/*-
* Copyright (c) 1990, 1993, 1994
* The Regents of the University of California. All rights reserved.
+ * Copyright (c) 2002 Networks Associates Technology, Inc.
+ * All rights reserved.
+ *
+ * Portions of this software were developed for the FreeBSD Project by
+ * ThinkSec AS and NAI Labs, the Security Research Division of Network
+ * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
+ * ("CBOSS"), as part of the DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
#include <sys/wait.h>
#include <err.h>
+#include <ctype.h>
#include <fcntl.h>
+#include <inttypes.h>
+#include <libgen.h>
#include <paths.h>
#include <pwd.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
-#include "pw_util.h"
+#include <libutil.h>
-extern char *tempname;
static pid_t editpid = -1;
-static int lockfd;
-static char _default_editor[] = _PATH_VI;
-static char _default_mppath[] = _PATH_PWD;
-static char _default_masterpasswd[] = _PATH_MASTERPASSWD;
-char *mppath = _default_mppath;
-char *masterpasswd = _default_masterpasswd;
-
-void pw_cont(int);
+static int lockfd = -1;
+static char masterpasswd[PATH_MAX];
+static char passwd_dir[PATH_MAX];
+static char tempname[PATH_MAX];
+static int initialized;
void
pw_cont(int sig)
kill(editpid, sig);
}
-void
-pw_init(void)
+/*
+ * Initialize statics and set limits, signals & umask to try to avoid
+ * interruptions, crashes etc. that might expose passord data.
+ */
+int
+pw_init(const char *dir, const char *master)
{
+#if 0
struct rlimit rlim;
+#endif
+
+ if (dir == NULL) {
+ strcpy(passwd_dir, _PATH_ETC);
+ } else {
+ if (strlen(dir) >= sizeof passwd_dir) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ strcpy(passwd_dir, dir);
+ }
+ if (master == NULL) {
+ if (dir == NULL) {
+ strcpy(masterpasswd, _PATH_MASTERPASSWD);
+ } else if (snprintf(masterpasswd, sizeof masterpasswd, "%s/%s",
+ passwd_dir, _MASTERPASSWD) > sizeof masterpasswd) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ } else {
+ if (strlen(master) >= sizeof masterpasswd) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ strcpy(masterpasswd, master);
+ }
+
+ /*
+ * The code that follows is extremely disruptive to the calling
+ * process, and is therefore disabled until someone can conceive
+ * of a realistic scenario where it would fend off a compromise.
+ * Race conditions concerning the temporary files can be guarded
+ * against in other ways than masking signals (by checking stat(2)
+ * results after creation).
+ */
+#if 0
/* Unlimited resource limits. */
rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
(void)setrlimit(RLIMIT_CPU, &rlim);
/* Create with exact permissions. */
(void)umask(0);
+#endif
+ initialized = 1;
+ return (0);
}
+/*
+ * Lock the master password file.
+ */
int
pw_lock(void)
{
+
+ if (*masterpasswd == '\0')
+ return (-1);
+
/*
* If the master password file doesn't exist, the system is hosed.
* Might as well try to build one. Set the close-on-exec bit so
lockfd = open(masterpasswd, O_RDONLY, 0);
if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
err(1, "%s", masterpasswd);
+ /* XXX vulnerable to race conditions */
if (flock(lockfd, LOCK_EX|LOCK_NB))
errx(1, "the password db file is busy");
return (lockfd);
}
+/*
+ * Create and open a presumably safe temp file for editing the password
+ * data, and copy the master password file into it.
