Annotation of src/usr.bin/su/su.c, Revision 1.38
1.38 ! millert 1: /* $OpenBSD: su.c,v 1.37 2001/05/31 17:34:17 millert Exp $ */
1.4 deraadt 2:
1.1 deraadt 3: /*
4: * Copyright (c) 1988 The Regents of the University of California.
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: * 3. All advertising materials mentioning features or use of this software
16: * must display the following acknowledgement:
17: * This product includes software developed by the University of
18: * California, Berkeley and its contributors.
19: * 4. Neither the name of the University nor the names of its contributors
20: * may be used to endorse or promote products derived from this software
21: * without specific prior written permission.
22: *
23: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33: * SUCH DAMAGE.
34: */
35:
36: #ifndef lint
37: char copyright[] =
38: "@(#) Copyright (c) 1988 The Regents of the University of California.\n\
39: All rights reserved.\n";
40: #endif /* not lint */
41:
42: #ifndef lint
43: /*static char sccsid[] = "from: @(#)su.c 5.26 (Berkeley) 7/6/91";*/
1.38 ! millert 44: static char rcsid[] = "$OpenBSD: su.c,v 1.37 2001/05/31 17:34:17 millert Exp $";
1.1 deraadt 45: #endif /* not lint */
46:
47: #include <sys/param.h>
48: #include <sys/time.h>
49: #include <sys/resource.h>
1.8 millert 50:
51: #include <err.h>
52: #include <errno.h>
53: #include <grp.h>
1.33 millert 54: #include <login_cap.h>
1.8 millert 55: #include <paths.h>
56: #include <pwd.h>
1.1 deraadt 57: #include <stdio.h>
58: #include <stdlib.h>
59: #include <string.h>
1.8 millert 60: #include <syslog.h>
1.1 deraadt 61: #include <unistd.h>
1.36 millert 62: #ifdef __STDC__
63: #include <stdarg.h>
1.1 deraadt 64: #else
1.36 millert 65: #include <varargs.h>
1.1 deraadt 66: #endif
1.36 millert 67: #include <bsd_auth.h>
68:
1.8 millert 69: char *ontty __P((void));
70: int chshell __P((char *));
1.36 millert 71: void usage __P((void));
72: void auth_err __P((auth_session_t *, int, const char *, ...));
73: void auth_errx __P((auth_session_t *, int, const char *, ...));
1.1 deraadt 74:
75: int
76: main(argc, argv)
77: int argc;
78: char **argv;
79: {
80: extern char **environ;
1.36 millert 81: enum { UNSET, YES, NO } iscsh;
82: struct passwd *pwd;
1.1 deraadt 83: struct group *gr;
1.9 millert 84: uid_t ruid;
1.33 millert 85: login_cap_t *lc;
1.36 millert 86: auth_session_t *as;
87: int asme, asthem, authok, ch, fastlogin, prio;
88: char *class, *style, *p, **g;
89: char *user, *shell, *avshell, *username, **np, *fullname;
1.1 deraadt 90: char shellbuf[MAXPATHLEN], avshellbuf[MAXPATHLEN];
91:
1.33 millert 92: iscsh = UNSET;
1.36 millert 93: class = shell = style = NULL;
1.1 deraadt 94: asme = asthem = fastlogin = 0;
1.37 millert 95: while ((ch = getopt(argc, argv, "-a:c:fKlm")) != -1)
1.36 millert 96: switch(ch) {
97: case 'a':
98: if (style)
99: usage();
100: style = optarg;
1.1 deraadt 101: break;
1.33 millert 102: case 'c':
1.36 millert 103: if (class)
104: usage();
1.33 millert 105: class = optarg;
