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openssh/openssh-7.8p1-role-mls.patch
Jakub Jelen def1debf2e openssh-8.0p1-1 + 0.10.3-7 
Resolves rhbz#1701072
2019-04-29 14:12:13 +02:00

886 lines
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diff -up openssh/auth2.c.role-mls openssh/auth2.c
--- openssh/auth2.c.role-mls 2018-08-20 07:57:29.000000000 +0200
+++ openssh/auth2.c 2018-08-22 11:14:56.815430916 +0200
@@ -256,6 +256,9 @@ input_userauth_request(int type, u_int32
Authctxt *authctxt = ssh->authctxt;
Authmethod *m = NULL;
char *user = NULL, *service = NULL, *method = NULL, *style = NULL;
+#ifdef WITH_SELINUX
+ char *role = NULL;
+#endif
int r, authenticated = 0;
double tstart = monotime_double();
@@ -268,6 +271,11 @@ 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;
@@ -296,8 +304,15 @@ 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(ssh);
if (auth2_setup_methods_lists(authctxt) != 0)
ssh_packet_disconnect(ssh,
diff -up openssh/auth2-gss.c.role-mls openssh/auth2-gss.c
--- openssh/auth2-gss.c.role-mls 2018-08-20 07:57:29.000000000 +0200
+++ openssh/auth2-gss.c 2018-08-22 11:15:42.459799171 +0200
@@ -281,6 +281,7 @@ input_gssapi_mic(int type, u_int32_t ple
Authctxt *authctxt = ssh->authctxt;
Gssctxt *gssctxt;
int r, authenticated = 0;
+ char *micuser;
struct sshbuf *b;
gss_buffer_desc mic, gssbuf;
const char *displayname;
@@ -298,7 +299,13 @@ input_gssapi_mic(int type, u_int32_t ple
fatal("%s: sshbuf_new failed", __func__);
mic.value = p;
mic.length = len;
- ssh_gssapi_buildmic(b, authctxt->user, authctxt->service,
+#ifdef WITH_SELINUX
+ if (authctxt->role && authctxt->role[0] != 0)
+ xasprintf(&micuser, "%s/%s", authctxt->user, authctxt->role);
+ else
+#endif
+ micuser = authctxt->user;
+ ssh_gssapi_buildmic(b, micuser, authctxt->service,
"gssapi-with-mic");
if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
@@ -311,6 +318,8 @@ input_gssapi_mic(int type, u_int32_t ple
logit("GSSAPI MIC check failed");
sshbuf_free(b);
+ if (micuser != authctxt->user)
+ free(micuser);
free(mic.value);
if ((!use_privsep || mm_is_monitor()) &&
diff -up openssh/auth2-hostbased.c.role-mls openssh/auth2-hostbased.c
--- openssh/auth2-hostbased.c.role-mls 2018-08-20 07:57:29.000000000 +0200
+++ openssh/auth2-hostbased.c 2018-08-22 11:14:56.816430924 +0200
@@ -123,7 +123,16 @@ userauth_hostbased(struct ssh *ssh)
/* reconstruct packet */
if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
(r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
+#ifdef WITH_SELINUX
+ (authctxt->role
+ ? ( (r = sshbuf_put_u32(b, strlen(authctxt->user)+strlen(authctxt->role)+1)) != 0 ||
+ (r = sshbuf_put(b, authctxt->user, strlen(authctxt->user))) != 0 ||
+ (r = sshbuf_put_u8(b, '/') != 0) ||
+ (r = sshbuf_put(b, authctxt->role, strlen(authctxt->role))) != 0)
+ : (r = sshbuf_put_cstring(b, authctxt->user)) != 0) ||
+#else
(r = sshbuf_put_cstring(b, authctxt->user)) != 0 ||
+#endif
(r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
(r = sshbuf_put_cstring(b, "hostbased")) != 0 ||
(r = sshbuf_put_string(b, pkalg, alen)) != 0 ||
diff -up openssh/auth2-pubkey.c.role-mls openssh/auth2-pubkey.c
--- openssh/auth2-pubkey.c.role-mls 2018-08-22 11:14:56.816430924 +0200
+++ openssh/auth2-pubkey.c 2018-08-22 11:17:07.331483958 +0200
@@ -169,9 +169,16 @@ userauth_pubkey(struct ssh *ssh)
goto done;
}
/* reconstruct packet */
- 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
+ );
if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
(r = sshbuf_put_cstring(b, userstyle)) != 0 ||
(r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
diff -up openssh/auth.h.role-mls openssh/auth.h
