/*

 * Copyright (c) 2012 Tim Ruehsen

 * Copyright (c) 2015-2024 Free Software Foundation, Inc.

 *

 * This file is part of libwget.

 *

 * Libwget 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 3 of the License, or

 * (at your option) any later version.

 *

 * Libwget 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 libwget.  If not, see <https://www.gnu.org/licenses/>.

 *

 *

 * Cookie parsing routines

 *

 * Changelog

 * 23.10.2012  Tim Ruehsen  created

 * 14.08.2019  Tim Ruehsen  split out from cookie.c

 *

 * see https://tools.ietf.org/html/rfc6265

 *

 */

#include <config.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <limits.h>

#include <ctype.h>

#include <time.h>

#include <c-ctype.h>

#include <wget.h>

#include "private.h"

#include "cookie.h"

bool cookie_domain_match(const char *domain, const char *host)

{

  size_t domain_length, host_length;

  const char *p;

  debug_printf("domain_match(%s,%s)", domain, host);

  if (!strcmp(domain, host))

    return true; // an exact match

  domain_length = strlen(domain);

  host_length = strlen(host);

  if (domain_length >= host_length)

    return false; // host is too short

  p = host + host_length - domain_length;

  if (!strcmp(p, domain) && p[-1] == '.')

    return true;

  return false;

}

bool cookie_path_match(const char *cookie_path, const char *request_path)

{

  const char *last_slash;

  size_t cookie_path_length, iri_path_length;

  bool cookie_path_slash = false;

  if (*cookie_path == '/') {

    cookie_path++;

    cookie_path_slash = true;

  }

  if (request_path && *request_path == '/')

    request_path++;

  debug_printf("path_match(/%s,/%s)\n", cookie_path, request_path ? request_path : "");

  // algorithm as described in RFC 6265 5.1.4

//  if (!request_path || *request_path != '/' || !(last_slash = strrchr(request_path + 1, '/'))) {

//    request_path = "/";

//    iri_path_length = 1;

  if (!request_path || !(last_slash = strrchr(request_path, '/'))) {

    request_path = "";

    iri_path_length = 0;

  } else {

    iri_path_length = last_slash - request_path;

  }

  cookie_path_length = strlen(cookie_path);

  if (iri_path_length < cookie_path_length)

    // cookie-path is not a prefix of request-path

    return false;

  if (iri_path_length == 0 && cookie_path_length == 0)

    // slash matches slash

    return true;

  if (!strncmp(cookie_path, request_path, cookie_path_length)) {

    if (!request_path[cookie_path_length])

      // the cookie-path and the request-path are identical

      return true;

    if ((cookie_path_length > 0 && cookie_path[cookie_path_length - 1] == '/') || cookie_path_slash)

      // the cookie-path is a prefix of the request-path, and the last

      // character of the cookie-path is %x2F ("/").

      return true;

    if (request_path[cookie_path_length] == '/')

      // the cookie-path is a prefix of the request-path, and the first

      // character of the request-path that is not included in the cookie-

      // path is a %x2F ("/") character.

      return true;

  }

  return false;

}

wget_cookie *wget_cookie_init(wget_cookie *cookie)

{

  if (!cookie) {

    cookie = wget_calloc(1, sizeof(wget_cookie));

    if (!cookie)

      return NULL;

  } else

    memset(cookie, 0, sizeof(*cookie));

  cookie->last_access = cookie->creation = time(NULL);

  return cookie;

}

void wget_cookie_deinit(wget_cookie *cookie)

{

  if (cookie) {

    xfree(cookie->name);

    xfree(cookie->value);

    xfree(cookie->domain);

    xfree(cookie->path);

  }

}

void wget_cookie_free(wget_cookie **cookie)

{

  if (cookie) {

    wget_cookie_deinit(*cookie);

    xfree(*cookie);

  }

}

// for vector destruction

void cookie_free(void *cookie)

{

  if (cookie) {

    wget_cookie_deinit(cookie);

    xfree(cookie);

