path: root/libidn/idna.c

/* idna.c	Convert to or from IDN strings.
 * Copyright (C) 2002, 2003, 2004, 2011  Simon Josefsson
 *
 * This file is part of GNU Libidn.
 *
 * GNU Libidn 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.
 *
 * GNU Libidn 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 GNU Libidn; if not, see <http://www.gnu.org/licenses/>.
 */

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdlib.h>
#include <string.h>
#include <stringprep.h>
#include <punycode.h>
#include <stdint.h>

#include "idna.h"

#define DOTP(c) ((c) == 0x002E || (c) == 0x3002 ||	\
		 (c) == 0xFF0E || (c) == 0xFF61)

/* Core functions */

/**
 * idna_to_ascii_4i
 * @in: input array with unicode code points.
 * @inlen: length of input array with unicode code points.
 * @out: output zero terminated string that must have room for at
 *       least 63 characters plus the terminating zero.
 * @flags: IDNA flags, e.g. IDNA_ALLOW_UNASSIGNED or IDNA_USE_STD3_ASCII_RULES.
 *
 * The ToASCII operation takes a sequence of Unicode code points that make
 * up one label and transforms it into a sequence of code points in the
 * ASCII range (0..7F). If ToASCII succeeds, the original sequence and the
 * resulting sequence are equivalent labels.
 *
 * It is important to note that the ToASCII operation can fail. ToASCII
 * fails if any step of it fails. If any step of the ToASCII operation
 * fails on any label in a domain name, that domain name MUST NOT be used
 * as an internationalized domain name. The method for deadling with this
 * failure is application-specific.
 *
 * The inputs to ToASCII are a sequence of code points, the AllowUnassigned
 * flag, and the UseSTD3ASCIIRules flag. The output of ToASCII is either a
 * sequence of ASCII code points or a failure condition.
 *
 * ToASCII never alters a sequence of code points that are all in the ASCII
 * range to begin with (although it could fail). Applying the ToASCII
 * operation multiple times has exactly the same effect as applying it just
 * once.
 *
 * Return value: Returns 0 on success, or an error code.
 */
int
idna_to_ascii_4i (const uint32_t * in, size_t inlen, char *out, int flags)
{
  size_t len, outlen;
  uint32_t *src;		/* XXX don't need to copy data? */
  int rc;

  /*
   * ToASCII consists of the following steps:
   *
   * 1. If all code points in the sequence are in the ASCII range (0..7F)
   * then skip to step 3.
   */

  {
    size_t i;
    int inasciirange;

    inasciirange = 1;
    for (i = 0; i < inlen; i++)
      if (in[i] > 0x7F)
	inasciirange = 0;
    if (inasciirange)
      {
	src = malloc (sizeof (in[0]) * (inlen + 1));
	if (src == NULL)
	  return IDNA_MALLOC_ERROR;

	memcpy (src, in, sizeof (in[0]) * inlen);
	src