From: "Mattias Engdegård" <mattiase@acm.org>
To: Stefan Monnier <monnier@iro.umontreal.ca>
Cc: alan@idiocy.org, 45198@debbugs.gnu.org, stefan@marxist.se,
Philipp <p.stephani2@gmail.com>,
joaotavora@gmail.com
Subject: bug#45198: 28.0.50; Sandbox mode
Date: Sat, 17 Apr 2021 20:59:06 +0200 [thread overview]
Message-ID: <78F41D0B-D2F6-444C-9B5C-9C50CFF2CFBD@acm.org> (raw)
In-Reply-To: <jwvim4k6ade.fsf-monnier+emacs@gnu.org>
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17 apr. 2021 kl. 20.21 skrev Stefan Monnier <monnier@iro.umontreal.ca>:
>> Very reasonable. Or would you prefer having the sandboxing in flymake?
>
> AFAICT this question refers to a minor implementation detail ;-)
Of course, sorry.
Looks like I forgot to attach the updated patch in a previous message. Here it is.
[-- Attachment #2: 0001-Add-macOS-sandboxing-bug-45198.patch --]
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From 78906da41140dc33119b419a410c4a4f0a3aee80 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mattias=20Engdeg=C3=A5rd?= <mattiase@acm.org>
Date: Sat, 17 Apr 2021 20:53:39 +0200
Subject: [PATCH] Add macOS sandboxing (bug#45198)
This is the corresponding low-level sandboxing facility corresponding
to the recently added Seccomp for Linux. `darwin-sandbox-init` gives
direct access to the system sandboxing call; `darwin-sandbox-enter` is
a wrapper that takes a list of directories under which files can be
read. These should be considered internal mechanisms for now.
* lisp/subr.el (darwin-sandbox-enter):
* src/sysdep.c (Fdarwin_sandbox_init): New functions.
* test/src/emacs-tests.el (emacs-tests/darwin-sandbox): New test.
---
lisp/subr.el | 18 +++++++++++
src/sysdep.c | 32 +++++++++++++++++++
test/src/emacs-tests.el | 70 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 120 insertions(+)
diff --git a/lisp/subr.el b/lisp/subr.el
index c2be26a15f..196512c0c6 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -6262,4 +6262,22 @@ internal--format-docstring-line
This is intended for internal use only."
(internal--fill-string-single-line (apply #'format string objects)))
+(when (eq system-type 'darwin)
+ (defun darwin-sandbox-enter (dirs)
+ "Enter a sandbox only permitting reading files under DIRS.
+DIRS is a list of directory names. Most other operations such as
+writing files and network access are disallowed.
+Existing open descriptors can still be used freely.
+
+This is not a supported interface and is for internal use only."
+ (darwin-sandbox-init
+ (concat "(version 1)\n"
+ "(deny default)\n"
+ ;; Emacs seems to need /dev/null; allowing it does no harm.
+ "(allow file-read* (path \"/dev/null\"))\n"
+ (mapconcat (lambda (dir)
+ (format "(allow file-read* (subpath %S))\n" dir))
+ dirs ""))))
+ )
+
;;; subr.el ends here
diff --git a/src/sysdep.c b/src/sysdep.c
index d940acc4e0..44e8b82bc6 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -4286,8 +4286,40 @@ str_collate (Lisp_Object s1, Lisp_Object s2,
}
#endif /* WINDOWSNT */
+#ifdef DARWIN_OS
+
+/* This function prototype is not in the platform header files.
+ See https://reverse.put.as/wp-content/uploads/2011/09/Apple-Sandbox-Guide-v1.0.pdf
+ and https://chromium.googlesource.com/chromium/src/+/master/sandbox/mac/seatbelt_sandbox_design.md */
+int sandbox_init_with_parameters(const char *profile,
+ uint64_t flags,
+ const char *const parameters[],
+ char **errorbuf);
+
+DEFUN ("darwin-sandbox-init", Fdarwin_sandbox_init, Sdarwin_sandbox_init,
+ 1, 1, 0,
+ doc: /* Enter a sandbox whose permitted access is curtailed by PROFILE.
+Already open descriptors can be used freely.
+PROFILE is a string in the macOS sandbox profile language,
+a set of rules in a Lisp-like syntax.
