/src/samba/source3/auth/pampass.c

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/*
   Unix SMB/CIFS implementation.
   PAM Password checking
   Copyright (C) Andrew Tridgell 1992-2001
   Copyright (C) John H Terpsta 1999-2001
   Copyright (C) Andrew Bartlett 2001
   Copyright (C) Jeremy Allison 2001

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

/*
 * This module provides PAM based functions for validation of
 * username/password pairs, account management, session and access control.
 * Note: SMB password checking is done in smbpass.c
 */

#include "includes.h"
#include "auth.h"
#include "../libcli/auth/pam_errors.h"
#include "lib/util/string_wrappers.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_AUTH

#ifdef WITH_PAM

/*******************************************************************
 * Handle PAM authentication
 *  - Access, Authentication, Session, Password
 *   Note: See PAM Documentation and refer to local system PAM implementation
 *   which determines what actions/limitations/allowances become affected.
 *********************************************************************/

#if defined(HAVE_SECURITY_PAM_APPL_H)
#include <security/pam_appl.h>
#elif defined(HAVE_PAM_PAM_APPL_H)
#include <pam/pam_appl.h>
#endif

/*
 * Structure used to communicate between the conversation function
 * and the server_login/change password functions.
 */

struct smb_pam_userdata {
  const char *PAM_username;
  const char *PAM_password;
  const char *PAM_newpassword;
};

typedef int (*smb_pam_conv_fn)(int, const struct pam_message **, struct pam_response **, void *appdata_ptr);

static char *smb_pam_copy_string(const char *s)
{
  if (s == NULL) {
    return NULL;
  }
  return SMB_STRDUP(s);
}

static char *smb_pam_copy_fstring(const char *s)
{
  if (s[0] == '\0') {
    return NULL;
  }
  return SMB_STRDUP(s);
}

/*******************************************************************
 PAM error handler.
 *********************************************************************/

static bool smb_pam_error_handler(pam_handle_t *pamh, int pam_error, const char *msg, int dbglvl)
{

  if( pam_error != PAM_SUCCESS) {
    DEBUG(dbglvl, ("smb_pam_error_handler: PAM: %s : %s\n",
        msg, pam_strerror(pamh, pam_error)));
    return False;
  }
  return True;
}

/*******************************************************************
 This function is a sanity check, to make sure that we NEVER report
 failure as success.
*********************************************************************/

static bool smb_pam_nt_status_error_handler(pam_handle_t *pamh, int pam_error,
              const char *msg, int dbglvl,
              NTSTATUS *nt_status)
{
  *nt_status = pam_to_nt_status(pam_error);

  if (smb_pam_error_handler(pamh, pam_error, msg, dbglvl))
    return True;

  if (NT_STATUS_IS_OK(*nt_status)) {
    /* Complain LOUDLY */
    DEBUG(0, ("smb_pam_nt_status_error_handler: PAM: BUG: PAM and NT_STATUS \
error MISMATCH, forcing to NT_STATUS_LOGON_FAILURE\n"));
    *nt_status = NT_STATUS_LOGON_FAILURE;
  }
  return False;
}

/*
 * PAM conversation function
 * Here we assume (for now, at least) that echo on means login name, and
 * echo off means password.
 */

static int smb_pam_conv(int num_msg,
        const struct pam_message **msg,
        struct pam_response **resp,
        void *appdata_ptr)
{
  int replies = 0;
  struct pam_response *reply = NULL;
  struct smb_pam_userdata *udp = (struct smb_pam_userdata *)appdata_ptr;

  if (resp != NULL) {
    *resp = NULL;
  }

  if (num_msg <= 0)
    return PAM_CONV_ERR;

  /*
   * Apparently HPUX has a buggy PAM that doesn't support the
   * appdata_ptr. Fail if this is the case. JRA.
   */

  if (udp == NULL) {
    DEBUG(0,("smb_pam_conv: PAM on this system is broken - appdata_ptr == NULL !\n"));
    return PAM_CONV_ERR;
  }

  reply = SMB_MALLOC_ARRAY(struct pam_response, num_msg);
  if (!reply)
    return PAM_CONV_ERR;

  memset(reply, '\0', sizeof(struct pam_response) * num_msg);

  for (replies = 0; replies < num_msg; replies++) {
    switch (msg[replies]->msg_style) {
      case PAM_PROMPT_ECHO_ON:
        reply[replies].resp_retcode = PAM_SUCCESS;
        reply[replies].resp = smb_pam_copy_string(
          udp->PAM_username);
        /* PAM frees resp */
        break;

