rpms/openssh
7
0
Fork 1
Code Issues Pull Requests Releases Activity
4189cebf7a
openssh/openssh-6.6p1-role-mls.patch
Jakub Jelen dd8e5419eb Fix use-after-free error (#1409433)
2017-01-03 14:30:50 +01:00

904 lines
27 KiB
Diff
Raw Blame History

diff -up openssh/auth-pam.c.role-mls openssh/auth-pam.c
--- openssh/auth-pam.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/auth-pam.c 2016-07-26 12:37:48.793593333 +0200
@@ -1095,7 +1095,7 @@ is_pam_session_open(void)
* during the ssh authentication process.
*/
int
-do_pam_putenv(char *name, char *value)
+do_pam_putenv(char *name, const char *value)
{
int ret = 1;
#ifdef HAVE_PAM_PUTENV
diff -up openssh/auth-pam.h.role-mls openssh/auth-pam.h
--- openssh/auth-pam.h.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/auth-pam.h 2016-07-26 12:37:48.793593333 +0200
@@ -38,7 +38,7 @@ void do_pam_session(void);
void do_pam_set_tty(const char *);
void do_pam_setcred(int );
void do_pam_chauthtok(void);
-int do_pam_putenv(char *, char *);
+int do_pam_putenv(char *, const char *);
char ** fetch_pam_environment(void);
char ** fetch_pam_child_environment(void);
void free_pam_environment(char **);
diff -up openssh/auth.h.role-mls openssh/auth.h
--- openssh/auth.h.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/auth.h 2016-07-26 12:37:48.793593333 +0200
@@ -62,6 +62,9 @@ struct Authctxt {
char *service;
struct passwd *pw; /* set if 'valid' */
char *style;
+#ifdef WITH_SELINUX
+ char *role;
+#endif
void *kbdintctxt;
char *info; /* Extra info for next auth_log */
#ifdef BSD_AUTH
diff -up openssh/auth1.c.role-mls openssh/auth1.c
--- openssh/auth1.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/auth1.c 2016-07-26 12:37:48.793593333 +0200
@@ -384,6 +384,9 @@ do_authentication(Authctxt *authctxt)
{
u_int ulen;
char *user, *style = NULL;
+#ifdef WITH_SELINUX
+ char *role=NULL;
+#endif
/* Get the name of the user that we wish to log in as. */
packet_read_expect(SSH_CMSG_USER);
@@ -392,11 +395,24 @@ do_authentication(Authctxt *authctxt)
user = packet_get_cstring(&ulen);
packet_check_eom();
+#ifdef WITH_SELINUX
+ if ((role = strchr(user, '/')) != NULL)
+ *role++ = '\0';
+#endif
+
if ((style = strchr(user, ':')) != NULL)
*style++ = '\0';
+#ifdef WITH_SELINUX
+ else
+ if (role && (style = strchr(role, ':')) != NULL)
+ *style++ = '\0';
+#endif
authctxt->user = user;
authctxt->style = style;
+#ifdef WITH_SELINUX
+ authctxt->role = role;
+#endif
/* Verify that the user is a valid user. */
if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL)
diff -up openssh/auth2-gss.c.role-mls openssh/auth2-gss.c
--- openssh/auth2-gss.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/auth2-gss.c 2016-07-26 12:37:48.794593332 +0200
@@ -255,6 +255,7 @@ input_gssapi_mic(int type, u_int32_t ple
Authctxt *authctxt = ctxt;
Gssctxt *gssctxt;
int authenticated = 0;
+ char *micuser;
Buffer b;
gss_buffer_desc mic, gssbuf;
u_int len;
@@ -267,7 +268,13 @@ input_gssapi_mic(int type, u_int32_t ple
mic.value = packet_get_string(&len);
mic.length = len;
- ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
+#ifdef WITH_SELINUX
+ if (authctxt->role && (strlen(authctxt->role) > 0))
+ xasprintf(&micuser, "%s/%s", authctxt->user, authctxt->role);
+ else
+#endif
+ micuser = authctxt->user;
+ ssh_gssapi_buildmic(&b, micuser, authctxt->service,
"gssapi-with-mic");
gssbuf.value = buffer_ptr(&b);
@@ -279,6 +286,8 @@ input_gssapi_mic(int type, u_int32_t ple
logit("GSSAPI MIC check failed");
buffer_free(&b);
