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New krb5 code from Frank Cusack <fcusack@iconnet.net>.

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This commit is contained in:
Todd C. Miller
1999-10-13 02:34:55 +00:00
parent e0a83ab41c
commit 3acdd5b02f
6 changed files with 205 additions and 226 deletions
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209
auth/kerb5.c
View File

@@ -3,7 +3,7 @@
* All rights reserved.
*
* This code is derived from software contributed by Frank Cusack
* <fcusack@iconnet.net>.
* <fcusack@fcusack.com>.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -62,11 +62,15 @@
static const char rcsid[] = "$Sudo$";
#endif /* lint */
char *realm = NULL;
static int xrealm = 0;
static krb5_context sudo_context = NULL;
static int verify_krb_v5_tgt __P((krb5_context, krb5_ccache, char *));
static struct _sudo_krb5_data {
krb5_context sudo_context;
krb5_principal princ;
krb5_ccache ccache;
} sudo_krb5_data = { NULL, NULL, NULL };
typedef struct _sudo_krb5_data *sudo_krb5_datap;
static int verify_krb_v5_tgt __P((krb5_ccache));
extern krb5_cc_ops krb5_mcc_ops;
int
kerb5_init(pw, promptp, auth)
@@ -74,87 +78,153 @@ kerb5_init(pw, promptp, auth)
char **promptp;
sudo_auth *auth;
{
char *lrealm;
krb5_context sudo_context;
krb5_ccache ccache;
krb5_principal princ;
krb5_error_code error;
extern int arg_prompt;
char cache_name[64];
char *pname;
/* XXX - make these errors non-fatal for better fallback? */
if (error = krb5_init_context(&sudo_context)) {
/* XXX - map error to error string? */
auth->data = (VOID *) &sudo_krb5_data; /* Stash all our data here */
if (error = krb5_init_context(&(sudo_krb5_data.sudo_context))) {
log_error(NO_EXIT|NO_MAIL,
"unable to initialize Kerberos V context");
return(AUTH_FATAL);
"%s: unable to initialize context: %s", auth->name,
error_message(error));
return(AUTH_FAILURE);
}
auth->data = (VOID *) &sudo_context; /* save a pointer to the context */
sudo_context = sudo_krb5_data.sudo_context;
krb5_init_ets(sudo_context);
if (error = krb5_get_default_realm(sudo_context, &lrealm)) {
if (error = krb5_parse_name(sudo_context, pw->pw_name,
&(sudo_krb5_data.princ))) {
log_error(NO_EXIT|NO_MAIL,
"unable to get default Kerberos V realm");
return(AUTH_FATAL);
"%s: unable to parse '%s': %s", auth->name, pw->pw_name,
error_message(error));
return(AUTH_FAILURE);
}
princ = sudo_krb5_data.princ;
if (realm) {
if (strcmp(realm, lrealm) != 0)
xrealm = 1; /* User supplied realm is not the system default */
free(lrealm);
} else
realm = lrealm;
/*
* Really, we need to tell the caller not to prompt for password.
* The API does not currently provide this unless the auth is standalone.
*/
#if 1
if (error = krb5_unparse_name(sudo_context, princ, &pname)) {
log_error(NO_EXIT|NO_MAIL,
"%s: unable to unparse princ ('%s'): %s", auth->name,
pw->pw_name, error_message(error));
return(AUTH_FAILURE);
}
/* Only rewrite prompt if user didn't specify their own. */
if (user_prompt == NULL)
easprintf(promptp, "Password for %s@%s: ", pw->pw_name, realm);
/*if (!strcmp(prompt, PASSPROMPT)) { */
easprintf(promptp, "Password for %s: ", pname);
/*}*/
free(pname);
#endif
/* For CNS compatibility */
if (error = krb5_cc_register(sudo_context, &krb5_mcc_ops, FALSE)) {
if (error != KRB5_CC_TYPE_EXISTS) {
log_error(NO_EXIT|NO_MAIL,
"%s: unable to use Memory ccache: %s", auth->name,
error_message(error));
return(AUTH_FAILURE);
}
}
(void) snprintf(cache_name, sizeof(cache_name), "MEMORY:sudocc_%ld",
(long) getpid());
if (error = krb5_cc_resolve(sudo_context, cache_name,
&(sudo_krb5_data.ccache))) {
log_error(NO_EXIT|NO_MAIL,
"%s: unable to resolve ccache: %s", auth->name,
error_message(error));
return(AUTH_FAILURE);
}
ccache = sudo_krb5_data.ccache;
if (error = krb5_cc_initialize(sudo_context, ccache, princ)) {
log_error(NO_EXIT|NO_MAIL,
"%s: unable to initialize ccache: %s", auth->name,
error_message(error));
return(AUTH_FAILURE);
}
return(AUTH_SUCCESS);
}
/* XXX - some of this should move into the init or setup function. */
int
kerb5_verify(pw, pass, auth)
struct passwd *pw;
char *pass;
sudo_auth *auth;
{
krb5_error_code error;
krb5_context sudo_context;
krb5_principal princ;
krb5_creds creds;
krb5_ccache ccache;
char cache_name[64];
char *princ_name;
krb5_creds creds;
krb5_error_code error;
krb5_get_init_creds_opt opts;
char cache_name[64];
/* Initialize */
sudo_context = ((sudo_krb5_datap) auth->data)->sudo_context;
princ = ((sudo_krb5_datap) auth->data)->princ;
ccache = ((sudo_krb5_datap) auth->data)->ccache;
