/* 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 */ #include #include "repair.h" static bool _notmuch_crypto_payload_has_legacy_display (GMimeObject *payload) { GMimeMultipart *mpayload; const char *protected_header_parameter; GMimeObject *first; 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); /* Early implementations that generated "Legacy Display" parts used * Content-Type: text/rfc822-headers, but text/plain is more widely * rendered, so it is now the standard choice. We accept either as a * Legacy Display part. */ if (! (g_mime_content_type_is_type (g_mime_object_get_content_type (first), "text", "plain") || 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; return true; } 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; } } /* see * https://tools.ietf.org/html/draft-dkg-openpgp-pgpmime-message-mangling-00#section-4.1.1 */ static bool _notmuch_is_mixed_up_mangled (GMimeObject *part) { GMimeMultipart *mpart = NULL; GMimeObject *parts[3] = { NULL, NULL, NULL }; GMimeContentType *type = NULL; char *prelude_string = NULL; bool prelude_is_empty; if (part == NULL) return false; type = g_mime_object_get_content_type (part); if (type == NULL) return false; if (! g_mime_content_type_is_type (type, "multipart", "mixed")) return false; if (! GMIME_IS_MULTIPART (part)) /* probably impossible */ return false; mpart = GMIME_MULTIPART (part); if (mpart == NULL) return false; if (g_mime_multipart_get_count (mpart) != 3) return false; parts[0] = g_mime_multipart_get_part (mpart, 0); if (! g_mime_content_type_is_type (g_mime_object_get_content_type (parts[0]), "text", "plain")) return false; if (! GMIME_IS_TEXT_PART (parts[0])) return false; parts[1] = g_mime_multipart_get_part (mpart, 1); if (! g_mime_content_type_is_type (g_mime_object_get_content_type (parts[1]), "application", "pgp-encrypted")) return false; parts[2] = g_mime_multipart_get_part (mpart, 2); if (! g_mime_content_type_is_type (g_mime_object_get_content_type (parts[2]), "application", "octet-stream")) return false; /* Is parts[0] length 0? */ prelude_string = g_mime_text_part_get_text (GMIME_TEXT_PART (parts[0])); prelude_is_empty = (prelude_string[0] == '\0'); g_free (prelude_string); if (! prelude_is_empty) return false; /* FIXME: after decoding and stripping whitespace, is parts[1] * subpart just "Version: 1" ? */ /* FIXME: can we determine that parts[2] subpart is *only* PGP * encrypted data? I tried g_mime_part_get_openpgp_data () but * found https://github.com/jstedfast/gmime/issues/60 */ return true; } /* see * https://tools.ietf.org/html/draft-dkg-openpgp-pgpmime-message-mangling-00#section-4.1.2 */ GMimeObject * _notmuch_repair_mixed_up_mangled (GMimeObject *part) { GMimeMultipart *mpart = NULL, *mpart_ret = NULL; GMimeObject *ret = NULL; if (! _notmuch_is_mixed_up_mangled (part)) return NULL; mpart = GMIME_MULTIPART (part); ret = GMIME_OBJECT (g_mime_multipart_encrypted_new ()); if (ret == NULL) return NULL; mpart_ret = GMIME_MULTIPART (ret); if (mpart_ret == NULL) { g_object_unref (ret); return NULL; } g_mime_object_set_content_type_parameter (ret, "protocol", "application/pgp-encrypted"); g_mime_multipart_insert (mpart_ret, 0, g_mime_multipart_get_part (mpart, 1)); g_mime_multipart_insert (mpart_ret, 1, g_mime_multipart_get_part (mpart, 2)); return ret; }