106: break;
1.1 deraadt 107: case 'f':
108: fastlogin = 1;
109: break;
1.36 millert 110: case 'K':
111: if (style)
112: usage();
113: style = "passwd";
114: break;
1.1 deraadt 115: case '-':
116: case 'l':
117: asme = 0;
118: asthem = 1;
119: break;
120: case 'm':
121: asme = 1;
122: asthem = 0;
123: break;
124: case '?':
125: default:
1.36 millert 126: usage();
1.1 deraadt 127: }
128: argv += optind;
129:
130: errno = 0;
131: prio = getpriority(PRIO_PROCESS, 0);
132: if (errno)
133: prio = 0;
134: (void)setpriority(PRIO_PROCESS, 0, -2);
135: openlog("su", LOG_CONS, 0);
136:
1.36 millert 137: if ((as = auth_open()) == NULL) {
138: syslog(LOG_ERR, "auth_open: %m");
139: err(1, "unable to begin authentication");
140: }
141:
1.1 deraadt 142: /* get current login name and shell */
143: ruid = getuid();
144: username = getlogin();
145: if (username == NULL || (pwd = getpwnam(username)) == NULL ||
146: pwd->pw_uid != ruid)
147: pwd = getpwuid(ruid);
1.8 millert 148: if (pwd == NULL)
1.36 millert 149: auth_errx(as, 1, "who are you?");
1.9 millert 150: if ((username = strdup(pwd->pw_name)) == NULL)
1.36 millert 151: auth_err(as, 1, "can't allocate memory");
1.31 art 152: if (asme) {
1.10 millert 153: if (pwd->pw_shell && *pwd->pw_shell) {
1.36 millert 154: strlcpy(shellbuf, pwd->pw_shell, sizeof(shellbuf));
155: shell = shellbuf;
1.10 millert 156: } else {
1.1 deraadt 157: shell = _PATH_BSHELL;
158: iscsh = NO;
159: }
1.31 art 160: }
1.1 deraadt 161:
162: /* get target login information, default to root */
163: user = *argv ? *argv : "root";
1.36 millert 164: np = *argv ? argv : argv - 1;
1.1 deraadt 165:
1.8 millert 166: if ((pwd = getpwnam(user)) == NULL)
1.36 millert 167: auth_errx(as, 1, "unknown login %s", user);
1.16 millert 168: if ((user = strdup(pwd->pw_name)) == NULL)
1.36 millert 169: auth_err(as, 1, "can't allocate memory");
1.1 deraadt 170:
1.33 millert 171: /* If the user specified a login class and we are root, use it */
172: if (ruid && class)
1.36 millert 173: auth_errx(as, 1, "only the superuser may specify a login class");
1.33 millert 174: if (class)
175: pwd->pw_class = class;
176: if ((lc = login_getclass(pwd->pw_class)) == NULL)
1.36 millert 177: auth_errx(as, 1, "no such login class: %s",
1.33 millert 178: class ? class : LOGIN_DEFCLASS);
179:
1.1 deraadt 180: if (ruid) {
1.36 millert 181: /*
182: * If we are trying to become root and the default style
183: * is being used, don't bother to look it up (we might be
184: * be su'ing up to fix /etc/login.conf)
185: */
186: if ((pwd->pw_uid || !style || strcmp(style, LOGIN_DEFSTYLE)) &&
187: (style = login_getstyle(lc, style, "auth-su")) == NULL)
188: auth_errx(as, 1, "invalid authentication type");
189: if (pwd->pw_uid || strcmp(user, "root") != 0)
190: fullname = user;
191: else {
192: if ((fullname =
193: malloc(strlen(username) + 6)) == NULL)
194: auth_err(as, 1, NULL);
195: (void)sprintf(fullname, "%s.root", username);
196: }
197: /*
198: * Let the authentication program know whether they are