/* Initialize options to defaults */
krb5_get_init_creds_opt_init(&opts);
princ_name = emalloc(strlen(pw->pw_name) + strlen(realm) + 2);
(void) sprintf(princ_name, "%s@%s", pw->pw_name, realm);
if (krb5_parse_name(sudo_context, princ_name, &princ))
/* Note that we always obtain a new TGT to verify the user */
if (error = krb5_get_init_creds_password(sudo_context, &creds, princ,
pass, krb5_prompter_posix,
NULL, 0, NULL, &opts)) {
if (error == KRB5KRB_AP_ERR_BAD_INTEGRITY) /* Bad password */
return(AUTH_FAILURE);
/* Set the ticket file to be in /tmp so we don't need to change perms. */
/* XXX - potential /tmp race? */
(void) snprintf(cache_name, sizeof(cache_name), "FILE:/tmp/sudocc_%ld",
(long) getpid());
if (krb5_cc_resolve(sudo_context, cache_name, &ccache)
return(AUTH_FAILURE);
if (krb5_get_init_creds_password(sudo_context, &creds, princ, pass,
krb5_prompter_posix, NULL, 0, NULL, &opts))
return(AUTH_FAILURE);
/* Stash the TGT so we can verify it. */
if (krb5_cc_initialize(sudo_context, ccache, princ))
return(AUTH_FAILURE);
if (krb5_cc_store_cred(sudo_context, ccache, &creds)) {
(void) krb5_cc_destroy(sudo_context, ccache);
/* Some other error */
log_error(NO_EXIT|NO_MAIL,
"%s: unable to get credentials: %s", auth->name,
error_message(error));
return(AUTH_FAILURE);
}
error = verify_krb_v5_tgt(ccache);
(void) krb5_cc_destroy(sudo_context, ccache);
/* Stash the TGT so we can verify it. */
if (error = krb5_cc_store_cred(sudo_context, ccache, &creds)) {
log_error(NO_EXIT|NO_MAIL,
"%s: unable to store credentials: %s", auth->name,
error_message(error));
} else {
error = verify_krb_v5_tgt(sudo_context, ccache, auth->name);
}
krb5_free_cred_contents(sudo_context, &creds);
return (error ? AUTH_FAILURE : AUTH_SUCCESS);
}
int
kerb5_cleanup(pw, auth)
struct passwd *pw;
sudo_auth *auth;
{
krb5_context sudo_context;
krb5_principal princ;
krb5_ccache ccache;
sudo_context = ((sudo_krb5_datap) auth->data)->sudo_context;
princ = ((sudo_krb5_datap) auth->data)->princ;
ccache = ((sudo_krb5_datap) auth->data)->ccache;
if (sudo_context) {
if (ccache)
krb5_cc_destroy(sudo_context, ccache);
if (princ)
krb5_free_principal(sudo_context, princ);
krb5_free_context(sudo_context);
}
return(AUTH_SUCCESS);
}
/*
* This routine with some modification is from the MIT V5B6 appl/bsd/login.c
*
@@ -162,19 +232,23 @@ kerb5_verify(pw, pass, auth)
* user. If the Kerberos server doesn't respond, assume the user is
* trying to fake us out (since we DID just get a TGT from what is
* supposedly our KDC). If the host/<host> service is unknown (i.e.,
* the local keytab doesn't have it), let her in.
* the local keytab doesn't have it), return success but log the error.
*
* This needs to run as root (to read the host service ticket).
*
* Returns 0 for successful authentication, non-zero for failure.
*/
static int
verify_krb_v5_tgt(ccache)
verify_krb_v5_tgt(sudo_context, ccache, auth_name)
krb5_context sudo_context;
krb5_ccache ccache;
char *auth_name; /* For error reporting */
{
char phost[BUFSIZ];
krb5_error_code error;
krb5_principal princ;
krb5_keyblock * keyblock = 0;
krb5_data packet;
krb5_keyblock *keyblock = 0;
krb5_auth_context auth_context = NULL;
packet.data = 0;
@@ -183,12 +257,17 @@ verify_krb_v5_tgt(ccache)
* Get the server principal for the local host.
* (Use defaults of "host" and canonicalized local name.)
*/
if (krb5_sname_to_principal(sudo_context, NULL, NULL,
KRB5_NT_SRV_HST, &princ))
if (error = krb5_sname_to_principal(sudo_context, NULL, NULL,
KRB5_NT_SRV_HST, &princ)) {
log_error(NO_EXIT|NO_MAIL,
"%s: unable to get host principal: %s", auth_name,
error_message(error));
return(-1);
}
/* Extract the name directly. */
strncpy(phost, krb5_princ_component(c, princ, 1)->data, sizeof(phost) - 1);
/* Extract the name directly. Yow. */
strncpy(phost, krb5_princ_component(sudo_context, princ, 1)->data,
sizeof(phost) - 1);
phost[sizeof(phost) - 1] = '\0';
/*
@@ -199,6 +278,10 @@ verify_krb_v5_tgt(ccache)
if (error = krb5_kt_read_service_key(sudo_context, NULL, princ, 0,
ENCTYPE_DES_CBC_MD5, &keyblock)) {
/* Keytab or service key does not exist. */
log_error(NO_EXIT,
"%s: host service key not found: %s", auth_name,
error_message(error));
error = 0;
goto cleanup;
}
if (keyblock)
@@ -221,5 +304,9 @@ cleanup:
krb5_free_data_contents(sudo_context, &packet);
krb5_free_principal(sudo_context, princ);
if (error)
log_error(NO_EXIT|NO_MAIL,
"%s: Cannot verify TGT! Possible attack!: %s", auth_name,
error_message(error));
return(error);
}

