crypto: index encrypted parts when indexopts try_decrypt is set.
authorDaniel Kahn Gillmor <dkg@fifthhorseman.net>
Sat, 21 Oct 2017 02:25:41 +0000 (22:25 -0400)
committerDavid Bremner <david@tethera.net>
Sat, 21 Oct 2017 22:53:19 +0000 (19:53 -0300)
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.

doc/man7/notmuch-properties.rst
lib/add-message.cc
lib/index.cc
lib/message.cc
lib/notmuch-private.h

index f70ffb3ca3ae706b7f74393eb48b1f0d6375d93d..4b47e8d7ac2c543b0abfb377e7b955c1f9747cf5 100644 (file)
@@ -47,6 +47,32 @@ CONVENTIONS
 Any property with a key that starts with "index." will be removed (and
 possibly re-set) upon reindexing (see **notmuch-reindex(1)**).
 
+MESSAGE PROPERTIES
+==================
+
+The following properties are set by notmuch internally in the course
+of its normal activity.
+
+**index.decryption**
+
+    If a message contains encrypted content, and notmuch tries to
+    decrypt that content during indexing, it will add the property
+    ``index.decryption=success`` when the cleartext was successfully
+    indexed.  If notmuch attempts to decrypt any part of a message
+    during indexing and that decryption attempt fails, it will add the
+    property ``index.decryption=failure`` to the message.
+
+    Note that it's possible for a single message to have both
+    ``index.decryption=success`` and ``index.decryption=failure``.
+    Consider an encrypted e-mail message that contains another
+    encrypted e-mail message as an attachment -- if the outer message
+    can be decrypted, but the attached part cannot, then both
+    properties will be set on the message as a whole.
+
+    If notmuch never tried to decrypt an encrypted message during
+    indexing (which is the default), then this property will not be
+    set on that message.
+
 SEE ALSO
 ========
 
index 34099ed59fbeed7896ebdc933d377005bbaaf71c..f5fac8be751fa2706d09383c07390652e73dc679 100644 (file)
@@ -546,7 +546,7 @@ notmuch_database_index_file (notmuch_database_t *notmuch,
            indexopts = def_indexopts;
        }
 
-       ret = _notmuch_message_index_file (message, message_file);
+       ret = _notmuch_message_index_file (message, indexopts, message_file);
        if (ret)
            goto DONE;
 
index e5ae2ba73d568027f1c661994e073aff8852a942..6e684f5fcda76dcc5fe81895e25194d7c1186e45 100644 (file)
@@ -364,9 +364,15 @@ _index_content_type (notmuch_message_t *message, GMimeObject *part)
     }
 }
 
+static void
+_index_encrypted_mime_part (notmuch_message_t *message, notmuch_indexopts_t *indexopts,
+                           GMimeContentType *content_type,
+                           GMimeMultipartEncrypted *part);
+
 /* Callback to generate terms for each mime part of a message. */
 static void
 _index_mime_part (notmuch_message_t *message,
+                 notmuch_indexopts_t *indexopts,
                  GMimeObject *part)
 {
     GMimeStream *stream, *filter;
@@ -385,6 +391,7 @@ _index_mime_part (notmuch_message_t *message,
     }
 
     _index_content_type (message, part);
+    content_type = g_mime_object_get_content_type (part);
 
     if (GMIME_IS_MULTIPART (part)) {
        GMimeMultipart *multipart = GMIME_MULTIPART (part);
@@ -409,17 +416,21 @@ _index_mime_part (notmuch_message_t *message,
                }
            }
            if (GMIME_IS_MULTIPART_ENCRYPTED (multipart)) {
-               /* Don't index encrypted parts, but index their content type. */
                _index_content_type (message,
                                     g_mime_multipart_get_part (multipart, i));
-               if ((i != GMIME_MULTIPART_ENCRYPTED_VERSION) &&
-                   (i != GMIME_MULTIPART_ENCRYPTED_CONTENT)) {
-                   _notmuch_database_log (_notmuch_message_database (message),
-                                          "Warning: Unexpected extra parts of multipart/encrypted.\n");
+               if (i == GMIME_MULTIPART_ENCRYPTED_CONTENT) {
+                   _index_encrypted_mime_part(message, indexopts,
+                                              content_type,
+                                              GMIME_MULTIPART_ENCRYPTED (part));
+               } else {
+                   if (i != GMIME_MULTIPART_ENCRYPTED_VERSION) {
+                       _notmuch_database_log (_notmuch_message_database (message),
+                                              "Warning: Unexpected extra parts of multipart/encrypted.\n");
+                   }
                }
                continue;
            }
-           _index_mime_part (message,
+           _index_mime_part (message, indexopts,
                              g_mime_multipart_get_part (multipart, i));
        }
        return;
@@ -430,7 +441,7 @@ _index_mime_part (notmuch_message_t *message,
 
        mime_message = g_mime_message_part_get_message (GMIME_MESSAGE_PART (part));
 
-       _index_mime_part (message, g_mime_message_get_mime_part (mime_message));
+       _index_mime_part (message, indexopts, g_mime_message_get_mime_part (mime_message));
 
        return;
     }
@@ -464,7 +475,6 @@ _index_mime_part (notmuch_message_t *message,
 
     filter = g_mime_stream_filter_new (stream);
 
