Annotation of src/usr.bin/skeyaudit/skeyaudit.c, Revision 1.29
1.29 ! deraadt 1: /* $OpenBSD: skeyaudit.c,v 1.28 2019/01/25 00:19:26 millert Exp $ */
1.2 millert 2:
3: /*
1.28 millert 4: * Copyright (c) 1997, 2000, 2003 Todd C. Miller <millert@openbsd.org>
1.2 millert 5: *
1.20 millert 6: * Permission to use, copy, modify, and distribute this software for any
7: * purpose with or without fee is hereby granted, provided that the above
8: * copyright notice and this permission notice appear in all copies.
1.2 millert 9: *
1.20 millert 10: * THE SOFTWARE IS PROVIDED "AS IS" AND TODD C. MILLER DISCLAIMS ALL
11: * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
12: * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER BE LIABLE
13: * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
15: * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
16: * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
1.17 millert 17: *
18: * Sponsored in part by the Defense Advanced Research Projects
19: * Agency (DARPA) and Air Force Research Laboratory, Air Force
20: * Materiel Command, USAF, under agreement number F39502-99-1-0512.
1.2 millert 21: */
22:
1.9 millert 23: #include <sys/wait.h>
24:
1.1 millert 25: #include <err.h>
26: #include <errno.h>
1.17 millert 27: #include <fcntl.h>
1.1 millert 28: #include <limits.h>
1.9 millert 29: #include <login_cap.h>
1.1 millert 30: #include <paths.h>
31: #include <pwd.h>
32: #include <stdio.h>
33: #include <stdlib.h>
34: #include <string.h>
35: #include <unistd.h>
36: #include <skey.h>
37:
1.12 millert 38: void notify(struct passwd *, int, int);
1.27 krw 39: void sanitise_stdfd(void);
1.12 millert 40: FILE *runsendmail(struct passwd *, int *);
1.14 millert 41: __dead void usage(void);
1.1 millert 42:
1.27 krw 43: void
44: sanitise_stdfd(void)
45: {
46: int nullfd, dupfd;
47:
48: if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
49: fprintf(stderr, "Couldn't open /dev/null: %s\n",
50: strerror(errno));
51: exit(1);
52: }
53: while (++dupfd <= STDERR_FILENO) {
54: /* Only populate closed fds. */
55: if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) {
56: if (dup2(nullfd, dupfd) == -1) {
57: fprintf(stderr, "dup2: %s\n", strerror(errno));
58: exit(1);
59: }
60: }
61: }
62: if (nullfd > STDERR_FILENO)
63: close(nullfd);
64: }
65:
1.1 millert 66: int
1.14 millert 67: main(int argc, char **argv)
1.1 millert 68: {
69: struct passwd *pw;
70: struct skey key;
1.6 millert 71: char *name;
1.14 millert 72: int ch, left, aflag, iflag, limit;
1.6 millert 73:
1.26 tim 74: if (pledge("stdio rpath wpath flock getpw proc exec id", NULL) == -1)
75: err(1, "pledge");
76:
1.17 millert 77: aflag = iflag = 0;
1.14 millert 78: limit = 12;
1.6 millert 79: while ((ch = getopt(argc, argv, "ail:")) != -1)
1.1 millert 80: switch(ch) {
1.6 millert 81: case 'a':
82: if (getuid() != 0)
83: errx(1, "only root may use the -a flag");
1.14 millert 84: aflag = 1;
1.6 millert 85: break;
1.1 millert 86: case 'i':
87: iflag = 1;
88: break;
89: case 'l':
90: errno = 0;
91: if ((limit = (int)strtol(optarg, NULL, 10)) == 0)
92: errno = ERANGE;
93: if (errno) {
94: warn("key limit");
95: usage();
96: }
97: break;
98: default:
99: usage();
1.26 tim 100: }
101:
102: if (iflag) {
103: if (pledge("stdio rpath wpath flock getpw", NULL) == -1)
104: err(1, "pledge");
1.1 millert 105: }
106:
1.27 krw 107: /* If we are in interactive mode, STDOUT_FILENO *must* be open. */
108: if (iflag && fcntl(STDOUT_FILENO, F_GETFL) == -1 && errno == EBADF)
109: exit(1);
110:
1.17 millert 111: /*
112: * Make sure STDIN_FILENO, STDOUT_FILENO, and STDERR_FILENO are open.
113: * If not, open /dev/null in their place or bail.
