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- support mls on labeled networks (#220487)

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- support mls level selection on unlabeled networks
- allow / in usernames in scp (only beginning /, ./, and ../ is special)
This commit is contained in:
Tomáš Mráz 2007-01-16 20:58:00 +00:00
parent 45f17da853
commit c2b35d09c0
2 changed files with 280 additions and 1 deletions
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272
openssh-4.5p1-mls.patch Normal file
View File

@ -0,0 +1,272 @@
--- openssh-4.5p1/openbsd-compat/port-linux.c.mls 2007-01-16 21:43:11.000000000 +0100
+++ openssh-4.5p1/openbsd-compat/port-linux.c 2007-01-16 21:40:13.000000000 +0100
@@ -33,12 +33,22 @@
#include "key.h"
#include "hostfile.h"
#include "auth.h"
+#include "xmalloc.h"
#include <selinux/selinux.h>
#include <selinux/flask.h>
+#include <selinux/context.h>
#include <selinux/get_context_list.h>
+#include <selinux/av_permissions.h>
+
+#ifdef HAVE_LINUX_AUDIT
+#include <libaudit.h>
+#include <sys/select.h>
+#endif
extern Authctxt *the_authctxt;
+extern int inetd_flag;
+extern int rexeced_flag;
/* Wrapper around is_selinux_enabled() to log its return value once only */
static int
@@ -54,17 +64,107 @@
return (enabled);
}
+/* Send audit message */
+static int
+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.");
+ goto out;
+ }
+ if (selinux_trans_to_raw_context(selected_context, &selected_raw) < 0) {
+ error("Error translating selected context.");
+ goto out;
+ }
+ if (asprintf(&msg, "sshd: default-context=%s selected-context=%s",
+ default_context ? default_raw : "?",
+ selected_context ? selected_raw : "?") < 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;
+ unsigned int bit = CONTEXT__CONTAINS;
+
+ retval = security_compute_av(src, dst, SECCLASS_CONTEXT, 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 (role != NULL && role[0])
+ return get_default_context_with_rolelevel(sename, role, lvl, NULL, &sc);
+ else
+ return get_default_context_with_level(sename, lvl, NULL, &sc);
+#else
+ if (role != NULL && role[0])
+ return get_default_context_with_role(sename, role, NULL, &sc);
+ else
+ return get_default_context(sename, NULL, &sc);
+#endif
+}
+
/* Return the default security context for the given username */
static security_context_t
ssh_selinux_getctxbyname(char *pwname)
{
- security_context_t sc = NULL;
+ security_context_t usersc = NULL;
+ security_context_t defsc = NULL;
char *sename, *lvl;
+ const char *reqlvl;
char *role = NULL;
int r = 0;
+ context_t con = NULL;
+
+ if (the_authctxt) {
+ if (the_authctxt->role != NULL) {
+ char *slash;
+ role = xstrdup(the_authctxt->role);
+ if ((slash = strchr(role, '/')) != NULL) {
+ *slash = '\0';
+ reqlvl = slash + 1;
+ }
+ }
+ }
- if (the_authctxt)
- role=the_authctxt->role;
#ifdef HAVE_GETSEUSERBYNAME
if (r=getseuserbyname(pwname, &sename, &lvl) != 0) {
sename = NULL;
@@ -72,23 +172,49 @@
}
#else
sename = pwname;
- lvl = NULL;
+ lvl = "";
#endif
if (r == 0) {
-#ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL
- if (role != NULL && role[0])
- r = get_default_context_with_rolelevel(sename, role, lvl, NULL, &sc);
- else
- r = get_default_context_with_level(sename, lvl, NULL, &sc);
-#else
- if (role != NULL && role[0])
- r = get_default_context_with_role(sename, role, NULL, &sc);
- else
- r = get_default_context(sename, NULL, &sc);
-#endif
+ r = get_user_context(sename, role, lvl, &defsc);
}
+ if (r == 0) {
+ /* If launched from xinetd, we must use current level */
+ if (inetd_flag && !rexeced_flag) {
+ security_context_t sshdsc=NULL;
+
+ if (getcon(&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);
+
+ debug("%s: current connection level '%s'", __func__, reqlvl);
+ }
+
+ if (reqlvl != NULL && reqlvl[0]) {
+ r = get_user_context(sename, role, reqlvl, &usersc);
+
+ if (r == 0) {
+ if (mls_range_allowed(defsc, usersc)) {
+ send_audit_message(1, defsc, usersc);
+ logit("permit MLS level %s (user range %s)", reqlvl, lvl);
+ } else {
+ send_audit_message(0, defsc, usersc);
+ if (security_getenforce() > 0)
+ fatal("deny MLS level %s (user range %s)", reqlvl, lvl);
+ else
+ error("deny MLS level %s (user range %s). Continuing in permissive mode", reqlvl, lvl);
+ }
+ }
+ freecon(defsc);
+ } else {
+ usersc = defsc;
+ }
+ }
if (r != 0) {
switch (security_getenforce()) {
case -1:
@@ -110,6 +236,10 @@
if (lvl != NULL)
xfree(lvl);
#endif
+ if (role != NULL)
+ xfree(role);
+ if (con)
+ context_free(con);
return (sc);
}
@@ -157,7 +287,10 @@
debug3("%s: setting TTY context on %s", __func__, tty);
- user_ctx = ssh_selinux_getctxbyname(pwname);
+ if (getexeccon(&user_context) < 0) {
+ error("%s: getexeccon: %s", __func__, strerror(errno));
+ goto out;
+ }
/* XXX: should these calls fatal() upon failure in enforcing mode? */
--- openssh-4.5p1/sshd.c.mls 2007-01-16 21:43:11.000000000 +0100
+++ openssh-4.5p1/sshd.c 2007-01-16 21:48:37.000000000 +0100
@@ -1833,6 +1833,9 @@
restore_uid();
}
#endif
+#ifdef WITH_SELINUX
+ ssh_selinux_setup_exec_context(authctxt->pw->pw_name);
+#endif
#ifdef USE_PAM
if (options.use_pam) {
do_pam_setcred(1);
--- openssh-4.5p1/misc.c.mls 2006-08-05 04:39:40.000000000 +0200
+++ openssh-4.5p1/misc.c 2007-01-16 21:56:40.000000000 +0100
@@ -418,6 +418,7 @@
colon(char *cp)
{
int flag = 0;
+ int start = 1;
if (*cp == ':') /* Leading colon is part of file name. */
return (0);
@@ -431,8 +432,13 @@
return (cp+1);
if (*cp == ':' && !flag)
return (cp);
- if (*cp == '/')
- return (0);
+ if (start) {
+ /* Slash on beginning or after dots only denotes file name. */
+ if (*cp == '/')
+ return (0);
+ if (*cp != '.')
+ start = 0;
+ }
}
return (0);
}
--- openssh-4.5p1/session.c.mls 2007-01-16 21:43:11.000000000 +0100
+++ openssh-4.5p1/session.c 2007-01-16 21:46:35.000000000 +0100
@@ -1347,10 +1347,6 @@
#endif
if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
-
-#ifdef WITH_SELINUX
- ssh_selinux_setup_exec_context(pw->pw_name);
-#endif
}
static void