      case PAM_PROMPT_ECHO_OFF:
        reply[replies].resp_retcode = PAM_SUCCESS;
        reply[replies].resp = smb_pam_copy_string(
          udp->PAM_password);
        /* PAM frees resp */
        break;

      case PAM_TEXT_INFO:
        FALL_THROUGH;

      case PAM_ERROR_MSG:
        /* ignore it... */
        reply[replies].resp_retcode = PAM_SUCCESS;
        reply[replies].resp = NULL;
        break;

      default:
        /* Must be an error of some sort... */
        SAFE_FREE(reply);
        return PAM_CONV_ERR;
    }
  }
  if (reply != NULL) {
    if (resp != NULL) {
      *resp = reply;
    } else {
      SAFE_FREE(reply);
    }
  }
  return PAM_SUCCESS;
}

/*
 * PAM password change conversation function
 * Here we assume (for now, at least) that echo on means login name, and
 * echo off means password.
 */

static void special_char_sub(char *buf)
{
  all_string_sub(buf, "\\n", "", 0);
  all_string_sub(buf, "\\r", "", 0);
  all_string_sub(buf, "\\s", " ", 0);
  all_string_sub(buf, "\\t", "\t", 0);
}

static void pwd_sub(char *buf, const char *username, const char *oldpass, const char *newpass)
{
  string_sub(buf, "%u", username, sizeof(fstring));
  all_string_sub(buf, "%o", oldpass, sizeof(fstring));
  all_string_sub(buf, "%n", newpass, sizeof(fstring));
}


struct chat_struct {
  struct chat_struct *next, *prev;
  fstring prompt;
  fstring reply;
};

static void free_pw_chat(struct chat_struct *list);

/**************************************************************
 Create a linked list containing chat data.
***************************************************************/

static struct chat_struct *make_pw_chat(const char *p)
{
  char *prompt;
  char *reply;
  struct chat_struct *list = NULL;
  struct chat_struct *t;
  TALLOC_CTX *frame = talloc_stackframe();

  while (1) {
    t = SMB_CALLOC_ARRAY(struct chat_struct, 1);
    if (!t) {
      DEBUG(0,("make_pw_chat: malloc failed!\n"));
      free_pw_chat(list);
      TALLOC_FREE(frame);
      return NULL;
    }

    DLIST_ADD_END(list, t);

    if (!next_token_talloc(frame, &p, &prompt, NULL)) {
      break;
    }

    if (strequal(prompt,".")) {
      fstrcpy(prompt,"*");
    }

    special_char_sub(prompt);
    fstrcpy(t->prompt, prompt);
    (void)strlower_m(t->prompt);
    trim_char(t->prompt, ' ', ' ');

    if (!next_token_talloc(frame, &p, &reply, NULL)) {
      break;
    }

    if (strequal(reply,".")) {
      fstrcpy(reply,"");
    }

    special_char_sub(reply);
    fstrcpy(t->reply, reply);
    (void)strlower_m(t->reply);
    trim_char(t->reply, ' ', ' ');

  }
  TALLOC_FREE(frame);
  return list;
}

static void free_pw_chat(struct chat_struct *list)
{
    while (list) {
        struct chat_struct *old_head = list;
        DLIST_REMOVE(list, list);
        SAFE_FREE(old_head);
    }
}

static int smb_pam_passchange_conv(int num_msg,
        const struct pam_message **msg,
        struct pam_response **resp,
        void *appdata_ptr)
{
  int replies = 0;
  struct pam_response *reply = NULL;
  fstring current_prompt;
  fstring current_reply;
  struct smb_pam_userdata *udp = (struct smb_pam_userdata *)appdata_ptr;
  struct chat_struct *pw_chat;
  struct chat_struct *t;
  const struct loadparm_substitution *lp_sub =
    loadparm_s3_global_substitution();
  bool found;
  *resp = NULL;

  DEBUG(10,("smb_pam_passchange_conv: starting conversation for %d messages\n", num_msg));

  if (num_msg <= 0)
    return PAM_CONV_ERR;

  if ((pw_chat = make_pw_chat(lp_passwd_chat(talloc_tos(), lp_sub))) == NULL)
    return PAM_CONV_ERR;

