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-rw-r--r--libidn/idna.c797
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diff --git a/libidn/idna.c b/libidn/idna.c
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+/* idna.c	Convert to or from IDN strings.
+ * Copyright (C) 2002, 2003, 2004  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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#if HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <stringprep.h>
+#include <punycode.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[inlen] = 0;
+
+	goto step3;
+      }
+  }
+
+  /*
+   * 2. Perform the steps specified in [NAMEPREP] and fail if there is
+   * an error. The AllowUnassigned flag is used in [NAMEPREP].
+   */
+
+  {
+    char *p;
+
+    p = stringprep_ucs4_to_utf8 (in, inlen, NULL, NULL);
+    if (p == NULL)
+      return IDNA_MALLOC_ERROR;
+
+    len = strlen (p);
+    do
+      {
+	len = 2 * len + 10;	/* XXX better guess? */
+	p = realloc (p, len);
+	if (p == NULL)
+	  return IDNA_MALLOC_ERROR;
+
+	if (flags & IDNA_ALLOW_UNASSIGNED)
+	  rc = stringprep_nameprep (p, len);
+	else
+	  rc = stringprep_nameprep_no_unassigned (p, len);
+      }
+    while (rc == STRINGPREP_TOO_SMALL_BUFFER);
+
+    if (rc != STRINGPREP_OK)
+      {
+	free (p);
+	return IDNA_STRINGPREP_ERROR;
+      }
+
+    src = stringprep_utf8_to_ucs4 (p, -1, NULL);
+
+    free (p);
+  }
+
+step3:
+  /*
+   * 3. If the UseSTD3ASCIIRules flag is set, then perform these checks:
+   *
+   * (a) Verify the absence of non-LDH ASCII code points; that is,
+   * the absence of 0..2C, 2E..2F, 3A..40, 5B..60, and 7B..7F.
+   *
+   * (b) Verify the absence of leading and trailing hyphen-minus;
+   * that is, the absence of U+002D at the beginning and end of
+   * the sequence.
+   */
+
+  if (flags & IDNA_USE_STD3_ASCII_RULES)
+    {
+      size_t i;
+
+      for (i = 0; src[i]; i++)
+	if (src[i] <= 0x2C || src[i] == 0x2E || src[i] == 0x2F ||
+	    (src[i] >= 0x3A && src[i] <= 0x40) ||
+	    (src[i] >= 0x5B && src[i] <= 0x60) ||
+	    (src[i] >= 0x7B && src[i] <= 0x7F))
+	  {
+	    free (src);
+	    return IDNA_CONTAINS_NON_LDH;
+	  }
+
+      if (src[0] == 0x002D || (i > 0 && src[i - 1] == 0x002D))
+	{
+	  free (src);
+	  return IDNA_CONTAINS_MINUS;
+	}
+    }
+
+  /*
+   * 4. If all code points in the sequence are in the ASCII range
+   * (0..7F), then skip to step 8.
+   */
+
+  {
+    size_t i;
+    int inasciirange;
+
+    inasciirange = 1;
+    for (i = 0; src[i]; i++)
+      {
+	if (src[i] > 0x7F)
+	  inasciirange = 0;
+	/* copy string to output buffer if we are about to skip to step8 */
+	if (i < 64)
+	  out[i] = src[i];
+      }
+    if (i < 64)
+      out[i] = '\0';
+    if (inasciirange)
+      goto step8;
+  }
+
+  /*
+   * 5. Verify that the sequence does NOT begin with the ACE prefix.
+   *
+   */
+
+  {
+    size_t i;
+    int match;
+
+    match = 1;
+    for (i = 0; match && i < strlen (IDNA_ACE_PREFIX); i++)
+      if (((uint32_t) IDNA_ACE_PREFIX[i] & 0xFF) != src[i])
+	match = 0;
+    if (match)
+      {
+	free (src);
+	return IDNA_CONTAINS_ACE_PREFIX;
+      }
+  }
+
+  /*
+   * 6. Encode the sequence using the encoding algorithm in [PUNYCODE]
+   * and fail if there is an error.
