Support Illumos/Solaris fine-grained privileges

Includes a pre-auth privsep sandbox and several pledge()
emulations. bz#2511, patch by Alex Wilson.

ok dtucker@

1 files changed, 107 insertions, 0 deletions

diff --git a/sandbox-solaris.c b/sandbox-solaris.c
new file mode 100644
index 000000000..98714e170
--- /dev/null
+++ b/sandbox-solaris.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2015 Joyent, Inc
+ * Author: Alex Wilson <alex.wilson@joyent.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.
+ */
+
+#include "includes.h"
+
+#ifdef SANDBOX_SOLARIS
+#ifndef USE_SOLARIS_PRIVS
+# error "--with-solaris-privs must be used with the Solaris sandbox"
+#endif
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#ifdef HAVE_PRIV_H
+# include <priv.h>
+#endif
+
+#include "log.h"
+#include "ssh-sandbox.h"
+#include "xmalloc.h"
+
+struct ssh_sandbox {
+        priv_set_t *pset;
+};
+
+struct ssh_sandbox *
+ssh_sandbox_init(struct monitor *monitor)
+{
+        struct ssh_sandbox *box = NULL;
+
+        box = xcalloc(1, sizeof(*box));
+        box->pset = priv_allocset();
+
+        if (box->pset == NULL) {
+                free(box);
+                return NULL;
+        }
+
+        /* Start with "basic" and drop everything we don't need. */
+        priv_basicset(box->pset);
+
+        /* Drop everything except the ability to use already-opened files */
+        if (priv_delset(box->pset, PRIV_FILE_LINK_ANY) != 0 ||
+            priv_delset(box->pset, PRIV_NET_ACCESS) != 0 ||
+            priv_delset(box->pset, PRIV_PROC_EXEC) != 0 ||
+            priv_delset(box->pset, PRIV_PROC_FORK) != 0 ||
+            priv_delset(box->pset, PRIV_PROC_INFO) != 0 ||
+            priv_delset(box->pset, PRIV_PROC_SESSION) != 0) {
+                free(box);
+                return NULL;
+        }
+
+        /* These may not be available on older Solaris-es */
+# if defined(PRIV_FILE_READ) && defined(PRIV_FILE_WRITE)
+        if (priv_delset(box->pset, PRIV_FILE_READ) != 0 ||
+            priv_delset(box->pset, PRIV_FILE_WRITE) != 0) {
+                free(box);
+                return NULL;
+        }
+# endif
+
+        return box;
+}
+
+void
+ssh_sandbox_child(struct ssh_sandbox *box)
+{
+        if (setppriv(PRIV_SET, PRIV_PERMITTED, box->pset) != 0 ||
+            setppriv(PRIV_SET, PRIV_LIMIT, box->pset) != 0 ||
+            setppriv(PRIV_SET, PRIV_INHERITABLE, box->pset) != 0)
+                fatal("setppriv: %s", strerror(errno));
+}
+
+void
+ssh_sandbox_parent_finish(struct ssh_sandbox *box)
+{
+        priv_freeset(box->pset);
+        box->pset = NULL;
+        free(box);
+}
+
+void
+ssh_sandbox_parent_preauth(struct ssh_sandbox *box, pid_t child_pid)
+{
+        /* Nothing to do here */
+}
+
+#endif /* SANDBOX_SOLARIS */