  /*
   * Apparently HPUX has a buggy PAM that doesn't support the
   * appdata_ptr. Fail if this is the case. JRA.
   */

  if (udp == NULL) {
    DEBUG(0,("smb_pam_passchange_conv: PAM on this system is broken - appdata_ptr == NULL !\n"));
    free_pw_chat(pw_chat);
    return PAM_CONV_ERR;
  }

  reply = SMB_MALLOC_ARRAY(struct pam_response, num_msg);
  if (!reply) {
    DEBUG(0,("smb_pam_passchange_conv: malloc for reply failed!\n"));
    free_pw_chat(pw_chat);
    return PAM_CONV_ERR;
  }

  for (replies = 0; replies < num_msg; replies++) {
    found = False;
    DEBUG(10,("smb_pam_passchange_conv: Processing message %d\n", replies));
    switch (msg[replies]->msg_style) {
    case PAM_PROMPT_ECHO_ON:
      DEBUG(10,("smb_pam_passchange_conv: PAM_PROMPT_ECHO_ON: PAM said: %s\n", msg[replies]->msg));
      fstrcpy(current_prompt, msg[replies]->msg);
      trim_char(current_prompt, ' ', ' ');
      for (t=pw_chat; t; t=t->next) {

        DEBUG(10,("smb_pam_passchange_conv: PAM_PROMPT_ECHO_ON: trying to match |%s| to |%s|\n",
            t->prompt, current_prompt ));

        if (unix_wild_match(t->prompt, current_prompt)) {
          fstrcpy(current_reply, t->reply);
          DEBUG(10,("smb_pam_passchange_conv: PAM_PROMPT_ECHO_ON: We sent: %s\n", current_reply));
          pwd_sub(current_reply, udp->PAM_username, udp->PAM_password, udp->PAM_newpassword);
#ifdef DEBUG_PASSWORD
          DEBUG(100,("smb_pam_passchange_conv: PAM_PROMPT_ECHO_ON: We actually sent: %s\n", current_reply));
#endif
          reply[replies].resp_retcode = PAM_SUCCESS;
          reply[replies].resp = smb_pam_copy_fstring(
            current_reply);
          found = True;
          break;
        }
      }
      /* PAM frees resp */
      if (!found) {
        DEBUG(3,("smb_pam_passchange_conv: Could not find reply for PAM prompt: %s\n",msg[replies]->msg));
        free_pw_chat(pw_chat);
        SAFE_FREE(reply);
        return PAM_CONV_ERR;
      }
      break;

    case PAM_PROMPT_ECHO_OFF:
      DEBUG(10,("smb_pam_passchange_conv: PAM_PROMPT_ECHO_OFF: PAM said: %s\n", msg[replies]->msg));
      fstrcpy(current_prompt, msg[replies]->msg);
      trim_char(current_prompt, ' ', ' ');
      for (t=pw_chat; t; t=t->next) {

        DEBUG(10,("smb_pam_passchange_conv: PAM_PROMPT_ECHO_OFF: trying to match |%s| to |%s|\n",
            t->prompt, current_prompt ));

        if (unix_wild_match(t->prompt, current_prompt)) {
          fstrcpy(current_reply, t->reply);
          DEBUG(10,("smb_pam_passchange_conv: PAM_PROMPT_ECHO_OFF: We sent: %s\n", current_reply));
          pwd_sub(current_reply, udp->PAM_username, udp->PAM_password, udp->PAM_newpassword);
          reply[replies].resp_retcode = PAM_SUCCESS;
          reply[replies].resp = smb_pam_copy_fstring(
            current_reply);
#ifdef DEBUG_PASSWORD
          DEBUG(100,("smb_pam_passchange_conv: PAM_PROMPT_ECHO_OFF: We actually sent: %s\n", current_reply));
#endif
          found = True;
          break;
        }
      }
      /* PAM frees resp */

      if (!found) {
        DEBUG(3,("smb_pam_passchange_conv: Could not find reply for PAM prompt: %s\n",msg[replies]->msg));
        free_pw_chat(pw_chat);
        SAFE_FREE(reply);
        return PAM_CONV_ERR;
      }
      break;

    case PAM_TEXT_INFO:
      FALL_THROUGH;

    case PAM_ERROR_MSG:
      /* ignore it... */
      reply[replies].resp_retcode = PAM_SUCCESS;
      reply[replies].resp = NULL;
      break;

    default:
      /* Must be an error of some sort... */
      free_pw_chat(pw_chat);
      SAFE_FREE(reply);
      return PAM_CONV_ERR;
    }
  }

  free_pw_chat(pw_chat);
  if (reply)
    *resp = reply;
  return PAM_SUCCESS;
}

/***************************************************************************
 Free up a malloced pam_conv struct.
****************************************************************************/

static void smb_free_pam_conv(struct pam_conv *pconv)
{
  if (pconv)
    SAFE_FREE(pconv->appdata_ptr);