+ if (micuser != authctxt->user)
+ free(micuser);
free(mic.value);
authctxt->postponed = 0;
diff -up openssh/auth2-hostbased.c.role-mls openssh/auth2-hostbased.c
--- openssh/auth2-hostbased.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/auth2-hostbased.c 2016-07-26 12:37:48.794593332 +0200
@@ -121,7 +121,15 @@ userauth_hostbased(Authctxt *authctxt)
buffer_put_string(&b, session_id2, session_id2_len);
/* reconstruct packet */
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
- buffer_put_cstring(&b, authctxt->user);
+#ifdef WITH_SELINUX
+ if (authctxt->role) {
+ buffer_put_int(&b, strlen(authctxt->user)+strlen(authctxt->role)+1);
+ buffer_append(&b, authctxt->user, strlen(authctxt->user));
+ buffer_put_char(&b, '/');
+ buffer_append(&b, authctxt->role, strlen(authctxt->role));
+ } else
+#endif
+ buffer_put_cstring(&b, authctxt->user);
buffer_put_cstring(&b, service);
buffer_put_cstring(&b, "hostbased");
buffer_put_string(&b, pkalg, alen);
diff -up openssh/auth2-pubkey.c.role-mls openssh/auth2-pubkey.c
--- openssh/auth2-pubkey.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/auth2-pubkey.c 2016-07-26 12:37:48.794593332 +0200
@@ -151,9 +151,15 @@ userauth_pubkey(Authctxt *authctxt)
}
/* reconstruct packet */
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
- xasprintf(&userstyle, "%s%s%s", authctxt->user,
+ xasprintf(&userstyle, "%s%s%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
- authctxt->style ? authctxt->style : "");
+ authctxt->style ? authctxt->style : "",
+#ifdef WITH_SELINUX
+ authctxt->role ? "/" : "",
+ authctxt->role ? authctxt->role : "");
+#else
+ "", "");
+#endif
buffer_put_cstring(&b, userstyle);
free(userstyle);
buffer_put_cstring(&b,
diff -up openssh/auth2.c.role-mls openssh/auth2.c
--- openssh/auth2.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/auth2.c 2016-07-26 12:37:48.794593332 +0200
@@ -215,6 +215,9 @@ input_userauth_request(int type, u_int32
Authctxt *authctxt = ctxt;
Authmethod *m = NULL;
char *user, *service, *method, *style = NULL;
+#ifdef WITH_SELINUX
+ char *role = NULL;
+#endif
int authenticated = 0;
if (authctxt == NULL)
@@ -226,6 +229,11 @@ input_userauth_request(int type, u_int32
debug("userauth-request for user %s service %s method %s", user, service, method);
debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
+#ifdef WITH_SELINUX
+ if ((role = strchr(user, '/')) != NULL)
+ *role++ = 0;
+#endif
+
if ((style = strchr(user, ':')) != NULL)
*style++ = 0;
@@ -251,8 +259,15 @@ input_userauth_request(int type, u_int32
use_privsep ? " [net]" : "");
authctxt->service = xstrdup(service);
authctxt->style = style ? xstrdup(style) : NULL;
- if (use_privsep)
+#ifdef WITH_SELINUX
+ authctxt->role = role ? xstrdup(role) : NULL;
+#endif
+ if (use_privsep) {
mm_inform_authserv(service, style);
+#ifdef WITH_SELINUX
+ mm_inform_authrole(role);
+#endif
+ }
userauth_banner();
if (auth2_setup_methods_lists(authctxt) != 0)
packet_disconnect("no authentication methods enabled");
diff -up openssh/misc.c.role-mls openssh/misc.c
--- openssh/misc.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/misc.c 2016-07-26 12:37:48.794593332 +0200
@@ -432,6 +432,7 @@ char *
colon(char *cp)
{
int flag = 0;
+ int start = 1;
if (*cp == ':') /* Leading colon is part of file name. */
return NULL;
@@ -447,6 +448,13 @@ colon(char *cp)
return (cp);
if (*cp == '/')
return NULL;
+ if (start) {
+ /* Slash on beginning or after dots only denotes file name. */
+ if (*cp == '/')
+ return (0);
+ if (*cp != '.')