2
auth/sudo_auth.c
View File

@@ -80,7 +80,7 @@ sudo_auth auth_switch[] = {
AUTH_ENTRY(0, "kerb4", kerb4_init, NULL, kerb4_verify, NULL)
# endif
# ifdef HAVE_KERB5
AUTH_ENTRY(0, "kerb5", kerb5_init, NULL, kerb5_verify, NULL)
AUTH_ENTRY(0, "kerb5", kerb5_init, NULL, kerb5_verify, kerb5_cleanup)
# endif
# ifdef HAVE_SKEY
AUTH_ENTRY(0, "S/Key", NULL, rfc1938_setup, rfc1938_verify, NULL)

1
auth/sudo_auth.h
View File

@@ -88,6 +88,7 @@ int kerb4_init __P((struct passwd *pw, char **prompt, sudo_auth *auth));
int kerb4_verify __P((struct passwd *pw, char *pass, sudo_auth *auth));
int kerb5_init __P((struct passwd *pw, char **prompt, sudo_auth *auth));
int kerb5_verify __P((struct passwd *pw, char *pass, sudo_auth *auth));
int kerb5_cleanup __P((struct passwd *pw, sudo_auth *auth));
int securid_init __P((struct passwd *pw, char **prompt, sudo_auth *auth));
int securid_setup __P((struct passwd *pw, char **prompt, sudo_auth *auth));
int securid_verify __P((struct passwd *pw, char *pass, sudo_auth *auth));

