/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

#include "curl_setup.h"

#ifdef HAVE_PWD_H
#include <pwd.h>
#endif

#include <curl/curl.h>
#include "netrc.h"
#include "strtok.h"
#include "strcase.h"

/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"

/* Get user and password from .netrc when given a machine name */

enum host_lookup_state {
  NOTHING,
  HOSTFOUND,    /* the 'machine' keyword was found */
  HOSTVALID     /* this is "our" machine! */
};

/*
 * @unittest: 1304
 *
 * *loginp and *passwordp MUST be allocated if they aren't NULL when passed
 * in.
 */
int Curl_parsenetrc(const char *host,
                    char **loginp,
                    char **passwordp,
                    bool *login_changed,
                    bool *password_changed,
                    char *netrcfile)
{
  FILE *file;
  int retcode = 1;
  char *login = *loginp;
  char *password = *passwordp;
  bool specific_login = (login && *login != 0);
  bool login_alloc = FALSE;
  bool password_alloc = FALSE;
  bool netrc_alloc = FALSE;
  enum host_lookup_state state = NOTHING;

  char state_login = 0;      /* Found a login keyword */
  char state_password = 0;   /* Found a password keyword */
  int state_our_login = FALSE;  /* With specific_login, found *our* login
                                   name */

#define NETRC DOT_CHAR "netrc"

  if(!netrcfile) {
    bool home_alloc = FALSE;
    char *home = curl_getenv("HOME"); /* portable environment reader */
    if(home) {
      home_alloc = TRUE;
#if defined(HAVE_GETPWUID_R) && defined(HAVE_GETEUID)
    }
    else {
      struct passwd pw, *pw_res;
      char pwbuf[1024];
      if(!getpwuid_r(geteuid(), &pw, pwbuf, sizeof(pwbuf), &pw_res)
         && pw_res) {
        home = strdup(pw.pw_dir);
        if(!home)
          return CURLE_OUT_OF_MEMORY;
        home_alloc = TRUE;
      }
#elif defined(HAVE_GETPWUID) && defined(HAVE_GETEUID)
    }
    else {
      struct passwd *pw;
      pw = getpwuid(geteuid());
      if(pw) {
        home = pw->pw_dir;
      }
#endif
    }

    if(!home)
      return retcode; /* no home directory found (or possibly out of memory) */

    netrcfile = curl_maprintf("%s%s%s", home, DIR_CHAR, NETRC);
    if(home_alloc)
      free(home);
    if(!netrcfile) {
      return -1;
    }
    netrc_alloc = TRUE;
  }

  file = fopen(netrcfile, FOPEN_READTEXT);
  if(netrc_alloc)
    free(netrcfile);
  if(file) {
    char *tok;
    char *tok_buf;
    bool done = FALSE;
    char netrcbuffer[4096];
    int  netrcbuffsize = (int)sizeof(netrcbuffer);

    while(!done && fgets(netrcbuffer, netrcbuffsize, file)) {
      tok = strtok_r(netrcbuffer, " \t\n", &tok_buf);
      if(tok && *tok == '#')
        /* treat an initial hash as a comment line */
        continue;
      while(!done && tok) {

        if((login && *login) && (password && *password)) {
          done = TRUE;
          break;
        }

        switch(state) {
        case NOTHING:
          if(strcasecompare("machine", tok)) {
            /* the next tok is the machine name, this is in itself the
               delimiter that starts the stuff entered for this machine,
               after this we need to search for 'login' and
               'password'. */
            state = HOSTFOUND;
          }
          else if(strcasecompare("default", tok)) {
            state = HOSTVALID;
            retcode = 0; /* we did find our host */
          }
          break;
        case HOSTFOUND:
          if(strcasecompare(host, tok)) {
            /* and yes, this is our host! */
            state = HOSTVALID;
            retcode = 0; /* we did find our host */
          }
          else
            /* not our host */
            state = NOTHING;
          break;
        case HOSTVALID:
          /* we are now parsing sub-keywords concerning "our" host */
          if(state_login) {
            if(specific_login) {
              state_our_login = strcasecompare(login, tok);
            }
            else if(!login || strcmp(login, tok)) {
              if(login_alloc) {
                free(login);
                login_alloc = FALSE;
              }
              login = strdup(tok);
              if(!login) {
                retcode = -1; /* allocation failed */
                goto out;
              }
              login_alloc = TRUE;
            }
            state_login = 0;
          }
          else if(state_password) {
            if((state_our_login || !specific_login)
                && (!password || strcmp(password, tok))) {
              if(password_alloc) {
                free(password);
                password_alloc = FALSE;
              }
              password = strdup(tok);
              if(!password) {
                retcode = -1; /* allocation failed */
                goto out;
              }
              password_alloc = TRUE;
            }
            state_password = 0;
          }
          else if(strcasecompare("login", tok))
            state_login = 1;
          else if(strcasecompare("password", tok))
            state_password = 1;
          else if(strcasecompare("machine", tok)) {
            /* ok, there's machine here go => */
            state = HOSTFOUND;
            state_our_login = FALSE;
          }
          break;
        } /* switch (state) */

        tok = strtok_r(NULL, " \t\n", &tok_buf);
      } /* while(tok) */
    } /* while fgets() */

    out:
    if(!retcode) {
      *login_changed = FALSE;
      *password_changed = FALSE;
      if(login_alloc) {
        if(*loginp)
          free(*loginp);
        *loginp = login;
        *login_changed = TRUE;
      }
      if(password_alloc) {
        if(*passwordp)
          free(*passwordp);
        *passwordp = password;
        *password_changed = TRUE;
      }
    }
    else {
      if(login_alloc)
        free(login);
      if(password_alloc)
        free(password);
    }
    fclose(file);
  }

  return retcode;
}