114: */
1.27 krw 115: sanitise_stdfd();
1.17 millert 116:
1.1 millert 117: if (argc - optind > 0)
118: usage();
119:
1.6 millert 120: /* Need key.keyfile zero'd at the very least */
121: (void)memset(&key, 0, sizeof(key));
122:
1.17 millert 123: left = 0;
1.6 millert 124: if (aflag) {
125: while ((ch = skeygetnext(&key)) == 0) {
1.1 millert 126: left = key.n - 1;
1.6 millert 127: if ((pw = getpwnam(key.logname)) == NULL)
128: continue;
129: if (left >= limit)
130: continue;
1.17 millert 131: (void)fclose(key.keyfile);
132: key.keyfile = NULL;
1.9 millert 133: notify(pw, left, iflag);
1.6 millert 134: }
135: if (ch == -1)
1.13 millert 136: errx(-1, "cannot open %s", _PATH_SKEYDIR);
1.6 millert 137: } else {
138: if ((pw = getpwuid(getuid())) == NULL)
139: errx(1, "no passwd entry for uid %u", getuid());
140: if ((name = strdup(pw->pw_name)) == NULL)
141: err(1, "cannot allocate memory");
142: sevenbit(name);
143:
1.14 millert 144: switch (skeylookup(&key, name)) {
1.6 millert 145: case 0: /* Success! */
146: left = key.n - 1;
147: break;
148: case -1: /* File error */
1.14 millert 149: errx(1, "cannot open %s/%s", _PATH_SKEYDIR,
150: name);
1.6 millert 151: break;
152: case 1: /* Unknown user */
1.14 millert 153: errx(1, "user %s is not listed in %s", name,
1.13 millert 154: _PATH_SKEYDIR);
1.6 millert 155: }
156: (void)fclose(key.keyfile);
157:
1.14 millert 158: if (left < limit)
1.9 millert 159: notify(pw, left, iflag);
1.1 millert 160: }
1.6 millert 161:
1.14 millert 162: exit(0);
1.6 millert 163: }
1.1 millert 164:
1.6 millert 165: void
1.14 millert 166: notify(struct passwd *pw, int seq, int interactive)
1.6 millert 167: {
1.25 deraadt 168: static char hostname[HOST_NAME_MAX+1];
1.14 millert 169: pid_t pid;
1.6 millert 170: FILE *out;
1.1 millert 171:
1.6 millert 172: /* Only set this once */
173: if (hostname[0] == '\0' && gethostname(hostname, sizeof(hostname)) == -1)
1.15 millert 174: strlcpy(hostname, "unknown", sizeof(hostname));
1.1 millert 175:
1.6 millert 176: if (interactive)
1.1 millert 177: out = stdout;
1.6 millert 178: else
1.9 millert 179: out = runsendmail(pw, &pid);
1.1 millert 180:
1.6 millert 181: if (!interactive)
1.1 millert 182: (void)fprintf(out,
1.23 deraadt 183: "Auto-Submitted: auto-generated\n"
1.9 millert 184: "To: %s\nSubject: IMPORTANT action required\n", pw->pw_name);
1.1 millert 185:
1.10 pjanzen 186: if (seq)
187: (void)fprintf(out,
1.1 millert 188: "\nYou are nearing the end of your current S/Key sequence for account\n\
189: %s on system %s.\n\n\
1.10 pjanzen 190: Your S/Key sequence number is now %d. When it reaches zero\n\
191: you will no longer be able to use S/Key to log into the system.\n\n",
1.9 millert 192: pw->pw_name, hostname, seq);
1.10 pjanzen 193: else
194: (void)fprintf(out,
195: "\nYou are at the end of your current S/Key sequence for account\n\
196: %s on system %s.\n\n\
197: At this point you can no longer use S/Key to log into the system.\n\n",
198: pw->pw_name, hostname);
199: (void)fprintf(out,
200: "Type \"skeyinit -s\" to reinitialize your sequence number.\n\n");
1.1 millert 201:
1.17 millert 202: if (!interactive) {
203: (void)fclose(out);
1.6 millert 204: (void)waitpid(pid, NULL, 0);
1.17 millert 205: }
1.1 millert 206: }
207:
1.6 millert 208: FILE *
1.14 millert 209: runsendmail(struct passwd *pw, pid_t *pidp)
1.6 millert 210: {
211: FILE *fp;
1.14 millert 212: int pfd[2];
213: pid_t pid;
1.6 millert 214:
1.29 ! deraadt 215: if (pipe(pfd) == -1)
1.6 millert 216: return(NULL);
217:
218: switch (pid = fork()) {
219: case -1: /* fork(2) failed */
220: (void)close(pfd[0]);
221: (void)close(pfd[1]);
222: return(NULL);
223: case 0: /* In child */
224: (void)close(pfd[1]);
225: (void)dup2(pfd[0], STDIN_FILENO);
226: (void)close(pfd[0]);
227:
228: /* Run sendmail as target user not root */
1.19 millert 229: if (getuid() == 0 &&
230: setusercontext(NULL, pw, pw->pw_uid, LOGIN_SETALL) != 0) {
1.9 millert 231: warn("cannot set user context");
232: _exit(127);
233: }
1.6 millert 234:
1.11 deraadt 235: execl(_PATH_SENDMAIL, "sendmail", "-t", (char *)NULL);
1.6 millert 236: warn("cannot run \"%s -t\"", _PATH_SENDMAIL);
237: _exit(127);
238: }
239:
240: /* In parent */
241: *pidp = pid;
242: fp = fdopen(pfd[1], "w");
243: (void)close(pfd[0]);
244:
245: return(fp);
246: }
1.14 millert 247:
248: __dead void
249: usage(void)
1.1 millert 250: {
1.14 millert 251: extern char *__progname;
252:
1.24 sobrado 253: (void)fprintf(stderr, "usage: %s [-ai] [-l limit]\n",
1.1 millert 254: __progname);
255: exit(1);
256: }
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