-/* $OpenBSD: doas.c,v 1.32 2015/07/29 00:00:31 tedu Exp $ */
+/* $OpenBSD: doas.c,v 1.52 2016/04/28 04:48:56 tedu Exp $ */
/*
* Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
*
#include <sys/types.h>
#include <sys/stat.h>
+#include <sys/ioctl.h>
#include <limits.h>
+#if __OpenBSD__
+# include <login_cap.h>
+# include <readpassphrase.h>
+#endif
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <errno.h>
-#include "openbsd.h"
+#include "includes.h"
#include "doas.h"
static void __dead
usage(void)
{
- fprintf(stderr, "usage: doas [-ns] [-C config] [-u user] command [args]\n");
+ fprintf(stderr, "usage: doas [-Lns] "
+#ifdef __OpenBSD__
+ "[-a style] "
+#endif
+ "[-C config] [-u user] command [args]\n");
exit(1);
}
-size_t
-arraylen(const char **arr)
-{
- size_t cnt = 0;
-
- while (*arr) {
- cnt++;
- arr++;
- }
- return cnt;
-}
-
static int
parseuid(const char *s, uid_t *uid)
{
}
static int
-permit(uid_t uid, gid_t *groups, int ngroups, struct rule **lastr,
+permit(uid_t uid, gid_t *groups, int ngroups, const struct rule **lastr,
uid_t target, const char *cmd, const char **cmdargs)
{
int i;
struct stat sb;
yyfp = fopen(filename, "r");
- if (!yyfp) {
- if (checkperms)
- fprintf(stderr, "doas is not enabled.\n");
- else
- warn("could not open config file");
- exit(1);
- }
+ if (!yyfp)
+ err(1, checkperms ? "doas is not enabled, %s" :
+ "could not open config file %s", filename);
if (checkperms) {
if (fstat(fileno(yyfp), &sb) != 0)
exit(1);
}
-/*
- * Copy the environment variables in safeset from oldenvp to envp.
- */
-static int
-copyenvhelper(const char **oldenvp, const char **safeset, int nsafe,
- char **envp, int ei)
-{
- int i;
-
- for (i = 0; i < nsafe; i++) {
- const char **oe = oldenvp;
- while (*oe) {
- size_t len = strlen(safeset[i]);
- if (strncmp(*oe, safeset[i], len) == 0 &&
- (*oe)[len] == '=') {
- if (!(envp[ei++] = strdup(*oe)))
- err(1, "strdup");
- break;
- }
- oe++;
- }
- }
- return ei;
-}
-
-static char **
-copyenv(const char **oldenvp, struct rule *rule)
-{
- const char *safeset[] = {
- "DISPLAY", "HOME", "LOGNAME", "MAIL",
- "PATH", "TERM", "USER", "USERNAME",
- NULL
- };
- const char *badset[] = {
- "ENV",
- NULL
- };
- char **envp;
- const char **extra;
- int ei;
- int nsafe, nbad;
- int nextras = 0;
-
- /* if there was no envvar whitelist, pass all except badset ones */
- nbad = arraylen(badset);
- if ((rule->options & KEEPENV) && !rule->envlist) {
- size_t iold, inew;
- size_t oldlen = arraylen(oldenvp);
- envp = reallocarray(NULL, oldlen + 1, sizeof(char *));
- if (!envp)
- err(1, "reallocarray");
- for (inew = iold = 0; iold < oldlen; iold++) {
- size_t ibad;
- for (ibad = 0; ibad < nbad; ibad++) {
- size_t len = strlen(badset[ibad]);
- if (strncmp(oldenvp[iold], badset[ibad], len) == 0 &&
- oldenvp[iold][len] == '=') {
- break;
- }
- }
- if (ibad == nbad) {
- if (!(envp[inew] = strdup(oldenvp[iold])))
- err(1, "strdup");
- inew++;
- }
- }
- envp[inew] = NULL;
- return envp;
- }
-
- nsafe = arraylen(safeset);
- if ((extra = rule->envlist)) {
- size_t isafe;
- nextras = arraylen(extra);
- for (isafe = 0; isafe < nsafe; isafe++) {
- size_t iextras;
- for (iextras = 0; iextras < nextras; iextras++) {
- if (strcmp(extra[iextras], safeset[isafe]) == 0) {
- nextras--;
- extra[iextras] = extra[nextras];
