/*

 * Transcoding support for CUPS.

 *

 * Copyright © 2020-2024 by OpenPrinting.

 * Copyright 2007-2014 by Apple Inc.

 * Copyright 1997-2007 by Easy Software Products.

 *

 * Licensed under Apache License v2.0.  See the file "LICENSE" for more information.

 */

/*

 * Include necessary headers...

 */

#include "cups-private.h"

#include "debug-internal.h"

#include <limits.h>

#include <time.h>

#ifdef HAVE_ICONV_H

#  include <iconv.h>

#endif /* HAVE_ICONV_H */

/*

 * Local globals...

 */

#ifdef HAVE_ICONV_H

static cups_mutex_t map_mutex = CUPS_MUTEX_INITIALIZER;

          /* Mutex to control access to maps */

static iconv_t    map_from_utf8 = (iconv_t)-1;

          /* Convert from UTF-8 to charset */

static iconv_t    map_to_utf8 = (iconv_t)-1;

          /* Convert from charset to UTF-8 */

static cups_encoding_t  map_encoding = CUPS_AUTO_ENCODING;

          /* Which charset is cached */

#endif /* HAVE_ICONV_H */

/*

 * '_cupsCharmapFlush()' - Flush all character set maps out of cache.

 */

void

_cupsCharmapFlush(void)

{

#ifdef HAVE_ICONV_H

  if (map_from_utf8 != (iconv_t)-1)

  {

    iconv_close(map_from_utf8);

    map_from_utf8 = (iconv_t)-1;

  }

  if (map_to_utf8 != (iconv_t)-1)

  {

    iconv_close(map_to_utf8);

    map_to_utf8 = (iconv_t)-1;

  }

  map_encoding = CUPS_AUTO_ENCODING;

#endif /* HAVE_ICONV_H */

}

/*

 * 'cupsCharsetToUTF8()' - Convert legacy character set to UTF-8.

 */

int         /* O - Count or -1 on error */

cupsCharsetToUTF8(

    cups_utf8_t           *dest,  /* O - Target string */

    const char            *src,   /* I - Source string */

    const int             maxout, /* I - Max output */

    const cups_encoding_t encoding) /* I - Encoding */

{

  cups_utf8_t *destptr;   /* Pointer into UTF-8 buffer */

#ifdef HAVE_ICONV_H

  size_t  srclen,     /* Length of source string */

    outBytesLeft;   /* Bytes remaining in output buffer */

#endif /* HAVE_ICONV_H */

 /*

  * Check for valid arguments...

  */

  DEBUG_printf("2cupsCharsetToUTF8(dest=%p, src=\"%s\", maxout=%d, encoding=%d)", (void *)dest, src, maxout, encoding);

  if (!dest || !src || maxout < 1)

  {

    if (dest)

      *dest = '\0';

    DEBUG_puts("3cupsCharsetToUTF8: Bad arguments, returning -1");

    return (-1);

  }

 /*

  * Handle identity conversions...

  */

  if (encoding == CUPS_UTF8 || encoding <= CUPS_US_ASCII ||

      encoding >= CUPS_ENCODING_VBCS_END)

  {

    cupsCopyString((char *)dest, src, (size_t)maxout);

    return ((int)strlen((char *)dest));

  }

 /*

  * Handle ISO-8859-1 to UTF-8 directly...

  */

  destptr = dest;

  if (encoding == CUPS_ISO8859_1)

  {

    int   ch;     /* Character from string */

    cups_utf8_t *destend;   /* End of UTF-8 buffer */

    destend = dest + maxout - 2;

    while (*src && destptr < destend)

    {

      ch = *src++ & 255;

      if (ch & 128)

      {

  *destptr++ = (cups_utf8_t)(0xc0 | (ch >> 6));

  *destptr++ = (cups_utf8_t)(0x80 | (ch & 0x3f));

      }

      else

  *destptr++ = (cups_utf8_t)ch;

    }

    *destptr = '\0';

    return ((int)(destptr - dest));

  }

 /*

  * Convert input legacy charset to UTF-8...