148
configure vendored
View File

@@ -7662,58 +7662,32 @@ fi
fi
if test "$with_kerb5" = "yes"; then
echo $ac_n "checking for krb5_get_init_creds_opt in -lkrb5""... $ac_c" 1>&6
echo "configure:7667: checking for krb5_get_init_creds_opt in -lkrb5" >&5
if test -n ""; then
ac_lib_var=`echo krb5'_'krb5_get_init_creds_opt | sed 'y% ./+-%___p_%'`
else
ac_lib_var=`echo krb5'_'krb5_get_init_creds_opt | sed 'y%./+-%__p_%'`
fi
if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
ac_save_LIBS="$LIBS"
LIBS="-lkrb5 $LIBS"
cat > conftest.$ac_ext <<EOF
#line 7679 "configure"
#include "confdefs.h"
/* Override any gcc2 internal prototype to avoid an error. */
/* We use char because int might match the return type of a gcc2
builtin and then its argument prototype would still apply. */
char krb5_get_init_creds_opt();
int main() {
krb5_get_init_creds_opt()
; return 0; }
EOF
if { (eval echo configure:7690: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
rm -rf conftest*
eval "ac_cv_lib_$ac_lib_var=yes"
else
echo "configure: failed program was:" >&5
cat conftest.$ac_ext >&5
rm -rf conftest*
eval "ac_cv_lib_$ac_lib_var=no"
fi
rm -f conftest*
LIBS="$ac_save_LIBS"
fi
if eval "test \"`echo '$ac_cv_lib_'$ac_lib_var`\" = yes"; then
echo "$ac_t""yes" 1>&6
cat >> confdefs.h <<\EOF
#define HAVE_KERB5 1
EOF
if test -f "/usr/local/include/krb5.h"; then
CPPFLAGS="$CPPFLAGS -I/usr/local/include"
elif test -f "/usr/local/kerberos/include/krb5.h"; then
CPPFLAGS="$CPPFLAGS -I/usr/local/kerberos/include"
elif test -f "/usr/local/krb5/include/krb5.h"; then
CPPFLAGS="$CPPFLAGS -I/usr/local/krb5/include"
else
echo 'Unable to locate kerberos 5 include files, you will have to edit the Makefile and add -I/path/to/krb/includes to CPPFLAGS'
fi
if test -f "/usr/local/lib/libkrb5.a"; then
SUDO_LDFLAGS="${SUDO_LDFLAGS} -L/usr/local/lib"
elif test -f "/usr/local/kerberos/lib/libkrb5.a"; then
SUDO_LDFLAGS="${SUDO_LDFLAGS} -L/usr/local/kerberos/lib"
elif test -f "/usr/local/krb5/lib/libkrb5.a"; then
SUDO_LDFLAGS="${SUDO_LDFLAGS} -L/usr/local/krb5/lib"
else
echo 'Unable to locate kerberos 5 libraries, you will have to edit the Makefile and add -L/path/to/krb/libs to SUDO_LDFLAGS'
fi
SUDO_LIBS="${SUDO_LIBS} -lkrb5 -lk5crypto -lcom_err"
AUTH_OBJS="${AUTH_OBJS} kerb5.o"
else
echo "$ac_t""no" 1>&6
with_kerb4=yes
fi
fi
if test "$with_kerb4" = "yes"; then
@@ -7743,93 +7717,22 @@ EOF
echo 'Unable to locate kerberos 4 libraries, you will have to edit the Makefile and add -L/path/to/krb/libs to SUDO_LDFLAGS'
fi
if test "$with_kerb5" = "yes"; then
echo $ac_n "checking for -lkrb4""... $ac_c" 1>&6
echo "configure:7749: checking for -lkrb4" >&5
if eval "test \"`echo '$''{'ac_cv_lib_krb4'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