  }

}

/*

int wget_cookie_equals(wget_cookie *cookie1, wget_cookie *cookie2)

{

  if (!cookie1)

    return !cookie2;

  if (!cookie2)

    return 0;

  if (wget_strcmp(cookie1->name, cookie2->name) ||

    wget_strcmp(cookie1->value, cookie2->value) ||

    wget_strcmp(cookie1->domain, cookie2->domain) ||

    wget_strcmp(cookie1->path, cookie2->path) ||

    cookie1->domain_dot != cookie2->domain_dot ||

    cookie1->normalized != cookie2->normalized ||

    cookie1->persistent != cookie2->persistent ||

    cookie1->host_only != cookie2->host_only ||

    cookie1->secure_only != cookie2->secure_only ||

    cookie1->http_only != cookie2->http_only)

  {

    return 0;

  }

  return 1;

}

*/

char *wget_cookie_to_setcookie(wget_cookie *cookie)

{

  char expires[32] = "";

  if (!cookie)

    return wget_strdup("(null)");

  if (cookie->expires)

    wget_http_print_date(cookie->expires, expires, sizeof(expires)); // date format from RFC 6265

  return wget_aprintf("%s=%s%s%s%s%s; domain=%s%s%s%s",

    cookie->name, cookie->value,

    *expires ? "; expires=" : "", *expires ? expires : "",

    cookie->path ? "; path=" : "", cookie->path ? cookie->path : "",

    cookie->host_only ? "" : ".", cookie->domain,

    cookie->http_only ? "; HttpOnly" : "",

    cookie->secure_only ? "; Secure" : "");

}

/*

 RFC 6265

 set-cookie-header = "Set-Cookie:" SP set-cookie-string

 set-cookie-string = cookie-pair *( ";" SP cookie-av )

 cookie-pair       = cookie-name "=" cookie-value

 cookie-name       = token

 cookie-value      = *cookie-octet / ( DQUOTE *cookie-octet DQUOTE )

 cookie-octet      = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E

                       ; US-ASCII characters excluding CTLs,

                       ; whitespace DQUOTE, comma, semicolon,

                       ; and backslash

 token             = <token, defined in [RFC2616], Section 2.2>

 cookie-av         = expires-av / max-age-av / domain-av /

                     path-av / secure-av / httponly-av /

                     extension-av

 expires-av        = "Expires=" sane-cookie-date

 sane-cookie-date  = <rfc1123-date, defined in [RFC2616], Section 3.3.1>

 max-age-av        = "Max-Age=" non-zero-digit *DIGIT

                       ; In practice, both expires-av and max-age-av

                       ; are limited to dates representable by the

                       ; user agent.

 non-zero-digit    = %x31-39

                       ; digits 1 through 9

 domain-av         = "Domain=" domain-value

 domain-value      = <subdomain>

                       ; defined in [RFC1034], Section 3.5, as

                       ; enhanced by [RFC1123], Section 2.1

 path-av           = "Path=" path-value

 path-value        = <any CHAR except CTLs or ";">

 secure-av         = "Secure"

 httponly-av       = "HttpOnly"

 extension-av      = <any CHAR except CTLs or ";">

*/

const char *wget_cookie_parse_setcookie(const char *s, wget_cookie **_cookie)

{

  const char *name, *p;

  wget_cookie *cookie = wget_cookie_init(NULL);

  // remove leading whitespace from cookie name

  while (c_isspace(*s)) s++;

  // s = wget_http_parse_token(s, &cookie->name);

  // also accept UTF-8 (NON-ASCII) characters in cookie name

  for (p = s; (*s >= 32 && *s <= 126 && *s != '=' && *s != ';') || *s < 0; s++);

  // remove trailing whitespace from cookie name

  while (s > p && c_isspace(s[-1])) s--;

  cookie->name = wget_strmemdup(p, s - p);

  // advance to next delimiter

  while (c_isspace(*s)) s++;

  if (cookie->name && *cookie->name && *s == '=') {

    // *cookie-octet / ( DQUOTE *cookie-octet DQUOTE )