  SAFE_FREE(pconv);
}

/***************************************************************************
 Allocate a pam_conv struct.
****************************************************************************/

static struct pam_conv *smb_setup_pam_conv(smb_pam_conv_fn smb_pam_conv_fnptr, const char *user,
          const char *passwd, const char *newpass)
{
  struct pam_conv *pconv = SMB_MALLOC_P(struct pam_conv);
  struct smb_pam_userdata *udp = SMB_MALLOC_P(struct smb_pam_userdata);

  if (pconv == NULL || udp == NULL) {
    SAFE_FREE(pconv);
    SAFE_FREE(udp);
    return NULL;
  }

  udp->PAM_username = user;
  udp->PAM_password = passwd;
  udp->PAM_newpassword = newpass;

  pconv->conv = smb_pam_conv_fnptr;
  pconv->appdata_ptr = (void *)udp;
  return pconv;
}

/*
 * PAM Closing out cleanup handler
 */

static bool smb_pam_end(pam_handle_t *pamh, struct pam_conv *smb_pam_conv_ptr)
{
  int pam_error;

  smb_free_pam_conv(smb_pam_conv_ptr);

  if( pamh != NULL ) {
    pam_error = pam_end(pamh, 0);
    if (pam_error == PAM_SUCCESS) {
      DBG_NOTICE("PAM: PAM_END OK.\n");
      return True;
    }

    DBG_WARNING("PAM: PAM_END FAILED (%d).\n", pam_error);
  } else {
    DBG_INFO("PAM: not initialised\n");
  }

  return False;
}

/*
 * Start PAM authentication for specified account
 */

static bool smb_pam_start(pam_handle_t **pamh, const char *user, const char *rhost, struct pam_conv *pconv)
{
  int pam_error;

  *pamh = (pam_handle_t *)NULL;

  DEBUG(4,("smb_pam_start: PAM: Init user: %s\n", user));

  pam_error = pam_start("samba", user, pconv, pamh);
  if( !smb_pam_error_handler(*pamh, pam_error, "Init Failed", 0)) {
    *pamh = (pam_handle_t *)NULL;
    return False;
  }

#ifdef HAVE_PAM_RHOST
  DEBUG(4,("smb_pam_start: PAM: setting rhost to: %s\n", rhost));
  pam_error = pam_set_item(*pamh, PAM_RHOST, rhost);
  if(!smb_pam_error_handler(*pamh, pam_error, "set rhost failed", 0)) {
    smb_pam_end(*pamh, pconv);
    *pamh = (pam_handle_t *)NULL;
    return False;
  }
#endif
#ifdef HAVE_PAM_TTY
  DEBUG(4,("smb_pam_start: PAM: setting tty\n"));
  pam_error = pam_set_item(*pamh, PAM_TTY, "samba");
  if (!smb_pam_error_handler(*pamh, pam_error, "set tty failed", 0)) {
    smb_pam_end(*pamh, pconv);
    *pamh = (pam_handle_t *)NULL;
    return False;
  }
#endif
  DEBUG(4,("smb_pam_start: PAM: Init passed for user: %s\n", user));
  return True;
}

/*
 * PAM Authentication Handler
 */
static NTSTATUS smb_pam_auth(pam_handle_t *pamh, const char *user)
{
  int pam_error;
  NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;

  /*
   * To enable debugging set in /etc/pam.d/samba:
   *  auth required /lib/security/pam_pwdb.so nullok shadow audit
   */