+   */
+  for (len = 0; src[len]; len++)
+    ;
+  src[len] = '\0';
+  outlen = 63 - strlen (IDNA_ACE_PREFIX);
+  rc = punycode_encode (len, src, NULL,
+			&outlen, &out[strlen (IDNA_ACE_PREFIX)]);
+  if (rc != PUNYCODE_SUCCESS)
+    {
+      free (src);
+      return IDNA_PUNYCODE_ERROR;
+    }
+  out[strlen (IDNA_ACE_PREFIX) + outlen] = '\0';
+
+  /*
+   * 7. Prepend the ACE prefix.
+   */
+
+  memcpy (out, IDNA_ACE_PREFIX, strlen (IDNA_ACE_PREFIX));
+
+  /*
+   * 8. Verify that the number of code points is in the range 1 to 63
+   * inclusive (0 is excluded).
+   */
+
+step8:
+  free (src);
+  if (strlen (out) < 1 || strlen (out) > 63)
+    return IDNA_INVALID_LENGTH;
+
+  return IDNA_SUCCESS;
+}
+
+/* ToUnicode().  May realloc() utf8in. */
+static int
+idna_to_unicode_internal (char *utf8in,
+			  uint32_t * out, size_t * outlen, int flags)
+{
+  int rc;
+  char tmpout[64];
+  size_t utf8len = strlen (utf8in) + 1;
+  size_t addlen = 0;
+
+  /*
+   * ToUnicode consists of the following steps:
+   *
+   * 1. If the sequence contains any code points outside the ASCII range
+   * (0..7F) then proceed to step 2, otherwise skip to step 3.
+   */
+
+  {
+    size_t i;
+    int inasciirange;
+
+    inasciirange = 1;
+    for (i = 0; utf8in[i]; i++)
+      if (utf8in[i] & ~0x7F)
+	inasciirange = 0;
+    if (inasciirange)
+      goto step3;
+  }
+
+  /*
+   * 2. Perform the steps specified in [NAMEPREP] and fail if there is an
+   * error. (If step 3 of ToASCII is also performed here, it will not
+   * affect the overall behavior of ToUnicode, but it is not
+   * necessary.) The AllowUnassigned flag is used in [NAMEPREP].
+   */
+  do
+    {
+      utf8in = realloc (utf8in, utf8len + addlen);
+      if (!utf8in)
+	return IDNA_MALLOC_ERROR;
+      if (flags & IDNA_ALLOW_UNASSIGNED)
+	rc = stringprep_nameprep (utf8in, utf8len + addlen);
+      else
+	rc = stringprep_nameprep_no_unassigned (utf8in, utf8len + addlen);
+      addlen += 1;
+    }
+  while (rc == STRINGPREP_TOO_SMALL_BUFFER);
+
+  if (rc != STRINGPREP_OK)
+    return IDNA_STRINGPREP_ERROR;
+
+  /* 3. Verify that the sequence begins with the ACE prefix, and save a
+   * copy of the sequence.
+   */
+
+step3:
+  if (memcmp (IDNA_ACE_PREFIX, utf8in, strlen (IDNA_ACE_PREFIX)) != 0)
+    return IDNA_NO_ACE_PREFIX;
+
+  /* 4. Remove the ACE prefix.
+   */
+
+  memmove (utf8in, &utf8in[strlen (IDNA_ACE_PREFIX)],
+	   strlen (utf8in) - strlen (IDNA_ACE_PREFIX) + 1);
+
+  /* 5. Decode the sequence using the decoding algorithm in [PUNYCODE]
+   * and fail if there is an error. Save a copy of the result of
+   * this step.
+   */
+
+  (*outlen)--;			/* reserve one for the zero */
+
+  rc = punycode_decode (strlen (utf8in), utf8in, outlen, out, NULL);
+  if (rc != PUNYCODE_SUCCESS)
+    return IDNA_PUNYCODE_ERROR;
+
+  out[*outlen] = 0;		/* add zero */
+
+  /* 6. Apply ToASCII.
+   */
+
+  rc = idna_to_ascii_4i (out, *outlen, tmpout, flags);
+  if (rc != IDNA_SUCCESS)
+    return rc;
+
+  /* 7. Verify that the result of step 6 matches the saved copy from
+   * step 3, using a case-insensitive ASCII comparison.