    // skip over delimiter and remove leading whitespace from cookie value

    for (s++; c_isspace(*s);) s++;

/* RFC compliance is too strict

    if (*s == '\"')

      s++;

    // cookie-octet      = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E

    for (p = s; *s > 32 && *s <= 126 && *s != '\\' && *s != ',' && *s != ';' && *s != '\"'; s++);

*/

    // also accept UTF-8 (NON-ASCII) characters in cookie value

    for (p = s; (*s >= 32 && *s <= 126 && *s != ';') || *s < 0; s++);

    // remove trailing whitespace from cookie value

    while (s > p && c_isspace(s[-1])) s--;

    cookie->value = wget_strmemdup(p, s - p);

    do {

      // find next delimiter

      while (*s && *s != ';') s++;

      if (!*s) break;

      // skip delimiter and remove leading spaces from attribute name

      for (s++; c_isspace(*s);) s++;

      if (!*s) break;

      s = wget_http_parse_token(s, &name);

      if (name) {

        // find next delimiter

        while (*s && *s != '=' && *s != ';') s++;

        // if (!*s) break;

        if (*s == '=') {

          // find end of value

          for (s++; c_isspace(*s);) s++;

          for (p = s; (*s >= 32 && *s <= 126 && *s != ';') || *s < 0; s++);

          if (!wget_strcasecmp_ascii(name, "expires")) {

            cookie->expires = wget_http_parse_full_date(p);

          } else if (!wget_strcasecmp_ascii(name, "max-age")) {

            long offset = atol(p);

            if (offset > 0) {

              // limit offset to avoid integer overflow

              if (offset > INT_MAX)

                offset = INT_MAX;

              cookie->maxage = time(NULL) + offset;

            } else

              cookie->maxage = 0;

          } else if (!wget_strcasecmp_ascii(name, "domain")) {

            if (p != s) {

              if (*p == '.') { // RFC 6265 5.2.3

                do { p++; } while (*p == '.');

                cookie->domain_dot = 1;

              } else

                cookie->domain_dot = 0;

              // remove trailing whitespace from attribute value

              while (s > p && c_isspace(s[-1])) s--;

              xfree(cookie->domain);

              cookie->domain = wget_strmemdup(p, s - p);

            }

          } else if (!wget_strcasecmp_ascii(name, "path")) {

            // remove trailing whitespace from attribute value

            while (s > p && c_isspace(s[-1])) s--;

            xfree(cookie->path);

            cookie->path = wget_strmemdup(p, s - p);

          } else if (!wget_strcasecmp_ascii(name, "secure")) {

            // here we ignore the value

            cookie->secure_only = 1;

          } else if (!wget_strcasecmp_ascii(name, "httponly")) {

            // here we ignore the value

            cookie->http_only = 1;

          } else {

            debug_printf("Unsupported cookie-av '%s'\n", name);

          }

        } else if (!wget_strcasecmp_ascii(name, "secure")) {

          cookie->secure_only = 1;

        } else if (!wget_strcasecmp_ascii(name, "httponly")) {

          cookie->http_only = 1;

        } else {

          debug_printf("Unsupported cookie-av '%s'\n", name);

        }

        xfree(name);

      }

    } while (*s);

  } else {

    wget_cookie_free(&cookie);

    error_printf(_("Cookie without name or assignment ignored\n"));

  }

  if (_cookie)

    *_cookie = cookie;

  else

    wget_cookie_free(&cookie);

  return s;

}

// normalize/sanitize and store cookies

static int cookie_normalize_cookie(const wget_iri *iri, wget_cookie *cookie)

{

/*

  debug_printf("normalize cookie %s=%s\n", cookie->name, cookie->value);

  debug_printf("<  %s=%s\n", cookie->name, cookie->value);

  debug_printf("<  expires=%lld max-age=%lld\n", (long long)cookie->expires, (long long)cookie->maxage);

  debug_printf("<  domain=%s\n", cookie->domain);

  debug_printf("<  path=%s\n", cookie->path);

  debug_printf("<  normalized=%d persistent=%d hostonly=%d secure=%d httponly=%d\n",

    cookie->normalized, cookie->persistent, cookie->host_only, cookie->secure_only, cookie->http_only);