9
openssh.spec
View File

@ -61,7 +61,7 @@
Summary: The OpenSSH implementation of SSH protocol versions 1 and 2 Summary: The OpenSSH implementation of SSH protocol versions 1 and 2
Name: openssh Name: openssh
Version: 4.5p1 Version: 4.5p1
Release: 1%{?dist}%{?rescue_rel} Release: 2%{?dist}%{?rescue_rel}
URL: http://www.openssh.com/portable.html URL: http://www.openssh.com/portable.html
#Source0: ftp://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-%{version}.tar.gz #Source0: ftp://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-%{version}.tar.gz
#Source1: ftp://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-%{version}.tar.gz.sig #Source1: ftp://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-%{version}.tar.gz.sig
@ -88,6 +88,7 @@ Patch39: openssh-4.3p2-no-v6only.patch
Patch44: openssh-4.3p2-allow-ip-opts.patch Patch44: openssh-4.3p2-allow-ip-opts.patch
Patch48: openssh-4.3p2-pam-session.patch Patch48: openssh-4.3p2-pam-session.patch
Patch49: openssh-4.3p2-gssapi-canohost.patch Patch49: openssh-4.3p2-gssapi-canohost.patch
Patch50: openssh-4.5p1-mls.patch
License: BSD License: BSD
Group: Applications/Internet Group: Applications/Internet
BuildRoot: %{_tmppath}/%{name}-%{version}-buildroot BuildRoot: %{_tmppath}/%{name}-%{version}-buildroot
@ -214,6 +215,7 @@ an X11 passphrase dialog for OpenSSH.
%patch44 -p1 -b .ip-opts %patch44 -p1 -b .ip-opts
%patch48 -p1 -b .pam-sesssion %patch48 -p1 -b .pam-sesssion
%patch49 -p1 -b .canohost %patch49 -p1 -b .canohost
%patch50 -p1 -b .mls
autoreconf autoreconf
@ -458,6 +460,11 @@ fi
%endif %endif
%changelog %changelog
* Tue Jan 16 2007 Tomas Mraz <tmraz@redhat.com> - 4.5p1-2
- support mls on labeled networks (#220487)
- support mls level selection on unlabeled networks
- allow / in usernames in scp (only beginning /, ./, and ../ is special)
* Thu Dec 21 2006 Tomas Mraz <tmraz@redhat.com> - 4.5p1-1 * Thu Dec 21 2006 Tomas Mraz <tmraz@redhat.com> - 4.5p1-1
- update to 4.5p1 (#212606) - update to 4.5p1 (#212606)