+ start = 0;
+ }
}
return NULL;
}
diff -up openssh/monitor.c.role-mls openssh/monitor.c
--- openssh/monitor.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/monitor.c 2016-07-26 12:44:19.363379490 +0200
@@ -128,6 +128,9 @@ int mm_answer_sign(int, Buffer *);
int mm_answer_pwnamallow(int, Buffer *);
int mm_answer_auth2_read_banner(int, Buffer *);
int mm_answer_authserv(int, Buffer *);
+#ifdef WITH_SELINUX
+int mm_answer_authrole(int, Buffer *);
+#endif
int mm_answer_authpassword(int, Buffer *);
int mm_answer_bsdauthquery(int, Buffer *);
int mm_answer_bsdauthrespond(int, Buffer *);
@@ -207,6 +210,9 @@ struct mon_table mon_dispatch_proto20[]
{MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
{MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
{MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
+#ifdef WITH_SELINUX
+ {MONITOR_REQ_AUTHROLE, MON_ONCE, mm_answer_authrole},
+#endif
{MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
{MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
#ifdef USE_PAM
@@ -863,6 +869,9 @@ mm_answer_pwnamallow(int sock, Buffer *m
else {
/* Allow service/style information on the auth context */
monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
+#ifdef WITH_SELINUX
+ monitor_permit(mon_dispatch, MONITOR_REQ_AUTHROLE, 1);
+#endif
monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
}
#ifdef USE_PAM
@@ -904,6 +913,25 @@ mm_answer_authserv(int sock, Buffer *m)
return (0);
}
+#ifdef WITH_SELINUX
+int
+mm_answer_authrole(int sock, Buffer *m)
+{
+ monitor_permit_authentications(1);
+
+ authctxt->role = buffer_get_string(m, NULL);
+ debug3("%s: role=%s",
+ __func__, authctxt->role);
+
+ if (strlen(authctxt->role) == 0) {
+ free(authctxt->role);
+ authctxt->role = NULL;
+ }
+
+ return (0);
+}
+#endif
+
int
mm_answer_authpassword(int sock, Buffer *m)
{
@@ -1300,7 +1328,7 @@ monitor_valid_userblob(u_char *data, u_i
{
Buffer b;
u_char *p;
- char *userstyle, *cp;
+ char *userstyle, *r, *cp;
u_int len;
int fail = 0;
@@ -1326,6 +1354,8 @@ monitor_valid_userblob(u_char *data, u_i
if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
fail++;
cp = buffer_get_cstring(&b, NULL);
+ if ((r = strchr(cp, '/')) != NULL)
+ *r = '\0';
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
@@ -1361,7 +1391,7 @@ monitor_valid_hostbasedblob(u_char *data
char *chost)
{
Buffer b;
- char *p, *userstyle;
+ char *p, *r, *userstyle;
u_int len;
int fail = 0;
@@ -1378,6 +1408,8 @@ monitor_valid_hostbasedblob(u_char *data
if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
fail++;
p = buffer_get_cstring(&b, NULL);
+ if ((r = strchr(p, '/')) != NULL)
+ *r = '\0';
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
diff -up openssh/monitor.h.role-mls openssh/monitor.h
--- openssh/monitor.h.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/monitor.h 2016-07-26 12:37:48.795593331 +0200
@@ -57,6 +57,10 @@ enum monitor_reqtype {
MONITOR_REQ_GSSCHECKMIC = 48, MONITOR_ANS_GSSCHECKMIC = 49,
MONITOR_REQ_TERM = 50,
+#ifdef WITH_SELINUX
+ MONITOR_REQ_AUTHROLE = 80,
+#endif
+
MONITOR_REQ_PAM_START = 100,
MONITOR_REQ_PAM_ACCOUNT = 102, MONITOR_ANS_PAM_ACCOUNT = 103,
