path: root/em-format/e-mail-parser-inlinepgp-signed.c

/*
 * e-mail-parser-inlinepgp-signed.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.
 *
 * 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 Lesser General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 */

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

#include <string.h>
#include <glib/gi18n-lib.h>

#include <e-util/e-util.h>

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

typedef EMailParserExtension EMailParserInlinePGPSigned;
typedef EMailParserExtensionClass EMailParserInlinePGPSignedClass;

GType e_mail_parser_inline_pgp_signed_get_type (void);

G_DEFINE_TYPE (
    EMailParserInlinePGPSigned,
    e_mail_parser_inline_pgp_signed,
    E_TYPE_MAIL_PARSER_EXTENSION)

static const gchar *parser_mime_types[] = {
    "application/x-inlinepgp-signed",
    NULL
};

static gboolean
empe_inlinepgp_signed_parse (EMailParserExtension *extension,
                             EMailParser *parser,
                             CamelMimePart *part,
                             GString *part_id,
                             GCancellable *cancellable,
                             GQueue *out_mail_parts)
{
    CamelStream *filtered_stream;
    CamelMimeFilterPgp *pgp_filter;
    CamelContentType *content_type;
    CamelCipherContext *cipher;
    CamelCipherValidity *valid;
    CamelDataWrapper *dw;
    CamelMimePart *opart;
    CamelStream *ostream;
    GQueue work_queue = G_QUEUE_INIT;
    GList *head, *link;
    gchar *type;
    gint len;
    GError *local_error = NULL;
    GByteArray *ba;

    if (g_cancellable_is_cancelled (cancellable) ||
        /* avoid recursion */
        (part_id->str && part_id->len > 17 && g_str_has_suffix (part_id->str, ".inlinepgp_signed")))
        return FALSE;

    cipher = camel_gpg_context_new (e_mail_parser_get_session (parser));

    /* Verify the signature of the message */
    valid = camel_cipher_context_verify_sync (
        cipher, part, cancellable, &local_error);

    if (local_error != NULL) {
        e_mail_parser_error (
            parser, out_mail_parts,
            _("Error verifying signature: %s"),
            local_error->message);

        g_error_free (local_error);

        e_mail_parser_parse_part_as (
            parser, part, part_id,
            "application/vnd.evolution.source",
            cancellable, out_mail_parts);

        g_object_unref (cipher);

        return TRUE;
    }

    /* Setup output stream */
    ostream = camel_stream_mem_new ();
    filtered_stream = camel_stream_filter_new (ostream);

    /* Add PGP header / footer filter */
    pgp_filter = (CamelMimeFilterPgp *) camel_mime_filter_pgp_new ();
    camel_stream_filter_add (
        CAMEL_STREAM_FILTER (filtered_stream),
        CAMEL_MIME_FILTER (pgp_filter));
    g_object_unref (pgp_filter);

    /* Pass through the filters that have been setup */
    dw = camel_medium_get_content ((CamelMedium *) part);
    camel_data_wrapper_decode_to_stream_sync (
        dw, (CamelStream *) filtered_stream, cancellable, NULL);
    camel_stream_flush ((CamelStream *) filtered_stream, cancellable, NULL);
    g_object_unref (filtered_stream);

    /* Create a new text/plain MIME part containing the signed
     * content preserving the original part's Content-Type params. */
    content_type = camel_mime_part_get_content_type (part);
    type = camel_content_type_format (content_type);
    content_type = camel_content_type_decode (type);
    g_free (type);

    g_free (content_type->type);
    content_type->type = g_strdup ("text");
    g_free (content_type->subtype);
    content_type->subtype = g_strdup ("plain");
    type = camel_content_type_format (content_type);
    camel_content_type_unref (content_type);

    ba = camel_stream_mem_get_byte_array ((CamelStreamMem *) ostream);
    opart = camel_mime_part_new ();
    camel_mime_part_set_content (opart, (gchar *) ba->data, ba->len, type);
    g_free (type);

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

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

    head = g_queue_peek_head_link (&work_queue);

    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_SIGNED |
            E_MAIL_PART_VALIDITY_PGP);
    }

    e_queue_transfer (&work_queue, out_mail_parts);

    g_string_truncate (part_id, len);

    /* Add a widget with details about the encryption, but only when
     * the encrypted 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, ".inlinepgp_signed.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_SIGNED |
                E_MAIL_PART_VALIDITY_PGP);

        e_queue_transfer (&work_queue, out_mail_parts);

        g_string_truncate (part_id, len);
    }

    /* Clean Up */
    camel_cipher_validity_free (valid);
    g_object_unref (opart);
    g_object_unref (ostream);
    g_object_unref (cipher);

    return TRUE;
}

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

static void
e_mail_parser_inline_pgp_signed_init (EMailParserExtension *extension)
{
}