Manoj Srivastava:

- Added SELinux capability, and turned it on be default. Added
  restorecon calls in preinst and postinst (should not matter if the
  machine is not SELinux aware). By and large, the changes made should
  have no effect unless the rules file calls --with-selinux; and even
  then there should be no performance hit for machines not actively
  running SELinux.
- Modified the preinst and postinst to call restorecon to set the
  security context for the generated public key files.
- Added a comment to /etc/pam.d/ssh to indicate that an SELinux system
  may want to also include pam_selinux.so.

1 files changed, 111 insertions, 0 deletions

diff --git a/selinux.c b/selinux.c
new file mode 100644
index 000000000..697c2910a
--- /dev/null
+++ b/selinux.c
@@ -0,0 +1,111 @@
+#include "includes.h"
+
+#include "auth.h"
+#include "log.h"
+
+#ifdef WITH_SELINUX
+
+#include <selinux/selinux.h>
+#include <selinux/flask.h>
+#include <selinux/context.h>
+#include <selinux/get_context_list.h>
+#include <selinux/get_default_type.h>
+
+extern Authctxt *the_authctxt;
+
+static const security_context_t
+selinux_get_user_context(const char *name)
+{
+        security_context_t user_context = NULL;
+        char *role = NULL;
+        int ret = 0;
+
+        if (the_authctxt)
+                role = the_authctxt->role;
+        if (role != NULL && role[0])
+                ret = get_default_context_with_role(name, role, NULL,
+                    &user_context);
+        else
+                ret = get_default_context(name, NULL, &user_context);
+        if (ret < 0) {
+                if (security_getenforce() > 0)
+                        fatal("Failed to get default security context for %s.",
+                            name);
+                else
+                        error("Failed to get default security context for %s. "
+                            "Continuing in permissive mode",
+                            name);
+        }
+        return user_context;
+}
+
+void
+setup_selinux_pty(const char *name, const char *tty)
+{
+        security_context_t new_tty_context, user_context, old_tty_context;
+
+        if (is_selinux_enabled() <= 0)
+                return;
+
+        new_tty_context = old_tty_context = NULL;
+        user_context = selinux_get_user_context(name);
+
+        if (getfilecon(tty, &old_tty_context) < 0) {
+                error("getfilecon(%.100s) failed: %.100s",
+                    tty, strerror(errno));
+        } else {
+                if (security_compute_relabel(user_context, old_tty_context,
+                    SECCLASS_CHR_FILE, &new_tty_context) != 0) {
+                        error("security_compute_relabel(%.100s) failed: "
+                            "%.100s", tty, strerror(errno));
+                } else {
+                        if (setfilecon(tty, new_tty_context) != 0)
+                                error("setfilecon(%.100s, %s) failed: %.100s",
+                                    tty, new_tty_context, strerror(errno));
+                        freecon(new_tty_context);
+                }
+                freecon(old_tty_context);
+        }
+        if (user_context)
+                freecon(user_context);
+}
+
+void
+setup_selinux_exec_context(const char *name)
+{
+        security_context_t user_context;
+
+        if (is_selinux_enabled() <= 0)
+                return;
+
+        user_context = selinux_get_user_context(name);
+
+        if (setexeccon(user_context)) {
+                if (security_getenforce() > 0)
+                        fatal("Failed to set exec security context %s for %s.",
+                            user_context, name);
+                else
+                        error("Failed to set exec security context %s for %s. "
+                            "Continuing in permissive mode",
+                            user_context, name);
+        }
+        if (user_context)
+                freecon(user_context);
+}
+
+#else /* WITH_SELINUX */
+
+void
+setup_selinux_pty(const char *name, const char *tty)
+{
+        (void) name;
+        (void) tty;
+}
+
+void
+setup_selinux_exec_context(const char *name)
+{
+        (void) name;
+}
+
+#endif /* WITH_SELINUX */