If you're going to store the cleartext index of an encrypted message,
in most situations you might just as well store the session key.
Doing this storage has efficiency and recoverability advantages.
Combined with a schedule of regular OpenPGP subkey rotation and
destruction, this can also offer security benefits, like "deletable
e-mail", which is the store-and-forward analog to "forward secrecy".
But wait, i hear you saying, i have a special need to store cleartext
indexes but it's really bad for me to store session keys! Maybe
(let's imagine) i get lots of e-mails with incriminating photos
attached, and i want to be able to search for them by the text in the
e-mail, but i don't want someone with access to the index to be
actually able to see the photos themselves.
Fret not, the next patch in this series will support your wacky
uncommon use case.
In our consolidation of _notmuch_crypto_decrypt, the callers lost
track a little bit of whether any actual decryption was attempted.
Now that we have the more-subtle "auto" policy, it's possible that
_notmuch_crypto_decrypt could be called without having any actual
decryption take place.
This change lets the callers be a little bit smarter about whether or
not any decryption was actually attempted.
This new automatic decryption policy should make it possible to
decrypt messages that we have stashed session keys for, without
incurring a call to the user's asymmetric keys.
Future patches in this series will introduce new policies; this merely
readies the way for them.
We also convert --try-decrypt to a keyword argument instead of a boolean.
When doing any decryption, if the notmuch database knows of any
session keys associated with the message in question, try them before
defaulting to using default symmetric crypto.
This changeset does the primary work in _notmuch_crypto_decrypt, which
grows some new parameters to handle it.
The primary advantage this patch offers is a significant speedup when
rendering large encrypted threads ("notmuch show") if session keys
happen to be cached.
Additionally, it permits message composition without access to
asymmetric secret keys ("notmuch reply"); and it permits recovering a
cleartext index when reindexing after a "notmuch restore" for those
messages that already have a session key stored.
Note that we may try multiple decryptions here (e.g. if there are
multiple session keys in the database), but we will ignore and throw
away all the GMime errors except for those that come from last
decryption attempt. Since we don't necessarily know at the time of
the decryption that this *is* the last decryption attempt, we'll ask
for the errors each time anyway.
This does nothing if no session keys are stashed in the database,
which is fine. Actually stashing session keys in the database will
come as a subsequent patch.
We will use this centralized function to consolidate the awkward
behavior around different gmime versions.
It's only invoked from two places: mime-node.c's
node_decrypt_and_verify() and lib/index.cc's
_index_encrypted_mime_part().
However, those two places have some markedly distinct logic, so the
interface for this _notmuch_crypto_decrypt function is going to get a
little bit clunky. It's worthwhile, though, for the sake of keeping
these #if directives reasonably well-contained.
If we see index options that ask us to decrypt when indexing a
message, and we encounter an encrypted part, we'll try to descend into
it.
If we can decrypt, we add the property index.decryption=success.
If we can't decrypt (or recognize the encrypted type of mail), we add
the property index.decryption=failure.
Note that a single message may have both values of the
"index.decryption" property: "success" and "failure". For example,
consider a message that includes multiple layers of encryption. If we
manage to decrypt the outer layer ("index.decryption=success"), but
fail on the inner layer ("index.decryption=failure").
Because of the property name, this will be automatically cleared (and
possibly re-set) during re-indexing. This means it will subsequently
correspond to the actual semantics of the stored index.
C99 stdbool turned 18 this year. There really is no reason to use our
own, except in the library interface for backward
compatibility. Convert the lib internally to stdbool.
This is a logical followup to "lib: index the content type of
signature parts", which will make it easier to record the message
structure of all messages.
It's useful (*) to be able to easily find messages with certain types
of signatures. Having the mimetype: prefix searches fail for some
content types is also genuinely surprising (*). Index the content type
of signature parts.
While at it, switch to the gmime convenience constants for content and
signature part indexes.
*) At least for developers of email software!
'g_object_newv' is deprecated, and prints annoying warnings. The
warnings suggest using 'g_object_new_with_properties', but that's only
available since glib 2.55 (i.e. a month ago as of this writing).
