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| | /* notmuch - Not much of an email program, (just index and search)
*
* Copyright © 2019 Daniel Kahn Gillmor
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see https://www.gnu.org/licenses/ .
*
* Authors: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
*/
#include <stdbool.h>
#include "repair.h"
static bool
_notmuch_crypto_payload_has_legacy_display (GMimeObject *payload)
{
GMimeMultipart *mpayload;
const char *protected_header_parameter;
GMimeTextPart *legacy_display;
char *legacy_display_header_text = NULL;
GMimeStream *stream = NULL;
GMimeParser *parser = NULL;
GMimeObject *legacy_header_object = NULL, *first;
GMimeHeaderList *legacy_display_headers = NULL, *protected_headers = NULL;
bool ret = false;
if (! g_mime_content_type_is_type (g_mime_object_get_content_type (payload),
"multipart", "mixed"))
return false;
protected_header_parameter = g_mime_object_get_content_type_parameter (payload, "protected-headers");
if ((! protected_header_parameter) || strcmp (protected_header_parameter, "v1"))
return false;
if (! GMIME_IS_MULTIPART (payload))
return false;
mpayload = GMIME_MULTIPART (payload);
if (mpayload == NULL)
return false;
if (g_mime_multipart_get_count (mpayload) != 2)
return false;
first = g_mime_multipart_get_part (mpayload, 0);
if (! g_mime_content_type_is_type (g_mime_object_get_content_type (first),
"text", "rfc822-headers"))
return false;
protected_header_parameter = g_mime_object_get_content_type_parameter (first, "protected-headers");
if ((! protected_header_parameter) || strcmp (protected_header_parameter, "v1"))
return false;
if (! GMIME_IS_TEXT_PART (first))
return false;
/* ensure that the headers in the first part all match the values
* found in the payload's own protected headers! if they don't,
* we should not treat this as a valid "legacy-display" part.
*
* Crafting a GMimeHeaderList object from the content of the
* text/rfc822-headers part is pretty clumsy; we should probably
* push something into GMime that makes this a one-shot
* operation. */
if ((protected_headers = g_mime_object_get_header_list (payload), protected_headers) &&
(legacy_display = GMIME_TEXT_PART (first), legacy_display) &&
(legacy_display_header_text = g_mime_text_part_get_text (legacy_display), legacy_display_header_text) &&
(stream = g_mime_stream_mem_new_with_buffer (legacy_display_header_text, strlen (legacy_display_header_text)), stream) &&
(g_mime_stream_write (stream, "\r\n\r\n", 4) == 4) &&
(g_mime_stream_seek (stream, 0, GMIME_STREAM_SEEK_SET) == 0) &&
(parser = g_mime_parser_new_with_stream (stream), parser) &&
(legacy_header_object = g_mime_parser_construct_part (parser, NULL), legacy_header_object) &&
(legacy_display_headers = g_mime_object_get_header_list (legacy_header_object), legacy_display_headers)) {
/* walk through legacy_display_headers, comparing them against
* their values in the protected_headers: */
ret = true;
for (int i = 0; i < g_mime_header_list_get_count (legacy_display_headers); i++) {
GMimeHeader *dh = g_mime_header_list_get_header_at (legacy_display_headers, i);
if (dh == NULL) {
ret = false;
break;
}
GMimeHeader *ph = g_mime_header_list_get_header (protected_headers, g_mime_header_get_name (dh));
if (ph == NULL) {
ret = false;
break;
}
if (strcmp (g_mime_header_get_value (dh), g_mime_header_get_value (ph))) {
ret = false;
break;
}
}
}
if (legacy_display_header_text)
g_free (legacy_display_header_text);
if (stream)
g_object_unref (stream);
if (parser)
g_object_unref (parser);
if (legacy_header_object)
g_object_unref (legacy_header_object);
return ret;
}
GMimeObject *
_notmuch_repair_crypto_payload_skip_legacy_display (GMimeObject *payload)
{
if (_notmuch_crypto_payload_has_legacy_display (payload)) {
return g_mime_multipart_get_part (GMIME_MULTIPART (payload), 1);
} else {
return payload;
}
}
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