  */

#ifdef HAVE_ICONV_H

  cupsMutexLock(&map_mutex);

  if (map_encoding != encoding)

  {

    char  toset[1024];    /* Destination character set */

    _cupsCharmapFlush();

    snprintf(toset, sizeof(toset), "%s//IGNORE", _cupsEncodingName(encoding));

    map_encoding  = encoding;

    map_from_utf8 = iconv_open(_cupsEncodingName(encoding), "UTF-8");

    map_to_utf8   = iconv_open("UTF-8", toset);

  }

  if (map_to_utf8 != (iconv_t)-1)

  {

    char *altdestptr = (char *)dest;  /* Silence bogus GCC type-punned */

    srclen       = strlen(src);

    outBytesLeft = (size_t)maxout - 1;

    iconv(map_to_utf8, (char **)&src, &srclen, &altdestptr, &outBytesLeft);

    *altdestptr = '\0';

    cupsMutexUnlock(&map_mutex);

    return ((int)(altdestptr - (char *)dest));

  }

  cupsMutexUnlock(&map_mutex);

#endif /* HAVE_ICONV_H */

 /*

  * No iconv() support, so error out...

  */

  *destptr = '\0';

  return (-1);

}

/*

 * 'cupsUTF8ToCharset()' - Convert UTF-8 to legacy character set.

 */

int         /* O - Count or -1 on error */

cupsUTF8ToCharset(

    char      *dest,  /* O - Target string */

    const cups_utf8_t   *src,   /* I - Source string */

    const int     maxout, /* I - Max output */

    const cups_encoding_t encoding) /* I - Encoding */

{

  char    *destptr;   /* Pointer into destination */

#ifdef HAVE_ICONV_H

  size_t  srclen,     /* Length of source string */

    outBytesLeft;   /* Bytes remaining in output buffer */

#endif /* HAVE_ICONV_H */

 /*

  * Check for valid arguments...

  */

  if (!dest || !src || maxout < 1)

  {

    if (dest)

      *dest = '\0';

    return (-1);

  }

 /*

  * Handle identity conversions...

  */

  if (encoding == CUPS_UTF8 ||

      encoding >= CUPS_ENCODING_VBCS_END)

  {

    cupsCopyString(dest, (char *)src, (size_t)maxout);

    return ((int)strlen(dest));

  }

 /*

  * Handle UTF-8 to ISO-8859-1 directly...

  */

  destptr = dest;

  if (encoding == CUPS_ISO8859_1 || encoding <= CUPS_US_ASCII)

  {

    int   ch,     /* Character from string */

    maxch;      /* Maximum character for charset */

    char  *destend;   /* End of ISO-8859-1 buffer */

    maxch   = encoding == CUPS_ISO8859_1 ? 256 : 128;

    destend = dest + maxout - 1;

    while (*src && destptr < destend)

    {

      ch = *src++;

      if ((ch & 0xe0) == 0xc0)

      {

  ch = ((ch & 0x1f) << 6) | (*src++ & 0x3f);

  if (ch < maxch)

          *destptr++ = (char)ch;

  else

          *destptr++ = '?';

      }

      else if ((ch & 0xf0) == 0xe0 ||

               (ch & 0xf8) == 0xf0)

        *destptr++ = '?';

      else if (!(ch & 0x80))

  *destptr++ = (char)ch;

    }

    *destptr = '\0';

    return ((int)(destptr - dest));

  }

#ifdef HAVE_ICONV_H

 /*

  * Convert input UTF-8 to legacy charset...