- extra[nextras] = NULL;
- iextras--;
- }
- }
- }
- }
-
- envp = reallocarray(NULL, nsafe + nextras + 1, sizeof(char *));
- if (!envp)
- err(1, "can't allocate new environment");
-
- ei = 0;
- ei = copyenvhelper(oldenvp, safeset, nsafe, envp, ei);
- ei = copyenvhelper(oldenvp, rule->envlist, nextras, envp, ei);
- envp[ei] = NULL;
-
- return envp;
-}
-
-static void __dead
-fail(void)
-{
- fprintf(stderr, "Permission denied\n");
- exit(1);
-}
-
static void __dead
checkconfig(const char *confpath, int argc, char **argv,
uid_t uid, gid_t *groups, int ngroups, uid_t target)
{
- struct rule *rule;
+ const struct rule *rule;
+
+ if (setresuid(uid, uid, uid) != 0)
+ err(1, "setresuid");
- setresuid(uid, uid, uid);
parseconfig(confpath, 0);
if (!argc)
exit(0);
}
}
+#ifdef USE_BSD_AUTH
+static void
+authuser(char *myname, char *login_style, int persist)
+{
+ char *challenge = NULL, *response, rbuf[1024], cbuf[128];
+ auth_session_t *as;
+ int fd = -1;
+
+ if (persist)
+ fd = open("/dev/tty", O_RDWR);
+ if (fd != -1) {
+ if (ioctl(fd, TIOCCHKVERAUTH) == 0)
+ goto good;
+ }
+
+ if (!(as = auth_userchallenge(myname, login_style, "auth-doas",
+ &challenge)))
+ errx(1, "Authorization failed");
+ if (!challenge) {
+ char host[HOST_NAME_MAX + 1];
+ if (gethostname(host, sizeof(host)))
+ snprintf(host, sizeof(host), "?");
+ snprintf(cbuf, sizeof(cbuf),
+ "\rdoas (%.32s@%.32s) password: ", myname, host);
+ challenge = cbuf;
+ }
+ response = readpassphrase(challenge, rbuf, sizeof(rbuf),
+ RPP_REQUIRE_TTY);
+ if (response == NULL && errno == ENOTTY) {
+ syslog(LOG_AUTHPRIV | LOG_NOTICE,
+ "tty required for %s", myname);
+ errx(1, "a tty is required");
+ }
+ if (!auth_userresponse(as, response, 0)) {
+ explicit_bzero(rbuf, sizeof(rbuf));
+ syslog(LOG_AUTHPRIV | LOG_NOTICE,
+ "failed auth for %s", myname);
+ errx(1, "Authorization failed");
+ }
+ explicit_bzero(rbuf, sizeof(rbuf));
+good:
+ if (fd != -1) {
+ int secs = 5 * 60;
+ ioctl(fd, TIOCSETVERAUTH, &secs);
+ close(fd);
+ }
+}
+#endif
+
int
-main(int argc, char **argv, char **envp)
+main(int argc, char **argv)
{
const char *safepath = "/bin:/sbin:/usr/bin:/usr/sbin:"
"/usr/local/bin:/usr/local/sbin";
char cmdline[LINE_MAX];
char myname[_PW_NAME_LEN + 1];
struct passwd *pw;
- struct rule *rule;
+ const struct rule *rule;
uid_t uid;
uid_t target = 0;
gid_t groups[NGROUPS_MAX + 1];
int i, ch;
int sflag = 0;
int nflag = 0;
+ char cwdpath[PATH_MAX];
+ const char *cwd;
+ char **envp;
+#ifdef USE_BSD_AUTH
+ char *login_style = NULL;
+#endif
+
+ setprogname("doas");
+
+ closefrom(STDERR_FILENO + 1);
uid = getuid();
- while ((ch = getopt(argc, argv, "C:nsu:")) != -1) {
+
+#ifdef USE_BSD_AUTH
+# define OPTSTRING "a:C:Lnsu:"
+#else
+# define OPTSTRING "+C:Lnsu:"
+#endif
+
+ while ((ch = getopt(argc, argv, OPTSTRING)) != -1) {
switch (ch) {
+#ifdef USE_BSD_AUTH
+ case 'a':
+ login_style = optarg;
+ break;
+#endif
case 'C':
confpath = optarg;
break;
+ case 'L':
+#if defined(USE_BSD_AUTH)
+ i = open("/dev/tty", O_RDWR);
+ if (i != -1)
+ ioctl(i, TIOCCLRVERAUTH);
+ exit(i == -1);
+#elif defined(USE_TIMESTAMP)
+ exit(timestamp_clear() == -1);
+#else
+ exit(0);
+#endif
case 'u':
if (parseuid(optarg, &target) != 0)
errx(1, "unknown user");
} else if ((!sflag && !argc) || (sflag && argc))
usage();
- uid = getuid();
