/*

    Copyright (C) 2015  ABRT team

    Copyright (C) 2015  RedHat Inc

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License along

    with this program; if not, write to the Free Software Foundation, Inc.,

    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

*/

#include "internal_libreport.h"

#include <regex.h>

int uri_userinfo_remove(const char *uri, char **result, char **scheme, char **hostname, char **username, char **password, char **location)

{

    /* https://www.ietf.org/rfc/rfc3986.txt

     * Appendix B.  Parsing a URI Reference with a Regular Expression

     *

     * scheme    = $2

     * authority = $4

     * location  = $5 <- introduced by jfilak

     * path      = $6

     * query     = $8

     * fragment  = $10

     *                         12            3  4          56       7   8        9 10 */

    const char *rfc3986_rx = "^(([^:/?#]+):)?(//([^/?#]*))?(([^?#]*)(\\?([^#]*))?(#(.*))?)$";

    regex_t re;

    int r = regcomp(&re, rfc3986_rx, REG_EXTENDED);

    assert(r == 0 || !"BUG: invalid regular expression");

    regmatch_t matchptr[10];

    r = regexec(&re, uri, ARRAY_SIZE(matchptr), matchptr, 0);

    if (r != 0)

    {

        log_debug("URI does not match RFC3986 regular expression.");

        return -EINVAL;

    }

    char *ptr = xzalloc((strlen(uri) + 1) * sizeof(char));

    *result = ptr;

    if (scheme != NULL)

        *scheme = NULL;

    if (hostname != NULL)

        *hostname = NULL;

    if (username != NULL)

        *username = NULL;

    if (password != NULL)

        *password = NULL;

    if (location != NULL)

        *location= NULL;

    /* https://www.ietf.org/rfc/rfc3986.txt

     * 5.3.  Component Recomposition

     *

      result = ""

      if defined(scheme) then

         append scheme to result;

         append ":" to result;

      endif;

      if defined(authority) then

         append "//" to result;

         append authority to result;

      endif;

      append path to result;

      if defined(query) then

         append "?" to result;

         append query to result;

      endif;

      if defined(fragment) then

         append "#" to result;

         append fragment to result;

      endif;

      return result;

    */

#define APPEND_MATCH(i, output) \

    if (matchptr[(i)].rm_so != -1) \

    { \

        size_t len = 0; \

        len = matchptr[(i)].rm_eo - matchptr[(i)].rm_so; \

        if (output) *output = xstrndup(uri + matchptr[(i)].rm_so, len); \

        strncpy(ptr, uri + matchptr[(i)].rm_so, len); \

        ptr += len; \

    }

    /* Append "scheme:" if defined */

    APPEND_MATCH(1, scheme);

    /* If authority is defined, append "//" */

    regmatch_t *match_authority = matchptr + 3;

    if (match_authority->rm_so != -1)

    {

        strcat(ptr, "//");

        ptr += 2;

    }

    ++match_authority;

    /* If authority has address part, remove userinfo and add the address */

    if (match_authority->rm_so != -1)

    {

        size_t len = match_authority->rm_eo - match_authority->rm_so;

        const char *authority = uri + match_authority->rm_so;

        /* Find the last '@'. Just for the case some used @ in username or

         * password */

        size_t at = len;

        while (at != 0)

        {

            if (authority[--at] != '@')

                continue;

            /* Find the first ':' before @. There should not be more ':' but this

             * is the most secure way -> avoid leaking an excerpt of a password

             * containing ':'.*/

            size_t colon = 0;

            while (colon < at)

            {

                if (authority[colon] != ':')

                {

                    ++colon;

                    continue;

                }

                if (password != NULL)

                    *password = xstrndup(authority + colon + 1, at - colon - 1);

                break;

            }

            if (username != NULL)

                *username = xstrndup(authority, colon);

            ++at;

            break;

        }

        len -= at;

        if (hostname != NULL)

            *hostname = xstrndup(authority + at, len);

        strncpy(ptr, authority + at, len);

        ptr += len;

    }

    /* Append path, query and fragment or "" */

    APPEND_MATCH(5, location);

    return 0;

}