/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */

/* egg-asn1.c - ASN.1 helper routines

   Copyright (C) 2007 Stefan Walter

   The Gnome Keyring Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Library General Public License as

   published by the Free Software Foundation; either version 2 of the

   License, or (at your option) any later version.

   The Gnome Keyring Library 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

   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public

   License along with the Gnome Library; see the file COPYING.LIB.  If not,

   see <http://www.gnu.org/licenses/>.

   Author: Stef Walter <stef@memberwebs.com>

*/

#include "config.h"

#include "egg-asn1-defs.h"

#include "egg-asn1x.h"

#include "egg-dn.h"

#include "egg-oid.h"

#include <string.h>

static const char HEXC[] = "0123456789ABCDEF";

static gchar*

dn_print_hex_value (GBytes *val)

{

	const gchar *data = g_bytes_get_data (val, NULL);

	gsize size = g_bytes_get_size (val);

	GString *result = g_string_sized_new (size * 2 + 1);

	gsize i;

	g_string_append_c (result, '#');

	for (i = 0; i < size; ++i) {

		g_string_append_c (result, HEXC[data[i] >> 4 & 0xf]);

		g_string_append_c (result, HEXC[data[i] & 0xf]);

	}

	return g_string_free (result, FALSE);

}

static gchar*

dn_print_oid_value_parsed (GQuark oid,

                           guint flags,

                           GNode *val)

{

	GNode *asn1, *node;

	GBytes *value;

	const gchar *data;

	gsize size;

	gchar *result;

	g_assert (val != NULL);

	asn1 = egg_asn1x_create_quark (pkix_asn1_tab, oid);

	g_return_val_if_fail (asn1, NULL);

	if (!egg_asn1x_get_any_into (val, asn1)) {

		g_message ("couldn't decode value for OID: %s: %s",

		           g_quark_to_string (oid), egg_asn1x_message (asn1));

		egg_asn1x_destroy (asn1);

		return NULL;

	}

	/*

	 * If it's a choice element, then we have to read depending

	 * on what's there.

	 */

	if (flags & EGG_OID_IS_CHOICE)

		node = egg_asn1x_get_choice (asn1);

	else

		node = asn1;

	value = egg_asn1x_get_value_raw (node);

	data = g_bytes_get_data (value, &size);

	/*

	 * Now we make sure it's UTF-8.

	 */

	if (!value) {

		g_message ("couldn't read value for OID: %s", g_quark_to_string (oid));

		result = NULL;

	} else if (!g_utf8_validate (data, size, NULL)) {

		result = dn_print_hex_value (value);

	} else {

		result = g_strndup (data, size);

	}

	g_bytes_unref (value);

	egg_asn1x_destroy (asn1);

	return result;

}

static gchar*

dn_print_oid_value (GQuark oid,

                    guint flags,

                    GNode *val)

{

	GBytes *der;

	gchar *value;

	g_assert (val != NULL);

	if (flags & EGG_OID_PRINTABLE) {

		value = dn_print_oid_value_parsed (oid, flags, val);

		if (value != NULL)

			return value;

	}

	der = egg_asn1x_get_element_raw (val);

	value = dn_print_hex_value (der);

	g_bytes_unref (der);

	return value;

}

static gchar*

dn_parse_rdn (GNode *asn)

{

	const gchar *name;

	guint flags;

	GQuark oid;

	GNode *value;

	gchar *display;

	gchar *result;

	g_assert (asn);

	oid = egg_asn1x_get_oid_as_quark (egg_asn1x_node (asn, "type", NULL));

	g_return_val_if_fail (oid, NULL);

	flags = egg_oid_get_flags (oid);

	name = egg_oid_get_name (oid);

	value = egg_asn1x_node (asn, "value", NULL);

	g_return_val_if_fail (value, NULL);

	display = dn_print_oid_value (oid, flags, value);

	result = g_strconcat ((flags & EGG_OID_PRINTABLE) ? name : g_quark_to_string (oid),

	                      "=", display, NULL);

	g_free (display);

	return result;

}

gchar*

egg_dn_read (GNode* asn)

{

	gboolean done = FALSE;

	GString *result;

	GNode *node;

	gchar *rdn;

	gint i, j;

	g_return_val_if_fail (asn, NULL);

	result = g_string_sized_new (64);

	/* Each (possibly multi valued) RDN */

	for (i = 1; !done; ++i) {

		/* Each type=value pair of an RDN */

		for (j = 1; TRUE; ++j) {

			node = egg_asn1x_node (asn, i, j, NULL);

			if (!node) {

				done = j == 1;

				break;

			}

			rdn = dn_parse_rdn (node);

			g_return_val_if_fail (rdn, NULL);

			/* Account for multi valued RDNs */

			if (j > 1)

				g_string_append (result, "+");

			else if (i > 1)

				g_string_append (result, ", ");

			g_string_append (result, rdn);

			g_free (rdn);