MONITOR_REQ_PAM_INIT_CTX = 104, MONITOR_ANS_PAM_INIT_CTX = 105,
diff -up openssh/monitor_wrap.c.role-mls openssh/monitor_wrap.c
--- openssh/monitor_wrap.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/monitor_wrap.c 2016-07-26 12:37:48.795593331 +0200
@@ -346,6 +346,25 @@ mm_inform_authserv(char *service, char *
buffer_free(&m);
}
+/* Inform the privileged process about role */
+
+#ifdef WITH_SELINUX
+void
+mm_inform_authrole(char *role)
+{
+ Buffer m;
+
+ debug3("%s entering", __func__);
+
+ buffer_init(&m);
+ buffer_put_cstring(&m, role ? role : "");
+
+ mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHROLE, &m);
+
+ buffer_free(&m);
+}
+#endif
+
/* Do the password authentication */
int
mm_auth_password(Authctxt *authctxt, char *password)
diff -up openssh/monitor_wrap.h.role-mls openssh/monitor_wrap.h
--- openssh/monitor_wrap.h.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/monitor_wrap.h 2016-07-26 12:37:48.795593331 +0200
@@ -42,6 +42,9 @@ int mm_is_monitor(void);
DH *mm_choose_dh(int, int, int);
int mm_key_sign(Key *, u_char **, u_int *, const u_char *, u_int, const char *);
void mm_inform_authserv(char *, char *);
+#ifdef WITH_SELINUX
+void mm_inform_authrole(char *);
+#endif
struct passwd *mm_getpwnamallow(const char *);
char *mm_auth2_read_banner(void);
int mm_auth_password(struct Authctxt *, char *);
diff -up openssh/openbsd-compat/Makefile.in.role-mls openssh/openbsd-compat/Makefile.in
--- openssh/openbsd-compat/Makefile.in.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/openbsd-compat/Makefile.in 2016-07-26 12:37:48.795593331 +0200
@@ -20,7 +20,7 @@ OPENBSD=base64.o basename.o bcrypt_pbkdf
COMPAT=arc4random.o bsd-asprintf.o bsd-closefrom.o bsd-cray.o bsd-cygwin_util.o bsd-getpeereid.o getrrsetbyname-ldns.o bsd-err.o bsd-misc.o bsd-nextstep.o bsd-openpty.o bsd-poll.o bsd-setres_id.o bsd-snprintf.o bsd-statvfs.o bsd-waitpid.o fake-rfc2553.o openssl-compat.o xmmap.o xcrypt.o kludge-fd_set.o
-PORTS=port-aix.o port-irix.o port-linux.o port-solaris.o port-tun.o port-uw.o
+PORTS=port-aix.o port-irix.o port-linux.o port-linux-sshd.o port-solaris.o port-tun.o port-uw.o
.c.o:
$(CC) $(CFLAGS) $(CPPFLAGS) -c $<
diff -up openssh/openbsd-compat/port-linux-sshd.c.role-mls openssh/openbsd-compat/port-linux-sshd.c
--- openssh/openbsd-compat/port-linux-sshd.c.role-mls 2016-07-26 12:37:48.796593331 +0200
+++ openssh/openbsd-compat/port-linux-sshd.c 2016-07-26 12:37:48.796593331 +0200
@@ -0,0 +1,424 @@
+/*
+ * Copyright (c) 2005 Daniel Walsh <dwalsh@redhat.com>
+ * Copyright (c) 2014 Petr Lautrbach <plautrba@redhat.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * Linux-specific portability code - just SELinux support for sshd at present
+ */
+
+#include "includes.h"
+
+#if defined(WITH_SELINUX) || defined(LINUX_OOM_ADJUST)
+#include <errno.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "log.h"
+#include "xmalloc.h"
+#include "misc.h" /* servconf.h needs misc.h for struct ForwardOptions */
+#include "servconf.h"
+#include "port-linux.h"
+#include "key.h"
+#include "hostfile.h"
+#include "auth.h"
+
+#ifdef WITH_SELINUX
+#include <selinux/selinux.h>
+#include <selinux/context.h>
