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PAM-related improvements:

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- if operating "as them" (su -l), use pam_{open,close}_session()
 - allow PAM to override $HOME (pam_chroot needs this)
 - chdir early, because later on we may be chrooted and chdir will fail

Also use pid_t instead of int where applicable.
This commit is contained in:
Dag-Erling Smørgrav 2003-04-08 16:59:53 +00:00
parent a8643c9882
commit 60b28daa8d
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=113262
1 changed files with 59 additions and 37 deletions
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96
usr.bin/su/su.c
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@ -74,36 +74,41 @@ static const char rcsid[] =
#include <security/pam_appl.h>
#include <security/openpam.h>
#define PAM_END() do { \
int local_ret; \
if (pamh != NULL && creds_set) { \
local_ret = pam_setcred(pamh, PAM_DELETE_CRED); \
if (local_ret != PAM_SUCCESS) \
syslog(LOG_ERR, "pam_setcred: %s", \
pam_strerror(pamh, local_ret)); \
local_ret = pam_end(pamh, local_ret); \
if (local_ret != PAM_SUCCESS) \
syslog(LOG_ERR, "pam_end: %s", \
pam_strerror(pamh, local_ret)); \
} \
#define PAM_END() do { \
int local_ret; \
if (pamh != NULL) { \
local_ret = pam_setcred(pamh, PAM_DELETE_CRED); \
if (local_ret != PAM_SUCCESS) \
syslog(LOG_ERR, "pam_setcred: %s", \
pam_strerror(pamh, local_ret)); \
if (asthem) { \
local_ret = pam_close_session(pamh, 0); \
if (local_ret != PAM_SUCCESS) \
syslog(LOG_ERR, "pam_close_session: %s",\
pam_strerror(pamh, local_ret)); \
} \
local_ret = pam_end(pamh, local_ret); \
if (local_ret != PAM_SUCCESS) \
syslog(LOG_ERR, "pam_end: %s", \
pam_strerror(pamh, local_ret)); \
} \
} while (0)
#define PAM_SET_ITEM(what, item) do { \
int local_ret; \
local_ret = pam_set_item(pamh, what, item); \
if (local_ret != PAM_SUCCESS) { \
syslog(LOG_ERR, "pam_set_item(" #what "): %s", \
pam_strerror(pamh, local_ret)); \
errx(1, "pam_set_item(" #what "): %s", \
pam_strerror(pamh, local_ret)); \
} \
#define PAM_SET_ITEM(what, item) do { \
int local_ret; \
local_ret = pam_set_item(pamh, what, item); \
if (local_ret != PAM_SUCCESS) { \
syslog(LOG_ERR, "pam_set_item(" #what "): %s", \
pam_strerror(pamh, local_ret)); \
errx(1, "pam_set_item(" #what "): %s", \
pam_strerror(pamh, local_ret)); \
} \
} while (0)
enum tristate { UNSET, YES, NO };
static pam_handle_t *pamh = NULL;
static int creds_set = 0;
static char **environ_pam;
static char *ontty(void);
@ -126,8 +131,9 @@ main(int argc, char *argv[])
char * const *b;
} np;
uid_t ruid;
pid_t child_pid, child_pgrp, pid;
int asme, ch, asthem, fastlogin, prio, i, setwhat, retcode,
statusp, child_pid, child_pgrp, ret_pid, setmaclabel;
statusp, setmaclabel;
char *username, *cleanenv, *class, shellbuf[MAXPATHLEN];
const char *p, *user, *shell, *mytty, **nargv;
struct sigaction sa, sa_int, sa_quit, sa_pipe;
@ -304,6 +310,12 @@ main(int argc, char *argv[])
}
setpriority(PRIO_PROCESS, 0, prio);
/* Switch to home directory */
if (asthem) {
if (chdir(pwd->pw_dir) < 0)
errx(1, "no directory");
}
/*
* PAM modules might add supplementary groups in pam_setcred(), so
* initialize them first.
@ -312,11 +324,19 @@ main(int argc, char *argv[])
err(1, "setusercontext");
retcode = pam_setcred(pamh, PAM_ESTABLISH_CRED);
if (retcode != PAM_SUCCESS)
syslog(LOG_ERR, "pam_setcred(pamh, PAM_ESTABLISH_CRED): %s",
if (retcode != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_setcred: %s",
pam_strerror(pamh, retcode));
else
creds_set = 1;
errx(1, "failed to establish credentials.");
}
if (asthem) {
retcode = pam_open_session(pamh, 0);
if (retcode != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_open_session: %s",
pam_strerror(pamh, retcode));
errx(1, "failed to open session.");
}
}
/*
* We must fork() before setuid() because we need to call
@ -344,8 +364,7 @@ main(int argc, char *argv[])
tcsetpgrp(1, child_pid);
close(fds[1]);
sigaction(SIGPIPE, &sa_pipe, NULL);
while ((ret_pid = waitpid(child_pid, &statusp, WUNTRACED)) !=
-1) {
while ((pid = waitpid(child_pid, &statusp, WUNTRACED)) != -1) {
if (WIFSTOPPED(statusp)) {
kill(getpid(), SIGSTOP);
child_pgrp = getpgid(child_pid);
@ -356,7 +375,7 @@ main(int argc, char *argv[])
}
break;
}
if (ret_pid == -1)
if (pid == -1)
err(1, "waitpid");
PAM_END();
exit(statusp);
@ -397,7 +416,14 @@ main(int argc, char *argv[])
if (asthem) {
p = getenv("TERM");
environ = &cleanenv;
}
if (asthem || pwd->pw_uid)
setenv("USER", pwd->pw_name, 1);
setenv("HOME", pwd->pw_dir, 1);
setenv("SHELL", shell, 1);
if (asthem) {
/*
* Add any environmental variables that the
* PAM modules may have set.
@ -412,13 +438,7 @@ main(int argc, char *argv[])
LOGIN_SETENV);
if (p)
setenv("TERM", p, 1);
if (chdir(pwd->pw_dir) < 0)
errx(1, "no directory");
}
if (asthem || pwd->pw_uid)
setenv("USER", pwd->pw_name, 1);
setenv("HOME", pwd->pw_dir, 1);
setenv("SHELL", shell, 1);
}
login_close(lc);
@ -459,12 +479,14 @@ export_pam_environment(void)
* - Make sure the string doesn't run on too long.
* - Do not export certain variables. This list was taken from the
* Solaris pam_putenv(3) man page.
* Note that if the user is chrooted, PAM may have a better idea than we
* do of where her home directory is.
*/
static int
ok_to_export(const char *s)
{
static const char *noexport[] = {
"SHELL", "HOME", "LOGNAME", "MAIL", "CDPATH",
"SHELL", /* "HOME", */ "LOGNAME", "MAIL", "CDPATH",
"IFS", "PATH", NULL
};
const char **pp;