--- openssh/auth.h.role-mls 2018-08-20 07:57:29.000000000 +0200
+++ openssh/auth.h 2018-08-22 11:14:56.816430924 +0200
@@ -65,6 +65,9 @@ struct Authctxt {
char *service;
struct passwd *pw; /* set if 'valid' */
char *style;
+#ifdef WITH_SELINUX
+ char *role;
+#endif
/* Method lists for multiple authentication */
char **auth_methods; /* modified from server config */
diff -up openssh/auth-pam.c.role-mls openssh/auth-pam.c
--- openssh/auth-pam.c.role-mls 2018-08-20 07:57:29.000000000 +0200
+++ openssh/auth-pam.c 2018-08-22 11:14:56.816430924 +0200
@@ -1172,7 +1172,7 @@ 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 2018-08-20 07:57:29.000000000 +0200
+++ openssh/auth-pam.h 2018-08-22 11:14:56.817430932 +0200
@@ -33,7 +33,7 @@ u_int do_pam_account(void);
void do_pam_session(struct ssh *);
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/configure.ac.role-mls openssh/configure.ac
--- openssh/configure.ac.role-mls 2018-08-20 07:57:29.000000000 +0200
+++ openssh/configure.ac 2018-08-22 11:14:56.820430957 +0200
@@ -4241,10 +4241,7 @@ AC_ARG_WITH([selinux],
LIBS="$LIBS -lselinux"
],
AC_MSG_ERROR([SELinux support requires libselinux library]))
- SSHLIBS="$SSHLIBS $LIBSELINUX"
- SSHDLIBS="$SSHDLIBS $LIBSELINUX"
AC_CHECK_FUNCS([getseuserbyname get_default_context_with_level])
- LIBS="$save_LIBS"
fi ]
)
AC_SUBST([SSHLIBS])
diff -up openssh/misc.c.role-mls openssh/misc.c
--- openssh/misc.c.role-mls 2018-08-20 07:57:29.000000000 +0200
+++ openssh/misc.c 2018-08-22 11:14:56.817430932 +0200
@@ -542,6 +542,7 @@ char *
colon(char *cp)
{
int flag = 0;
+ int start = 1;
if (*cp == ':') /* Leading colon is part of file name. */
return NULL;
@@ -557,6 +558,13 @@ 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 2018-08-20 07:57:29.000000000 +0200
+++ openssh/monitor.c 2018-08-22 11:19:56.006844867 +0200
@@ -115,6 +115,9 @@ int mm_answer_sign(int, struct sshbuf *)
int mm_answer_pwnamallow(struct ssh *, int, struct sshbuf *);
int mm_answer_auth2_read_banner(struct ssh *, int, struct sshbuf *);
int mm_answer_authserv(struct ssh *, int, struct sshbuf *);
+#ifdef WITH_SELINUX
+int mm_answer_authrole(struct ssh *, int, struct sshbuf *);
+#endif
int mm_answer_authpassword(struct ssh *, int, struct sshbuf *);
int mm_answer_bsdauthquery(struct ssh *, int, struct sshbuf *);
int mm_answer_bsdauthrespond(struct ssh *, int, struct sshbuf *);
@@ -189,6 +192,9 @@ 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
@@ -796,6 +802,9 @@ mm_answer_pwnamallow(int sock, struct ss
/* 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
@@ -842,6 +851,26 @@ mm_answer_authserv(int sock, struct sshb
return found;
}
+#ifdef WITH_SELINUX
+int
+mm_answer_authrole(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ int r;
+ monitor_permit_authentications(1);
+
+ if ((r = sshbuf_get_cstring(m, &authctxt->role, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ 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(struct ssh *ssh, int sock, struct sshbuf *m)
{
@@ -1218,7 +1247,7 @@ monitor_valid_userblob(u_char *data, u_i
{
struct sshbuf *b;
const u_char *p;
- char *userstyle, *cp;
+ char *userstyle, *s, *cp;
size_t len;
u_char type;
int r, fail = 0;
@@ -1251,6 +1280,8 @@ monitor_valid_userblob(u_char *data, u_i
fail++;
if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ if ((s = strchr(cp, '/')) != NULL)
+ *s = '\0';
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
@@ -1286,7 +1317,7 @@ monitor_valid_hostbasedblob(u_char *data
{
struct sshbuf *b;
const u_char *p;
- char *cp, *userstyle;
+ char *cp, *s, *userstyle;
size_t len;
int r, fail = 0;
u_char type;