  */

  cupsMutexLock(&map_mutex);

  if (map_encoding != encoding)

  {

    char  toset[1024];    /* Destination character set */

    _cupsCharmapFlush();

    snprintf(toset, sizeof(toset), "%s//IGNORE", _cupsEncodingName(encoding));

    map_encoding  = encoding;

    map_from_utf8 = iconv_open(_cupsEncodingName(encoding), "UTF-8");

    map_to_utf8   = iconv_open("UTF-8", toset);

  }

  if (map_from_utf8 != (iconv_t)-1)

  {

    char *altsrc = (char *)src;   /* Silence bogus GCC type-punned */

    srclen       = strlen((char *)src);

    outBytesLeft = (size_t)maxout - 1;

    iconv(map_from_utf8, &altsrc, &srclen, &destptr, &outBytesLeft);

    *destptr = '\0';

    cupsMutexUnlock(&map_mutex);

    return ((int)(destptr - dest));

  }

  cupsMutexUnlock(&map_mutex);

#endif /* HAVE_ICONV_H */

 /*

  * No iconv() support, so error out...

  */

  *destptr = '\0';

  return (-1);

}

/*

 * 'cupsUTF8ToUTF32()' - Convert UTF-8 to UTF-32.

 *

 * 32-bit UTF-32 (actually 21-bit) maps to UTF-8 as follows...

 *

 *   UTF-32 char     UTF-8 char(s)

 *   --------------------------------------------------

 *    0 to 127 = 0xxxxxxx (US-ASCII)

 *     128 to 2047 = 110xxxxx 10yyyyyy

 *   2048 to 65535 = 1110xxxx 10yyyyyy 10zzzzzz

 *     > 65535 = 11110xxx 10yyyyyy 10zzzzzz 10xxxxxx

 *

 * UTF-32 prohibits chars beyond Plane 16 (> 0x10ffff) in UCS-4,

 * which would convert to five- or six-octet UTF-8 sequences...

 */

int         /* O - Count or -1 on error */

cupsUTF8ToUTF32(

    cups_utf32_t      *dest,    /* O - Target string */

    const cups_utf8_t *src,   /* I - Source string */

    const int         maxout)   /* I - Max output */

{

  int   i;      /* Looping variable */

  cups_utf8_t ch;     /* Character value */

  cups_utf8_t next;     /* Next character value */

  cups_utf32_t  ch32;     /* UTF-32 character value */

 /*

  * Check for valid arguments and clear output...

  */

  DEBUG_printf("2cupsUTF8ToUTF32(dest=%p, src=\"%s\", maxout=%d)", (void *)dest, src, maxout);

  if (dest)

    *dest = 0;

  if (!dest || !src || maxout < 1 || maxout > CUPS_MAX_USTRING)

  {

    DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad arguments)");

    return (-1);

  }

 /*

  * Convert input UTF-8 to output UTF-32...

  */

  for (i = maxout - 1; *src && i > 0; i --)

  {

    ch = *src++;

   /*

    * Convert UTF-8 character(s) to UTF-32 character...

    */

    if (!(ch & 0x80))

    {

     /*

      * One-octet UTF-8 <= 127 (US-ASCII)...

      */

      *dest++ = ch;

      DEBUG_printf("4cupsUTF8ToUTF32: %02x => %08X", src[-1], ch);

      continue;

    }

    else if ((ch & 0xe0) == 0xc0)

    {

     /*

      * Two-octet UTF-8 <= 2047 (Latin-x)...

      */

      next = *src++;

      if ((next & 0xc0) != 0x80)

      {

        DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad UTF-8 sequence)");

  return (-1);

      }

      ch32 = (cups_utf32_t)((ch & 0x1f) << 6) | (cups_utf32_t)(next & 0x3f);

     /*

      * Check for non-shortest form (invalid UTF-8)...

      */

      if (ch32 < 0x80)

      {

        DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad UTF-8 sequence)");

  return (-1);

      }

      *dest++ = ch32;

      DEBUG_printf("4cupsUTF8ToUTF32: %02x %02x => %08X", src[-2], src[-1], (unsigned)ch32);

    }

    else if ((ch & 0xf0) == 0xe0)

    {

     /*

      * Three-octet UTF-8 <= 65535 (Plane 0 - BMP)...