  DEBUG(4,("smb_pam_auth: PAM: Authenticate User: %s\n", user));
  pam_error = pam_authenticate(pamh, PAM_SILENT | (lp_null_passwords() ? 0 : PAM_DISALLOW_NULL_AUTHTOK));
  switch( pam_error ){
    case PAM_AUTH_ERR:
      DEBUG(2, ("smb_pam_auth: PAM: Authentication Error for user %s\n", user));
      break;
    case PAM_CRED_INSUFFICIENT:
      DEBUG(2, ("smb_pam_auth: PAM: Insufficient Credentials for user %s\n", user));
      break;
    case PAM_AUTHINFO_UNAVAIL:
      DEBUG(2, ("smb_pam_auth: PAM: Authentication Information Unavailable for user %s\n", user));
      break;
    case PAM_USER_UNKNOWN:
      DEBUG(2, ("smb_pam_auth: PAM: Username %s NOT known to Authentication system\n", user));
      break;
    case PAM_MAXTRIES:
      DEBUG(2, ("smb_pam_auth: PAM: One or more authentication modules reports user limit for user %s exceeeded\n", user));
      break;
    case PAM_ABORT:
      DEBUG(0, ("smb_pam_auth: PAM: One or more PAM modules failed to load for user %s\n", user));
      break;
    case PAM_SUCCESS:
      DEBUG(4, ("smb_pam_auth: PAM: User %s Authenticated OK\n", user));
      break;
    default:
      DEBUG(0, ("smb_pam_auth: PAM: UNKNOWN ERROR while authenticating user %s\n", user));
      break;
  }

  smb_pam_nt_status_error_handler(pamh, pam_error, "Authentication Failure", 2, &nt_status);
  return nt_status;
}

/*
 * PAM Account Handler
 */
static NTSTATUS smb_pam_account(pam_handle_t *pamh, const char * user)
{
  int pam_error;
  NTSTATUS nt_status = NT_STATUS_ACCOUNT_DISABLED;

  DEBUG(4,("smb_pam_account: PAM: Account Management for User: %s\n", user));
  pam_error = pam_acct_mgmt(pamh, PAM_SILENT); /* Is user account enabled? */
  switch( pam_error ) {
    case PAM_AUTHTOK_EXPIRED:
      DEBUG(2, ("smb_pam_account: PAM: User %s is valid but password is expired\n", user));
      break;
    case PAM_ACCT_EXPIRED:
      DEBUG(2, ("smb_pam_account: PAM: User %s no longer permitted to access system\n", user));
      break;
    case PAM_AUTH_ERR:
      DEBUG(2, ("smb_pam_account: PAM: There was an authentication error for user %s\n", user));
      break;
    case PAM_PERM_DENIED:
      DEBUG(0, ("smb_pam_account: PAM: User %s is NOT permitted to access system at this time\n", user));
      break;
    case PAM_USER_UNKNOWN:
      DEBUG(0, ("smb_pam_account: PAM: User \"%s\" is NOT known to account management\n", user));
      break;
    case PAM_SUCCESS:
      DEBUG(4, ("smb_pam_account: PAM: Account OK for User: %s\n", user));
      break;
    default:
      DEBUG(0, ("smb_pam_account: PAM: UNKNOWN PAM ERROR (%d) during Account Management for User: %s\n", pam_error, user));
      break;
  }

  smb_pam_nt_status_error_handler(pamh, pam_error, "Account Check Failed", 2, &nt_status);
  return nt_status;
}

/*
 * PAM Credential Setting
 */

static NTSTATUS smb_pam_setcred(pam_handle_t *pamh, const char * user)
{
  int pam_error;
  NTSTATUS nt_status = NT_STATUS_NO_TOKEN;

  /*
   * This will allow samba to acquire a kerberos token. And, when
   * exporting an AFS cell, be able to /write/ to this cell.
   */

  DEBUG(4,("PAM: Account Management SetCredentials for User: %s\n", user));
  pam_error = pam_setcred(pamh, (PAM_ESTABLISH_CRED|PAM_SILENT));
  switch( pam_error ) {
    case PAM_CRED_UNAVAIL:
      DEBUG(0, ("smb_pam_setcred: PAM: Credentials not found for user:%s\n", user ));
      break;
    case PAM_CRED_EXPIRED:
      DEBUG(0, ("smb_pam_setcred: PAM: Credentials for user: \"%s\" EXPIRED!\n", user ));
      break;
    case PAM_USER_UNKNOWN:
      DEBUG(0, ("smb_pam_setcred: PAM: User: \"%s\" is NOT known so can not set credentials!\n", user ));
      break;
    case PAM_CRED_ERR:
      DEBUG(0, ("smb_pam_setcred: PAM: Unknown setcredentials error - unable to set credentials for %s\n", user ));
      break;
    case PAM_SUCCESS:
      DEBUG(4, ("smb_pam_setcred: PAM: SetCredentials OK for User: %s\n", user));
      break;
    default:
      DEBUG(0, ("smb_pam_setcred: PAM: UNKNOWN PAM ERROR (%d) during SetCredentials for User: %s\n", pam_error, user));
      break;
  }

  smb_pam_nt_status_error_handler(pamh, pam_error, "Set Credential Failure", 2, &nt_status);
  return nt_status;
}