+#include <selinux/get_context_list.h>
+#include <selinux/get_default_type.h>
+
+#ifdef HAVE_LINUX_AUDIT
+#include <libaudit.h>
+#include <unistd.h>
+#endif
+
+extern ServerOptions options;
+extern Authctxt *the_authctxt;
+extern int inetd_flag;
+extern int rexeced_flag;
+
+/* Send audit message */
+static int
+sshd_selinux_send_audit_message(int success, security_context_t default_context,
+ security_context_t selected_context)
+{
+ int rc=0;
+#ifdef HAVE_LINUX_AUDIT
+ char *msg = NULL;
+ int audit_fd = audit_open();
+ security_context_t default_raw=NULL;
+ security_context_t selected_raw=NULL;
+ rc = -1;
+ if (audit_fd < 0) {
+ if (errno == EINVAL || errno == EPROTONOSUPPORT ||
+ errno == EAFNOSUPPORT)
+ return 0; /* No audit support in kernel */
+ error("Error connecting to audit system.");
+ return rc;
+ }
+ if (selinux_trans_to_raw_context(default_context, &default_raw) < 0) {
+ error("Error translating default context.");
+ default_raw = NULL;
+ }
+ if (selinux_trans_to_raw_context(selected_context, &selected_raw) < 0) {
+ error("Error translating selected context.");
+ selected_raw = NULL;
+ }
+ if (asprintf(&msg, "sshd: default-context=%s selected-context=%s",
+ default_raw ? default_raw : (default_context ? default_context: "?"),
+ selected_context ? selected_raw : (selected_context ? selected_context :"?")) < 0) {
+ error("Error allocating memory.");
+ goto out;
+ }
+ if (audit_log_user_message(audit_fd, AUDIT_USER_ROLE_CHANGE,
+ msg, NULL, NULL, NULL, success) <= 0) {
+ error("Error sending audit message.");
+ goto out;
+ }
+ rc = 0;
+ out:
+ free(msg);
+ freecon(default_raw);
+ freecon(selected_raw);
+ close(audit_fd);
+#endif
+ return rc;
+}
+
+static int
+mls_range_allowed(security_context_t src, security_context_t dst)
+{
+ struct av_decision avd;
+ int retval;
+ access_vector_t bit;
+ security_class_t class;
+
+ debug("%s: src:%s dst:%s", __func__, src, dst);
+ class = string_to_security_class("context");
+ if (!class) {
+ error("string_to_security_class failed to translate security class context");
+ return 1;
+ }
+ bit = string_to_av_perm(class, "contains");
+ if (!bit) {
+ error("string_to_av_perm failed to translate av perm contains");
+ return 1;
+ }
+ retval = security_compute_av(src, dst, class, bit, &avd);
+ if (retval || ((bit & avd.allowed) != bit))
+ return 0;
+
+ return 1;
+}
+
+static int
+get_user_context(const char *sename, const char *role, const char *lvl,
+ security_context_t *sc) {
+#ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL
+ if (lvl == NULL || lvl[0] == '\0' || get_default_context_with_level(sename, lvl, NULL, sc) != 0) {
+ /* User may have requested a level completely outside of his
+ allowed range. We get a context just for auditing as the
+ range check below will certainly fail for default context. */
+#endif
+ if (get_default_context(sename, NULL, sc) != 0) {
+ *sc = NULL;
+ return -1;
+ }
+#ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL
+ }
+#endif
+ if (role != NULL && role[0]) {
+ context_t con;
+ char *type=NULL;
+ if (get_default_type(role, &type) != 0) {
+ error("get_default_type: failed to get default type for '%s'",