pw = getpwuid(uid);
if (!pw)
err(1, "getpwuid failed");
if (sflag) {
sh = getenv("SHELL");
- if (sh == NULL || *sh == '\0')
- shargv[0] = pw->pw_shell;
- else
+ if (sh == NULL || *sh == '\0') {
+ shargv[0] = strdup(pw->pw_shell);
+ if (shargv[0] == NULL)
+ err(1, NULL);
+ } else
shargv[0] = sh;
argv = shargv;
argc = 1;
exit(1); /* fail safe */
}
+ if (geteuid())
+ errx(1, "not installed setuid");
+
parseconfig("/etc/doas.conf", 1);
/* cmdline is used only for logging, no need to abort on truncate */
- (void) strlcpy(cmdline, argv[0], sizeof(cmdline));
+ (void)strlcpy(cmdline, argv[0], sizeof(cmdline));
for (i = 1; i < argc; i++) {
if (strlcat(cmdline, " ", sizeof(cmdline)) >= sizeof(cmdline))
break;
cmd = argv[0];
if (!permit(uid, groups, ngroups, &rule, target, cmd,
- (const char**)argv + 1)) {
+ (const char **)argv + 1)) {
syslog(LOG_AUTHPRIV | LOG_NOTICE,
"failed command for %s: %s", myname, cmdline);
- fail();
+ errc(1, EPERM, NULL);
}
+#if defined(__OpenBSD__)
if (!(rule->options & NOPASS)) {
if (nflag)
errx(1, "Authorization required");
- if (!auth_userokay(myname, NULL, NULL, NULL)) {
- syslog(LOG_AUTHPRIV | LOG_NOTICE,
- "failed password for %s", myname);
- fail();
- }
+
+ authuser(myname, login_style, rule->options & PERSIST);
+ }
+
+ if (pledge("stdio rpath getpw exec id", NULL) == -1)
+ err(1, "pledge");
+
+ pw = getpwuid(target);
+ if (!pw)
+ errx(1, "no passwd entry for target");
+
+#elif defined(USE_SHADOW)
+ if (!(rule->options & NOPASS)) {
+ if (nflag)
+ errx(1, "Authorization required");
+
+ shadowauth(myname, rule->options & PERSIST);
}
- envp = copyenv((const char **)envp, rule);
pw = getpwuid(target);
if (!pw)
errx(1, "no passwd entry for target");
+
+#elif defined(USE_PAM)
+ pw = getpwuid(target);
+ if (!pw)
+ errx(1, "no passwd entry for target");
+
+ pamauth(pw->pw_name, myname, !nflag, rule->options & NOPASS,
+ rule->options & PERSIST);
+
+#else
+ (void) nflag;
+ if (!(rule->options & NOPASS)) {
+ errx(1, "Authorization required");
+ }
+#endif
+
+#ifdef HAVE_SETUSERCONTEXT
if (setusercontext(NULL, pw, target, LOGIN_SETGROUP |
LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | LOGIN_SETUMASK |
LOGIN_SETUSER) != 0)
errx(1, "failed to set user context for target");
-
- syslog(LOG_AUTHPRIV | LOG_INFO, "%s ran command as %s: %s",
- myname, pw->pw_name, cmdline);
- if (setenv("PATH", safepath, 1) == -1)
- err(1, "failed to set PATH '%s'", safepath);
+#else
+ if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0)
+ err(1, "setresgid");
+ if (initgroups(pw->pw_name, pw->pw_gid) != 0)
+ err(1, "initgroups");
+ if (setresuid(target, target, target) != 0)
+ err(1, "setresuid");
+#endif
+
+#ifdef __OpenBSD__
+ if (pledge("stdio rpath exec", NULL) == -1)
+ err(1, "pledge");
+#endif
+
+ if (getcwd(cwdpath, sizeof(cwdpath)) == NULL)
+ cwd = "(failed)";
+ else
+ cwd = cwdpath;
+
+#ifdef __OpenBSD__
+ if (pledge("stdio exec", NULL) == -1)
+ err(1, "pledge");
+#endif
+
+ syslog(LOG_AUTHPRIV | LOG_INFO, "%s ran command %s as %s from %s",
+ myname, cmdline, pw->pw_name, cwd);
+
+ envp = prepenv(rule);
+
+ if (rule->cmd) {
+ if (setenv("PATH", safepath, 1) == -1)
+ err(1, "failed to set PATH '%s'", safepath);
+ }
execvpe(cmd, argv, envp);
if (errno == ENOENT)
errx(1, "%s: command not found", cmd);
projects / opendoas.git / blobdiff