+   */
+
+  if (strcasecmp (utf8in, tmpout + strlen (IDNA_ACE_PREFIX)) != 0)
+    return IDNA_ROUNDTRIP_VERIFY_ERROR;
+
+  /* 8. Return the saved copy from step 5.
+   */
+
+  return IDNA_SUCCESS;
+}
+
+/**
+ * idna_to_unicode_44i
+ * @in: input array with unicode code points.
+ * @inlen: length of input array with unicode code points.
+ * @out: output array with unicode code points.
+ * @outlen: on input, maximum size of output array with unicode code points,
+ *          on exit, actual size of output array with unicode code points.
+ * @flags: IDNA flags, e.g. IDNA_ALLOW_UNASSIGNED or IDNA_USE_STD3_ASCII_RULES.
+ *
+ * The ToUnicode operation takes a sequence of Unicode code points
+ * that make up one label and returns a sequence of Unicode code
+ * points. If the input sequence is a label in ACE form, then the
+ * result is an equivalent internationalized label that is not in ACE
+ * form, otherwise the original sequence is returned unaltered.
+ *
+ * ToUnicode never fails. If any step fails, then the original input
+ * sequence is returned immediately in that step.
+ *
+ * The Punycode decoder can never output more code points than it
+ * inputs, but Nameprep can, and therefore ToUnicode can.  Note that
+ * the number of octets needed to represent a sequence of code points
+ * depends on the particular character encoding used.
+ *
+ * The inputs to ToUnicode are a sequence of code points, the
+ * AllowUnassigned flag, and the UseSTD3ASCIIRules flag. The output of
+ * ToUnicode is always a sequence of Unicode code points.
+ *
+ * Return value: Returns error condition, but it must only be used for
+ *               debugging purposes.  The output buffer is always
+ *               guaranteed to contain the correct data according to
+ *               the specification (sans malloc induced errors).  NB!
+ *               This means that you normally ignore the return code
+ *               from this function, as checking it means breaking the
+ *               standard.
+ */
+int
+idna_to_unicode_44i (const uint32_t * in, size_t inlen,
+		     uint32_t * out, size_t * outlen, int flags)
+{
+  int rc;
+  size_t outlensave = *outlen;
+  char *p;
+
+  p = stringprep_ucs4_to_utf8 (in, inlen, NULL, NULL);
+  if (p == NULL)
+    return IDNA_MALLOC_ERROR;
+
+  rc = idna_to_unicode_internal (p, out, outlen, flags);
+  if (rc != IDNA_SUCCESS)
+    {
+      memcpy (out, in, sizeof (in[0]) * (inlen < outlensave ?
+					 inlen : outlensave));
+      *outlen = inlen;
+    }
+
+  free (p);
+
+  return rc;
+}
+
+/* Wrappers that handle several labels */
+
+/**
+ * idna_to_ascii_4z:
+ * @input: zero terminated input Unicode string.
+ * @output: pointer to newly allocated output string.
+ * @flags: IDNA flags, e.g. IDNA_ALLOW_UNASSIGNED or IDNA_USE_STD3_ASCII_RULES.
+ *
+ * Convert UCS-4 domain name to ASCII string.  The domain name may
+ * contain several labels, separated by dots.  The output buffer must
+ * be deallocated by the caller.
+ *
+ * Return value: Returns IDNA_SUCCESS on success, or error code.