/*
 * PAM Internal Session Handler
 */
static bool smb_internal_pam_session(pam_handle_t *pamh, const char *user, const char *tty, bool flag)
{
  int pam_error;

#ifdef HAVE_PAM_TTY
  DEBUG(4,("smb_internal_pam_session: PAM: tty set to: %s\n", tty));
  pam_error = pam_set_item(pamh, PAM_TTY, tty);
  if (!smb_pam_error_handler(pamh, pam_error, "set tty failed", 0))
    return False;
#endif

  if (flag) {
    pam_error = pam_open_session(pamh, PAM_SILENT);
    if (!smb_pam_error_handler(pamh, pam_error, "session setup failed", 0))
      return False;
  } else {
    pam_setcred(pamh, (PAM_DELETE_CRED|PAM_SILENT)); /* We don't care if this fails */
    pam_error = pam_close_session(pamh, PAM_SILENT); /* This will probably pick up the error anyway */
    if (!smb_pam_error_handler(pamh, pam_error, "session close failed", 0))
      return False;
  }
  return (True);
}

/*
 * Internal PAM Password Changer.
 */

static bool smb_pam_chauthtok(pam_handle_t *pamh, const char * user)
{
  int pam_error;

  DEBUG(4,("smb_pam_chauthtok: PAM: Password Change for User: %s\n", user));

  pam_error = pam_chauthtok(pamh, PAM_SILENT); /* Change Password */

  switch( pam_error ) {
  case PAM_AUTHTOK_ERR:
    DEBUG(2, ("PAM: unable to obtain the new authentication token - is password to weak?\n"));
    break;

  /* This doesn't seem to be defined on Solaris. JRA */
#ifdef PAM_AUTHTOK_RECOVER_ERR
  case PAM_AUTHTOK_RECOVER_ERR:
    DEBUG(2, ("PAM: unable to obtain the old authentication token - was the old password wrong?.\n"));
    break;
#endif

  case PAM_AUTHTOK_LOCK_BUSY:
    DEBUG(2, ("PAM: unable to change the authentication token since it is currently locked.\n"));
    break;
  case PAM_AUTHTOK_DISABLE_AGING:
    DEBUG(2, ("PAM: Authentication token aging has been disabled.\n"));
    break;
  case PAM_PERM_DENIED:
    DEBUG(0, ("PAM: Permission denied.\n"));
    break;
  case PAM_TRY_AGAIN:
    DEBUG(0, ("PAM: Could not update all authentication token(s). No authentication tokens were updated.\n"));
    break;
  case PAM_USER_UNKNOWN:
    DEBUG(0, ("PAM: User not known to PAM\n"));
    break;
  case PAM_SUCCESS:
    DEBUG(4, ("PAM: Account OK for User: %s\n", user));
    break;
  default:
    DEBUG(0, ("PAM: UNKNOWN PAM ERROR (%d) for User: %s\n", pam_error, user));
  }

  if(!smb_pam_error_handler(pamh, pam_error, "Password Change Failed", 2)) {
    return False;
  }

  /* If this point is reached, the password has changed. */
  return True;
}

/*
 * PAM Externally accessible Session handler
 */

bool smb_pam_claim_session(const char *user, const char *tty, const char *rhost)
{
  pam_handle_t *pamh = NULL;
  struct pam_conv *pconv = NULL;

  /* Ignore PAM if told to. */

  if (!lp_obey_pam_restrictions())
    return True;

  if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, NULL, NULL)) == NULL)
    return False;

  if (!smb_pam_start(&pamh, user, rhost, pconv))
    return False;

  if (!smb_internal_pam_session(pamh, user, tty, True)) {
    smb_pam_end(pamh, pconv);
    return False;
  }

  return smb_pam_end(pamh, pconv);
}

/*
 * PAM Externally accessible Session handler
 */

bool smb_pam_close_session(const char *user, const char *tty, const char *rhost)
{
  pam_handle_t *pamh = NULL;
  struct pam_conv *pconv = NULL;

