/*

 * Copyright (C) 2011 Collabora Ltd.

 * Copyright (C) 2013 Red Hat Inc.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 *     * Redistributions of source code must retain the above

 *       copyright notice, this list of conditions and the

 *       following disclaimer.

 *     * Redistributions in binary form must reproduce the

 *       above copyright notice, this list of conditions and

 *       the following disclaimer in the documentation and/or

 *       other materials provided with the distribution.

 *     * The names of contributors to this software may not be

 *       used to endorse or promote products derived from this

 *       software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE

 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,

 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS

 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF

 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * Author: Stef Walter <stefw@collabora.co.uk>

 */

#include "config.h"

#include "debug.h"

#include "url.h"

#include <assert.h>

#include <ctype.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

const static char HEX_CHARS_UPPER[] = "0123456789ABCDEF";

const static char HEX_CHARS_LOWER[] = "0123456789abcdef";

unsigned char *

p11_url_decode (const char *value,

                const char *end,

                const char *skip,

                size_t *length)

{

  char *a, *b;

  unsigned char *result, *p;

  assert (value <= end);

  assert (skip != NULL);

  /* String can only get shorter */

  result = malloc ((end - value) + 1);

  return_val_if_fail (result != NULL, NULL);

  /* Now loop through looking for escapes */

  p = result;

  while (value != end) {

    /*

     * A percent sign followed by two hex digits means

     * that the digits represent an escaped character.

     */

    if (*value == '%') {

      value++;

      if (end - value < 2) {

        free (result);

        return NULL;

      }

      a = strchr (HEX_CHARS_UPPER, p11_ascii_toupper (value[0]));

      b = strchr (HEX_CHARS_UPPER, p11_ascii_toupper (value[1]));

      if (!a || !b) {

        free (result);

        return NULL;

      }

      *p = (a - HEX_CHARS_UPPER) << 4;

      *(p++) |= (b - HEX_CHARS_UPPER);

      value += 2;

    /* Ignore whitespace characters */

    } else if (strchr (skip, *value)) {

      value++;

    /* A different character */

    } else {

      *(p++) = *(value++);

    }

  }

  /* Null terminate string, in case its a string */

  *p = 0;

  if (length)

    *length = p - result;

  return result;

}

void

p11_url_encode (const unsigned char *value,

                const unsigned char *end,

                const char *verbatim,

                p11_buffer *buf)

{

  char hex[3];

  const char *env;

  const char *hex_chars;

  assert (value <= end);

  /* Opt to output lowercase hex-digits for compatibility */

  env = secure_getenv ("P11_KIT_URI_LOWERCASE");

  if (env && *env != '\0')

    hex_chars = HEX_CHARS_LOWER;

  else

    hex_chars = HEX_CHARS_UPPER;

  /* Now loop through looking for escapes */

  while (value != end) {

    /* These characters we let through verbatim */

    if (*value && strchr (verbatim, *value) != NULL) {

      p11_buffer_add (buf, value, 1);

    /* All others get encoded */

    } else {

      hex[0] = '%';

      hex[1] = hex_chars[((unsigned char)*value) >> 4];

      hex[2] = hex_chars[((unsigned char)*value) & 0x0F];

      p11_buffer_add (buf, hex, 3);

    }

    ++value;

  }

}