/*

 * Copyright (C) 2010-2016 Free Software Foundation, Inc.

 * Copyright (C) 2015-2016 Red Hat, Inc.

 *

 * Author: Nikos Mavrogiannopoulos

 *

 * This file is part of GnuTLS.

 *

 * The GnuTLS 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 2.1 of

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

 *

 * This 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

 * Lesser 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/>

 *

 */

#include <config.h>

#include <system.h>

#include "gnutls_int.h"

#include "errors.h"

#include <sys/socket.h>

#include <errno.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <unistr.h>

#include <uninorm.h>

#include "num.h"

static void change_u16_endianness(uint8_t *dst, const uint8_t *src, unsigned size, unsigned be)

{

	unsigned convert = 0;

	unsigned i;

	uint8_t tmp;

#ifdef WORDS_BIGENDIAN

	if (!be)

		convert = 1;

#else

	if (be)

		convert = 1;

#endif

	/* convert to LE */

	if (convert) {

		for (i = 0; i < size; i += 2) {

			tmp = src[i];

			dst[i] = src[1 + i];

			dst[1 + i] = tmp;

		}

	} else {

		if (dst != src)

			memcpy(dst, src, size);

	}

}

int _gnutls_ucs2_to_utf8(const void *data, size_t size,

			 gnutls_datum_t * output, unsigned be)

{

	int ret;

	size_t dstlen;

	void *src;

	uint8_t *tmp_dst = NULL;

	uint8_t *dst = NULL;

	if (size > 2 && ((uint8_t *) data)[size-1] == 0 && ((uint8_t *) data)[size-2] == 0) {

		size -= 2;

	}

	if (size == 0)

		return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

	src = gnutls_malloc(size+2);

	if (src == NULL)

		return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);

	/* convert to LE if needed */

	change_u16_endianness(src, data, size, be);

	dstlen = 0;

	tmp_dst = u16_to_u8((uint16_t*)src, size/2, NULL, &dstlen);

	if (tmp_dst == NULL) {

		ret = gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);

		goto fail;

	}

	dst = gnutls_malloc(dstlen+1);

	if (dst == NULL) {

		gnutls_assert();

		ret = GNUTLS_E_MEMORY_ERROR;

		goto fail;

	}

	memcpy(dst, tmp_dst, dstlen);

	dst[dstlen] = 0;

	output->data = (void *) dst;

	output->size = dstlen;

	ret = 0;

	goto cleanup;

 fail:

	gnutls_free(dst);

 cleanup:

	gnutls_free(src);

	free(tmp_dst);

	return ret;

}

/* This is big-endian output only */

int _gnutls_utf8_to_ucs2(const void *data, size_t size,

			 gnutls_datum_t * output)

{

	int ret;

	size_t dstlen, nrm_size = 0, tmp_size = 0;

	uint16_t *tmp_dst = NULL;

	uint16_t *nrm_dst = NULL;

	uint8_t *dst = NULL;

	if (size == 0)

		return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

	tmp_dst = u8_to_u16(data, size, NULL, &tmp_size);

	if (tmp_dst == NULL)

		return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);

	nrm_dst = u16_normalize(UNINORM_NFC, tmp_dst, tmp_size, NULL, &nrm_size);

	if (nrm_dst == NULL) {

		ret = gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);

		goto fail;

	}

	dstlen = nrm_size * 2; /* convert to bytes */

	dst = gnutls_malloc(dstlen+2);

	if (dst == NULL) {

		gnutls_assert();

		ret = GNUTLS_E_MEMORY_ERROR;

		goto fail;

	}

	/* convert to BE */

	change_u16_endianness(dst, (uint8_t*)tmp_dst, dstlen, 1);

	dst[dstlen] = 0;

	dst[dstlen+1] = 0;

	output->data = (void *) dst;

	output->size = dstlen;

	ret = 0;

	goto cleanup;

 fail:

	gnutls_free(dst);

 cleanup:

	free(tmp_dst);

	free(nrm_dst);

	return ret;

}