  /* Ignore PAM if told to. */

  if (!lp_obey_pam_restrictions())
    return True;

  if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, NULL, NULL)) == NULL)
    return False;

  if (!smb_pam_start(&pamh, user, rhost, pconv))
    return False;

  if (!smb_internal_pam_session(pamh, user, tty, False)) {
    smb_pam_end(pamh, pconv);
    return False;
  }

  return smb_pam_end(pamh, pconv);
}

/*
 * PAM Externally accessible Account handler
 */

NTSTATUS smb_pam_accountcheck(const char *user, const char *rhost)
{
  NTSTATUS nt_status = NT_STATUS_ACCOUNT_DISABLED;
  pam_handle_t *pamh = NULL;
  struct pam_conv *pconv = NULL;

  /* Ignore PAM if told to. */

  if (!lp_obey_pam_restrictions())
    return NT_STATUS_OK;

  if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, NULL, NULL)) == NULL)
    return NT_STATUS_NO_MEMORY;

  if (!smb_pam_start(&pamh, user, rhost, pconv))
    return NT_STATUS_ACCOUNT_DISABLED;

  if (!NT_STATUS_IS_OK(nt_status = smb_pam_account(pamh, user)))
    DEBUG(0, ("smb_pam_accountcheck: PAM: Account Validation Failed - Rejecting User %s!\n", user));

  smb_pam_end(pamh, pconv);
  return nt_status;
}

/*
 * PAM Password Validation Suite
 */

NTSTATUS smb_pam_passcheck(const char * user, const char * rhost,
         const char * password)
{
  pam_handle_t *pamh = NULL;
  NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
  struct pam_conv *pconv = NULL;

  /*
   * Note we can't ignore PAM here as this is the only
   * way of doing auths on plaintext passwords when
   * compiled --with-pam.
   */

  if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, password, NULL)) == NULL)
    return NT_STATUS_LOGON_FAILURE;

  if (!smb_pam_start(&pamh, user, rhost, pconv))
    return NT_STATUS_LOGON_FAILURE;

  if (!NT_STATUS_IS_OK(nt_status = smb_pam_auth(pamh, user))) {
    DEBUG(0, ("smb_pam_passcheck: PAM: smb_pam_auth failed - Rejecting User %s !\n", user));
    smb_pam_end(pamh, pconv);
    return nt_status;
  }

  if (!NT_STATUS_IS_OK(nt_status = smb_pam_account(pamh, user))) {
    DEBUG(0, ("smb_pam_passcheck: PAM: smb_pam_account failed - Rejecting User %s !\n", user));
    smb_pam_end(pamh, pconv);
    return nt_status;
  }

  if (!NT_STATUS_IS_OK(nt_status = smb_pam_setcred(pamh, user))) {
    DEBUG(0, ("smb_pam_passcheck: PAM: smb_pam_setcred failed - Rejecting User %s !\n", user));
    smb_pam_end(pamh, pconv);
    return nt_status;
  }

  smb_pam_end(pamh, pconv);
  return nt_status;
}

/*
 * PAM Password Change Suite
 */

bool smb_pam_passchange(const char *user, const char *rhost,
      const char *oldpassword, const char *newpassword)
{
  /* Appropriate quantities of root should be obtained BEFORE calling this function */
  struct pam_conv *pconv = NULL;
  pam_handle_t *pamh = NULL;

  if ((pconv = smb_setup_pam_conv(smb_pam_passchange_conv, user, oldpassword, newpassword)) == NULL)
    return False;

  if(!smb_pam_start(&pamh, user, rhost, pconv))
    return False;

  if (!smb_pam_chauthtok(pamh, user)) {
    DEBUG(0, ("smb_pam_passchange: PAM: Password Change Failed for user %s!\n", user));
    smb_pam_end(pamh, pconv);
    return False;
  }

  return smb_pam_end(pamh, pconv);
}

#else

/* If PAM not used, no PAM restrictions on accounts. */
NTSTATUS smb_pam_accountcheck(const char *user, const char *rhost)
{
  return NT_STATUS_OK;
}

/* If PAM not used, also no PAM restrictions on sessions. */
bool smb_pam_claim_session(const char *user, const char *tty, const char *rhost)
{
  return True;
}

/* If PAM not used, also no PAM restrictions on sessions. */
bool smb_pam_close_session(const char *in_user, const char *tty, const char *rhost)
{
  return True;
}
#endif /* WITH_PAM */

Coverage Report

Created: 2025-07-23 07:04