+ role);
+ goto out;
+ }
+ con = context_new(*sc);
+ if (!con) {
+ goto out;
+ }
+ context_role_set(con, role);
+ context_type_set(con, type);
+ freecon(*sc);
+ *sc = strdup(context_str(con));
+ context_free(con);
+ if (!*sc)
+ return -1;
+ }
+#ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL
+ if (lvl != NULL && lvl[0]) {
+ /* verify that the requested range is obtained */
+ context_t con;
+ security_context_t obtained_raw;
+ security_context_t requested_raw;
+ con = context_new(*sc);
+ if (!con) {
+ goto out;
+ }
+ context_range_set(con, lvl);
+ if (selinux_trans_to_raw_context(*sc, &obtained_raw) < 0) {
+ context_free(con);
+ goto out;
+ }
+ if (selinux_trans_to_raw_context(context_str(con), &requested_raw) < 0) {
+ freecon(obtained_raw);
+ context_free(con);
+ goto out;
+ }
+
+ debug("get_user_context: obtained context '%s' requested context '%s'",
+ obtained_raw, requested_raw);
+ if (strcmp(obtained_raw, requested_raw)) {
+ /* set the context to the real requested one but fail */
+ freecon(requested_raw);
+ freecon(obtained_raw);
+ freecon(*sc);
+ *sc = strdup(context_str(con));
+ context_free(con);
+ return -1;
+ }
+ freecon(requested_raw);
+ freecon(obtained_raw);
+ context_free(con);
+ }
+#endif
+ return 0;
+ out:
+ freecon(*sc);
+ *sc = NULL;
+ return -1;
+}
+
+static void
+ssh_selinux_get_role_level(char **role, const char **level)
+{
+ *role = NULL;
+ *level = NULL;
+ if (the_authctxt) {
+ if (the_authctxt->role != NULL) {
+ char *slash;
+ *role = xstrdup(the_authctxt->role);
+ if ((slash = strchr(*role, '/')) != NULL) {
+ *slash = '\0';
+ *level = slash + 1;
+ }
+ }
+ }
+}
+
+/* Return the default security context for the given username */
+static int
+sshd_selinux_getctxbyname(char *pwname,
+ security_context_t *default_sc, security_context_t *user_sc)
+{
+ char *sename, *lvl;
+ char *role;
+ const char *reqlvl;
+ int r = 0;
+ context_t con = NULL;
+
+ ssh_selinux_get_role_level(&role, &reqlvl);
+
+#ifdef HAVE_GETSEUSERBYNAME
+ if ((r=getseuserbyname(pwname, &sename, &lvl)) != 0) {
+ sename = NULL;
+ lvl = NULL;
+ }
+#else
+ sename = pwname;
+ lvl = "";
+#endif
+
+ if (r == 0) {
+#ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL
+ r = get_default_context_with_level(sename, lvl, NULL, default_sc);
+#else
+ r = get_default_context(sename, NULL, default_sc);
+#endif
+ }
+
+ if (r == 0) {
+ /* If launched from xinetd, we must use current level */
+ if (inetd_flag && !rexeced_flag) {
+ security_context_t sshdsc=NULL;
+
+ if (getcon_raw(&sshdsc) < 0)
+ fatal("failed to allocate security context");
+
+ if ((con=context_new(sshdsc)) == NULL)
+ fatal("failed to allocate selinux context");
+ reqlvl = context_range_get(con);
+ freecon(sshdsc);
+ if (reqlvl !=NULL && lvl != NULL && strcmp(reqlvl, lvl) == 0)
+ /* we actually don't change level */
+ reqlvl = "";
+
+ debug("%s: current connection level '%s'", __func__, reqlvl);
+
+ }
+
+ if ((reqlvl != NULL && reqlvl[0]) || (role != NULL && role[0])) {
+ r = get_user_context(sename, role, reqlvl, user_sc);
+
+ if (r == 0 && reqlvl != NULL && reqlvl[0]) {
+ security_context_t default_level_sc = *default_sc;
+ if (role != NULL && role[0]) {
