path: root/smime/lib/e-asn1-object.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* e-cert.c
 *
 * Copyright (C) 2003 Ximian, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU 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 General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Author: Chris Toshok (toshok@ximian.com)
 */

/* The following is the mozilla license blurb, as the bodies some of
   these functions were derived from the mozilla source. */

/*
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is the Netscape security libraries.
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are 
 * Copyright (C) 2000 Netscape Communications Corporation.  All
 * Rights Reserved.
 * 
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License Version 2 or later (the
 * "GPL"), in which case the provisions of the GPL are applicable 
 * instead of those above.  If you wish to allow use of your 
 * version of this file only under the terms of the GPL and not to
 * allow others to use your version of this file under the MPL,
 * indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by
 * the GPL.  If you do not delete the provisions above, a recipient
 * may use your version of this file under either the MPL or the
 * GPL.
 *
 */


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

#include "e-asn1-object.h"

#include "secasn1.h"

struct _EASN1ObjectPrivate {
    PRUint32 tag;
    PRUint32 type;
    gboolean valid_container;

    GList *children;

    char *display_name;
    char *value;

    char *data;
    guint data_len;
};

#define PARENT_TYPE G_TYPE_OBJECT
static GObjectClass *parent_class;

static void
e_asn1_object_dispose (GObject *object)
{
    EASN1Object *obj = E_ASN1_OBJECT (object);
    if (obj->priv) {

        if (obj->priv->display_name)
            g_free (obj->priv->display_name);

        if (obj->priv->value)
            g_free (obj->priv->value);

        g_list_foreach (obj->priv->children, (GFunc)g_object_unref, NULL);
        g_list_free (obj->priv->children);

        g_free (obj->priv);
        obj->priv = NULL;
    }
}

static void
e_asn1_object_class_init (EASN1ObjectClass *klass)
{
    GObjectClass *object_class;

    object_class = G_OBJECT_CLASS(klass);

    parent_class = g_type_class_ref (PARENT_TYPE);

    object_class->dispose = e_asn1_object_dispose;
}

static void
e_asn1_object_init (EASN1Object *asn1)
{
    asn1->priv = g_new0 (EASN1ObjectPrivate, 1);

    asn1->priv->valid_container = TRUE;
}

GType
e_asn1_object_get_type (void)
{
    static GType asn1_object_type = 0;

    if (!asn1_object_type) {
        static const GTypeInfo asn1_object_info =  {
            sizeof (EASN1ObjectClass),
            NULL,           /* base_init */
            NULL,           /* base_finalize */
            (GClassInitFunc) e_asn1_object_class_init,
            NULL,           /* class_finalize */
            NULL,           /* class_data */
            sizeof (EASN1Object),
            0,             /* n_preallocs */
            (GInstanceInitFunc) e_asn1_object_init,
        };

        asn1_object_type = g_type_register_static (PARENT_TYPE, "EASN1Object", &asn1_object_info, 0);
    }

    return asn1_object_type;
}


/* This function is used to interpret an integer that
   was encoded in a DER buffer. This function is used
   when converting a DER buffer into a nsIASN1Object 
   structure.  This interprets the buffer in data
   as defined by the DER (Distinguised Encoding Rules) of
   ASN1.
*/
static int
get_integer_256 (unsigned char *data, unsigned int nb)
{
    int val;

    switch (nb) {
    case 1:
        val = data[0];
        break;
    case 2:
        val = (data[0] << 8) | data[1];
        break;
    case 3:
        val = (data[0] << 16) | (data[1] << 8) | data[2];
        break;
    case 4:
        val = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3];
        break;
    default:
        return -1;
    }

    return val;
}

/* This function is used to retrieve the lenght of a DER encoded
   item.  It looks to see if this a multibyte length and then
   interprets the buffer accordingly to get the actual length value.
   This funciton is used mostly while parsing the DER headers.
   
   A DER encoded item has the following structure:

   <tag><length<data consisting of lenght bytes>
*/
static guint32
get_der_item_length (unsigned char *data, unsigned char *end,
             unsigned long *bytesUsed, gboolean *indefinite)
{
    unsigned char lbyte = *data++;
    PRInt32 length = -1;
  
    *indefinite = FALSE;
    if (lbyte >= 0x80) {
        /* Multibyte length */
        unsigned nb = (unsigned) (lbyte & 0x7f);
        if (nb > 4) {
            return -1;
        }
        if (nb > 0) {
            
            if ((data+nb) > end) {
                return -1;
            }
            length = get_integer_256 (data, nb);
            if (length < 0)
                return -1;
        } else {
            *indefinite = TRUE;
            length = 0;
        }
        *bytesUsed = nb+1;
    } else {
        length = lbyte;
        *bytesUsed = 1; 
    }
    return length;
}

static gboolean
build_from_der (EASN1Object *parent, char *data, char *end)
{
    unsigned long bytesUsed;
    gboolean indefinite;
    PRInt32 len;
    PRUint32 type;
    unsigned char code, tagnum;
    EASN1Object *asn1object = NULL;

    if (data >= end)
        return TRUE;