+ */
int
-pw_tmp(void)
+pw_tmp(int mfd)
{
- static char path[MAXPATHLEN];
- int fd;
- char *p;
-
- strncpy(path, masterpasswd, MAXPATHLEN - 1);
- path[MAXPATHLEN] = '\0';
+ char buf[8192];
+ ssize_t nr, nw;
+ const char *p;
+ int tfd;
- if ((p = strrchr(path, '/')))
+ if (*masterpasswd == '\0')
+ return (-1);
+ if ((p = strrchr(masterpasswd, '/')))
++p;
else
- p = path;
- strcpy(p, "pw.XXXXXX");
- if ((fd = mkstemp(path)) == -1)
- err(1, "%s", path);
- tempname = path;
- return (fd);
+ p = masterpasswd;
+ if (snprintf(tempname, sizeof tempname, "%.*spw.XXXXXX",
+ (int)(p - masterpasswd), masterpasswd) >= sizeof tempname) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ if ((tfd = mkstemp(tempname)) == -1)
+ return (-1);
+ if (mfd != -1) {
+ while ((nr = read(mfd, buf, sizeof buf)) > 0)
+ if ((nw = write(tfd, buf, nr)) != nr)
+ break;
+ if (nr != 0) {
+ unlink(tempname);
+ *tempname = '\0';
+ close(tfd);
+ return (-1);
+ }
+ }
+ return (tfd);
}
+/*
+ * Regenerate the password database.
+ */
int
-pw_mkdb(const char *username)
+pw_mkdb(const char *user)
{
int pstat;
pid_t pid;
(void)fflush(stderr);
- if (!(pid = fork())) {
- if(!username) {
- warnx("rebuilding the database...");
- execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", "-d", mppath,
- tempname, (char *)NULL);
- } else {
- warnx("updating the database...");
- execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", "-d", mppath,
- "-u", username, tempname, (char *)NULL);
- }
- pw_error(_PATH_PWD_MKDB, 1, 1);
+ switch ((pid = fork())) {
+ case -1:
+ return (-1);
+ case 0:
+ /* child */
+ if (user == NULL)
+ execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
+ "-d", passwd_dir, tempname, NULL);
+ else
+ execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
+ "-d", passwd_dir, "-u", user, tempname, NULL);
+ _exit(1);
+ default:
+ /* parent */
+ break;
}
- pid = waitpid(pid, &pstat, 0);
- if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0)
+ if (waitpid(pid, &pstat, 0) == -1)
+ return (-1);
+ if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0)
return (0);
- warnx("done");
- return (1);
+ errno = 0;
+ return (-1);
}
-void
+/*
+ * Edit the temp file. Return -1 on error, >0 if the file was modified, 0
+ * if it was not.
+ */
+int
pw_edit(int notsetuid)
{
+ struct stat st1, st2;
+ const char *editor;
int pstat;
- char *p, *editor;
-
- if (!(editor = getenv("EDITOR")))
- editor = _default_editor;
- if ((p = strrchr(editor, '/')))
- ++p;
- else
- p = editor;
- if (!(editpid = fork())) {
+ if ((editor = getenv("EDITOR")) == NULL)
+ editor = _PATH_VI;
+ if (stat(tempname, &st1) == -1)
+ return (-1);
+ switch ((editpid = fork())) {
+ case -1:
+ return (-1);
+ case 0:
+ /* child */
if (notsetuid) {
(void)setgid(getgid());
(void)setuid(getuid());
}
errno = 0;
- execlp(editor, p, tempname, (char *)NULL);
+ execlp(editor, basename(editor), tempname, NULL);
_exit(errno);
+ default:
+ /* parent */
+ break;
}
for (;;) {
- editpid = waitpid(editpid, (int *)&pstat, WUNTRACED);
- errno = WEXITSTATUS(pstat);
- if (editpid == -1)
- pw_error(editor, 1, 1);
- else if (WIFSTOPPED(pstat))
+ editpid = waitpid(editpid, &pstat, WUNTRACED);
+ if (editpid == -1) {
+ unlink(tempname);
+ return (-1);
+ } else if (WIFSTOPPED(pstat)) {
raise(WSTOPSIG(pstat));
- else if (WIFEXITED(pstat) && errno == 0)
+ } else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0) {
+ editpid = -1;
break;
- else
- pw_error(editor, 1, 1);
+ } else {
+ unlink(tempname);
+ *tempname = '\0';
+ editpid = -1;
+ return (-1);
+ }
}
- editpid = -1;
+ if (stat(tempname, &st2) == -1)
+ return (-1);
+ return (st1.st_mtime != st2.st_mtime);
}
+/*
+ * Clean up. Preserve errno for the caller's convenience.