+ if (get_user_context(sename, role, lvl, &default_level_sc) < 0)
+ default_level_sc = *default_sc;
+ }
+ /* verify that the requested range is contained in the user range */
+ if (mls_range_allowed(default_level_sc, *user_sc)) {
+ logit("permit MLS level %s (user range %s)", reqlvl, lvl);
+ } else {
+ r = -1;
+ error("deny MLS level %s (user range %s)", reqlvl, lvl);
+ }
+ if (default_level_sc != *default_sc)
+ freecon(default_level_sc);
+ }
+ } else {
+ *user_sc = *default_sc;
+ }
+ }
+ if (r != 0) {
+ error("%s: Failed to get default SELinux security "
+ "context for %s", __func__, pwname);
+ }
+
+#ifdef HAVE_GETSEUSERBYNAME
+ free(sename);
+ free(lvl);
+#endif
+
+ if (role != NULL)
+ free(role);
+ if (con)
+ context_free(con);
+
+ return (r);
+}
+
+/* Setup environment variables for pam_selinux */
+static int
+sshd_selinux_setup_pam_variables(void)
+{
+ const char *reqlvl;
+ char *role;
+ char *use_current;
+ int rv;
+
+ debug3("%s: setting execution context", __func__);
+
+ ssh_selinux_get_role_level(&role, &reqlvl);
+
+ rv = do_pam_putenv("SELINUX_ROLE_REQUESTED", role ? role : "");
+
+ if (inetd_flag && !rexeced_flag) {
+ use_current = "1";
+ } else {
+ use_current = "";
+ rv = rv || do_pam_putenv("SELINUX_LEVEL_REQUESTED", reqlvl ? reqlvl: "");
+ }
+
+ rv = rv || do_pam_putenv("SELINUX_USE_CURRENT_RANGE", use_current);
+
+ if (role != NULL)
+ free(role);
+
+ return rv;
+}
+
+/* Set the execution context to the default for the specified user */
+void
+sshd_selinux_setup_exec_context(char *pwname)
+{
+ security_context_t user_ctx = NULL;
+ int r = 0;
+ security_context_t default_ctx = NULL;
+
+ if (!ssh_selinux_enabled())
+ return;
+
+ if (options.use_pam) {
+ /* do not compute context, just setup environment for pam_selinux */
+ if (sshd_selinux_setup_pam_variables()) {
+ switch (security_getenforce()) {
+ case -1:
+ fatal("%s: security_getenforce() failed", __func__);
+ case 0:
+ error("%s: SELinux PAM variable setup failure. Continuing in permissive mode.",
+ __func__);
+ break;
+ default:
+ fatal("%s: SELinux PAM variable setup failure. Aborting connection.",
+ __func__);
+ }
+ }
+ return;
+ }
+
+ debug3("%s: setting execution context", __func__);
+
+ r = sshd_selinux_getctxbyname(pwname, &default_ctx, &user_ctx);
+ if (r >= 0) {
+ r = setexeccon(user_ctx);
+ if (r < 0) {
+ error("%s: Failed to set SELinux execution context %s for %s",
+ __func__, user_ctx, pwname);
+ }
+#ifdef HAVE_SETKEYCREATECON
+ else if (setkeycreatecon(user_ctx) < 0) {
+ error("%s: Failed to set SELinux keyring creation context %s for %s",
+ __func__, user_ctx, pwname);
+ }
+#endif
+ }
+ if (user_ctx == NULL) {
+ user_ctx = default_ctx;
+ }
+ if (r < 0 || user_ctx != default_ctx) {
+ /* audit just the case when user changed a role or there was
+ a failure */
+ sshd_selinux_send_audit_message(r >= 0, default_ctx, user_ctx);
+ }
+ if (r < 0) {
+ switch (security_getenforce()) {
+ case -1:
+ fatal("%s: security_getenforce() failed", __func__);
+ case 0:
+ error("%s: SELinux failure. Continuing in permissive mode.",
+ __func__);
+ break;
+ default:
+ fatal("%s: SELinux failure. Aborting connection.",