      */

      next = *src++;

      if ((next & 0xc0) != 0x80)

      {

        DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad UTF-8 sequence)");

  return (-1);

      }

      ch32 = (cups_utf32_t)((ch & 0x0f) << 6) | (cups_utf32_t)(next & 0x3f);

      next = *src++;

      if ((next & 0xc0) != 0x80)

      {

        DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad UTF-8 sequence)");

  return (-1);

      }

      ch32 = (ch32 << 6) | (cups_utf32_t)(next & 0x3f);

     /*

      * Check for non-shortest form (invalid UTF-8)...

      */

      if (ch32 < 0x800)

      {

        DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad UTF-8 sequence)");

  return (-1);

      }

      *dest++ = ch32;

      DEBUG_printf("4cupsUTF8ToUTF32: %02x %02x %02x => %08X", src[-3], src[-2], src[-1], (unsigned)ch32);

    }

    else if ((ch & 0xf8) == 0xf0)

    {

     /*

      * Four-octet UTF-8...

      */

      next = *src++;

      if ((next & 0xc0) != 0x80)

      {

        DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad UTF-8 sequence)");

  return (-1);

      }

      ch32 = (cups_utf32_t)((ch & 0x07) << 6) | (cups_utf32_t)(next & 0x3f);

      next = *src++;

      if ((next & 0xc0) != 0x80)

      {

        DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad UTF-8 sequence)");

  return (-1);

      }

      ch32 = (ch32 << 6) | (cups_utf32_t)(next & 0x3f);

      next = *src++;

      if ((next & 0xc0) != 0x80)

      {

        DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad UTF-8 sequence)");

  return (-1);

      }

      ch32 = (ch32 << 6) | (cups_utf32_t)(next & 0x3f);

     /*

      * Check for non-shortest form (invalid UTF-8)...

      */

      if (ch32 < 0x10000)

      {

        DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad UTF-8 sequence)");

  return (-1);

      }

      *dest++ = ch32;

      DEBUG_printf("4cupsUTF8ToUTF32: %02x %02x %02x %02x => %08X", src[-4], src[-3], src[-2], src[-1], (unsigned)ch32);

    }

    else

    {

     /*

      * More than 4-octet (invalid UTF-8 sequence)...

      */

      DEBUG_puts("3cupsUTF8ToUTF32: Returning -1 (bad UTF-8 sequence)");

      return (-1);

    }

   /*

    * Check for UTF-16 surrogate (illegal UTF-8)...

    */

    if (ch32 >= 0xd800 && ch32 <= 0xdfff)

      return (-1);

  }

  *dest = 0;

  DEBUG_printf("3cupsUTF8ToUTF32: Returning %d characters", maxout - 1 - i);

  return (maxout - 1 - i);

}

/*

 * 'cupsUTF32ToUTF8()' - Convert UTF-32 to UTF-8.

 *

 * 32-bit UTF-32 (actually 21-bit) maps to UTF-8 as follows...

 *

 *   UTF-32 char     UTF-8 char(s)

 *   --------------------------------------------------

 *    0 to 127 = 0xxxxxxx (US-ASCII)

 *     128 to 2047 = 110xxxxx 10yyyyyy

 *   2048 to 65535 = 1110xxxx 10yyyyyy 10zzzzzz

 *     > 65535 = 11110xxx 10yyyyyy 10zzzzzz 10xxxxxx

 *

 * UTF-32 prohibits chars beyond Plane 16 (> 0x10ffff) in UCS-4,

 * which would convert to five- or six-octet UTF-8 sequences...

 */

int         /* O - Count or -1 on error */

cupsUTF32ToUTF8(

    cups_utf8_t        *dest,   /* O - Target string */

    const cups_utf32_t *src,    /* I - Source string */

    const int          maxout)    /* I - Max output */

{

  cups_utf8_t *start;     /* Start of destination string */

  int   i;      /* Looping variable */

  int   swap;     /* Byte-swap input to output */

  cups_utf32_t  ch;     /* Character value */

 /*

  * Check for valid arguments and clear output...

