Re: libnettle/libhogweed WIP

[Paul Eggert]

Ted Zlatanov wrote:
> Can you give me a recipe to reproduce the problem with your distribution
> and packages?

I can reliably reproduce what appears to be this problem (or one closely related 
to it) on Ubuntu 16.04.2 LTS x86-64 when running Emacs master. My guess is that 
GnuTLS silently changed the semantics of the affected C functions. The 
problematic version of Ubuntu has GnuTLS 3.4.10. I do not observe a problem on 
Fedora 26, which has GnuTLS 3.5.14. If my guess is right, a simple workaround 
would be to not use the affected functions unless running GnuTLS 3.5.14 or later.

"make check" reports:

   passed  6/7  test-gnutls-004-symmetric-ciphers
Test test-gnutls-005-aead-ciphers backtrace:
  signal(ert-test-failed (((should (gnutls-tests-hexstring-equal input
  ert-fail(((should (gnutls-tests-hexstring-equal input reverse)) :for
  (if (unwind-protect (setq value-152 (apply fn-150 args-151)) (setq f
  (let (form-description-154) (if (unwind-protect (setq value-152 (app
  (let ((value-152 'ert-form-evaluation-aborted-153)) (let (form-descr
  (let ((fn-150 (function gnutls-tests-hexstring-equal)) (args-151 (li
  (let* ((iv (gnutls-tests-pad-or-trim iv (plist-get cplist :cipher-iv
  (while --dolist-tail-- (setq iv (car --dolist-tail--)) (gnutls-tests
  (let ((--dolist-tail-- (append ivs (list (list 'iv-auto ivsize)))) i
  (let* ((cplist (cdr (assq cipher (gnutls-ciphers)))) (key (gnutls-te
  (while --dolist-tail-- (setq key (car --dolist-tail--)) (let* ((cpli
  (let ((--dolist-tail-- keys) key) (while --dolist-tail-- (setq key (
  (while --dolist-tail-- (setq auth (car --dolist-tail--)) (let ((--do
  (let ((--dolist-tail-- auths) auth) (while --dolist-tail-- (setq aut
  (while --dolist-tail-- (setq input (car --dolist-tail--)) (let ((--d
  (let ((--dolist-tail-- inputs) input) (while --dolist-tail-- (setq i
  (while --dolist-tail-- (setq cipher (car --dolist-tail--)) (let ((--
  (let ((--dolist-tail-- ciphers) cipher) (while --dolist-tail-- (setq
  (let ((keys '("mykey" "mykey2")) (inputs gnutls-tests-mondo-strings)
  (lambda nil (let ((fn-120 (function memq)) (args-121 (list 'AEAD-cip
  ert--run-test-internal(#s(ert--test-execution-info :test #s(ert-test
  ert-run-test(#s(ert-test :name test-gnutls-005-aead-ciphers :documen
  ert-run-or-rerun-test(#s(ert--stats :selector (not (tag :expensive-t
  ert-run-tests((not (tag :expensive-test)) #f(compiled-function (even
  ert-run-tests-batch((not (tag :expensive-test)))
  ert-run-tests-batch-and-exit((not (tag :expensive-test)))
  eval((ert-run-tests-batch-and-exit '(not (tag :expensive-test))))
  command-line-1(("-L" ":." "-l" "ert" "-l" "lisp/net/gnutls-tests.el"
  command-line()
  normal-top-level()
Test test-gnutls-005-aead-ciphers condition:
    (ert-test-failed
     ((should
       (gnutls-tests-hexstring-equal input reverse))
      :form
      (gnutls-tests-hexstring-equal "                " " 
address@hidden@address@hidden@address@hidden@address@hidden@^@")
      :value nil))
   FAILED  7/7  test-gnutls-005-aead-ciphers


In the above report, the "address@hidden@address@hidden@address@hidden@address@hidden@^@" stands for a sequence of 11 
control characters.