/*

   +----------------------------------------------------------------------+

   | Copyright © The PHP Group and Contributors.                          |

   +----------------------------------------------------------------------+

   | This source file is subject to the Modified BSD License that is      |

   | bundled with this package in the file LICENSE, and is available      |

   | through the World Wide Web at <https://www.php.net/license/>.        |

   |                                                                      |

   | SPDX-License-Identifier: BSD-3-Clause                                |

   +----------------------------------------------------------------------+

   | Author: Kirill Maximov <kir@actimind.com>                            |

   +----------------------------------------------------------------------+

 */

#include <stdlib.h>

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

#include <string.h>

#include <errno.h>

#include "php.h"

#include "quot_print.h"

#include <stdio.h>

/*

*  Converting HEX char to INT value

*/

static char php_hex2int(int c) /* {{{ */

{

  if (isdigit(c)) {

    return c - '0';

  } else if (c >= 'A' && c <= 'F') {

    return c - 'A' + 10;

  } else {

    ZEND_ASSERT(c >= 'a' && c <= 'f');

    return c - 'a' + 10;

  }

}

/* }}} */

PHPAPI zend_string *php_quot_print_decode(const unsigned char *str, size_t length, int replace_us_by_ws) /* {{{ */

{

  size_t i;

  unsigned const char *p1;

  unsigned char *p2;

  unsigned int h_nbl, l_nbl;

  size_t decoded_len, buf_size;

  zend_string *retval;

  static unsigned int hexval_tbl[256] = {

    64, 64, 64, 64, 64, 64, 64, 64, 64, 32, 16, 64, 64, 16, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    32, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

     0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 64, 64, 64, 64, 64, 64,

    64, 10, 11, 12, 13, 14, 15, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 10, 11, 12, 13, 14, 15, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,

    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64

  };

  if (replace_us_by_ws) {

    replace_us_by_ws = '_';

  }

  i = length, p1 = str; buf_size = length;

  while (i > 1 && *p1 != '\0') {

    if (*p1 == '=') {

      buf_size -= 2;

      p1++;

      i--;

    }

    p1++;

    i--;

  }

  retval = zend_string_alloc(buf_size, 0);

  i = length; p1 = str; p2 = (unsigned char*)ZSTR_VAL(retval);

  decoded_len = 0;

  while (i > 0 && *p1 != '\0') {

    if (*p1 == '=') {

      i--, p1++;

      if (i == 0 || *p1 == '\0') {

        break;

      }

      h_nbl = hexval_tbl[*p1];

      if (h_nbl < 16) {

        /* next char should be a hexadecimal digit */

        if ((--i) == 0 || (l_nbl = hexval_tbl[*(++p1)]) >= 16) {

          efree(retval);

          return NULL;

        }

        *(p2++) = (h_nbl << 4) | l_nbl, decoded_len++;

        i--, p1++;

      } else if (h_nbl < 64) {

        /* soft line break */

        while (h_nbl == 32) {

          if (--i == 0 || (h_nbl = hexval_tbl[*(++p1)]) == 64) {

            efree(retval);

            return NULL;

          }

        }

        if (p1[0] == '\r' && i >= 2 && p1[1] == '\n') {

          i--, p1++;

        }

        i--, p1++;

      } else {

        efree(retval);

        return NULL;

      }

    } else {

      *(p2++) = (replace_us_by_ws == *p1 ? '\x20': *p1);

      i--, p1++, decoded_len++;

    }

  }

  *p2 = '\0';

  ZSTR_LEN(retval) = decoded_len;

  return retval;

}

/* }}} */

#define PHP_QPRINT_MAXL 75

PHPAPI zend_string *php_quot_print_encode(const unsigned char *str, size_t length) /* {{{ */

{

  zend_ulong lp = 0;

  unsigned char c, *d;

  const char *hex = "0123456789ABCDEF";

  zend_string *ret;

  ret = zend_string_safe_alloc(3, (length + (((3 * length)/(PHP_QPRINT_MAXL-9)) + 1)), 0, 0);

  d = (unsigned char*)ZSTR_VAL(ret);

  while (length--) {

    if (((c = *str++) == '\015') && (*str == '\012') && length > 0) {

      *d++ = '\015';