+ */
void
-pw_prompt(void)
+pw_fini(void)
{
- int c, first;
-
- (void)printf("re-edit the password file? [y]: ");
- (void)fflush(stdout);
- first = c = getchar();
- while (c != '\n' && c != EOF)
- c = getchar();
- if (first == 'n')
- pw_error(NULL, 0, 0);
+ int serrno, status;
+
+ if (!initialized)
+ return;
+ initialized = 0;
+ serrno = errno;
+ if (editpid != -1) {
+ kill(editpid, SIGTERM);
+ kill(editpid, SIGCONT);
+ waitpid(editpid, &status, 0);
+ editpid = -1;
+ }
+ if (*tempname != '\0') {
+ unlink(tempname);
+ *tempname = '\0';
+ }
+ if (lockfd != -1)
+ close(lockfd);
+ errno = serrno;
}
-void
-pw_error(const char *name, int error, int eval)
+/*
+ * Compares two struct pwds.
+ */
+int
+pw_equal(struct passwd *pw1, struct passwd *pw2)
{
- if (error) {
- if (name != NULL)
- warn("%s", name);
- else
- warn(NULL);
+ return (strcmp(pw1->pw_name, pw2->pw_name) == 0 &&
+ pw1->pw_uid == pw2->pw_uid &&
+ pw1->pw_gid == pw2->pw_gid &&
+ strcmp(pw1->pw_class, pw2->pw_class) == 0 &&
+ pw1->pw_change == pw2->pw_change &&
+ pw1->pw_expire == pw2->pw_expire &&
+ strcmp(pw1->pw_gecos, pw2->pw_gecos) == 0 &&
+ strcmp(pw1->pw_dir, pw2->pw_dir) == 0 &&
+ strcmp(pw1->pw_shell, pw2->pw_shell) == 0);
+}
+
+/*
+ * Make a passwd line out of a struct passwd.
+ */
+char *
+pw_make(struct passwd *pw)
+{
+ char *line;
+
+ asprintf(&line, "%s:%s:%ju:%ju:%s:%ju:%ju:%s:%s:%s", pw->pw_name,
+ pw->pw_passwd, (uintmax_t)pw->pw_uid, (uintmax_t)pw->pw_gid,
+ pw->pw_class, (uintmax_t)pw->pw_change, (uintmax_t)pw->pw_expire,
+ pw->pw_gecos, pw->pw_dir, pw->pw_shell);
+ return line;
+}
+
+/*
+ * Copy password file from one descriptor to another, replacing or adding
+ * a single record on the way.
+ */
+int
+pw_copy(int ffd, int tfd, struct passwd *pw, struct passwd *old_pw)
+{
+ char buf[8192], *end, *line, *p, *q, *r, t;
+ struct passwd *fpw;
+ ssize_t len;
+ int eof;
+
+ if ((line = pw_make(pw)) == NULL)
+ return (-1);
+
+ eof = 0;
+ len = 0;
+ p = q = end = buf;
+ for (;;) {
+ /* find the end of the current line */
+ for (p = q; q < end && *q != '\0'; ++q)
+ if (*q == '\n')
+ break;
+
+ /* if we don't have a complete line, fill up the buffer */
+ if (q >= end) {
+ if (eof)
+ break;
+ if (q - p >= sizeof buf) {
+ warnx("passwd line too long");
+ errno = EINVAL; /* hack */
+ goto err;
+ }
+ if (p < end) {
+ q = memmove(buf, p, end - p);
+ end -= p - buf;
+ } else {
+ p = q = end = buf;
+ }
+ len = read(ffd, end, sizeof buf - (end - buf));
+ if (len == -1)
+ goto err;
+ if (len == 0 && p == buf)
+ break;
+ end += len;
+ len = end - buf;
+ if (len < sizeof buf) {
+ eof = 1;
+ if (len > 0 && buf[len - 1] != '\n')
+ ++len, *end++ = '\n';
+ }
+ continue;
+ }
+
+ /* is it a blank line or a comment? */
+ for (r = p; r < q && isspace(*r); ++r)
+ /* nothing */ ;
+ if (r == q || *r == '#') {