ac_save_LIBS="$LIBS"
LIBS="-lkrb4 $LIBS"
cat > conftest.$ac_ext <<EOF
#line 7756 "configure"
#include "confdefs.h"
int main() {
main()
; return 0; }
EOF
if { (eval echo configure:7763: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
rm -rf conftest*
ac_cv_lib_krb4=yes
else
echo "configure: failed program was:" >&5
cat conftest.$ac_ext >&5
rm -rf conftest*
ac_cv_lib_krb4=no
fi
rm -f conftest*
LIBS="$ac_save_LIBS"
fi
echo "$ac_t""$ac_cv_lib_krb4" 1>&6
if test "$ac_cv_lib_krb4" = yes; then
SUDO_LIBS="${SUDO_LIBS} -lkrb4"
else
SUDO_LIBS="${SUDO_LIBS} -lkrb"
fi
echo $ac_n "checking for -ldes""... $ac_c" 1>&6
echo "configure:7784: checking for -ldes" >&5
echo "configure:7722: checking for -ldes" >&5
if eval "test \"`echo '$''{'ac_cv_lib_des'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
ac_save_LIBS="$LIBS"
LIBS="-ldes $LIBS"
cat > conftest.$ac_ext <<EOF
#line 7791 "configure"
#line 7729 "configure"
#include "confdefs.h"
int main() {
main()
; return 0; }
EOF
if { (eval echo configure:7798: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
rm -rf conftest*
ac_cv_lib_des=yes
else
echo "configure: failed program was:" >&5
cat conftest.$ac_ext >&5
rm -rf conftest*
ac_cv_lib_des=no
fi
rm -f conftest*
LIBS="$ac_save_LIBS"
fi
echo "$ac_t""$ac_cv_lib_des" 1>&6
if test "$ac_cv_lib_des" = yes; then
SUDO_LIBS="${SUDO_LIBS} -ldes"
fi
SUDO_LIBS="${SUDO_LIBS} -ldes425 -lkrb5 -lcrypto -lcom_err"
else
echo $ac_n "checking for -ldes""... $ac_c" 1>&6
echo "configure:7819: checking for -ldes" >&5
if eval "test \"`echo '$''{'ac_cv_lib_des'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
ac_save_LIBS="$LIBS"
LIBS="-ldes $LIBS"
cat > conftest.$ac_ext <<EOF
#line 7826 "configure"
#include "confdefs.h"
int main() {
main()
; return 0; }
EOF
if { (eval echo configure:7833: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
if { (eval echo configure:7736: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
rm -rf conftest*
ac_cv_lib_des=yes
else
@@ -7850,7 +7753,6 @@ else
fi
AUTH_OBJS="${AUTH_OBJS} kerb4.o"
fi
fi
if test "$with_pam" = "yes"; then
@@ -7953,7 +7855,7 @@ if test "$with_authenticate" = "yes"; then
fi
echo $ac_n "checking for log file location""... $ac_c" 1>&6
echo "configure:7957: checking for log file location" >&5
echo "configure:7859: checking for log file location" >&5
if test -n "$with_logpath"; then
echo "$ac_t""$with_logpath" 1>&6
cat >> confdefs.h <<EOF
@@ -7983,7 +7885,7 @@ else
fi
echo $ac_n "checking for timestamp file location""... $ac_c" 1>&6
echo "configure:7987: checking for timestamp file location" >&5
echo "configure:7889: checking for timestamp file location" >&5
if test -n "$with_timedir"; then
echo "$ac_t""$with_timedir" 1>&6
cat >> confdefs.h <<EOF

