path: root/em-format/e-mail-parser-multipart-encrypted.c

/*
 * e-mail-parser-multipart-encrypted.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <glib/gi18n-lib.h>

#include <libedataserver/libedataserver.h>

#include "e-mail-parser-extension.h"
#include "e-mail-part-utils.h"

typedef EMailParserExtension EMailParserMultipartEncrypted;
typedef EMailParserExtensionClass EMailParserMultipartEncryptedClass;

GType e_mail_parser_multipart_encrypted_get_type (void);

G_DEFINE_TYPE (
    EMailParserMultipartEncrypted,
    e_mail_parser_multipart_encrypted,
    E_TYPE_MAIL_PARSER_EXTENSION)

static const gchar *parser_mime_types[] = {
    "multipart/encrypted",
    NULL
};

static gboolean
empe_mp_encrypted_parse (EMailParserExtension *extension,
                         EMailParser *parser,
                         CamelMimePart *part,
                         GString *part_id,
                         GCancellable *cancellable,
                         GQueue *out_mail_parts)
{
    CamelCipherContext *context;
    const gchar *protocol;
    CamelMimePart *opart;
    CamelCipherValidity *valid;
    CamelMultipartEncrypted *mpe;
    GQueue work_queue = G_QUEUE_INIT;
    GList *head, *link;
    GError *local_error = NULL;
    gint len;

    mpe = (CamelMultipartEncrypted *) camel_medium_get_content ((CamelMedium *) part);
    if (!CAMEL_IS_MULTIPART_ENCRYPTED (mpe)) {
        e_mail_parser_error (
            parser, out_mail_parts,
            _("Could not parse MIME message. "
            "Displaying as source."));
        e_mail_parser_parse_part_as (
            parser, part, part_id,
            "application/vnd.evolution/source",
            cancellable, out_mail_parts);

        return TRUE;
    }

    /* Currently we only handle RFC2015-style PGP encryption. */
    protocol = camel_content_type_param (
        ((CamelDataWrapper *) mpe)->mime_type, "protocol");
    if (!protocol || g_ascii_strcasecmp (protocol, "application/pgp-encrypted") != 0) {
        e_mail_parser_error (
            parser, out_mail_parts,
            _("Unsupported encryption type for multipart/encrypted"));
        e_mail_parser_parse_part_as (
            parser, part, part_id, "multipart/mixed",
            cancellable, out_mail_parts);

        return TRUE;
    }

    context = camel_gpg_context_new (e_mail_parser_get_session (parser));

    opart = camel_mime_part_new ();
    valid = camel_cipher_context_decrypt_sync (
        context, part, opart, cancellable, &local_error);

    e_mail_part_preserve_charset_in_content_type (part, opart);

    if (local_error != NULL) {
        e_mail_parser_error (
            parser, out_mail_parts,
            _("Could not parse PGP/MIME message: %s"),
            local_error->message);
        e_mail_parser_parse_part_as (
            parser, part, part_id, "multipart/mixed",
            cancellable, out_mail_parts);

        g_object_unref (opart);
        g_object_unref (context);
        g_error_free (local_error);

        return TRUE;
    }

    len = part_id->len;
    g_string_append (part_id, ".encrypted");

    e_mail_parser_parse_part (
        parser, opart, part_id, cancellable, &work_queue);

    g_string_truncate (part_id, len);

    head = g_queue_peek_head_link (&work_queue);

    /* Update validity of all encrypted sub-parts */
    for (link = head; link != NULL; link = g_list_next (link)) {
        EMailPart *mail_part = link->data;

        e_mail_part_update_validity (
            mail_part, valid,
            E_MAIL_PART_VALIDITY_ENCRYPTED |
            E_MAIL_PART_VALIDITY_PGP);
    }

    e_queue_transfer (&work_queue, out_mail_parts);

    /* Add a widget with details about the encryption, but only when
     * the decrypted part isn't itself secured, in that case it has
     * created the button itself. */
    if (!e_mail_part_is_secured (opart)) {
        EMailPart *mail_part;

        g_string_append (part_id, ".encrypted.button");

        e_mail_parser_parse_part_as (
            parser, part, part_id,
            "application/vnd.evolution.widget.secure-button",
            cancellable, &work_queue);

        mail_part = g_queue_peek_head (&work_queue);

        if (mail_part != NULL)
            e_mail_part_update_validity (
                mail_part, valid,
                E_MAIL_PART_VALIDITY_ENCRYPTED |
                E_MAIL_PART_VALIDITY_PGP);

        e_queue_transfer (&work_queue, out_mail_parts);

        g_string_truncate (part_id, len);
    }

    camel_cipher_validity_free (valid);

    /* TODO: Make sure when we finalize this part, it is zero'd out */
    g_object_unref (opart);
    g_object_unref (context);

    return TRUE;
}

static void
e_mail_parser_multipart_encrypted_class_init (EMailParserExtensionClass *class)
{
    class->mime_types = parser_mime_types;
    class->priority = G_PRIORITY_LOW;
    class->parse = empe_mp_encrypted_parse;
}

static void
e_mail_parser_multipart_encrypted_init (EMailParserExtension *extension)
{
}