      *d++ = *str++;

      length--;

      lp = 0;

    } else {

      if (iscntrl (c) || (c == 0x7f) || (c & 0x80) || (c == '=') || ((c == ' ') && (*str == '\015'))) {

        if ((((lp+= 3) > PHP_QPRINT_MAXL) && (c <= 0x7f))

            || ((c > 0x7f) && (c <= 0xdf) && ((lp + 3) > PHP_QPRINT_MAXL))

            || ((c > 0xdf) && (c <= 0xef) && ((lp + 6) > PHP_QPRINT_MAXL))

            || ((c > 0xef) && (c <= 0xf4) && ((lp + 9) > PHP_QPRINT_MAXL))) {

          *d++ = '=';

          *d++ = '\015';

          *d++ = '\012';

          lp = 3;

        }

        *d++ = '=';

        *d++ = hex[c >> 4];

        *d++ = hex[c & 0xf];

      } else {

        if ((++lp) > PHP_QPRINT_MAXL) {

          *d++ = '=';

          *d++ = '\015';

          *d++ = '\012';

          lp = 1;

        }

        *d++ = c;

      }

    }

  }

  *d = '\0';

  ret = zend_string_truncate(ret, d - (unsigned char*)ZSTR_VAL(ret), 0);

  return ret;

}

/* }}} */

/*

*

* Decoding  Quoted-printable string.

*

*/

/* {{{ Convert a quoted-printable string to an 8 bit string */

PHP_FUNCTION(quoted_printable_decode)

{

  zend_string *arg1;

  char *str_in;

  zend_string *str_out;

  size_t i = 0, j = 0, k;

  ZEND_PARSE_PARAMETERS_START(1, 1)

    Z_PARAM_STR(arg1)

  ZEND_PARSE_PARAMETERS_END();

  if (ZSTR_LEN(arg1) == 0) {

    /* shortcut */

    RETURN_EMPTY_STRING();

  }

  str_in = ZSTR_VAL(arg1);

  str_out = zend_string_alloc(ZSTR_LEN(arg1), 0);

  while (str_in[i]) {

    switch (str_in[i]) {

    case '=':

      if (str_in[i + 1] && str_in[i + 2] &&

        isxdigit((unsigned char)str_in[i + 1]) &&

        isxdigit((unsigned char)str_in[i + 2]))

      {

        ZSTR_VAL(str_out)[j++] = (php_hex2int((unsigned char)str_in[i + 1]) << 4)

            + php_hex2int((unsigned char)str_in[i + 2]);

        i += 3;

      } else  /* check for soft line break according to RFC 2045*/ {

        k = 1;

        while (str_in[i + k] && ((str_in[i + k] == 32) || (str_in[i + k] == 9))) {

          /* Possibly, skip spaces/tabs at the end of line */

          k++;

        }

        if (!str_in[i + k]) {

          /* End of line reached */

          i += k;

        }

        else if ((str_in[i + k] == 13) && (str_in[i + k + 1] == 10)) {

          /* CRLF */

          i += k + 2;

        }

        else if ((str_in[i + k] == 13) || (str_in[i + k] == 10)) {

          /* CR or LF */

          i += k + 1;

        }

        else {

          ZSTR_VAL(str_out)[j++] = str_in[i++];

        }

      }

      break;

    default:

      ZSTR_VAL(str_out)[j++] = str_in[i++];

    }

  }

  ZSTR_VAL(str_out)[j] = '\0';

  ZSTR_LEN(str_out) = j;

  RETVAL_NEW_STR(str_out);

}

/* }}} */

/* {{{ */

PHP_FUNCTION(quoted_printable_encode)

{

  zend_string *str;

  zend_string *new_str;

  ZEND_PARSE_PARAMETERS_START(1, 1)

    Z_PARAM_STR(str)

  ZEND_PARSE_PARAMETERS_END();

  if (!ZSTR_LEN(str)) {

    RETURN_EMPTY_STRING();

  }

  new_str = php_quot_print_encode((unsigned char *)ZSTR_VAL(str), ZSTR_LEN(str));

  RETURN_STR(new_str);

}

/* }}} */