199: * in group wheel or not (if trying to become super user)
200: */
1.3 deraadt 201: if (pwd->pw_uid == 0 && (gr = getgrgid((gid_t)0))
1.36 millert 202: && gr->gr_mem && *(gr->gr_mem)) {
203: for (g = gr->gr_mem; *g; ++g) {
204: if (strcmp(username, *g) == 0) {
205: auth_setoption(as, "wheel", "yes");
1.1 deraadt 206: break;
1.36 millert 207: }
208: }
209: if (!*g)
210: auth_setoption(as, "wheel", "no");
1.1 deraadt 211: }
1.36 millert 212:
213: auth_verify(as, style, fullname, lc->lc_class, NULL);
214: authok = auth_getstate(as);
215: if ((authok & AUTH_ALLOW) == 0) {
216: if ((p = auth_getvalue(as, "errormsg")) != NULL)
217: fprintf(stderr, "%s\n", p);
218: fprintf(stderr, "Sorry\n");
219: syslog(LOG_AUTH|LOG_WARNING,
220: "BAD SU %s to %s%s", username, user, ontty());
221: auth_close(as);
222: exit(1);
1.1 deraadt 223: }
224: }
225:
226: if (asme) {
227: /* if asme and non-standard target shell, must be root */
1.8 millert 228: if (!chshell(pwd->pw_shell) && ruid)
1.36 millert 229: auth_errx(as, 1, "permission denied (shell).");
1.1 deraadt 230: } else if (pwd->pw_shell && *pwd->pw_shell) {
231: shell = pwd->pw_shell;
232: iscsh = UNSET;
233: } else {
234: shell = _PATH_BSHELL;
235: iscsh = NO;
236: }
237:
1.30 deraadt 238: if ((p = strrchr(shell, '/')))
1.1 deraadt 239: avshell = p+1;
240: else
241: avshell = shell;
242:
243: /* if we're forking a csh, we want to slightly muck the args */
244: if (iscsh == UNSET)
245: iscsh = strcmp(avshell, "csh") ? NO : YES;
246:
247: if (!asme) {
248: if (asthem) {
249: p = getenv("TERM");
1.23 deraadt 250: if ((environ = calloc(1, sizeof (char *))) == NULL)
1.36 millert 251: auth_errx(as, 1, "calloc");
1.33 millert 252: if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETPATH))
1.36 millert 253: auth_err(as, 1, "unable to set user context");
254: if (p && setenv("TERM", p, 1) == -1)
255: auth_err(as, 1, "unable to set environment");
1.5 deraadt 256:
257: seteuid(pwd->pw_uid);
258: setegid(pwd->pw_gid);
1.8 millert 259: if (chdir(pwd->pw_dir) < 0)
1.36 millert 260: auth_err(as, 1, "%s", pwd->pw_dir);
1.5 deraadt 261: seteuid(0);
262: setegid(0); /* XXX use a saved gid instead? */
1.33 millert 263: } else if (pwd->pw_uid == 0) {
264: if (setusercontext(lc,
265: pwd, pwd->pw_uid, LOGIN_SETPATH|LOGIN_SETUMASK))
1.36 millert 266: auth_err(as, 1, "unable to set user context");
1.1 deraadt 267: }
1.15 millert 268: if (asthem || pwd->pw_uid) {
1.34 deraadt 269: if (setenv("LOGNAME", pwd->pw_name, 1) == -1 ||
270: setenv("USER", pwd->pw_name, 1) == -1)
1.36 millert 271: auth_err(as, 1, "unable to set environment");
1.15 millert 272: }
1.34 deraadt 273: if (setenv("HOME", pwd->pw_dir, 1) == -1 ||
274: setenv("SHELL", shell, 1) == -1)
1.36 millert 275: auth_err(as, 1, "unable to set environment");
1.34 deraadt 276: }
1.28 deraadt 277:
1.1 deraadt 278: if (iscsh == YES) {
279: if (fastlogin)
280: *np-- = "-f";
281: if (asme)
282: *np-- = "-m";
283: }
284:
285: if (asthem) {
286: avshellbuf[0] = '-';
1.36 millert 287: strlcpy(avshellbuf+1, avshell, sizeof(avshellbuf) - 1);