Since we don't actuall pass any properties, it seems we can just call
'g_object_new'.
We want to reuse the scanner definition with a different table. This
is mainly code movement, and making the state table part of the filter
struct/class.
Many of the external links found in the notmuch source can be resolved
using https instead of http. This changeset addresses as many as i
could find, without touching the e-mail corpus or expected outputs
found in tests.
Cleaned the following whitespace in lib/* files:
lib/index.cc: 1 line: trailing whitespace
lib/database.cc 5 lines: 8 spaces at the beginning of line
lib/notmuch-private.h: 4 lines: 8 spaces at the beginning of line
lib/message.cc: 1 line: trailing whitespace
lib/sha1.c: 1 line: empty lines at the end of file
lib/query.cc: 2 lines: 8 spaces at the beginning of line
lib/gen-version-script.sh: 1 line: trailing whitespace
Per RFC 2183, the values for Content-Disposition values are not
case-sensitive. While at it, use the gmime function for getting at the
disposition string instead of referencing the field directly.
This fixes "attachment" tagging and filename term generation for
attachments while indexing.
This is not supposed to change any functionality from an end user
point of view. Note that it will eliminate some output to stderr. The
query debugging output is left as is; it doesn't really fit with the
current primitive logging model. The remaining "bad" fprintf will need
an internal API change.
This adds the indexing support for the "mimetype:" term and removes
the broken test flag. The indexing is probablistic in Xapian terms,
which gives a better experience to end users. Standard content-types
of the form "foo/bar" are automatically interpreted as phrases in
Xapian due to the embedded slash.
Assume, separate messages with application/pdf and application/x-pdf
are indexed, then:
- mimetype:application/x-pdf will find only the application/x-pdf
- mimetype:application/pdf will find only the application/pdf
- mimetype:pdf will find both of the messages
Previously, we indexed the name and address parts of from/to headers
with two calls to _notmuch_message_gen_terms. In general, this
indicates that these parts are separate phrases. However, because of
an implementation quirk, the two calls to _notmuch_message_gen_terms
generated adjacent term positions for the prefixed terms, which
happens to be the right thing to do in this case, but the wrong thing
to do for all other calls. Furthermore, _notmuch_message_gen_terms
produced potentially overlapping term positions for the un-prefixed
copies of the terms, which is simply wrong.
This change indexes both the name and address in a single call to
_notmuch_message_gen_terms, indicating that they should be part of a
single phrase. This masks the problem with the un-prefixed terms
(fixing the two known-broken tests) and puts us in a position to fix
the unintentionally phrases generated by other calls to
_notmuch_message_gen_terms.
The notmuch library includes a full blown message header parser. Yet
the same message headers are parsed by gmime during indexing. Switch
to gmime parsing completely.
These are the main changes:
* Gmime stops header parsing at the first invalid header, and presumes
the message body starts from there. The current parser is quite
liberal in accepting broken headers. The change means we will be
much pickier about accepting invalid messages.
* The current parser converts tabs used in header folding to
spaces. Gmime preserve the tabs. Due to a broken python library used
in mailman, there are plenty of mailing lists that produce headers
with tabs in header folding, and we'll see plenty of tabs. (This
change has been mitigated in preparatory patches.)
* For pure header parsing, the current parser is likely faster than
gmime, which parses the whole message rather than just the
headers. Since we parse the message and its headers using gmime for
indexing anyway, this avoids and extra header parsing round when
adding new messages. In case of duplicate messages, we'll end up
parsing the full message although just headers would be
sufficient. All in all this should still speed up 'notmuch new'.
* Calls to notmuch_message_get_header() may be slightly slower than
previously for headers that are not indexed in the database, due to
parsing of the whole message. Within the notmuch code base, notmuch
reply is the only such user.
We've supported mbox files containing a single message for historical
reasons, but the support has been deprecated, with a warning message
while indexing, since Notmuch 0.15. Finally drop the support, and
consider all mbox files non-email.
As explained by Jeffrey Stedfast, the author of GMime, quoted in [1]:
> Passing the GMIME_ENABLE_RFC2047_WORKAROUNDS flag to g_mime_init()
> *should* solve the decoding problem mentioned in the thread. This
> flag should be safe to pass into g_mime_init() without any bad side
> effects and my unit tests do test that code-path.