-    content_type = g_mime_object_get_content_type (part);
     discard_non_term_filter = notmuch_filter_discard_non_term_new (content_type);
 
     g_mime_stream_filter_add (GMIME_STREAM_FILTER (filter),
@@ -502,8 +512,71 @@ _index_mime_part (notmuch_message_t *message,
     }
 }
 
+/* descend (if desired) into the cleartext part of an encrypted MIME
+ * part while indexing. */
+static void
+_index_encrypted_mime_part (notmuch_message_t *message,
+                           notmuch_indexopts_t *indexopts,
+                           g_mime_3_unused(GMimeContentType *content_type),
+                           GMimeMultipartEncrypted *encrypted_data)
+{
+    notmuch_status_t status;
+    GError *err = NULL;
+    notmuch_database_t * notmuch = NULL;
+    GMimeObject *clear = NULL;
+
+    if (!indexopts || !notmuch_indexopts_get_try_decrypt (indexopts))
+       return;
+
+    notmuch = _notmuch_message_database (message);
+
+#if (GMIME_MAJOR_VERSION < 3)
+    {
+       GMimeCryptoContext* crypto_ctx = NULL;
+       const char *protocol = NULL;
+       protocol = g_mime_content_type_get_parameter (content_type, "protocol");
+       status = _notmuch_crypto_get_gmime_ctx_for_protocol (&(indexopts->crypto),
+                                                        protocol, &crypto_ctx);
+       if (status) {
+           _notmuch_database_log (notmuch, "Warning: setup failed for decrypting "
+                                  "during indexing. (%d)\n", status);
+           status = notmuch_message_add_property (message, "index.decryption", "failure");
+           if (status)
+               _notmuch_database_log_append (notmuch, "failed to add index.decryption "
+                                             "property (%d)\n", status);
+           return;
+       }
+       clear = g_mime_multipart_encrypted_decrypt(encrypted_data, crypto_ctx,
+                                                  NULL, &err);
+    }
+#else
+    clear = g_mime_multipart_encrypted_decrypt(encrypted_data, GMIME_DECRYPT_NONE, NULL,
+                                              NULL, &err);
+#endif
+    if (err) {
+       _notmuch_database_log (notmuch, "Failed to decrypt during indexing. (%d:%d) [%s]\n",
+                              err->domain, err->code, err->message);
+       g_error_free(err);
+       /* Indicate that we failed to decrypt during indexing */
+       status = notmuch_message_add_property (message, "index.decryption", "failure");
+       if (status)
+           _notmuch_database_log_append (notmuch, "failed to add index.decryption "
+                                         "property (%d)\n", status);
+       return;
+    }
+    _index_mime_part (message, indexopts, clear);
+    g_object_unref (clear);
+
+    status = notmuch_message_add_property (message, "index.decryption", "success");
+    if (status)
+       _notmuch_database_log (notmuch, "failed to add index.decryption "
+                              "property (%d)\n", status);
+
+}
+
 notmuch_status_t
 _notmuch_message_index_file (notmuch_message_t *message,
+                            notmuch_indexopts_t *indexopts,
                             notmuch_message_file_t *message_file)
 {
     GMimeMessage *mime_message;
@@ -531,7 +604,7 @@ _notmuch_message_index_file (notmuch_message_t *message,
     subject = g_mime_message_get_subject (mime_message);
     _notmuch_message_gen_terms (message, "subject", subject);
 
-    _index_mime_part (message, g_mime_message_get_mime_part (mime_message));
+    _index_mime_part (message, indexopts, g_mime_message_get_mime_part (mime_message));
 
     return NOTMUCH_STATUS_SUCCESS;
 }
index e819f27a40da831a0371b03fc8f56b938dabb8e2..12743460a4895e1acfc1849f6ac19ac2979ca698 100644 (file)
@@ -1961,7 +1961,7 @@ _notmuch_message_frozen (notmuch_message_t *message)
 
 notmuch_status_t
 notmuch_message_reindex (notmuch_message_t *message,
-                        notmuch_indexopts_t unused (*indexopts))
+                        notmuch_indexopts_t *indexopts)
 {
     notmuch_database_t *notmuch = NULL;
     notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
@@ -2042,7 +2042,7 @@ notmuch_message_reindex (notmuch_message_t *message,
        if (found == 0)
            _notmuch_message_set_header_values (message, date, from, subject);
 
-       ret = _notmuch_message_index_file (message, message_file);
+       ret = _notmuch_message_index_file (message, indexopts, message_file);
 
        if (ret == NOTMUCH_STATUS_FILE_ERROR)
            continue;
index 4c4083966ee409ae686daf38320c687e547c5d33..1093429cfc77026289f49754c7ea5c84330c71e6 100644 (file)
@@ -448,6 +448,7 @@ _notmuch_database_link_message_to_parents (notmuch_database_t *notmuch,
 
 notmuch_status_t
 _notmuch_message_index_file (notmuch_message_t *message,
+                            notmuch_indexopts_t *indexopts,
                             notmuch_message_file_t *message_file);
 
 /* messages.c */