+ **/
+int
+idna_to_ascii_4z (const uint32_t * input, char **output, int flags)
+{
+  const uint32_t *start = input;
+  const uint32_t *end = input;
+  char buf[64];
+  char *out = NULL;
+  int rc;
+
+  /* 1) Whenever dots are used as label separators, the following
+     characters MUST be recognized as dots: U+002E (full stop),
+     U+3002 (ideographic full stop), U+FF0E (fullwidth full stop),
+     U+FF61 (halfwidth ideographic full stop). */
+
+  if (input[0] == 0)
+    {
+      /* Handle implicit zero-length root label. */
+      *output = malloc (1);
+      if (!*output)
+	return IDNA_MALLOC_ERROR;
+      strcpy (*output, "");
+      return IDNA_SUCCESS;
+    }
+
+  if (DOTP (input[0]) && input[1] == 0)
+    {
+      /* Handle explicit zero-length root label. */
+      *output = malloc (2);
+      if (!*output)
+	return IDNA_MALLOC_ERROR;
+      strcpy (*output, ".");
+      return IDNA_SUCCESS;
+    }
+
+  *output = NULL;
+  do
+    {
+      end = start;
+
+      for (; *end && !DOTP (*end); end++)
+	;
+
+      if (*end == '\0' && start == end)
+	{
+	  /* Handle explicit zero-length root label. */
+	  buf[0] = '\0';
+	}
+      else
+	{
+	  rc = idna_to_ascii_4i (start, end - start, buf, flags);
+	  if (rc != IDNA_SUCCESS)
+	    return rc;
+	}
+
+      if (out)
+	{
+	  out = realloc (out, strlen (out) + 1 + strlen (buf) + 1);
+	  if (!out)
+	    return IDNA_MALLOC_ERROR;
+	  strcat (out, ".");
+	  strcat (out, buf);
+	}
+      else
+	{
+	  out = (char *) malloc (strlen (buf) + 1);
+	  if (!out)
+	    return IDNA_MALLOC_ERROR;
+	  strcpy (out, buf);
+	}
+
+      start = end + 1;
+    }
+  while (*end);
+
+  *output = out;
+
+  return IDNA_SUCCESS;
+}
+
+/**
+ * idna_to_ascii_8z:
+ * @input: zero terminated input UTF-8 string.
+ * @output: pointer to newly allocated output string.
+ * @flags: IDNA flags, e.g. IDNA_ALLOW_UNASSIGNED or IDNA_USE_STD3_ASCII_RULES.
+ *
+ * Convert UTF-8 domain name to ASCII string.  The domain name may
+ * contain several labels, separated by dots.  The output buffer must
+ * be deallocated by the caller.
+ *
+ * Return value: Returns IDNA_SUCCESS on success, or error code.
+ **/
+int
+idna_to_ascii_8z (const char *input, char **output, int flags)
+{
+  uint32_t *ucs4;
+  size_t ucs4len;
+  int rc;
+
+  ucs4 = stringprep_utf8_to_ucs4 (input, -1, &ucs4len);
+  if (!ucs4)
+    return IDNA_ICONV_ERROR;
+
+  rc = idna_to_ascii_4z (ucs4, output, flags);
+
+  free (ucs4);
+
+  return rc;
+
+}
+
+/**
+ * idna_to_ascii_lz:
+ * @input: zero terminated input UTF-8 string.
+ * @output: pointer to newly allocated output string.
+ * @flags: IDNA flags, e.g. IDNA_ALLOW_UNASSIGNED or IDNA_USE_STD3_ASCII_RULES.
+ *
+ * Convert domain name in the locale's encoding to ASCII string.  The
+ * domain name may contain several labels, separated by dots.  The
+ * output buffer must be deallocated by the caller.
+ *
+ * Return value: Returns IDNA_SUCCESS on success, or error code.
+ **/
+int
+idna_to_ascii_lz (const char *input, char **output, int flags)
+{
+  char *utf8;
+  int rc;
+
+  utf8 = stringprep_locale_to_utf8 (input);
+  if (!utf8)
+    return IDNA_ICONV_ERROR;
+
+  rc = idna_to_ascii_8z (utf8, output, flags);
+
+  free (utf8);
+
+  return rc;
+}
+
+/**
+ * idna_to_unicode_4z4z:
+ * @input: zero-terminated Unicode string.
+ * @output: pointer to newly allocated output Unicode string.
+ * @flags: IDNA flags, e.g. IDNA_ALLOW_UNASSIGNED or IDNA_USE_STD3_ASCII_RULES.
+ *
+ * Convert possibly ACE encoded domain name in UCS-4 format into a
+ * UCS-4 string.  The domain name may contain several labels,
+ * separated by dots.  The output buffer must be deallocated by the
+ * caller.
+ *
+ * Return value: Returns IDNA_SUCCESS on success, or error code.
