/*

 * Dropbear SSH

 * 

 * Copyright (c) 2002,2003 Matt Johnston

 * All rights reserved.

 * 

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 * 

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 * 

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE. */

#include "includes.h"

#include "buffer.h"

#include "dbutil.h"

#include "session.h"

#include "ssh.h"

#include "runopts.h"

#include "atomicio.h"

#if DROPBEAR_CLI_PASSWORD_AUTH

#if DROPBEAR_CLI_ASKPASS_HELPER

/* Returns 1 if we want to use the askpass program, 0 otherwise */

static int want_askpass()

{

  char* askpass_prog = NULL;

  askpass_prog = getenv("SSH_ASKPASS");

  return askpass_prog && 

    ((!isatty(STDIN_FILENO) && getenv("DISPLAY") )

      || getenv("SSH_ASKPASS_ALWAYS"));

}

/* returns a statically allocated password from a helper app, or NULL

 * on failure */

static char *gui_getpass(const char *prompt) {

  pid_t pid;

  int p[2], status;

  static char buf[DROPBEAR_MAX_CLI_PASS + 1];

  size_t len;

  char* helper = NULL;

  TRACE(("enter gui_getpass"))

  helper = getenv("SSH_ASKPASS");

  if (!helper)

  {

    TRACE(("leave gui_getpass: no askpass program"))

    return NULL;

  }

  if (pipe(p) < 0) {

    TRACE(("error creating child pipe"))

    return NULL;

  }

  pid = fork();

  if (pid < 0) {

    TRACE(("fork error"))

    return NULL;

  }

  if (!pid) {

    /* child */

    close(p[0]);

    if (dup2(p[1], STDOUT_FILENO) < 0) {

      TRACE(("error redirecting stdout"))

      exit(1);

    }

    close(p[1]);

    execlp(helper, helper, prompt, (char *)0);

    TRACE(("execlp error"))

    exit(1);

  }

  close(p[1]);

  len = atomicio(read, p[0], buf, sizeof(buf)-1);

  close(p[0]);

  while (waitpid(pid, &status, 0) < 0 && errno == EINTR)

    ;

  if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)

    return(NULL);

  buf[len] = '\0';

  if (len > 0 && buf[len - 1] == '\n')

    buf[len - 1] = '\0';

  TRACE(("leave gui_getpass"))

  return(buf);

}

#endif /* DROPBEAR_CLI_ASKPASS_HELPER */

void cli_auth_password() {

  char* password = NULL;

  char prompt[80];

  DEBUG1(("enter cli_auth_password"))

  CHECKCLEARTOWRITE();

  snprintf(prompt, sizeof(prompt), "%s@%s's password: ", 

        cli_opts.username, cli_opts.remotehost);

#if DROPBEAR_CLI_ASKPASS_HELPER

  if (want_askpass())

  {

    password = gui_getpass(prompt);

    if (!password) {

      dropbear_exit("No password");

    }

  } else

#endif

  {

    password = getpass_or_cancel(prompt);

  }

  buf_putbyte(ses.writepayload, SSH_MSG_USERAUTH_REQUEST);

  buf_putstring(ses.writepayload, cli_opts.username,

      strlen(cli_opts.username));

  buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION,

      SSH_SERVICE_CONNECTION_LEN);

  buf_putstring(ses.writepayload, AUTH_METHOD_PASSWORD,

      AUTH_METHOD_PASSWORD_LEN);

  buf_putbyte(ses.writepayload, 0); /* FALSE - so says the spec */

  buf_putstring(ses.writepayload, password, strlen(password));

  encrypt_packet();

  m_burn(password, strlen(password));

  cli_ses.is_trivial_auth = 0;

  TRACE(("leave cli_auth_password"))

}

#endif  /* DROPBEAR_CLI_PASSWORD_AUTH */