+ /* yep */
+ if (write(tfd, p, q - p + 1) != q - p + 1)
+ goto err;
+ ++q;
+ continue;
+ }
+
+ /* is it the one we're looking for? */
+ t = *q;
+ *q = '\0';
+ fpw = pw_scan(r, PWSCAN_MASTER);
+ *q = t;
+ if (old_pw == NULL || !pw_equal(pw, old_pw)) {
+ /* nope */
+ free(fpw);
+ if (write(tfd, p, q - p + 1) != q - p + 1)
+ goto err;
+ ++q;
+ continue;
+ }
+ free(fpw);
+
+ /* it is, replace it */
+ len = strlen(line);
+ if (write(tfd, line, len) != len)
+ goto err;
+
+ /* we're done, just copy the rest over */
+ for (;;) {
+ if (write(tfd, q, end - q) != end - q)
+ goto err;
+ q = buf;
+ len = read(ffd, buf, sizeof buf);
+ if (len == 0)
+ break;
+ if (len == -1)
+ goto err;
+ end = buf + len;
+ }
+ goto done;
+ }
+
+ /* if we got here, we have a new entry */
+ len = strlen(line);
+ if (write(tfd, line, len) != len)
+ goto err;
+ done:
+ free(line);
+ return (0);
+ err:
+ free(line);
+ return (-1);
+}
+
+/*
+ * Return the current value of tempname.
+ */
+const char *
+pw_tempname(void)
+{
+
+ return (tempname);
+}
+
+/*
+ * Duplicate a struct passwd.
+ */
+struct passwd *
+pw_dup(struct passwd *pw)
+{
+ struct passwd *npw;
+ size_t len;
+
+ len = sizeof *npw +
+ (pw->pw_name ? strlen(pw->pw_name) + 1 : 0) +
+ (pw->pw_passwd ? strlen(pw->pw_passwd) + 1 : 0) +
+ (pw->pw_class ? strlen(pw->pw_class) + 1 : 0) +
+ (pw->pw_gecos ? strlen(pw->pw_gecos) + 1 : 0) +
+ (pw->pw_dir ? strlen(pw->pw_dir) + 1 : 0) +
+ (pw->pw_shell ? strlen(pw->pw_shell) + 1 : 0);
+ if ((npw = malloc(len)) == NULL)
+ return (NULL);
+ memcpy(npw, pw, sizeof *npw);
+ len = sizeof *npw;
+ if (pw->pw_name) {
+ npw->pw_name = ((char *)npw) + len;
+ len += sprintf(npw->pw_name, "%s", pw->pw_name) + 1;
+ }
+ if (pw->pw_passwd) {
+ npw->pw_passwd = ((char *)npw) + len;
+ len += sprintf(npw->pw_passwd, "%s", pw->pw_passwd) + 1;
+ }
+ if (pw->pw_class) {
+ npw->pw_class = ((char *)npw) + len;
+ len += sprintf(npw->pw_class, "%s", pw->pw_class) + 1;
+ }
+ if (pw->pw_gecos) {
+ npw->pw_gecos = ((char *)npw) + len;
+ len += sprintf(npw->pw_gecos, "%s", pw->pw_gecos) + 1;
+ }
+ if (pw->pw_dir) {
+ npw->pw_dir = ((char *)npw) + len;
+ len += sprintf(npw->pw_dir, "%s", pw->pw_dir) + 1;
+ }
+ if (pw->pw_shell) {
+ npw->pw_shell = ((char *)npw) + len;
+ len += sprintf(npw->pw_shell, "%s", pw->pw_shell) + 1;
+ }
+ return (npw);
+}
+
+#include "pw_scan.h"
+
+/*
+ * Wrapper around an internal libc function
+ */
+struct passwd *
+pw_scan(const char *line, int flags)
+{
+ struct passwd pw, *ret;
+ char *bp;
+
+ if ((bp = strdup(line)) == NULL)
+ return (NULL);
+ if (!__pw_scan(bp, &pw, flags)) {
+ free(bp);
+ return (NULL);
}
- warnx("password information unchanged");
- (void)unlink(tempname);
- exit(eval);
+ ret = pw_dup(&pw);
+ free(bp);
+ return (ret);
}
git.ckatri.com / pw-darwin.git / commitdiff