+ **/
+int
+idna_to_unicode_4z4z (const uint32_t * input, uint32_t ** output, int flags)
+{
+  const uint32_t *start = input;
+  const uint32_t *end = input;
+  uint32_t *buf;
+  size_t buflen;
+  uint32_t *out = NULL;
+  size_t outlen = 0;
+  int rc;
+
+  *output = NULL;
+
+  do
+    {
+      end = start;
+
+      for (; *end && !DOTP (*end); end++)
+	;
+
+      buflen = end - start;
+      buf = malloc (sizeof (buf[0]) * (buflen + 1));
+      if (!buf)
+	return IDNA_MALLOC_ERROR;
+
+      rc = idna_to_unicode_44i (start, end - start, buf, &buflen, flags);
+      /* don't check rc as per specification! */
+
+      if (out)
+	{
+	  out = realloc (out, sizeof (out[0]) * (outlen + 1 + buflen + 1));
+	  if (!out)
+	    return IDNA_MALLOC_ERROR;
+	  out[outlen++] = 0x002E;	/* '.' (full stop) */
+	  memcpy (out + outlen, buf, sizeof (buf[0]) * buflen);
+	  outlen += buflen;
+	  out[outlen] = 0x0;
+	  free (buf);
+	}
+      else
+	{
+	  out = buf;
+	  outlen = buflen;
+	  out[outlen] = 0x0;
+	}
+
+      start = end + 1;
+    }
+  while (*end);
+
+  *output = out;
+
+  return IDNA_SUCCESS;
+}
+
+/**
+ * idna_to_unicode_8z4z:
+ * @input: zero-terminated UTF-8 string.
+ * @output: pointer to newly allocated output Unicode string.
+ * @flags: IDNA flags, e.g. IDNA_ALLOW_UNASSIGNED or IDNA_USE_STD3_ASCII_RULES.
+ *
+ * Convert possibly ACE encoded domain name in UTF-8 format into a
+ * UCS-4 string.  The domain name may contain several labels,
+ * separated by dots.  The output buffer must be deallocated by the
+ * caller.
+ *
+ * Return value: Returns IDNA_SUCCESS on success, or error code.
+ **/
+int
+idna_to_unicode_8z4z (const char *input, uint32_t ** output, int flags)
+{
+  uint32_t *ucs4;
+  size_t ucs4len;
+  int rc;
+
+  ucs4 = stringprep_utf8_to_ucs4 (input, -1, &ucs4len);
+  if (!ucs4)
+    return IDNA_ICONV_ERROR;
+
+  rc = idna_to_unicode_4z4z (ucs4, output, flags);
+  free (ucs4);
+
+  return rc;
+}
+
+/**
+ * idna_to_unicode_8z8z:
+ * @input: zero-terminated UTF-8 string.
+ * @output: pointer to newly allocated output UTF-8 string.
+ * @flags: IDNA flags, e.g. IDNA_ALLOW_UNASSIGNED or IDNA_USE_STD3_ASCII_RULES.
+ *
+ * Convert possibly ACE encoded domain name in UTF-8 format into a
+ * UTF-8 string.  The domain name may contain several labels,
+ * separated by dots.  The output buffer must be deallocated by the
+ * caller.
+ *
+ * Return value: Returns IDNA_SUCCESS on success, or error code.
+ **/
+int
+idna_to_unicode_8z8z (const char *input, char **output, int flags)
+{
+  uint32_t *ucs4;
+  int rc;
+
+  rc = idna_to_unicode_8z4z (input, &ucs4, flags);
+  *output = stringprep_ucs4_to_utf8 (ucs4, -1, NULL, NULL);
+  free (ucs4);
+
+  if (!*output)
+    return IDNA_ICONV_ERROR;
+
+  return rc;
+}
+
+/**
+ * idna_to_unicode_8zlz:
+ * @input: zero-terminated UTF-8 string.
+ * @output: pointer to newly allocated output string encoded in the
+ *   current locale's character set.
+ * @flags: IDNA flags, e.g. IDNA_ALLOW_UNASSIGNED or IDNA_USE_STD3_ASCII_RULES.
