Commit | Line | Data |
---|---|---|
31e00b32 | 1 | /* |
7d5e1706 KB |
2 | * Copyright (c) 1988 The Regents of the University of California. |
3 | * All rights reserved. | |
4 | * | |
cb956e54 | 5 | * %sccs.include.redist.c% |
31e00b32 DF |
6 | */ |
7 | ||
8 | #ifndef lint | |
9 | char copyright[] = | |
7d5e1706 | 10 | "@(#) Copyright (c) 1988 The Regents of the University of California.\n\ |
31e00b32 | 11 | All rights reserved.\n"; |
7d5e1706 | 12 | #endif /* not lint */ |
31e00b32 | 13 | |
13dd8b1d | 14 | #ifndef lint |
58a34b62 | 15 | static char sccsid[] = "@(#)su.c 5.21 (Berkeley) %G%"; |
7d5e1706 | 16 | #endif /* not lint */ |
13dd8b1d | 17 | |
a8d8c335 | 18 | #include <sys/param.h> |
4f4c2c68 SL |
19 | #include <sys/time.h> |
20 | #include <sys/resource.h> | |
7d5e1706 KB |
21 | #include <syslog.h> |
22 | #include <stdio.h> | |
23 | #include <pwd.h> | |
24 | #include <grp.h> | |
d9e13dc0 | 25 | #include <string.h> |
dbf8133b | 26 | #include <unistd.h> |
3a7a366d | 27 | #include "pathnames.h" |
3a265c7a | 28 | |
d9e13dc0 | 29 | #ifdef KERBEROS |
302dd6d2 | 30 | #include <kerberosIV/des.h> |
ba1b9d1d | 31 | #include <kerberosIV/krb.h> |
094e5ff2 | 32 | #include <netdb.h> |
d9e13dc0 | 33 | |
e5b1d5e7 | 34 | #define ARGSTR "-Kflm" |
d9e13dc0 KB |
35 | |
36 | int use_kerberos = 1; | |
094e5ff2 KF |
37 | #else |
38 | #define ARGSTR "-flm" | |
39 | #endif | |
40 | ||
7d5e1706 | 41 | main(argc, argv) |
13dd8b1d | 42 | int argc; |
7d5e1706 | 43 | char **argv; |
3a265c7a | 44 | { |
7d5e1706 KB |
45 | extern char **environ; |
46 | extern int errno, optind; | |
7d5e1706 KB |
47 | register struct passwd *pwd; |
48 | register char *p, **g; | |
49 | struct group *gr; | |
a8d8c335 | 50 | uid_t ruid, getuid(); |
e5b1d5e7 | 51 | int asme, ch, asthem, fastlogin, prio; |
a8d8c335 | 52 | enum { UNSET, YES, NO } iscsh = UNSET; |
6964f298 | 53 | char *user, *shell, *username, *cleanenv[2], *nargv[4], **np; |
d9e13dc0 | 54 | char shellbuf[MAXPATHLEN]; |
dbf8133b | 55 | char *crypt(), *getpass(), *getenv(), *getlogin(), *mytty(); |
3a265c7a | 56 | |
6964f298 KB |
57 | np = &nargv[3]; |
58 | *np-- = NULL; | |
e5b1d5e7 | 59 | asme = asthem = fastlogin = 0; |
094e5ff2 | 60 | while ((ch = getopt(argc, argv, ARGSTR)) != EOF) |
7d5e1706 | 61 | switch((char)ch) { |
e5b1d5e7 KB |
62 | #ifdef KERBEROS |
63 | case 'K': | |
64 | use_kerberos = 0; | |
65 | break; | |
66 | #endif | |
a8d8c335 KB |
67 | case 'f': |
68 | fastlogin = 1; | |
69 | break; | |
7d5e1706 KB |
70 | case '-': |
71 | case 'l': | |
e5b1d5e7 KB |
72 | asme = 0; |
73 | asthem = 1; | |
7d5e1706 | 74 | break; |
6964f298 KB |
75 | case 'm': |
76 | asme = 1; | |
e5b1d5e7 | 77 | asthem = 0; |
6964f298 | 78 | break; |
7d5e1706 KB |
79 | case '?': |
80 | default: | |
d9e13dc0 KB |
81 | (void)fprintf(stderr, "usage: su [%s] [login]\n", |
82 | ARGSTR); | |
7d5e1706 KB |
83 | exit(1); |
84 | } | |
85 | argv += optind; | |
da31c6da | 86 | |
6964f298 KB |
87 | errno = 0; |
88 | prio = getpriority(PRIO_PROCESS, 0); | |
89 | if (errno) | |
90 | prio = 0; | |
91 | (void)setpriority(PRIO_PROCESS, 0, -2); | |
92 | ||
93 | /* get current login name and shell */ | |
a8d8c335 | 94 | if ((pwd = getpwuid(ruid = getuid())) == NULL) { |
7d5e1706 | 95 | fprintf(stderr, "su: who are you?\n"); |