@@ -1308,6 +1339,8 @@ monitor_valid_hostbasedblob(u_char *data
fail++;
if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ if ((s = strchr(p, '/')) != NULL)
+ *s = '\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 2018-08-20 07:57:29.000000000 +0200
+++ openssh/monitor.h 2018-08-22 11:14:56.818430941 +0200
@@ -55,6 +55,10 @@ 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 2018-08-22 11:14:56.818430941 +0200
+++ openssh/monitor_wrap.c 2018-08-22 11:21:47.938747968 +0200
@@ -390,6 +390,27 @@ mm_inform_authserv(char *service, char *
sshbuf_free(m);
}
+/* Inform the privileged process about role */
+
+#ifdef WITH_SELINUX
+void
+mm_inform_authrole(char *role)
+{
+ int r;
+ struct sshbuf *m;
+
+ debug3("%s entering", __func__);
+
+ if ((m = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed", __func__);
+ if ((r = sshbuf_put_cstring(m, role ? role : "")) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHROLE, m);
+
+ sshbuf_free(m);
+}
+#endif
+
/* Do the password authentication */
int
mm_auth_password(struct ssh *ssh, char *password)
diff -up openssh/monitor_wrap.h.role-mls openssh/monitor_wrap.h
--- openssh/monitor_wrap.h.role-mls 2018-08-22 11:14:56.818430941 +0200
+++ openssh/monitor_wrap.h 2018-08-22 11:22:10.439929513 +0200
@@ -44,6 +44,9 @@ DH *mm_choose_dh(int, int, int);
int mm_sshkey_sign(struct ssh *, struct sshkey *, u_char **, size_t *,
const u_char *, size_t, const char *, u_int compat);
void mm_inform_authserv(char *, char *);
+#ifdef WITH_SELINUX
+void mm_inform_authrole(char *);
+#endif
struct passwd *mm_getpwnamallow(struct ssh *, const char *);
char *mm_auth2_read_banner(void);
int mm_auth_password(struct ssh *, char *);
diff -up openssh/openbsd-compat/Makefile.in.role-mls openssh/openbsd-compat/Makefile.in
--- openssh/openbsd-compat/Makefile.in.role-mls 2018-08-20 07:57:29.000000000 +0200
+++ openssh/openbsd-compat/Makefile.in 2018-08-22 11:14:56.819430949 +0200
@@ -92,7 +92,8 @@ PORTS= port-aix.o \
port-linux.o \
port-solaris.o \
port-net.o \
- port-uw.o
+ port-uw.o \
+ port-linux-sshd.o
.c.o:
$(CC) $(CFLAGS) $(CPPFLAGS) -c $<
diff -up openssh/openbsd-compat/port-linux.c.role-mls openssh/openbsd-compat/port-linux.c
--- openssh/openbsd-compat/port-linux.c.role-mls 2018-08-20 07:57:29.000000000 +0200
+++ openssh/openbsd-compat/port-linux.c 2018-08-22 11:14:56.819430949 +0200
@@ -100,37 +100,6 @@ 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)
@@ -145,7 +114,11 @@ 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 2018-08-20 07:57:29.000000000 +0200
+++ openssh/openbsd-compat/port-linux.h 2018-08-22 11:14:56.819430949 +0200
@@ -20,9 +20,10 @@
#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/openbsd-compat/port-linux-sshd.c.role-mls openssh/openbsd-compat/port-linux-sshd.c
--- openssh/openbsd-compat/port-linux-sshd.c.role-mls 2018-08-22 11:14:56.819430949 +0200
+++ openssh/openbsd-compat/port-linux-sshd.c 2018-08-22 11:14:56.819430949 +0200
@@ -0,0 +1,425 @@
+/*
+ * 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 <stdlib.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 "sshkey.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/platform.c.role-mls openssh/platform.c
--- openssh/platform.c.role-mls 2018-08-20 07:57:29.000000000 +0200
+++ openssh/platform.c 2018-08-22 11:14:56.819430949 +0200
@@ -183,7 +183,7 @@ 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 2018-08-20 07:57:29.000000000 +0200
+++ openssh/sshd.c 2018-08-22 11:14:56.820430957 +0200
@@ -2186,6 +2186,9 @@ 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);
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