+
+This is not a supported interface and is for internal use only. */)
+ (Lisp_Object profile)
+{
+ CHECK_STRING (profile);
+ char *err = NULL;
+ if (sandbox_init_with_parameters (SSDATA (profile), 0, NULL, &err) != 0)
+ error ("sandbox error: %s", err);
+ return Qnil;
+}
+
+#endif /* DARWIN_OS */
+
void
syms_of_sysdep (void)
{
defsubr (&Sget_internal_run_time);
+#ifdef DARWIN_OS
+ defsubr (&Sdarwin_sandbox_init);
+#endif
}
diff --git a/test/src/emacs-tests.el b/test/src/emacs-tests.el
index 09f9a248ef..c1a741c359 100644
--- a/test/src/emacs-tests.el
+++ b/test/src/emacs-tests.el
@@ -210,4 +210,74 @@ emacs-tests/bwrap/allows-stdout
(should (eql status 0)))
(should (equal (string-trim (buffer-string)) "Hi"))))))
+(defun emacs-tests--darwin-run-sandboxed-emacs (sandbox-dirs body)
+ "Run Emacs and evaluate BODY, only allowing reads from SANDBOX-DIRS.
+If SANDBOX-DIRS is `no-sandbox', then run without sandbox.
+Return (EXIT-STATUS . OUTPUT), where OUTPUT is stderr and stdout."
+ (let ((emacs (expand-file-name invocation-name invocation-directory))
+ (process-environment nil))
+ (with-temp-buffer
+ (let* ((prog `(progn
+ ,@(and (not (eq sandbox-dirs 'no-sandbox))
+ `((darwin-sandbox-enter ',sandbox-dirs)))
+ ,@body))
+ (res (call-process emacs nil t nil
+ "--quick" "--batch"
+ (format "--eval=%S" prog))))
+ (cons res (buffer-string))))))
+
+(ert-deftest emacs-tests/darwin-sandbox ()
+ (skip-unless (eq system-type 'darwin))
+ (emacs-tests--with-temp-file test-file ("test")
+ (let ((some-text "abcdef")
+ (other-text "ghijkl")
+ (test-file (file-truename test-file))) ; resolve symlinks
+ (with-temp-buffer
+ (insert some-text)
+ (write-file test-file))
+
+ ;; Read the file without allowing its directory -- should fail.
+ (let ((res-out (emacs-tests--darwin-run-sandboxed-emacs
+ nil
+ `((find-file-literally ,test-file)
+ (message "OK: %s" (buffer-string))))))
+ (ert-info ((cdr res-out) :prefix "output: ")
+ (should-not (equal (car res-out) 0))
+ (should-not (string-search some-text (cdr res-out)))))
+
+ ;; Read the file allowing its directory -- should succeed.
+ (let ((res-out (emacs-tests--darwin-run-sandboxed-emacs
+ (list (file-name-directory test-file))
+ `((find-file-literally ,test-file)
+ (message "OK: %s" (buffer-string))))))
+ (should (equal res-out (cons 0 (format "OK: %s\n" some-text)))))
+
+ ;; Write to the file allowing directory reads -- should fail.
+ (let ((res-out (emacs-tests--darwin-run-sandboxed-emacs
+ (list (file-name-directory test-file))
+ `((with-temp-buffer
+ (insert ,other-text)
+ (write-file ,test-file))))))
+ (ert-info ((cdr res-out) :prefix "output: ")
+ (should-not (equal (car res-out) 0))
+ ;; The file should be unchanged.
+ (let ((contents (with-temp-buffer
+ (insert-file-contents-literally test-file)
+ (buffer-string))))
+ (should (equal contents some-text)))))
+
+ ;; Write to the file without sandbox -- should succeed.
+ (let ((res-out (emacs-tests--darwin-run-sandboxed-emacs
+ 'no-sandbox
+ `((with-temp-buffer
+ (insert ,other-text)
+ (write-file ,test-file))))))
+ (ert-info ((cdr res-out) :prefix "output: ")
+ (should (equal (car res-out) 0))
+ ;; The file should be changed.