  */

  DEBUG_printf("2cupsUTF32ToUTF8(dest=%p, src=%p, maxout=%d)", (void *)dest, (void *)src, maxout);

  if (dest)

    *dest = '\0';

  if (!dest || !src || maxout < 1)

  {

    DEBUG_puts("3cupsUTF32ToUTF8: Returning -1 (bad args)");

    return (-1);

  }

 /*

  * Check for leading BOM in UTF-32 and inverted BOM...

  */

  start = dest;

  swap  = *src == 0xfffe0000;

  DEBUG_printf("4cupsUTF32ToUTF8: swap=%d", swap);

  if (*src == 0xfffe0000 || *src == 0xfeff)

    src ++;

 /*

  * Convert input UTF-32 to output UTF-8...

  */

  for (i = maxout - 1; *src && i > 0;)

  {

    ch = *src++;

   /*

    * Byte swap input UTF-32, if necessary...

    * (only byte-swapping 24 of 32 bits)

    */

    if (swap)

      ch = ((ch >> 24) | ((ch >> 8) & 0xff00) | ((ch << 8) & 0xff0000));

   /*

    * Check for beyond Plane 16 (invalid UTF-32)...

    */

    if (ch > 0x10ffff)

    {

      DEBUG_puts("3cupsUTF32ToUTF8: Returning -1 (character out of range)");

      return (-1);

    }

   /*

    * Convert UTF-32 character to UTF-8 character(s)...

    */

    if (ch < 0x80)

    {

     /*

      * One-octet UTF-8 <= 127 (US-ASCII)...

      */

      *dest++ = (cups_utf8_t)ch;

      i --;

      DEBUG_printf("4cupsUTF32ToUTF8: %08x => %02x", (unsigned)ch, dest[-1]);

    }

    else if (ch < 0x800)

    {

     /*

      * Two-octet UTF-8 <= 2047 (Latin-x)...

      */

      if (i < 2)

      {

        DEBUG_puts("3cupsUTF32ToUTF8: Returning -1 (too long 2)");

        return (-1);

      }

      *dest++ = (cups_utf8_t)(0xc0 | ((ch >> 6) & 0x1f));

      *dest++ = (cups_utf8_t)(0x80 | (ch & 0x3f));

      i -= 2;

      DEBUG_printf("4cupsUTF32ToUTF8: %08x => %02x %02x", (unsigned)ch, dest[-2], dest[-1]);

    }

    else if (ch < 0x10000)

    {

     /*

      * Three-octet UTF-8 <= 65535 (Plane 0 - BMP)...

      */

      if (i < 3)

      {

        DEBUG_puts("3cupsUTF32ToUTF8: Returning -1 (too long 3)");

        return (-1);

      }

      *dest++ = (cups_utf8_t)(0xe0 | ((ch >> 12) & 0x0f));

      *dest++ = (cups_utf8_t)(0x80 | ((ch >> 6) & 0x3f));

      *dest++ = (cups_utf8_t)(0x80 | (ch & 0x3f));

      i -= 3;

      DEBUG_printf("4cupsUTF32ToUTF8: %08x => %02x %02x %02x", (unsigned)ch, dest[-3], dest[-2], dest[-1]);

    }

    else

    {

     /*

      * Four-octet UTF-8...

      */

      if (i < 4)

      {

        DEBUG_puts("3cupsUTF32ToUTF8: Returning -1 (too long 4)");

        return (-1);

      }

      *dest++ = (cups_utf8_t)(0xf0 | ((ch >> 18) & 0x07));

      *dest++ = (cups_utf8_t)(0x80 | ((ch >> 12) & 0x3f));

      *dest++ = (cups_utf8_t)(0x80 | ((ch >> 6) & 0x3f));

      *dest++ = (cups_utf8_t)(0x80 | (ch & 0x3f));

      i -= 4;

      DEBUG_printf("4cupsUTF32ToUTF8: %08x => %02x %02x %02x %02x", (unsigned)ch, dest[-4], dest[-3], dest[-2], dest[-1]);

    }

  }

  *dest = '\0';

  DEBUG_printf("3cupsUTF32ToUTF8: Returning %d", (int)(dest - start));

  return ((int)(dest - start));

}