-/* $OpenBSD: doas.c,v 1.13 2015/07/20 01:00:48 tedu Exp $ */
+/* $OpenBSD: doas.c,v 1.53 2016/06/05 00:46:34 djm 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
match(uid_t uid, gid_t *groups, int ngroups, uid_t target, const char *cmd,
- struct rule *r)
+ const char **cmdargs, struct rule *r)
{
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])
}
if (r->target && uidcheck(r->target, target) != 0)
return 0;
- if (r->cmd && strcmp(r->cmd, cmd) != 0)
- return 0;
+ if (r->cmd) {
+ if (strcmp(r->cmd, cmd))
+ return 0;
+ if (r->cmdargs) {
+ /* if arguments were given, they should match explicitly */
+ for (i = 0; r->cmdargs[i]; i++) {
+ if (!cmdargs[i])
+ return 0;
+ if (strcmp(r->cmdargs[i], cmdargs[i]))
+ return 0;
+ }
+ if (cmdargs[i])
+ return 0;
+ }
+ }
return 1;
}
static int
permit(uid_t uid, gid_t *groups, int ngroups, struct rule **lastr,
- uid_t target, const char *cmd)
+ uid_t target, const char *cmd, const char **cmdargs)
{
int i;
*lastr = NULL;
for (i = 0; i < nrules; i++) {
- if (match(uid, groups, ngroups, target, cmd, 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);
}
+/*
+ * Copy the environment variables in safeset from oldenvp to envp.
+ */
static int
-copyenvhelper(const char **oldenvp, const char **safeset, int nsafe,
+copyenvhelper(const char **oldenvp, const char **safeset, size_t nsafe,
char **envp, int ei)
{
- int i;
+ size_t i;
for (i = 0; i < nsafe; i++) {
const char **oe = oldenvp;
char **envp;
const char **extra;
int ei;
- int nsafe, nbad;
- int nextras = 0;
-
+ size_t nsafe, nbad;
+ size_t nextras = 0;
+
+ /* if there was no envvar whitelist, pass all except badset ones */
nbad = arraylen(badset);
if ((rule->options & KEEPENV) && !rule->envlist) {
- size_t i, ii;
+ size_t iold, inew;
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] == '=') {
+ 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 (j == nbad) {
- if (!(envp[ii] = strdup(oldenvp[i])))
+ if (ibad == nbad) {
+ if (!(envp[inew] = strdup(oldenvp[iold])))
err(1, "strdup");
- ii++;
+ inew++;
}
}
- envp[ii] = NULL;
+ envp[inew] = NULL;
return envp;
}
nsafe = arraylen(safeset);
if ((extra = rule->envlist)) {
- size_t i;
+ size_t isafe;
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--];
+ 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--;
}
}
}
return envp;
}
+/* find index of 'name' in environment envp */
+static int
+findenv(const char **envp, const char *name, size_t namelen)
+{
+ int i;
+
+ for (i = 0 ; envp[i] != NULL; i++) {
+ if (strlen(envp[i]) < namelen + 1)
+ continue;
+ if (strncmp(envp[i], name, namelen) == 0 &&
+ envp[i][namelen] == '=')
+ return i;
+ }
+ return -1;
+}
+
+/* merge rule->setenvlist into environment list; frees oldenvp */
+static char **
+dosetenv(char **oldenvp, struct rule *rule)
+{
+ size_t n, i, nset, nold;
+ char **envp, *cp, *cp2;
+ int found;
+
+ if (!(rule->options & SETENV))
+ return oldenvp;
+
+ nset = arraylen(rule->setenvlist);
+ nold = arraylen((const char**)oldenvp);
+
+ /* insert new variables */
+ n = 0;
+ envp = NULL;
+ for (i = 0; i < nset; i++) {
+ if ((cp = strchr(rule->setenvlist[i], '=')) == NULL)
+ errx(1, "invalid setenv"); /* shouldn't happen */
+ if (cp[1] == '\0' || cp - rule->setenvlist[i] > INT_MAX)
