-/* $OpenBSD: doas.c,v 1.16 2015/07/21 16:12:04 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/stat.h>
#include <limits.h>
-#include <login_cap.h>
-#include <bsd_auth.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <errno.h>
+#include "includes.h"
+
#include "doas.h"
+static void __dead
+version(void)
+{
+ fprintf(stderr, "doas: version %s built %s\n", VERSION, __DATE__);
+ exit(1);
+}
+
static void __dead
usage(void)
{
- fprintf(stderr, "usage: doas [-s] [-u user] command [args]\n");
+ fprintf(stderr, "usage: doas [-nsv] [-a style] [-C config] [-u user]"
+ " command [args]\n");
exit(1);
}
{
size_t cnt = 0;
- while (*arr) {
- cnt++;
- arr++;
+ if (arr) {
+ while (*arr) {
+ cnt++;
+ arr++;
+ }
}
return cnt;
}
return 0;
}
-static gid_t
-strtogid(const char *s)
+static int
+parsegid(const char *s, gid_t *gid)
{
struct group *gr;
const char *errstr;
- gid_t gid;
- if ((gr = getgrnam(s)) != NULL)
- return gr->gr_gid;
- gid = strtonum(s, 0, GID_MAX, &errstr);
+ if ((gr = getgrnam(s)) != NULL) {
+ *gid = gr->gr_gid;
+ return 0;
+ }
+ *gid = strtonum(s, 0, GID_MAX, &errstr);
if (errstr)
return -1;
- return gid;
+ return 0;
}
static int
int i;
if (r->ident[0] == ':') {
- gid_t rgid = strtogid(r->ident + 1);
- if (rgid == -1)
+ gid_t rgid;
+ if (parsegid(r->ident + 1, &rgid) == -1)
return 0;
for (i = 0; i < ngroups; i++) {
if (rgid == groups[i])
*lastr = NULL;
for (i = 0; i < nrules; i++) {
- if (match(uid, groups, ngroups, target, cmd, cmdargs, rules[i]))
+ if (match(uid, groups, ngroups, target, cmd,
+ cmdargs, rules[i]))
*lastr = rules[i];
}
if (!*lastr)
}
static void
-parseconfig(const char *filename)
+parseconfig(const char *filename, int checkperms)
{
extern FILE *yyfp;
extern int yyparse(void);
struct stat sb;
yyfp = fopen(filename, "r");
- if (!yyfp) {
- fprintf(stderr, "doas is not enabled.\n");
- 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)
+ err(1, "fstat(\"%s\")", filename);
+ if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0)
+ errx(1, "%s is writable by group or other", filename);
+ if (sb.st_uid != 0)
+ errx(1, "%s is not owned by root", filename);
}
- if (fstat(fileno(yyfp), &sb) != 0)
- err(1, "fstat(\"%s\")", filename);
- if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0)
- errx(1, "%s is writable by group or other", filename);
- if (sb.st_uid != 0)
- errx(1, "%s is not owned by root", filename);
-
yyparse();
fclose(yyfp);
+ if (parse_errors)
+ exit(1);
}
-static int
-copyenvhelper(const char **oldenvp, const char **safeset, int nsafe,
- char **envp, int ei)
+static void __dead
+checkconfig(const char *confpath, int argc, char **argv,
+ uid_t uid, gid_t *groups, int ngroups, uid_t target)
{
- int i;
+ struct rule *rule;
- 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;
-}
+ if (setresuid(uid, uid, uid) != 0)
+ err(1, "setresuid");
-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;
-
- nbad = arraylen(badset);
- if ((rule->options & KEEPENV) && !rule->envlist) {
- size_t i, ii;
- size_t oldlen = arraylen(oldenvp);
- envp = reallocarray(NULL, oldlen + 1, sizeof(char *));
- if (!envp)
- err(1, "reallocarray");
- for (ii = i = 0; i < oldlen; i++) {
- size_t j;
- for (j = 0; j < nbad; j++) {
- size_t len = strlen(badset[j]);
- if (strncmp(oldenvp[i], badset[j], len) == 0 &&
- oldenvp[i][len] == '=') {
- break;
- }
- }
- if (j == nbad) {
- if (!(envp[ii] = strdup(oldenvp[i])))
- err(1, "strdup");
- ii++;
- }
- }
- envp[ii] = NULL;
- return envp;
- }
+ parseconfig(confpath, 0);
+ if (!argc)
+ exit(0);
- nsafe = arraylen(safeset);
- if ((extra = rule->envlist)) {
- size_t i;
- nextras = arraylen(extra);
- for (i = 0; i < nsafe; i++) {
- size_t j;
- for (j = 0; j < nextras; j++) {
- if (strcmp(extra[j], safeset[i]) == 0) {
- extra[j--] = extra[nextras--];
- extra[nextras] = NULL;
- }
- }
- }
+ if (permit(uid, groups, ngroups, &rule, target, argv[0],
+ (const char **)argv + 1)) {
+ printf("permit%s\n", (rule->options & NOPASS) ? " nopass" : "");
+ exit(0);
+ } else {
+ printf("deny\n");
+ exit(1);
}
-
- 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);
}
int
{
const char *safepath = "/bin:/sbin:/usr/bin:/usr/sbin:"
"/usr/local/bin:/usr/local/sbin";
+ const char *confpath = NULL;