96f93d9e RC |
96 | exit(1); |
97 | } | |
d9e13dc0 | 98 | username = strdup(pwd->pw_name); |
6964f298 | 99 | if (asme) |
a8d8c335 KB |
100 | if (pwd->pw_shell && *pwd->pw_shell) |
101 | shell = strcpy(shellbuf, pwd->pw_shell); | |
102 | else { | |
3a7a366d | 103 | shell = _PATH_BSHELL; |
a8d8c335 KB |
104 | iscsh = NO; |
105 | } | |
7d5e1706 | 106 | |
094e5ff2 | 107 | /* get target login information, default to root */ |
6964f298 | 108 | user = *argv ? *argv : "root"; |
96f93d9e | 109 | if ((pwd = getpwnam(user)) == NULL) { |
7d5e1706 | 110 | fprintf(stderr, "su: unknown login %s\n", user); |
96f93d9e RC |
111 | exit(1); |
112 | } | |
7d5e1706 KB |
113 | |
114 | /* only allow those in group zero to su to root. */ | |
a8d8c335 | 115 | if (pwd->pw_uid == 0 && (gr = getgrgid((gid_t)0))) |
7d5e1706 KB |
116 | for (g = gr->gr_mem;; ++g) { |
117 | if (!*g) { | |
12d409ff KB |
118 | (void)fprintf(stderr, |
119 | "su: you are not in the correct group to su %s.\n", user); | |
7d5e1706 KB |
120 | exit(1); |
121 | } | |
122 | if (!strcmp(username, *g)) | |
123 | break; | |
a8a168db | 124 | } |
12d409ff | 125 | openlog("su", LOG_CONS, 0); |
a8a168db | 126 | |
d9e13dc0 KB |
127 | if (ruid) { |
128 | #ifdef KERBEROS | |
129 | if (!use_kerberos || kerberos(username, user, pwd->pw_uid)) | |
094e5ff2 | 130 | #endif |
d9e13dc0 KB |
131 | /* if target requires a password, verify it */ |
132 | if (*pwd->pw_passwd) { | |
133 | p = getpass("Password:"); | |
134 | if (strcmp(pwd->pw_passwd, crypt(p, pwd->pw_passwd))) { | |
135 | fprintf(stderr, "Sorry\n"); | |
58a34b62 KF |
136 | syslog(LOG_AUTH|LOG_CRIT, |
137 | "BAD SU %s on %s to %s", username, | |
138 | mytty(), user); | |
d9e13dc0 KB |
139 | exit(1); |
140 | } | |
3a265c7a | 141 | } |
3a265c7a | 142 | } |
a8d8c335 | 143 | |
6fad2abb KB |
144 | if (asme) { |
145 | /* if asme and non-standard target shell, must be root */ | |
146 | if (!chshell(pwd->pw_shell) && ruid) { | |
58a34b62 KF |
147 | (void)fprintf(stderr, |
148 | "su: permission denied (shell).\n"); | |
6fad2abb | 149 | exit(1); |
a8d8c335 | 150 | } |
d9e13dc0 | 151 | } else if (pwd->pw_shell && *pwd->pw_shell) { |
6fad2abb KB |
152 | shell = pwd->pw_shell; |
153 | iscsh = UNSET; | |
154 | } else { | |
3a7a366d | 155 | shell = _PATH_BSHELL; |
6fad2abb KB |
156 | iscsh = NO; |
157 | } | |
a8d8c335 | 158 | |
6964f298 | 159 | /* if we're forking a csh, we want to slightly muck the args */ |
a8d8c335 KB |
160 | if (iscsh == UNSET) { |
161 | if (p = rindex(shell, '/')) | |
162 | ++p; | |
163 | else | |
164 | p = shell; | |
165 | iscsh = strcmp(p, "csh") ? NO : YES; | |
166 | } | |
167 | ||
6964f298 | 168 | /* set permissions */ |
13dd8b1d SL |
169 | if (setgid(pwd->pw_gid) < 0) { |
170 | perror("su: setgid"); | |
7d5e1706 | 171 | exit(1); |
13dd8b1d | 172 | } |
4f4c2c68 | 173 | if (initgroups(user, pwd->pw_gid)) { |
d9e13dc0 | 174 | (void)fprintf(stderr, "su: initgroups failed.\n"); |
7d5e1706 | 175 | exit(1); |
13dd8b1d SL |
176 | } |
177 | if (setuid(pwd->pw_uid) < 0) { | |
178 | perror("su: setuid"); | |
7d5e1706 | 179 | exit(1); |
13dd8b1d | 180 | } |
6964f298 KB |
181 | |
182 | if (!asme) { | |
e5b1d5e7 | 183 | if (asthem) { |
6964f298 | 184 | p = getenv("TERM"); |
3a7a366d | 185 | cleanenv[0] = _PATH_SEARCHPATH; |