    /*
      A DER item has the form of |tag|len|data
      tag is one byte and describes the type of elment
      we are dealing with.
      len is a DER encoded int telling us how long the data is
      data is a buffer that is len bytes long and has to be
      interpreted according to its type.
    */

    while (data < end) {
        code = *data;
        tagnum = code & SEC_ASN1_TAGNUM_MASK;

        /*
         * NOTE: This code does not (yet) handle the high-tag-number form!
         */
        if (tagnum == SEC_ASN1_HIGH_TAG_NUMBER) {
            return FALSE;
        }
        data++;
        len = get_der_item_length ((unsigned char *)data, (unsigned char *)end, &bytesUsed, &indefinite);
        data += bytesUsed;
        if ((len < 0) || ((data+len) > end))
            return FALSE;

        if (code & SEC_ASN1_CONSTRUCTED) {
            if (len > 0 || indefinite) {
                switch (code & SEC_ASN1_CLASS_MASK) {
                case SEC_ASN1_UNIVERSAL:
                    type = tagnum;
                    break;
                case SEC_ASN1_APPLICATION:
                    type = E_ASN1_OBJECT_TYPE_APPLICATION;
                    break;
                case SEC_ASN1_CONTEXT_SPECIFIC:
                    type = E_ASN1_OBJECT_TYPE_CONTEXT_SPECIFIC;
                    break;
                case SEC_ASN1_PRIVATE:
                    type = E_ASN1_OBJECT_TYPE_PRIVATE;
                    break;
                default:
                    g_warning ("bad DER");
                    return FALSE;
                }

                asn1object = e_asn1_object_new ();
                asn1object->priv->tag = tagnum;
                asn1object->priv->type = type;
                
                if (!build_from_der (asn1object, data, (len == 0) ? end : data + len)) {
                    g_object_unref (asn1object);
                    return FALSE;
                }
            }
        } else {
            asn1object = e_asn1_object_new ();

            asn1object->priv->type = tagnum;
            asn1object->priv->tag = tagnum;

            /*printableItem->SetData((char*)data, len);*/
        }
        data += len;

        parent->priv->children = g_list_append (parent->priv->children, asn1object);
    }

    return TRUE;
}

EASN1Object*
e_asn1_object_new_from_der (char *data, guint32 len)
{
    EASN1Object *obj = g_object_new (E_TYPE_ASN1_OBJECT, NULL);

    if (!build_from_der (obj, data, data + len)) {
        g_object_unref (obj);
        return NULL;
    }

    return obj;
}

EASN1Object*
e_asn1_object_new (void)
{
    return E_ASN1_OBJECT (g_object_new (E_TYPE_ASN1_OBJECT, NULL));
}


void
e_asn1_object_set_valid_container (EASN1Object *obj, gboolean flag)
{
    obj->priv->valid_container = flag;
}

gboolean
e_asn1_object_is_valid_container (EASN1Object *obj)
{
    return obj->priv->valid_container;
}

PRUint32
e_asn1_object_get_asn1_type (EASN1Object *obj)
{
    return obj->priv->type;
}

PRUint32
e_asn1_object_get_asn1_tag (EASN1Object *obj)
{
    return obj->priv->tag;
}

GList*
e_asn1_object_get_children (EASN1Object *obj)
{
    GList *children = g_list_copy (obj->priv->children);

    g_list_foreach (children, (GFunc)g_object_ref, NULL);

    return children;
}

void
e_asn1_object_append_child (EASN1Object *parent, EASN1Object *child)
{
    parent->priv->children = g_list_append (parent->priv->children, g_object_ref (child));
}

void
e_asn1_object_set_display_name (EASN1Object *obj, const char *name)
{
    g_free (obj->priv->display_name);
    obj->priv->display_name = g_strdup (name);
}

const char*
e_asn1_object_get_display_name (EASN1Object *obj)
{
    return obj->priv->display_name;
}

void
e_asn1_object_set_display_value (EASN1Object *obj, const char *value)
{
    g_free (obj->priv->value);
    obj->priv->value = g_strdup (value);
}

const char*
e_asn1_object_get_display_value (EASN1Object *obj)
{
    return obj->priv->value;
}

void
e_asn1_object_get_data (EASN1Object *obj, char **data, guint32 *len)
{
    *data = obj->priv->data;
    *len = obj->priv->data_len;
}