+ (let ((contents (with-temp-buffer
+ (insert-file-contents-literally test-file)
+ (buffer-string))))
+ (should (equal contents other-text))))))))
+
;;; emacs-tests.el ends here
--
2.21.1 (Apple Git-122.3)
next prev parent reply other threads:[~2021-04-17 18:59 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-12 18:01 bug#45198: 28.0.50; Sandbox mode Stefan Monnier
2020-12-12 19:48 ` Eli Zaretskii
2020-12-12 21:06 ` Stefan Monnier
2020-12-13 3:29 ` Eli Zaretskii
2020-12-13 4:25 ` Stefan Monnier
2020-12-13 11:14 ` João Távora
2020-12-13 17:07 ` Philipp Stephani
2020-12-13 15:31 ` Mattias Engdegård
2020-12-13 17:09 ` Philipp Stephani
2020-12-13 17:04 ` Philipp Stephani
2020-12-13 17:57 ` Stefan Monnier
2020-12-13 18:13 ` Philipp Stephani
2020-12-13 18:43 ` Stefan Monnier
2020-12-14 11:05 ` Philipp Stephani
2020-12-14 14:44 ` Stefan Monnier
2020-12-14 15:37 ` Philipp Stephani
2020-12-19 22:41 ` Philipp Stephani
2020-12-19 23:16 ` Stefan Monnier
2020-12-20 12:28 ` Philipp Stephani
2020-12-22 10:57 ` Philipp Stephani
2020-12-22 14:43 ` Stefan Monnier
2020-12-19 18:18 ` Philipp Stephani
2021-04-10 17:44 ` Philipp Stephani
2020-12-19 22:22 ` Philipp Stephani
2020-12-20 15:09 ` Eli Zaretskii
2020-12-20 18:14 ` Philipp Stephani
2020-12-20 18:29 ` Eli Zaretskii
2020-12-20 18:39 ` Philipp Stephani
2020-12-29 13:50 ` Philipp Stephani
2020-12-29 15:43 ` Eli Zaretskii
2020-12-29 16:05 ` Philipp Stephani
2020-12-29 17:09 ` Eli Zaretskii
2020-12-31 15:05 ` Philipp Stephani
2020-12-31 16:50 ` Eli Zaretskii
2021-04-10 19:11 ` Philipp Stephani
2020-12-13 18:52 ` Stefan Monnier
2020-12-13 20:13 ` João Távora
2020-12-14 11:12 ` Mattias Engdegård
2020-12-14 13:44 ` Philipp Stephani
2020-12-14 14:48 ` Stefan Monnier
2020-12-14 15:59 ` Mattias Engdegård
2020-12-17 13:08 ` Philipp Stephani
2020-12-17 17:55 ` Mattias Engdegård
2020-12-18 15:21 ` Philipp Stephani
2020-12-18 18:50 ` Mattias Engdegård
2020-12-19 15:08 ` Philipp Stephani
2020-12-19 17:19 ` Mattias Engdegård
2020-12-19 18:11 ` Stefan Monnier
2020-12-19 18:46 ` Mattias Engdegård
2020-12-19 19:48 ` João Távora
2020-12-19 21:01 ` Stefan Monnier
2020-12-20 13:15 ` Mattias Engdegård
2020-12-20 14:02 ` Stefan Monnier
2020-12-20 14:12 ` Mattias Engdegård
2020-12-20 15:08 ` Stefan Monnier
2020-12-22 11:12 ` Philipp Stephani
2020-12-28 8:23 ` Stefan Kangas
2020-12-29 13:58 ` Philipp Stephani
2020-12-30 14:59 ` Mattias Engdegård
2020-12-30 15:36 ` Alan Third
2021-04-17 15:26 ` Mattias Engdegård
2021-04-17 15:44 ` Philipp
2021-04-17 15:57 ` Eli Zaretskii
2021-04-17 16:10 ` Philipp
2021-04-17 16:15 ` Eli Zaretskii
2021-04-17 16:19 ` Eli Zaretskii
2021-04-17 16:20 ` Philipp Stephani
2021-04-17 16:33 ` Eli Zaretskii
2021-04-17 19:14 ` Philipp Stephani
2021-04-17 19:23 ` Eli Zaretskii
2021-04-17 19:52 ` Philipp
2021-04-18 6:20 ` Eli Zaretskii
2021-04-18 9:11 ` Philipp Stephani
2021-04-18 9:23 ` Eli Zaretskii
2021-04-17 17:48 ` Mattias Engdegård
2021-04-17 18:21 ` Stefan Monnier
2021-04-17 18:59 ` Mattias Engdegård [this message]
2021-04-17 19:42 ` Philipp
2021-04-17 19:57 ` Alan Third
2021-04-19 15:41 ` Mattias Engdegård
2021-04-17 19:19 ` Philipp Stephani
2021-04-17 17:22 ` Mattias Engdegård
2021-04-17 17:57 ` Stefan Monnier
2021-04-17 19:21 ` Philipp Stephani
2021-04-17 19:16 ` Philipp Stephani
2021-04-17 16:58 ` Stefan Monnier
2021-04-17 17:14 ` Eli Zaretskii
2021-04-17 17:53 ` Stefan Monnier
2021-04-17 18:15 ` Eli Zaretskii
2021-04-17 18:47 ` Stefan Monnier
2021-04-17 19:14 ` Eli Zaretskii
2021-04-17 20:26 ` Stefan Monnier
2021-04-18 6:24 ` Eli Zaretskii
2021-04-18 14:25 ` Stefan Monnier
2021-07-05 19:12 ` Philipp
2021-09-17 12:13 ` Mattias Engdegård
2021-09-17 13:20 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-09-17 19:49 ` Mattias Engdegård
2022-09-11 11:28 ` Lars Ingebrigtsen
2022-09-13 12:37 ` mattiase
2022-09-13 12:53 ` João Távora
2022-09-13 13:02 ` João Távora
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