*/

  if (!cookie)

    return -1;

  cookie->normalized = 0;

  if (cookie->maxage)

    cookie->expires = cookie->maxage;

  cookie->persistent = cookie->expires != 0;

  // convert domain to lowercase

  wget_strtolower((char *)cookie->domain);

  if (iri) {

    // cookies comes from a HTTP header and needs checking

    // check prefixes as proposed in https://tools.ietf.org/html/draft-ietf-httpbis-cookie-prefixes-00

    if (!wget_strncmp(cookie->name, "__Secure-", 9)) {

      if (!cookie->secure_only || iri->scheme != WGET_IRI_SCHEME_HTTPS) {

        debug_printf("Cookie prefix requires secure origin: %s %s\n", cookie->name, iri->host);

        return -1; // ignore cookie

      }

    }

    else if (!wget_strncmp(cookie->name, "__Host-", 7)) {

      if (!cookie->secure_only || iri->scheme != WGET_IRI_SCHEME_HTTPS) {

        debug_printf("Cookie prefix requires secure origin: %s %s\n", cookie->name, iri->host);

        return -1; // ignore cookie

      }

      if (!cookie->host_only) {

        debug_printf("Cookie prefix requires hostonly flag: %s %s\n", cookie->name, iri->host);

        return -1; // ignore cookie

      }

      if (wget_strcmp(cookie->path, "/")) {

        debug_printf("Cookie prefix requires path \"/\": %s %s\n", cookie->name, iri->host);

        return -1; // ignore cookie

      }

    }

    if (cookie->domain && *cookie->domain) {

      if (!strcmp(cookie->domain, iri->host)) {

        cookie->host_only = 1;

      } else if (cookie_domain_match(cookie->domain, iri->host)) {

        cookie->host_only = 0;

      } else {

        debug_printf("Domain mismatch: %s %s\n", cookie->domain, iri->host);

        return -1; // ignore cookie

      }

    } else {

      xfree(cookie->domain);

      cookie->domain = wget_strdup(iri->host);

      cookie->host_only = 1;

    }

    if (!cookie->path || *cookie->path != '/') {

      const char *p = iri->path ? strrchr(iri->path, '/') : NULL;

      xfree(cookie->path);

      if (p && p != iri->path) {

        cookie->path = wget_strmemdup(iri->path, p - iri->path);

      } else {

        cookie->path = wget_strdup("/");

        // err_printf(_("Unexpected URI without '/': %s\n"), iri->path);

        // return -1; // ignore cookie

      }

    }

  }

  cookie->normalized = 1;

/*

  debug_printf(">  %s=%s\n", cookie->name, cookie->value);

  debug_printf(">  expires=%lld max-age=%lld\n", (long long)cookie->expires, (long long)cookie->maxage);

  debug_printf(">  domain=%s\n", cookie->domain);

  debug_printf(">  path=%s\n", cookie->path);

  debug_printf(">  normalized=%d persistent=%d hostonly=%d secure=%d httponly=%d\n",

    cookie->normalized, cookie->persistent, cookie->host_only, cookie->secure_only, cookie->http_only);

*/

  return 0;

}

int wget_cookie_normalize(const wget_iri *iri, wget_cookie *cookie)

{

//  wget_thread_mutex_lock(&_cookies_mutex);

  int ret = cookie_normalize_cookie(iri, cookie);

//  wget_thread_mutex_unlock(&_cookies_mutex);

  return ret;

}

void wget_cookie_normalize_cookies(const wget_iri *iri, const wget_vector *cookies)

{

//  wget_thread_mutex_lock(&_cookies_mutex);

  for (int it = 0; it < wget_vector_size(cookies); it++)

    cookie_normalize_cookie(iri, wget_vector_get(cookies, it));

//  wget_thread_mutex_unlock(&_cookies_mutex);

}