/***************************************************************************

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms

 * are also available at https://curl.se/docs/copyright.html.

 *

 * You may opt to use, copy, modify, merge, publish, distribute and/or sell

 * copies of the Software, and permit persons to whom the Software is

 * furnished to do so, under the terms of the COPYING file.

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY

 * KIND, either express or implied.

 *

 * SPDX-License-Identifier: curl

 *

 ***************************************************************************/

 /*

  * IDN conversions

  */

#include "curl_setup.h"

#include "urldata.h"

#include "idn.h"

#include "sendf.h"

#include "curl_multibyte.h"

#include "warnless.h"

#ifdef USE_LIBIDN2

#include <idn2.h>

#if defined(_WIN32) && defined(UNICODE)

#define IDN2_LOOKUP(name, host, flags)                                  \

  idn2_lookup_u8((const uint8_t *)name, (uint8_t **)host, flags)

#else

#define IDN2_LOOKUP(name, host, flags)                          \

  idn2_lookup_ul((const char *)name, (char **)host, flags)

#endif

#endif  /* USE_LIBIDN2 */

/* The last 3 #include files should be in this order */

#include "curl_printf.h"

#include "curl_memory.h"

#include "memdebug.h"

#ifdef USE_WIN32_IDN

/* using Windows kernel32 and normaliz libraries. */

#if !defined(_WIN32_WINNT) || _WIN32_WINNT < 0x600

WINBASEAPI int WINAPI IdnToAscii(DWORD dwFlags,

                                 const WCHAR *lpUnicodeCharStr,

                                 int cchUnicodeChar,

                                 WCHAR *lpASCIICharStr,

                                 int cchASCIIChar);

WINBASEAPI int WINAPI IdnToUnicode(DWORD dwFlags,

                                   const WCHAR *lpASCIICharStr,

                                   int cchASCIIChar,

                                   WCHAR *lpUnicodeCharStr,

                                   int cchUnicodeChar);

#endif

#define IDN_MAX_LENGTH 255

static CURLcode win32_idn_to_ascii(const char *in, char **out)

{

  wchar_t *in_w = curlx_convert_UTF8_to_wchar(in);

  *out = NULL;

  if(in_w) {

    wchar_t punycode[IDN_MAX_LENGTH];

    int chars = IdnToAscii(0, in_w, (int)(wcslen(in_w) + 1), punycode,

                           IDN_MAX_LENGTH);

    curlx_unicodefree(in_w);

    if(chars) {

      char *mstr = curlx_convert_wchar_to_UTF8(punycode);

      if(mstr) {

        *out = strdup(mstr);

        curlx_unicodefree(mstr);

        if(!*out)

          return CURLE_OUT_OF_MEMORY;

      }

      else

        return CURLE_OUT_OF_MEMORY;

    }

    else

      return CURLE_URL_MALFORMAT;

  }

  else

    return CURLE_URL_MALFORMAT;

  return CURLE_OK;

}

static CURLcode win32_ascii_to_idn(const char *in, char **output)

{

  char *out = NULL;

  wchar_t *in_w = curlx_convert_UTF8_to_wchar(in);

  if(in_w) {

    WCHAR idn[IDN_MAX_LENGTH]; /* stores a UTF-16 string */

    int chars = IdnToUnicode(0, in_w, (int)(wcslen(in_w) + 1), idn,

                             IDN_MAX_LENGTH);

    if(chars) {

      /* 'chars' is "the number of characters retrieved" */

      char *mstr = curlx_convert_wchar_to_UTF8(idn);

      if(mstr) {

        out = strdup(mstr);

        curlx_unicodefree(mstr);

        if(!out)

          return CURLE_OUT_OF_MEMORY;

      }

    }

    else

      return CURLE_URL_MALFORMAT;

  }

  else

    return CURLE_URL_MALFORMAT;

  *output = out;

  return CURLE_OK;

}

#endif /* USE_WIN32_IDN */

/*

 * Helpers for IDNA conversions.

 */

bool Curl_is_ASCII_name(const char *hostname)

{

  /* get an UNSIGNED local version of the pointer */

  const unsigned char *ch = (const unsigned char *)hostname;

  if(!hostname) /* bad input, consider it ASCII! */

    return TRUE;

  while(*ch) {

    if(*ch++ & 0x80)

      return FALSE;

  }

  return TRUE;

}

#ifdef USE_IDN

/*

 * Curl_idn_decode() returns an allocated IDN decoded string if it was

 * possible. NULL on error.