+ __func__);
+ }
+ }
+ if (user_ctx != NULL && user_ctx != default_ctx)
+ freecon(user_ctx);
+ if (default_ctx != NULL)
+ freecon(default_ctx);
+
+ debug3("%s: done", __func__);
+}
+
+#endif
+#endif
+
diff -up openssh/openbsd-compat/port-linux.c.role-mls openssh/openbsd-compat/port-linux.c
--- openssh/openbsd-compat/port-linux.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/openbsd-compat/port-linux.c 2016-07-26 12:37:48.796593331 +0200
@@ -103,37 +103,6 @@ ssh_selinux_getctxbyname(char *pwname)
return sc;
}
-/* Set the execution context to the default for the specified user */
-void
-ssh_selinux_setup_exec_context(char *pwname)
-{
- security_context_t user_ctx = NULL;
-
- if (!ssh_selinux_enabled())
- return;
-
- debug3("%s: setting execution context", __func__);
-
- user_ctx = ssh_selinux_getctxbyname(pwname);
- if (setexeccon(user_ctx) != 0) {
- switch (security_getenforce()) {
- case -1:
- fatal("%s: security_getenforce() failed", __func__);
- case 0:
- error("%s: Failed to set SELinux execution "
- "context for %s", __func__, pwname);
- break;
- default:
- fatal("%s: Failed to set SELinux execution context "
- "for %s (in enforcing mode)", __func__, pwname);
- }
- }
- if (user_ctx != NULL)
- freecon(user_ctx);
-
- debug3("%s: done", __func__);
-}
-
/* Set the TTY context for the specified user */
void
ssh_selinux_setup_pty(char *pwname, const char *tty)
@@ -147,7 +116,11 @@ ssh_selinux_setup_pty(char *pwname, cons
debug3("%s: setting TTY context on %s", __func__, tty);
- user_ctx = ssh_selinux_getctxbyname(pwname);
+ if (getexeccon(&user_ctx) != 0) {
+ error("%s: getexeccon: %s", __func__, strerror(errno));
+ goto out;
+ }
+
/* XXX: should these calls fatal() upon failure in enforcing mode? */
diff -up openssh/openbsd-compat/port-linux.h.role-mls openssh/openbsd-compat/port-linux.h
--- openssh/openbsd-compat/port-linux.h.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/openbsd-compat/port-linux.h 2016-07-26 12:37:48.796593331 +0200
@@ -22,9 +22,10 @@
#ifdef WITH_SELINUX
int ssh_selinux_enabled(void);
void ssh_selinux_setup_pty(char *, const char *);
-void ssh_selinux_setup_exec_context(char *);
void ssh_selinux_change_context(const char *);
void ssh_selinux_setfscreatecon(const char *);
+
+void sshd_selinux_setup_exec_context(char *);
#endif
#ifdef LINUX_OOM_ADJUST
diff -up openssh/platform.c.role-mls openssh/platform.c
--- openssh/platform.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/platform.c 2016-07-26 12:37:48.796593331 +0200
@@ -186,7 +186,7 @@ platform_setusercontext_post_groups(stru
}
#endif /* HAVE_SETPCRED */
#ifdef WITH_SELINUX
- ssh_selinux_setup_exec_context(pw->pw_name);
+ sshd_selinux_setup_exec_context(pw->pw_name);
#endif
}
diff -up openssh/sshd.c.role-mls openssh/sshd.c
--- openssh/sshd.c.role-mls 2016-07-24 13:50:13.000000000 +0200
+++ openssh/sshd.c 2016-07-26 12:37:48.796593331 +0200
@@ -2295,6 +2295,9 @@ main(int ac, char **av)
restore_uid();
}
#endif
+#ifdef WITH_SELINUX
+ sshd_selinux_setup_exec_context(authctxt->pw->pw_name);
+#endif
#ifdef USE_PAM
if (options.use_pam) {
do_pam_setcred(1);
Reference in New Issue View Git Blame Copy Permalink