+ *
+ * Convert possibly ACE encoded domain name in UTF-8 format into a
+ * string encoded in the current locale's character set.  The domain
+ * name may contain several labels, separated by dots.  The output
+ * buffer must be deallocated by the caller.
+ *
+ * Return value: Returns IDNA_SUCCESS on success, or error code.
+ **/
+int
+idna_to_unicode_8zlz (const char *input, char **output, int flags)
+{
+  char *utf8;
+  int rc;
+
+  rc = idna_to_unicode_8z8z (input, &utf8, flags);
+  *output = stringprep_utf8_to_locale (utf8);
+  free (utf8);
+
+  if (!*output)
+    return IDNA_ICONV_ERROR;
+
+  return rc;
+}
+
+/**
+ * idna_to_unicode_lzlz:
+ * @input: zero-terminated string encoded in the current locale's
+ *   character set.
+ * @output: pointer to newly allocated output string encoded in the
+ *   current locale's character set.
+ * @flags: IDNA flags, e.g. IDNA_ALLOW_UNASSIGNED or IDNA_USE_STD3_ASCII_RULES.
+ *
+ * Convert possibly ACE encoded domain name in the locale's character
+ * set into a string encoded in the current locale's character set.
+ * The domain name may contain several labels, separated by dots.  The
+ * output buffer must be deallocated by the caller.
+ *
+ * Return value: Returns IDNA_SUCCESS on success, or error code.
+ **/
+int
+idna_to_unicode_lzlz (const char *input, char **output, int flags)
+{
+  char *utf8;
+  int rc;
+
+  utf8 = stringprep_locale_to_utf8 (input);
+  if (!utf8)
+    return IDNA_ICONV_ERROR;
+
+  rc = idna_to_unicode_8zlz (utf8, output, flags);
+  free (utf8);
+
+  return rc;
+}
+
+/**
+ * IDNA_ACE_PREFIX
+ *
+ * The IANA allocated prefix to use for IDNA. "xn--"
+ */
+
+/**
+ * Idna_rc:
+ * @IDNA_SUCCESS: Successful operation.  This value is guaranteed to
+ *   always be zero, the remaining ones are only guaranteed to hold
+ *   non-zero values, for logical comparison purposes.
+ * @IDNA_STRINGPREP_ERROR:  Error during string preparation.
+ * @IDNA_PUNYCODE_ERROR: Error during punycode operation.
+ * @IDNA_CONTAINS_NON_LDH: For IDNA_USE_STD3_ASCII_RULES, indicate that
+ *   the string contains non-LDH ASCII characters.
+ * @IDNA_CONTAINS_MINUS: For IDNA_USE_STD3_ASCII_RULES, indicate that
+ *   the string contains a leading or trailing hyphen-minus (U+002D).
+ * @IDNA_INVALID_LENGTH: The final output string is not within the
+ *   (inclusive) range 1 to 63 characters.
+ * @IDNA_NO_ACE_PREFIX: The string does not contain the ACE prefix
+ *   (for ToUnicode).
+ * @IDNA_ROUNDTRIP_VERIFY_ERROR: The ToASCII operation on output
+ *   string does not equal the input.
+ * @IDNA_CONTAINS_ACE_PREFIX: The input contains the ACE prefix (for
+ *   ToASCII).
+ * @IDNA_ICONV_ERROR: Could not convert string in locale encoding.
+ * @IDNA_MALLOC_ERROR: Could not allocate buffer (this is typically a
+ *   fatal error).
+ *
+ * Enumerated return codes of idna_to_ascii_4i(),
+ * idna_to_unicode_44i() functions (and functions derived from those
+ * functions).  The value 0 is guaranteed to always correspond to
+ * success.
+ */
+
+
+/**
+ * Idna_flags:
+ * @IDNA_ALLOW_UNASSIGNED: Don't reject strings containing unassigned
+ *   Unicode code points.
+ * @IDNA_USE_STD3_ASCII_RULES: Validate strings according to STD3
+ *   rules (i.e., normal host name rules).
+ *
+ * Flags to pass to idna_to_ascii_4i(), idna_to_unicode_44i() etc.
+ */