 *

 * CURLE_URL_MALFORMAT - the host name could not be converted

 * CURLE_OUT_OF_MEMORY - memory problem

 *

 */

static CURLcode idn_decode(const char *input, char **output)

{

  char *decoded = NULL;

  CURLcode result = CURLE_OK;

#ifdef USE_LIBIDN2

  if(idn2_check_version(IDN2_VERSION)) {

    int flags = IDN2_NFC_INPUT

#if IDN2_VERSION_NUMBER >= 0x00140000

      /* IDN2_NFC_INPUT: Normalize input string using normalization form C.

         IDN2_NONTRANSITIONAL: Perform Unicode TR46 non-transitional

         processing. */

      | IDN2_NONTRANSITIONAL

#endif

      ;

    int rc = IDN2_LOOKUP(input, &decoded, flags);

    if(rc != IDN2_OK)

      /* fallback to TR46 Transitional mode for better IDNA2003

         compatibility */

      rc = IDN2_LOOKUP(input, &decoded, IDN2_TRANSITIONAL);

    if(rc != IDN2_OK)

      result = CURLE_URL_MALFORMAT;

  }

  else

    /* a too old libidn2 version */

    result = CURLE_NOT_BUILT_IN;

#elif defined(USE_WIN32_IDN)

  result = win32_idn_to_ascii(input, &decoded);

#endif

  if(!result)

    *output = decoded;

  return result;

}

static CURLcode idn_encode(const char *puny, char **output)

{

  char *enc = NULL;

#ifdef USE_LIBIDN2

  int rc = idn2_to_unicode_8z8z(puny, &enc, 0);

  if(rc != IDNA_SUCCESS)

    return rc == IDNA_MALLOC_ERROR ? CURLE_OUT_OF_MEMORY : CURLE_URL_MALFORMAT;

#elif defined(USE_WIN32_IDN)

  CURLcode result = win32_ascii_to_idn(puny, &enc);

  if(result)

    return result;

#endif

  *output = enc;

  return CURLE_OK;

}

CURLcode Curl_idn_decode(const char *input, char **output)

{

  char *d = NULL;

  CURLcode result = idn_decode(input, &d);

#ifdef USE_LIBIDN2

  if(!result) {

    char *c = strdup(d);

    idn2_free(d);

    if(c)

      d = c;

    else

      result = CURLE_OUT_OF_MEMORY;

  }

#endif

  if(!result)

    *output = d;

  return result;

}

CURLcode Curl_idn_encode(const char *puny, char **output)

{

  char *d = NULL;

  CURLcode result = idn_encode(puny, &d);

#ifdef USE_LIBIDN2

  if(!result) {

    char *c = strdup(d);

    idn2_free(d);

    if(c)

      d = c;

    else

      result = CURLE_OUT_OF_MEMORY;

  }

#endif

  if(!result)

    *output = d;

  return result;

}

/*

 * Frees data allocated by idnconvert_hostname()

 */

void Curl_free_idnconverted_hostname(struct hostname *host)

{

  if(host->encalloc) {

    /* must be freed with idn2_free() if allocated by libidn */

    Curl_idn_free(host->encalloc);

    host->encalloc = NULL;

  }

}

#endif /* USE_IDN */

/*

 * Perform any necessary IDN conversion of hostname

 */

CURLcode Curl_idnconvert_hostname(struct hostname *host)

{

  /* set the name we use to display the host name */

  host->dispname = host->name;

#ifdef USE_IDN

  /* Check name for non-ASCII and convert hostname if we can */

  if(!Curl_is_ASCII_name(host->name)) {

    char *decoded;

    CURLcode result = idn_decode(host->name, &decoded);

    if(!result) {

      if(!*decoded) {

        /* zero length is a bad host name */

        Curl_idn_free(decoded);

        return CURLE_URL_MALFORMAT;

      }

      /* successful */

      host->encalloc = decoded;

      /* change the name pointer to point to the encoded hostname */

      host->name = host->encalloc;

    }

    else

      return result;

  }

#endif

  return CURLE_OK;

}