_sudoers(const char *file, char **outfile, bool doedit, bool *keepopen)
{
struct stat sb;
FILE *fp = NULL;
const char *base;
int error, fd;
debug_decl(open_sudoers, SUDOERS_DEBUG_UTIL);
/* Report errors using the basename for consistent test output. */
base = sudo_basename(file);
fd = sudo_secure_open_file(file, sudoers_file_uid(), sudoers_file_gid(),
&sb, &error);
if (fd != -1) {
if ((fp = fdopen(fd, "r")) == NULL) {
sudo_warn("unable to open %s", base);
close(fd);
}
} else {
switch (error) {
case SUDO_PATH_MISSING:
sudo_warn("unable to open %s", base);
break;
case SUDO_PATH_BAD_TYPE:
sudo_warnx("%s is not a regular file", base);
break;
case SUDO_PATH_WRONG_OWNER:
sudo_warnx("%s should be owned by uid %u",
base, (unsigned int) sudoers_file_uid());
break;
case SUDO_PATH_WORLD_WRITABLE:
sudo_warnx("%s is world writable", base);
break;
case SUDO_PATH_GROUP_WRITABLE:
sudo_warnx("%s should be owned by gid %u",
base, (unsigned int) sudoers_file_gid());
break;
default:
sudo_warnx("%s: internal error, unexpected error %d",
__func__, error);
break;
}
}
debug_return_ptr(fp);
}
bool
init_envtables(void)
{
return(true);
}
bool
set_perms(const struct sudoers_context *ctx, int perm)
{
return true;
}
bool
restore_perms(void)
{
return true;
}
void
init_eventlog_config(void)
{
return;
}
bool
pivot_root(const char *new_root, struct sudoers_pivot *state)
{
return true;
}
bool
unpivot_root(struct sudoers_pivot *state)
{
return true;
}
int
set_cmnd_path(struct sudoers_context *ctx, const char *runchroot)
{
/* Reallocate test_ctx.user.cmnd to catch bugs in command_matches(). */
char *new_cmnd = strdup(orig_cmnd);
if (new_cmnd == NULL)
return NOT_FOUND_ERROR;
free(ctx->user.cmnd);
ctx->user.cmnd = new_cmnd;
return FOUND;
}
static void
cb_lookup(const struct sudoers_parse_tree *parse_tree,
const struct userspec *us, int user_match, const struct privilege *priv,
int host_match, const struct cmndspec *cs, int date_match, int runas_match,
int cmnd_match, void *closure)
{
static const struct privilege *prev_priv;
struct sudo_lbuf lbuf;
/* Only output info for the selected user. */
if (user_match != ALLOW) {
prev_priv = NULL;
return;
}
if (priv != prev_priv) {
/* No word wrap on output. */
sudo_lbuf_init(&lbuf, testsudoers_output, 0, NULL, 0);
sudo_lbuf_append(&lbuf, "\n");
sudoers_format_privilege(&lbuf, &parsed_policy, priv, false);
sudo_lbuf_print(&lbuf);
sudo_lbuf_destroy(&lbuf);
printf("\thost %s\n", host_match == ALLOW ? "allowed" :
host_match == DENY ? "denied" : "unmatched");
}
if (host_match == ALLOW) {
if (date_match != UNSPEC)
printf("\tdate %s\n", date_match == ALLOW ? "allowed" : "denied");
if (date_match != DENY) {
printf("\trunas %s\n", runas_match == ALLOW ? "allowed" :
runas_match == DENY ? "denied" : "unmatched");
if (runas_match == ALLOW) {
printf("\tcmnd %s\n", cmnd_match == ALLOW ? "allowed" :
cmnd_match == DENY ? "denied" : "unmatched");
}
}
}
prev_priv = priv;
}
static int
testsudoers_query(struct sudoers_context *ctx, const struct sudo_nss *nss,
struct passwd *pw)
{
/* Nothing to do. */
return 0;
}
static bool
print_defaults(struct sudo_lbuf *lbuf)
{
struct defaults *def, *next;
debug_decl(print_defaults, SUDOERS_DEBUG_UTIL);
TAILQ_FOREACH_SAFE(def, &parsed_policy.defaults, entries, next)
sudoers_format_default_line(lbuf, &parsed_policy, def, &next, false);
debug_return_bool(!sudo_lbuf_error(lbuf));
}
static int
print_alias(struct sudoers_parse_tree *parse_tree, struct alias *a, void *v)
{
struct sudo_lbuf *lbuf = v;
struct member *m;
debug_decl(print_alias, SUDOERS_DEBUG_UTIL);
sudo_lbuf_append(lbuf, "%s %s = ", alias_type_to_string(a->type),
a->name);
TAILQ_FOREACH(m, &a->members, entries) {
if (m != TAILQ_FIRST(&a->members))
sudo_lbuf_append(lbuf, ", ");
sudoers_format_member(lbuf, parse_tree, m, NULL, UNSPEC);
}
sudo_lbuf_append(lbuf, "\n");
debug_return_int(sudo_lbuf_error(lbuf) ? -1 : 0);
}
static bool
print_aliases(struct sudo_lbuf *lbuf)
{
debug_decl(print_aliases, SUDOERS_DEBUG_UTIL);
debug_return_bool(alias_apply(&parsed_policy, print_alias, lbuf));
}
static void
dump_sudoers(void)
{
struct sudo_lbuf lbuf;
debug_decl(dump_sudoers, SUDOERS_DEBUG_UTIL);
/* No word wrap on output. */
sudo_lbuf_init(&lbuf, testsudoers_output, 0, NULL, 0);
/* Print Defaults */
if (!print_defaults(&lbuf))
goto done;
if (lbuf.len > 0) {
sudo_lbuf_print(&lbuf);
sudo_lbuf_append(&lbuf, "\n");
}
/* Print Aliases */
if (!print_aliases(&lbuf))
goto done;
if (lbuf.len > 1) {
sudo_lbuf_print(&lbuf);
sudo_lbuf_append(&lbuf, "\n");
}
/* Print User_Specs */
if (!sudoers_format_userspecs(&lbuf, &parsed_policy, NULL, false, true))
goto done;
if (lbuf.len > 1) {
sudo_lbuf_print(&lbuf);
}
done:
if (sudo_lbuf_error(&lbuf)) {
if (errno == ENOMEM)
sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
}
sudo_lbuf_destroy(&lbuf);
debug_return;
}
static int
testsudoers_output(const char * restrict buf)
{
return fputs(buf, stdout);
}
static int
testsudoers_error(const char *restrict buf)
{
return fputs(buf, stderr);
}
sudo_noreturn static void
usage(void)
{
(void) fprintf(stderr, "usage: %s [-dltv] [-G sudoers_gid] [-g group] [-h host] [-i input_format] [-L list_user] [-P grfile] [-p pwfile] [-S shells] [-U sudoers_uid] [-u user] <user> <command> [args]\n", getprogname());
exit(EXIT_FAILURE);
}