]> git.armaanb.net Git - opendoas.git/blobdiff - doas.c
sync with upstream (setenv)
[opendoas.git] / doas.c
diff --git a/doas.c b/doas.c
index 7a525e6e9b55432d673c719d7bc145a243813d5d..c3b520fb529797414b9021e3a1e728ccf68eaa5e 100644 (file)
--- a/doas.c
+++ b/doas.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: doas.c,v 1.32 2015/07/29 00:00:31 tedu Exp $ */
+/* $OpenBSD: doas.c,v 1.53 2016/06/05 00:46:34 djm Exp $ */
 /*
  * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
  *
@@ -19,8 +19,6 @@
 #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 [-ns] [-C config] [-u user] command [args]\n");
+       fprintf(stderr, "usage: doas [-nsv] [-a style] [-C config] [-u user]"
+           " command [args]\n");
        exit(1);
 }
 
@@ -45,9 +53,11 @@ arraylen(const char **arr)
 {
        size_t cnt = 0;
 
-       while (*arr) {
-               cnt++;
-               arr++;
+       if (arr) {
+               while (*arr) {
+                       cnt++;
+                       arr++;
+               }
        }
        return cnt;
 }
@@ -161,13 +171,9 @@ parseconfig(const char *filename, int checkperms)
        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)
@@ -188,10 +194,10 @@ parseconfig(const char *filename, int checkperms)
  * 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;
@@ -224,8 +230,8 @@ copyenv(const char **oldenvp, struct rule *rule)
        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);
@@ -283,11 +289,79 @@ copyenv(const char **oldenvp, struct rule *rule)
        return envp;
 }
 
-static void __dead
-fail(void)
+/* find index of 'name' in environment envp */
+static int
+findenv(const char **envp, const char *name, size_t namelen)
 {
-       fprintf(stderr, "Permission denied\n");
-       exit(1);
+       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
@@ -296,7 +370,9 @@ checkconfig(const char *confpath, int argc, char **argv,
 {
        struct rule *rule;
 
-       setresuid(uid, uid, uid);
+       if (setresuid(uid, uid, uid) != 0)
+               err(1, "setresuid");
+
        parseconfig(confpath, 0);
        if (!argc)
                exit(0);
@@ -331,10 +407,35 @@ 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;
+#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); */
 
        uid = getuid();
-       while ((ch = getopt(argc, argv, "C:nsu:")) != -1) {
+
+#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;
@@ -348,6 +449,9 @@ main(int argc, char **argv, char **envp)
                case 's':
                        sflag = 1;
                        break;
+               case 'v':
+                       vflag = 1;
+                       break;
                default:
                        usage();
                        break;
@@ -356,13 +460,15 @@ main(int argc, char **argv, char **envp)
        argv += optind;
        argc -= optind;
 
+       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");
@@ -405,32 +511,87 @@ main(int argc, char **argv, char **envp)
            (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 (nflag)
                        errx(1, "Authorization required");
-               if (!auth_userokay(myname, NULL, NULL, NULL)) {
+
+               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));
        }
-       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);