6964f298 KB |
186 | cleanenv[1] = NULL; |
187 | environ = cleanenv; | |
188 | (void)setenv("TERM", p, 1); | |
189 | if (chdir(pwd->pw_dir) < 0) { | |
190 | fprintf(stderr, "su: no directory\n"); | |
191 | exit(1); | |
192 | } | |
193 | } | |
e5b1d5e7 | 194 | if (asthem || pwd->pw_uid) |
6964f298 | 195 | (void)setenv("USER", pwd->pw_name, 1); |
a8d8c335 KB |
196 | (void)setenv("HOME", pwd->pw_dir, 1); |
197 | (void)setenv("SHELL", shell, 1); | |
3a265c7a | 198 | } |
3a265c7a | 199 | |
6964f298 KB |
200 | if (iscsh == YES) { |
201 | if (fastlogin) | |
202 | *np-- = "-f"; | |
203 | if (asme) | |
204 | *np-- = "-m"; | |
205 | } | |
a8d8c335 KB |
206 | |
207 | /* csh strips the first character... */ | |
e5b1d5e7 | 208 | *np = asthem ? "-su" : iscsh == YES ? "_su" : "su"; |
7d5e1706 | 209 | |
58a34b62 | 210 | syslog(LOG_NOTICE|LOG_AUTH, "%s on %s to %s", username, mytty(), user); |
7d5e1706 KB |
211 | |
212 | (void)setpriority(PRIO_PROCESS, 0, prio); | |
213 | ||
6964f298 | 214 | execv(shell, np); |
d9e13dc0 | 215 | (void)fprintf(stderr, "su: %s not found.\n", shell); |
7d5e1706 | 216 | exit(1); |
3a265c7a | 217 | } |
7b34c4f8 KB |
218 | |
219 | chshell(sh) | |
220 | char *sh; | |
221 | { | |
d9e13dc0 KB |
222 | register char *cp; |
223 | char *getusershell(); | |
7b34c4f8 KB |
224 | |
225 | while ((cp = getusershell()) != NULL) | |
226 | if (!strcmp(cp, sh)) | |
227 | return(1); | |
228 | return(0); | |
229 | } | |
094e5ff2 | 230 | |
dbf8133b KB |
231 | char * |
232 | mytty() | |
233 | { | |
234 | char *p, *ttyname(); | |
235 | ||
236 | return((p = ttyname(STDERR_FILENO)) ? p : "UNKNOWN TTY"); | |
237 | } | |
238 | ||
d9e13dc0 KB |
239 | #ifdef KERBEROS |
240 | kerberos(username, user, uid) | |
241 | char *username, *user; | |
242 | int uid; | |
243 | { | |
244 | extern char *krb_err_txt[]; | |
245 | KTEXT_ST ticket; | |
246 | AUTH_DAT authdata; | |
247 | struct hostent *hp; | |
248 | register char *p; | |
249 | int kerno; | |
250 | u_long faddr; | |
58a34b62 | 251 | char lrealm[REALM_SZ], krbtkfile[MAXPATHLEN]; |
d9e13dc0 | 252 | char hostname[MAXHOSTNAMELEN], savehost[MAXHOSTNAMELEN]; |
dbf8133b | 253 | char *mytty(); |
d9e13dc0 KB |
254 | |
255 | if (krb_get_lrealm(lrealm, 1) != KSUCCESS) { | |
256 | (void)fprintf(stderr, "su: couldn't get local realm.\n"); | |
257 | return(1); | |
258 | } | |
259 | if (koktologin(username, lrealm, user) && !uid) { | |
260 | (void)fprintf(stderr, "kerberos su: not in %s's ACL.\n", user); | |
261 | return(1); | |
262 | } | |
263 | (void)sprintf(krbtkfile, "%s_%s_%d", TKT_ROOT, user, getuid()); | |
d9e13dc0 KB |
264 | |
265 | (void)setenv("KRBTKFILE", krbtkfile, 1); | |
d9e13dc0 KB |
266 | if (setuid(0) < 0) { |
267 | perror("su: setuid"); | |
268 | return(1); | |
269 | } | |
270 | (void)unlink(krbtkfile); | |
d9e13dc0 | 271 | |
58a34b62 KF |
272 | /* |
273 | * Little trick here -- if we are su'ing to root, | |
274 | * we need to get a ticket for "xxx.root", where xxx represents | |
275 | * the name of the person su'ing. Otherwise (non-root case), | |
276 | * we need to get a ticket for "yyy.", where yyy represents | |
277 | * the name of the person being su'd to, and the instance is null | |
278 | * | |
279 | * Also: POLICY: short ticket lifetime for root | |
280 | */ | |
