]> git.armaanb.net Git - opendoas.git/blobdiff - doas.c
timestamp: error out if fstat and lstat st_ino and st_dev are not the same
[opendoas.git] / doas.c
diff --git a/doas.c b/doas.c
index 643d3d809235d8dead863739fcf4b6e17fdd4dff..6223aff219168fa87f9a38909f9f072535114c21 100644 (file)
--- a/doas.c
+++ b/doas.c
 
 #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 "includes.h"
 
 #include "doas.h"
-#include "version.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 [-nsv] [-a style] [-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;
-
-       if (arr) {
-               while (*arr) {
-                       cnt++;
-                       arr++;
-               }
-       }
-       return cnt;
-}
-
 static int
 parseuid(const char *s, uid_t *uid)
 {
@@ -148,7 +134,7 @@ match(uid_t uid, gid_t *groups, int ngroups, uid_t target, const char *cmd,
 }
 
 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;
@@ -191,112 +177,15 @@ parseconfig(const char *filename, int checkperms)
                exit(1);
 }
 
-/*
- * Copy the environment variables in safeset from oldenvp to envp.
- */
-static int
-copyenvhelper(const char **oldenvp, const char **safeset, size_t nsafe,
-    char **envp, int ei)
-{
-       size_t 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;
-       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 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
 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);
@@ -311,8 +200,57 @@ checkconfig(const char *confpath, int argc, char **argv,
        }
 }
 
+#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";
@@ -323,7 +261,7 @@ main(int argc, char **argv, char **envp)
        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];
@@ -331,28 +269,46 @@ main(int argc, char **argv, char **envp)
        int i, ch;
        int sflag = 0;
        int nflag = 0;
-       int vflag = 0;
        char cwdpath[PATH_MAX];
        const char *cwd;
+       char **envp;
+#ifdef USE_BSD_AUTH
        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); */
+       closefrom(STDERR_FILENO + 1);
 
        uid = getuid();
 
-       while ((ch = getopt(argc, argv, "a:C:nsu:v")) != -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");
@@ -363,9 +319,6 @@ main(int argc, char **argv, char **envp)
                case 's':
                        sflag = 1;
                        break;
-               case 'v':
-                       vflag = 1;
-                       break;
                default:
                        usage();
                        break;
@@ -374,9 +327,6 @@ main(int argc, char **argv, char **envp)
        argv += optind;
        argc -= optind;
 
-       if (vflag)
-               version();
-
        if (confpath) {
                if (sflag)
                        usage();
@@ -395,9 +345,11 @@ main(int argc, char **argv, char **envp)
 
        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;
@@ -409,10 +361,13 @@ main(int argc, char **argv, char **envp)
                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;
@@ -422,51 +377,18 @@ main(int argc, char **argv, char **envp)
 
        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);
                errc(1, EPERM, NULL);
        }
 
+#if defined(__OpenBSD__)
        if (!(rule->options & NOPASS)) {
                if (nflag)
                        errx(1, "Authorization required");
 
-#ifdef HAVE_BSD_AUTH_H
-               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 auth for %s", myname);
-                       errc(1, EPERM, NULL);
-               }
-               explicit_bzero(rbuf, sizeof(rbuf));
-#else
-               if (!auth_userokay(myname, NULL, NULL, NULL)) {
-                       syslog(LOG_AUTHPRIV | LOG_NOTICE,
-                           "failed auth for %s", myname);
-                       errc(1, EPERM, NULL);
-               }
-#endif /* HAVE_BSD_AUTH_H */
+               authuser(myname, login_style, rule->options & PERSIST);
        }
 
        if (pledge("stdio rpath getpw exec id", NULL) == -1)
@@ -476,26 +398,66 @@ main(int argc, char **argv, char **envp)
        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);
+       }
+
+       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");
-
+#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 = copyenv((const char **)envp, rule);
+       envp = prepenv(rule);
 
        if (rule->cmd) {
                if (setenv("PATH", safepath, 1) == -1)