+ continue; /* skip variables with empty values */
+ if ((envp = reallocarray(envp, n + 2, sizeof(*envp))) == NULL)
+ errx(1, "reallocarray failed");
+ if (cp[1] == '$') {
+ /* FOO=$BAR: lookup and copy */
+ if ((cp2 = getenv(cp + 2)) == NULL)
+ continue; /* not found; skip */
+ if (asprintf(&(envp[n++]), "%.*s=%s",
+ (int)(cp - rule->setenvlist[i]),
+ rule->setenvlist[i], cp2) == -1)
+ errx(1, "asprintf failed");
+ continue;
+ } else {
+ /* plain setenv */
+ if ((envp[n++] = strdup(rule->setenvlist[i])) == NULL)
+ errx(1, "strdup failed");
+ }
+ }
+ /* move old variables, dropping ones already set */
+ for (i = 0; i < nold; i++) {
+ if ((cp = strchr(oldenvp[i], '=')) == NULL)
+ errx(1, "invalid env"); /* shouldn't happen */
+ found = findenv(rule->setenvlist, oldenvp[i], cp - oldenvp[i]);
+ if (found != -1)
+ free(oldenvp[i]); /* discard */
+ else {
+ if ((envp = reallocarray(envp, n + 2,
+ sizeof(*envp))) == NULL)
+ errx(1, "reallocarray failed");
+ envp[n++] = oldenvp[i]; /* move */
+ }
+ }
+ free(oldenvp);
+ if (n > 0)
+ envp[n] = NULL;
+ return envp;
+}
+
static void __dead
-fail(void)
+checkconfig(const char *confpath, int argc, char **argv,
+ uid_t uid, gid_t *groups, int ngroups, uid_t target)
{
- fprintf(stderr, "Permission denied\n");
- exit(1);
+ struct rule *rule;
+
+ if (setresuid(uid, uid, uid) != 0)
+ err(1, "setresuid");
+
+ parseconfig(confpath, 0);
+ if (!argc)
+ exit(0);
+
+ 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);
+ }
}
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;
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");
- parseconfig("/etc/doas.conf");
+ if (pledge("stdio rpath getpw tty proc exec id", NULL) == -1)
+ err(1, "pledge");
- while ((ch = getopt(argc, argv, "su:")) != -1) {
+ /* closefrom(STDERR_FILENO + 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':
+ 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))
+ if (vflag)
+ version();
+
+ 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;
}
- if (!permit(uid, groups, ngroups, &rule, target, cmd)) {
+ 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);
}
+#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,
+ "tty required for %s", myname);
+ errx(1, "a tty is required");
+ }
+ if (!auth_userresponse(as, response, 0)) {
syslog(LOG_AUTHPRIV | LOG_NOTICE,
- "failed password for %s", myname);
- fail();
+ "failed auth for %s", myname);
+ errc(1, EPERM, NULL);
}
+ explicit_bzero(rbuf, sizeof(rbuf));
}
- envp = copyenv((const char **)envp, rule);
+#elif HAVE_PAM_APPL_H
+ if (!doas_pam(myname, !nflag, rule->options & NOPASS)) {
+ syslog(LOG_AUTHPRIV | LOG_NOTICE,
+ "failed auth for %s", myname);
+ errc(1, EPERM, NULL);
+ }
+#else
+ if (!(rule->options & NOPASS)) {
+ errx(1, "Authorization required");
+#endif /* HAVE_BSD_AUTH_H */
+
+ if (pledge("stdio rpath getpw exec id", NULL) == -1)
+ err(1, "pledge");
pw = getpwuid(target);
if (!pw)
errx(1, "no passwd entry for target");
+
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);
+ 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);
+
+ envp = copyenv((const char **)envp, rule);
+
+ envp = dosetenv(envp, 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