1.1 deraadt 288: avshell = avshellbuf;
289: } else if (iscsh == YES) {
290: /* csh strips the first character... */
291: avshellbuf[0] = '_';
1.36 millert 292: strlcpy(avshellbuf+1, avshell, sizeof(avshellbuf) - 1);
1.1 deraadt 293: avshell = avshellbuf;
294: }
295:
296: *np = avshell;
297:
298: if (ruid != 0)
299: syslog(LOG_NOTICE|LOG_AUTH, "%s to %s%s",
300: username, user, ontty());
301:
302: (void)setpriority(PRIO_PROCESS, 0, prio);
1.33 millert 303: if (setusercontext(lc, pwd, pwd->pw_uid,
304: (asthem ? (LOGIN_SETPRIORITY | LOGIN_SETUMASK) : 0) |
305: LOGIN_SETRESOURCES | LOGIN_SETGROUP | LOGIN_SETUSER))
1.36 millert 306: auth_err(as, 1, "unable to set user context");
307: if (pwd->pw_uid && auth_approval(as, lc, pwd->pw_name, "su") <= 0)
308: auth_err(as, 1, "approval failure");
309: auth_close(as);
1.1 deraadt 310:
311: execv(shell, np);
1.32 millert 312: err(1, "%s", shell);
1.1 deraadt 313: }
314:
315: int
316: chshell(sh)
317: char *sh;
318: {
1.36 millert 319: char *cp;
1.1 deraadt 320:
321: while ((cp = getusershell()) != NULL)
1.8 millert 322: if (strcmp(cp, sh) == 0)
1.1 deraadt 323: return (1);
324: return (0);
325: }
326:
327: char *
328: ontty()
329: {
330: static char buf[MAXPATHLEN + 4];
1.36 millert 331: char *p;
1.1 deraadt 332:
333: buf[0] = 0;
1.30 deraadt 334: if ((p = ttyname(STDERR_FILENO)))
1.8 millert 335: snprintf(buf, sizeof(buf), " on %s", p);
1.1 deraadt 336: return (buf);
337: }
338:
1.36 millert 339: void
340: usage()
1.1 deraadt 341: {
1.36 millert 342: extern char *__progname;
1.1 deraadt 343:
1.37 millert 344: fprintf(stderr, "usage: %s [-fKlm] [-a auth-type] %s ", __progname,
1.38 ! millert 345: "[-c login-class] [login [shell arguments]]\n");
1.36 millert 346: exit(1);
1.1 deraadt 347: }
348:
1.36 millert 349: void
350: #ifdef __STDC__
351: auth_err(auth_session_t *as, int eval, const char *fmt, ...)
352: #else
353: auth_err(va_alist)
354: va_dcl
355: #endif
1.1 deraadt 356: {
1.36 millert 357: va_list ap;
358: #ifdef __STDC__
359: va_start(ap, fmt);
360: #else
361: auth_session_t *as;
362: int eval;
363: const char *fmt;
364:
365: va_start(ap);
366: as = va_arg(ap, auth_session_t *);
367: eval = va_arg(ap, int);
368: fmt = va_arg(ap, const char *);
369: #endif
370: verr(eval, fmt, ap);
371: auth_close(as);
372: va_end(ap);
1.28 deraadt 373: }
374:
1.36 millert 375: void
376: #ifdef __STDC__
377: auth_errx(auth_session_t *as, int eval, const char *fmt, ...)
378: #else
379: auth_errx(va_alist)
380: va_dcl
381: #endif
1.28 deraadt 382: {
1.36 millert 383: va_list ap;
384: #ifdef __STDC__
385: va_start(ap, fmt);
386: #else
387: auth_session_t *as;
388: int eval;
389: const char *fmt;
390:
391: va_start(ap);
392: as = va_arg(ap, auth_session_t *);
393: eval = va_arg(ap, int);
394: fmt = va_arg(ap, const char *);
395: #endif
396: verrx(eval, fmt, ap);
397: auth_close(as);
398: va_end(ap);
1.1 deraadt 399: }
![[BACK]](/icons/back.gif){kind=icon}
Return to su.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / su