jegrp (Jan Echternach)
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Mar 27 2017, 4:47 PM (132 w, 6 d)
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Recent Activity

Mar 26 2019

jegrp added a comment to T4333: Job objects on Windows interfere with automatic start of gpg-agent.

From: aheinecke (Andre Heinecke)
Sent: Montag, 28. Januar 2019 19:25

fwiw. Your patch is beautiful in which it follows our coding style and
debug output. I'm confident that we will accept it but currently I have
to read up on Job's a bit.

Is there a way I could help you with this? This issue is hampering adoption
of GnuPG 2 here.

--

Jan Echternach

Mar 26 2019, 6:49 PM · patch, Windows, gpgagent, Bug Report

Jan 23 2019

jegrp created T4338: gpg-agent fails to start on Windows if GNUPGHOME is longer than 80 characters.
Jan 23 2019, 9:10 PM · Windows, gpgagent, Bug Report

Jan 21 2019

jegrp added a project to T4333: Job objects on Windows interfere with automatic start of gpg-agent: patch.

I've developed a simple patch that sets the CREATE_BREAKAWAY_FROM_JOB flag when creating a new background process. This flag requires a special permission on the job object, which is tested first. This means that the patch only works if the parent process sets JOB_OBJECT_LIMIT_BREAKAWAY_OK on the job object, otherwise the behavior should be as without the patch.

Jan 21 2019, 7:06 PM · patch, Windows, gpgagent, Bug Report
jegrp created T4333: Job objects on Windows interfere with automatic start of gpg-agent.
Jan 21 2019, 6:58 PM · patch, Windows, gpgagent, Bug Report

Nov 9 2012

jegrp added a comment to T1439: Windows: race condition on random_seed.

I'm not able to reproduce the problem with commit b1abc01. It was reproducible
with the preceding revision (commit a74f05c), so I can confirm that b1abc01 has
fixed it.

Nov 9 2012, 6:48 PM · libgcrypt, Bug Report

Sep 26 2012

jegrp added a comment to T1439: Windows: race condition on random_seed.

I'm not sure what you mean by "no portable advisory locking in Windows".
There's LockFile()/UnlockFile() as used in the new dotlock code. Would it be a
problem if the locks on random_seed were mandatory locks? If so, then using the
dotlock code is certainly the shortest path to a perfect solution.

Regarding gpg 1.4, however: The reason why I opened this bug is that gpg
randomly fails to encrypt what it was told to encrypt. This is as bad as if it
would be randomly crashing. I don't mind an occasional "note: random_seed file
is empty" message nor a performance penalty from needlessly re-generating the
seed file. Modifying the error handling after read() as I tried to outline in
my previous message ought to be enough to get rid of the random fatal errors.
Do you consider such a change suitable for gpg 1.4?

Sep 26 2012, 5:52 PM · libgcrypt, Bug Report

Sep 18 2012

jegrp added a comment to T1439: Windows: race condition on random_seed.

This is known but a problem from a security POV.

I suppose you mean "NOT a problem"? I think it might be a problem in
opportunistic encryption scenarios if gpg encryption failures caused by
random_seed access conflicts are ignored like failures caused by missing keys.
But usually it's just a nuisance like any other randomly failing program.

The non-locking read is on purpose - if it works: okay. Otherwise we
re-generate a seed file.

I see that the code tries to tolerate access conflicts, but there's still a race
condition if the random_seed file is truncated between fstat() and read(). The
read() error handling is incomplete. Maybe this pseudo-patch explains best what
I mean:

diff -ru gnupg-1.4.12/cipher/random.c gnupg-1.4.12/cipher/random.c

  • gnupg-1.4.12/cipher/random.c 2012-01-24 09:45:41.000000000 +0100

+++ gnupg-1.4.12/cipher/random.c 2012-09-18 19:47:54.449578800 +0200
@@ -492,11 +492,17 @@

    do {
	n = read( fd, buffer, POOLSIZE );
    } while( n == -1 && errno == EINTR );
  • if( n != POOLSIZE ) {

+ if( n == -1 ) {

	log_fatal(_("can't read `%s': %s\n"), seed_file_name,strerror(errno) );
	close(fd);
	return 0;
    }

+ else if ( n == 0 ) {
+ ... handle like sb.st_size == 0
+ }
+ else if ( n != POOLSIZE ) {
+ ...
handle like sb.st_size != POOLSIZ
+ }

     close(fd);

Yes, we could do the file locking

Proper locking would be the ideal solution, but a better read() error handling
would already be sufficient to avoid the sporadic fatal errors on random_seed
accesses.

and iirc, we do this in libgcrypt (GnuPG-2).

I'm just checking this and ... sorry, no. The gpg2.exe from Gpg4win 2.1.0 shows
the very same error:

note: random_seed file is empty
note: random_seed file is empty
Fatal: can't read `C:/Dokumente und
Einstellungen/jechternach/Anwendungsdaten/GnuPG /random_seed': No such file or
directory

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
note: random_seed file is empty

Sep 18 2012, 7:52 PM · libgcrypt, Bug Report

Aug 29 2012

jegrp added projects to T1439: Windows: race condition on random_seed: Windows, Windows 32, Bug Report.
Aug 29 2012, 6:03 PM · libgcrypt, Bug Report
jegrp set Version to 1.4.12 on T1439: Windows: race condition on random_seed.
Aug 29 2012, 6:03 PM · libgcrypt, Bug Report