char *shargv[] = { NULL, NULL };
char *sh;
const char *cmd;
+ struct env *env;
char cmdline[LINE_MAX];
char myname[_PW_NAME_LEN + 1];
struct passwd *pw;
int ngroups;
int i, ch;
int sflag = 0;
+ int nflag = 0;
+ int vflag = 0;
+ char cwdpath[PATH_MAX];
+ const char *cwd;
+#ifdef HAVE_BSD_AUTH_H
+ char *login_style = NULL;
+#endif
+
+ setprogname("doas");
+
+ if (pledge("stdio rpath getpw tty proc exec id", NULL) == -1)
+ err(1, "pledge");
+
+ /* closefrom(STDERR_FILENO + 1); */
- while ((ch = getopt(argc, argv, "C:su:")) != -1) {
+ uid = getuid();
+
+#ifdef HAVE_BSD_AUTH_H
+# define OPTSTRING "a:C:nsu:v"
+#else
+# define OPTSTRING "C:nsu:v"
+#endif
+
+ while ((ch = getopt(argc, argv, OPTSTRING)) != -1) {
switch (ch) {
+#ifdef HAVE_BSD_AUTH_H
+ case 'a':
+ login_style = optarg;
+ break;
+#endif
case 'C':
- target = getuid();
- setresuid(target, target, target);
- parseconfig(optarg);
- exit(0);
+ confpath = optarg;
+ break;
case 'u':
if (parseuid(optarg, &target) != 0)
errx(1, "unknown user");
break;
+ case 'n':
+ nflag = 1;
+ break;
case 's':
sflag = 1;
break;
+ case 'v':
+ vflag = 1;
+ break;
default:
usage();
break;
argv += optind;
argc -= optind;
- if ((!sflag && !argc) || (sflag && argc))
- usage();
+ if (vflag)
+ version();
- parseconfig("/etc/doas.conf");
+ if (confpath) {
+ if (sflag)
+ usage();
+ } else if ((!sflag && !argc) || (sflag && argc))
+ usage();
- uid = getuid();
pw = getpwuid(uid);
if (!pw)
err(1, "getpwuid failed");
argc = 1;
}
- cmd = argv[0];
- if (strlcpy(cmdline, argv[0], sizeof(cmdline)) >= sizeof(cmdline))
- errx(1, "command line too long");
+ if (confpath) {
+ checkconfig(confpath, argc, argv, uid, groups, ngroups,
+ target);
+ exit(1); /* fail safe */
+ }
+
+ parseconfig("/etc/doas.conf", 1);
+
+ /* cmdline is used only for logging, no need to abort on truncate */
+ (void) strlcpy(cmdline, argv[0], sizeof(cmdline));
for (i = 1; i < argc; i++) {
if (strlcat(cmdline, " ", sizeof(cmdline)) >= sizeof(cmdline))
- errx(1, "command line too long");
+ break;
if (strlcat(cmdline, argv[i], sizeof(cmdline)) >= sizeof(cmdline))
- errx(1, "command line too long");
+ break;
}
+ cmd = argv[0];
if (!permit(uid, groups, ngroups, &rule, target, cmd,
(const char**)argv + 1)) {
syslog(LOG_AUTHPRIV | LOG_NOTICE,
"failed command for %s: %s", myname, cmdline);
- fail();
+ errc(1, EPERM, NULL);
}
+ pw = getpwuid(target);
+ if (!pw)
+ errx(1, "no passwd entry for target");
+
+#ifdef HAVE_BSD_AUTH_H
if (!(rule->options & NOPASS)) {
- if (!auth_userokay(myname, NULL, NULL, NULL)) {
+ if (nflag)
+ errx(1, "Authorization required");
+
+ char *challenge = NULL, *response, rbuf[1024], cbuf[128];
+ auth_session_t *as;
+
+ 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,
- "failed password for %s", myname);
- fail();
+ "tty required for %s", myname);
+ errx(1, "a tty is required");
}
+ if (!auth_userresponse(as, response, 0)) {
+ syslog(LOG_AUTHPRIV | LOG_NOTICE,
+ "failed auth for %s", myname);
+ errc(1, EPERM, NULL);
+ }
+ explicit_bzero(rbuf, sizeof(rbuf));
+ }
+#elif HAVE_PAM_APPL_H
+ if (!doas_pam(pw->pw_name, myname, !nflag, rule->options & NOPASS)) {
+ syslog(LOG_AUTHPRIV | LOG_NOTICE, "failed auth for %s", myname);
+ errc(1, EPERM, NULL);
}
- envp = copyenv((const char **)envp, rule);
+#else
+ if (!(rule->options & NOPASS)) {
+ errx(1, "Authorization required");
+#endif /* HAVE_BSD_AUTH_H */
- pw = getpwuid(target);
- if (!pw)
- errx(1, "no passwd entry for target");
+ if (pledge("stdio rpath getpw exec id", NULL) == -1)
+ err(1, "pledge");
+
+#ifdef HAVE_BSD_AUTH_H
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)
+ errx(1, "setgid");
+ if (initgroups(pw->pw_name, pw->pw_gid) != 0)
+ errx(1, "initgroups");
+ if (setresuid(target, target, target) != 0)
+ errx(1, "setuid");
+#endif
+
+ if (pledge("stdio rpath exec", NULL) == -1)
+ err(1, "pledge");
+
+ if (getcwd(cwdpath, sizeof(cwdpath)) == NULL)
+ cwd = "(failed)";
+ else
+ cwd = cwdpath;
+
+ if (pledge("stdio exec", NULL) == -1)
+ err(1, "pledge");
+
+ syslog(LOG_AUTHPRIV | LOG_INFO, "%s ran command %s as %s from %s",
+ myname, cmdline, pw->pw_name, cwd);
+
+ env = createenv(envp);
+ env = filterenv(env, rule);
+ envp = flattenenv(env);
+
+ 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