281 | kerno = krb_get_pw_in_tkt((uid == 0 ? username : user), | |
282 | (uid == 0 ? "root" : ""), lrealm, | |
283 | "krbtgt", lrealm, (uid == 0 ? 2 : DEFAULT_TKT_LIFE), 0); | |
d9e13dc0 KB |
284 | |
285 | if (kerno != KSUCCESS) { | |
58a34b62 KF |
286 | if (kerno == KDC_PR_UNKNOWN) { |
287 | fprintf(stderr, "principal unknown: %s.%s@%s\n", | |
288 | (uid == 0 ? username : user), | |
289 | (uid == 0 ? "root" : ""), lrealm); | |
d9e13dc0 | 290 | return(1); |
58a34b62 | 291 | } |
d9e13dc0 KB |
292 | (void)printf("su: unable to su: %s\n", krb_err_txt[kerno]); |
293 | syslog(LOG_NOTICE|LOG_AUTH, | |
58a34b62 KF |
294 | "su: BAD Kerberos SU: %s on %s to %s: %s", |
295 | username, mytty(), user, krb_err_txt[kerno]); | |
d9e13dc0 KB |
296 | return(1); |
297 | } | |
298 | ||
299 | if (chown(krbtkfile, uid, -1) < 0) { | |
300 | perror("su: chown:"); | |
301 | (void)unlink(krbtkfile); | |
302 | return(1); | |
303 | } | |
304 | ||
305 | (void)setpriority(PRIO_PROCESS, 0, -2); | |
306 | ||
307 | if (gethostname(hostname, sizeof(hostname)) == -1) { | |
308 | perror("su: hostname"); | |
309 | dest_tkt(); | |
310 | return(1); | |
311 | } | |
312 | ||
313 | (void)strncpy(savehost, krb_get_phost(hostname), sizeof(savehost)); | |
314 | savehost[sizeof(savehost) - 1] = '\0'; | |
315 | ||
316 | kerno = krb_mk_req(&ticket, "rcmd", savehost, lrealm, 33); | |
317 | ||
318 | if (kerno == KDC_PR_UNKNOWN) { | |
319 | (void)printf("Warning: tgt not verified.\n"); | |
58a34b62 KF |
320 | syslog(LOG_NOTICE|LOG_AUTH, |
321 | "su: %s on %s to %s, TGT not verified", | |
322 | username, mytty(), user); | |
d9e13dc0 | 323 | } else if (kerno != KSUCCESS) { |
58a34b62 KF |
324 | (void)printf("Unable to use TGT: %s\n", krb_err_txt[kerno]); |
325 | syslog(LOG_NOTICE|LOG_AUTH, "su: failed su: %s on %s to %s: %s", | |
326 | username, mytty(), user, krb_err_txt[kerno]); | |
d9e13dc0 KB |
327 | dest_tkt(); |
328 | return(1); | |
329 | } else { | |
330 | if (!(hp = gethostbyname(hostname))) { | |
331 | (void)printf("su: can't get addr of %s\n", hostname); | |
332 | dest_tkt(); | |
333 | return(1); | |
334 | } | |
335 | (void)bcopy((char *)hp->h_addr, (char *)&faddr, sizeof(faddr)); | |
336 | ||
337 | if ((kerno = krb_rd_req(&ticket, "rcmd", savehost, faddr, | |
338 | &authdata, "")) != KSUCCESS) { | |
339 | (void)printf("su: unable to verify rcmd ticket: %s\n", | |
340 | krb_err_txt[kerno]); | |
341 | syslog(LOG_NOTICE|LOG_AUTH, | |
58a34b62 KF |
342 | "su: failed su: %s on %s to %s: %s", username, |
343 | mytty(), user, krb_err_txt[kerno]); | |
d9e13dc0 KB |
344 | dest_tkt(); |
345 | return(1); | |
346 | } | |
347 | } | |
348 | return(0); | |
349 | } | |
350 | ||
094e5ff2 | 351 | koktologin(name, realm, toname) |
d9e13dc0 | 352 | char *name, *realm, *toname; |
094e5ff2 | 353 | { |
d9e13dc0 KB |
354 | register AUTH_DAT *kdata; |
355 | AUTH_DAT kdata_st; | |
094e5ff2 | 356 | |
d9e13dc0 | 357 | kdata = &kdata_st; |
094e5ff2 | 358 | bzero((caddr_t) kdata, sizeof(*kdata)); |
d9e13dc0 KB |
359 | (void)strcpy(kdata->pname, name); |
360 | (void)strcpy(kdata->pinst, | |
361 | ((strcmp(toname, "root") == 0) ? "root" : "")); | |
362 | (void)strcpy(kdata->prealm, realm); | |
094e5ff2 KF |
363 | return(kuserok(kdata, toname)); |
364 | } | |
365 | #endif |