32
configure.in
View File

@@ -1467,15 +1467,29 @@ dnl
dnl Kerberos 5
dnl
if test "$with_kerb5" = "yes"; then
dnl
dnl Starting with Kerberos 5, 1.1 we use the new creds API
dnl Otherwise, just use the old Kerberos 4 stuff.
dnl
AC_CHECK_LIB(krb5, krb5_get_init_creds_opt, [
AC_DEFINE(HAVE_KERB5)
if test -f "/usr/local/include/krb5.h"; then
CPPFLAGS="$CPPFLAGS -I/usr/local/include"
elif test -f "/usr/local/kerberos/include/krb5.h"; then
CPPFLAGS="$CPPFLAGS -I/usr/local/kerberos/include"
elif test -f "/usr/local/krb5/include/krb5.h"; then
CPPFLAGS="$CPPFLAGS -I/usr/local/krb5/include"
else
echo 'Unable to locate kerberos 5 include files, you will have to edit the Makefile and add -I/path/to/krb/includes to CPPFLAGS'
fi
if test -f "/usr/local/lib/libkrb5.a"; then
SUDO_LDFLAGS="${SUDO_LDFLAGS} -L/usr/local/lib"
elif test -f "/usr/local/kerberos/lib/libkrb5.a"; then
SUDO_LDFLAGS="${SUDO_LDFLAGS} -L/usr/local/kerberos/lib"
elif test -f "/usr/local/krb5/lib/libkrb5.a"; then
SUDO_LDFLAGS="${SUDO_LDFLAGS} -L/usr/local/krb5/lib"
else
echo 'Unable to locate kerberos 5 libraries, you will have to edit the Makefile and add -L/path/to/krb/libs to SUDO_LDFLAGS'
fi
SUDO_LIBS="${SUDO_LIBS} -lkrb5 -lk5crypto -lcom_err"
AUTH_OBJS="${AUTH_OBJS} kerb5.o"
], with_kerb4=yes)
fi
dnl
@@ -1505,14 +1519,8 @@ if test "$with_kerb4" = "yes"; then
echo 'Unable to locate kerberos 4 libraries, you will have to edit the Makefile and add -L/path/to/krb/libs to SUDO_LDFLAGS'
fi
if test "$with_kerb5" = "yes"; then
AC_HAVE_LIBRARY(krb4, SUDO_LIBS="${SUDO_LIBS} -lkrb4", SUDO_LIBS="${SUDO_LIBS} -lkrb")
AC_HAVE_LIBRARY(des, SUDO_LIBS="${SUDO_LIBS} -ldes")
SUDO_LIBS="${SUDO_LIBS} -ldes425 -lkrb5 -lcrypto -lcom_err"
else
AC_HAVE_LIBRARY(des, SUDO_LIBS="${SUDO_LIBS} -lkrb -ldes", SUDO_LIBS="${SUDO_LIBS} -lkrb")
AUTH_OBJS="${AUTH_OBJS} kerb4.o"
fi
fi
dnl

19
sudo.c
View File

@@ -556,9 +556,6 @@ parse_args()
{
int rval = MODE_RUN; /* what mode is suod to be run in? */
int excl = 0; /* exclusive arg, no others allowed */
#ifdef HAVE_KERB5
extern char *realm; /* kerb5 realm (may be user-specified */
#endif /* HAVE_KERB5 */
NewArgv = Argv + 1;
NewArgc = Argc - 1;
@@ -578,19 +575,6 @@ parse_args()
}
switch (NewArgv[0][1]) {
#ifdef HAVE_KERB5
case 'r':
/* Must have an associated realm. */
if (NewArgv[1] == NULL)
usage(1);
realm = NewArgv[1];
/* Shift Argv over and adjust Argc. */
NewArgc--;
NewArgv++;
break;
#endif /* HAVE_KERB5 */
case 'p':
/* Must have an associated prompt. */
if (NewArgv[1] == NULL)
@@ -1035,9 +1019,6 @@ usage(exit_val)
(void) fprintf(stderr,
"usage: %s -V | -h | -L | -l | -v | -k | -K | -H | [-b] [-p prompt]\n%*s",
Argv[0], (int) strlen(Argv[0]) + 8, " ");
#ifdef HAVE_KERB5
(void) fprintf(stderr, "[-r realm] ");
#endif /* HAVE_KERB5 */
(void) fprintf(stderr, "[-u username/#uid] -s | <command>\n");
exit(exit_val);
}