The thread being referred to is [2].
[1] id:87bo56viyo.fsf@nikula.org
[2] id:08cb1dcd-c5db-4e33-8b09-7730cb3d59a2@gmail.com
Apparently as of GMime 2.4, you don't need to call
internet_address_list_destroy anymore, but you still need to call
g_object_unref (from the GMime Changelog).
On the medium performance corpus, valgrind shows "possibly lost"
leakage in "notmuch new" dropping from 7M to 300k.
Previously, we would treat multi-message mboxes as one giant email,
which, besides the obvious incorrect indexing, often led to
out-of-memory errors for archival mboxes. Now we explicitly reject
multi-message mboxes. For historical reasons, we retain support for
single-message mboxes, but official deprecate this behavior.
This fixes a bug that didn't allow to search for non-ASCII words such
parts. The code here was copied from show_text_part_content(), because
the show command already does the needed conversion when showing the
message.
It appears to be an oversight that encrypted parts were indexed
previously. The terms generated from encrypted parts are meaningless
and do nothing but add bloat to the database. It is not worth
indexing the encrypted content, just as it's not worth indexing the
signatures in signed parts.
This patch adds the tag "signed" to messages with any multipart/signed
parts, and the tag "encrypted" to messages with any
multipart/encrypted parts. This only occurs when messages are indexed
during notmuch new, so a database rebuild is required to have old
messages tagged.
This was a misfeature where notmuch had extra code that just threw
away legitimate information. It was never indexing an initial "Re"
term in a subject. But some users have legitimately wanted to search
for this term.
The original code was written this way merely for strict compatiblity
with the indexing performed by sup, but we're not taking advantage of
that now anyway.
These various functions and data are all used only locally, so should
be marked static. Ensuring we get these right will avoid us accidentally
leaking unintended symbols through the library interface.
notmuch previously unconditionally checked mime parts for various
properties, but not for NULL, which is the case if libgmime encounters
an empty mime part.
Upon encounter of an empty mime part, the following is printed to
stderr (the second line due to my patch):
(process:17197): gmime-CRITICAL **: g_mime_message_get_mime_part: assertion `GMIME_IS_MESSAGE (message)' failed
Warning: Not indexing empty mime part.
This is probably a bug that should get addressed in libgmime, but for
not, my patch is an acceptable workaround.
Signed-off-by: martin f. krafft <madduck@madduck.net>
If we had external users of this filter then they might expect some of
these macros to exist. But since this is just internal, that's just
unneeded noise.
With modern MIME attachments, we're already avoiding indexing the
attachments. But for old-school uuencoded data in the mail, we have
been directly indexing the encoded data as terms, (which is not useful
at all---nobody will ever ytry to search based on the seemingly random
uuencoded data).
Additionally, indexing a modestly large uuencoded file seems to make
Xapian go insane, (consuming *lots* of memory).
We fix both problems by detecting uuencoded content and not performing
any indexing of it.
In the presentation we often omit citations and signatures, but this
is not content that should be omitted from the index, (especially
when the citation detection is wrong---see cases where a line
beginning with "From" is corrupted to ">From" by mail processing
tools).
Instead of storing the complete message filename in the data portion
of a mail document we now store a 'direntry' term that contains the
document ID of a directory document and also the basename of the
message filename within that directory. This will allow us to easily
store multple filenames for a single message, and will also allow us
to find mail documents for files that previously existed in a
directory but that have since been deleted.
We carefully noted the fact that we had locally allocated the string
here, but then we neglected to free it. Switch to talloc instead
which makes it easier to get the behavior we want. It's simpler since
we can just call talloc_free unconditionally, without having to track
the state of whether we allocated the storage for name or not.
We never did export any interface to get at these, and when I went to
use these, I found them inadequate, (because I wanted to distinguish
address found in from: from those found in To:). Meanwhile, it was
easy enough to extract addresses with a search like:
notmuch show tag:sent | grep ^To:
so the storage of contact terms was just wasting space. Stop that.