		}

	}

	/* Returns null when string is empty */

	return g_string_free (result, (result->len == 0));

}

gchar*

egg_dn_read_part (GNode *asn, const gchar *match)

{

	gboolean done = FALSE;

	const gchar *name;

	GNode *node;

	GQuark oid;

	gint i, j;

	g_return_val_if_fail (asn, NULL);

	g_return_val_if_fail (match, NULL);

	/* Each (possibly multi valued) RDN */

	for (i = 1; !done; ++i) {

		/* Each type=value pair of an RDN */

		for (j = 1; TRUE; ++j) {

			node = egg_asn1x_node (asn, i, j, "type", NULL);

			if (!node) {

				done = j == 1;

				break;

			}

			oid = egg_asn1x_get_oid_as_quark (node);

			g_return_val_if_fail (oid, NULL);

			/* Does it match either the OID or the displayable? */

			if (g_ascii_strcasecmp (g_quark_to_string (oid), match) != 0) {

				name = egg_oid_get_name (oid);

				if (!g_ascii_strcasecmp (name, match) == 0)

					continue;

			}

			node = egg_asn1x_node (asn, i, j, "value", NULL);

			g_return_val_if_fail (node, NULL);

			return dn_print_oid_value (oid, egg_oid_get_flags (oid), node);

		}

	}

	return NULL;

}

gboolean

egg_dn_parse (GNode *asn, EggDnCallback callback, gpointer user_data)

{

	gboolean done = FALSE;

	GNode *node;

	GQuark oid;

	guint i, j;

	g_return_val_if_fail (asn, FALSE);

	/* Each (possibly multi valued) RDN */

	for (i = 1; !done; ++i) {

		/* Each type=value pair of an RDN */

		for (j = 1; TRUE; ++j) {

			/* Dig out the type */

			node = egg_asn1x_node (asn, i, j, "type", NULL);

			if (!node) {

				done = j == 1;

				break;

			}

			oid = egg_asn1x_get_oid_as_quark (node);

			g_return_val_if_fail (oid, FALSE);

			/* Dig out the value */

			node = egg_asn1x_node (asn, i, j, "value", NULL);

			if (!node) {

				done = j == 1;

				break;

			}

			if (callback)

				(callback) (i, oid, node, user_data);

		}

	}

	return i > 1;

}

gchar *

egg_dn_print_value (GQuark oid,

                    GNode *value)

{

	g_return_val_if_fail (oid != 0, NULL);

	g_return_val_if_fail (value != NULL, NULL);

	return dn_print_oid_value (oid, egg_oid_get_flags (oid), value);

}

static gboolean

is_ascii_string (const gchar *string)

{

	const gchar *p = string;

	g_return_val_if_fail (string != NULL, FALSE);

	for (p = string; *p != '\0'; p++) {

		if (!g_ascii_isspace (*p) && *p < ' ')

			return FALSE;

	}

	return TRUE;

}

static gboolean

is_printable_string (const gchar *string)

{

	const gchar *p = string;

	g_return_val_if_fail (string != NULL, FALSE);

	for (p = string; *p != '\0'; p++) {

		if (!g_ascii_isalnum (*p) && !strchr (" '()+,-./:=?", *p))

			return FALSE;

	}

	return TRUE;

}

void

egg_dn_add_string_part (GNode *asn,

                        GQuark oid,

                        const gchar *string)

{

	GNode *node;

	GNode *value;

	GNode *val;

	guint flags;

	g_return_if_fail (asn != NULL);

	g_return_if_fail (oid != 0);

	g_return_if_fail (string != NULL);

	flags = egg_oid_get_flags (oid);

	g_return_if_fail (flags & EGG_OID_PRINTABLE);

	/* Add the RelativeDistinguishedName */

	node = egg_asn1x_append (asn);

	/* Add the AttributeTypeAndValue */

	node = egg_asn1x_append (node);

	egg_asn1x_set_oid_as_quark (egg_asn1x_node (node, "type", NULL), oid);

	value = egg_asn1x_create_quark (pkix_asn1_tab, oid);

	if (egg_asn1x_type (value) == EGG_ASN1X_CHOICE) {

		if (is_printable_string (string))

			val = egg_asn1x_node (value, "printableString", NULL);

		else if (is_ascii_string (string))

			val = egg_asn1x_node (value, "ia5String", NULL);

		else

			val = egg_asn1x_node (value, "utf8String", NULL);

		egg_asn1x_set_choice (value, val);

	} else {

		val = value;

	}

	egg_asn1x_set_string_as_utf8 (val, g_strdup (string), g_free);

	egg_asn1x_set_any_from (egg_asn1x_node (node, "value", NULL), value);

	egg_asn1x_destroy (value);

}