source: vendor/3.5.10/source3/auth/auth_unix.c

/* 
   Unix SMB/CIFS implementation.
   Password and authentication handling
   Copyright (C) Andrew Bartlett              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/>.
*/

#include "includes.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_AUTH

/**
 * update the encrypted smbpasswd file from the plaintext username and password
 *  
 *  this ugly hack needs to die, but not quite yet, I think people still use it...
 **/
static bool update_smbpassword_file(const char *user, const char *password)
{
        struct samu     *sampass;
        bool            ret;
        
        if ( !(sampass = samu_new( NULL )) ) {
                return False;
        }
        
        become_root();
        ret = pdb_getsampwnam(sampass, user);
        unbecome_root();

        if(ret == False) {
                DEBUG(0,("pdb_getsampwnam returned NULL\n"));
                TALLOC_FREE(sampass);
                return False;
        }

        /*
         * Remove the account disabled flag - we are updating the
         * users password from a login.
         */
        if (!pdb_set_acct_ctrl(sampass, pdb_get_acct_ctrl(sampass) & ~ACB_DISABLED, PDB_CHANGED)) {
                TALLOC_FREE(sampass);
                return False;
        }

        if (!pdb_set_plaintext_passwd (sampass, password)) {
                TALLOC_FREE(sampass);
                return False;
        }

        /* Now write it into the file. */
        become_root();

        ret = NT_STATUS_IS_OK(pdb_update_sam_account (sampass));

        unbecome_root();

        if (ret) {
                DEBUG(3,("pdb_update_sam_account returned %d\n",ret));
        }

        TALLOC_FREE(sampass);
        return ret;
}


/** Check a plaintext username/password
 *
 * Cannot deal with an encrupted password in any manner whatsoever,
 * unless the account has a null password.
 **/

static NTSTATUS check_unix_security(const struct auth_context *auth_context,
                             void *my_private_data, 
                             TALLOC_CTX *mem_ctx,
                             const auth_usersupplied_info *user_info, 
                             auth_serversupplied_info **server_info)
{
        NTSTATUS nt_status;
        struct passwd *pass = NULL;

        become_root();
        pass = Get_Pwnam_alloc(talloc_tos(), user_info->internal_username);

        
        /** @todo This call assumes a ASCII password, no charset transformation is 
            done.  We may need to revisit this **/
        nt_status = pass_check(pass,
                                pass ? pass->pw_name : user_info->internal_username, 
                                (char *)user_info->plaintext_password.data,
                                user_info->plaintext_password.length-1,
                                lp_update_encrypted() ? 
                                update_smbpassword_file : NULL,
                                True);
        
        unbecome_root();

        if (NT_STATUS_IS_OK(nt_status)) {
                if (pass) {
                        /* if a real user check pam account restrictions */
                        /* only really perfomed if "obey pam restriction" is true */
                        nt_status = smb_pam_accountcheck(pass->pw_name);
                        if (  !NT_STATUS_IS_OK(nt_status)) {
                                DEBUG(1, ("PAM account restriction prevents user login\n"));
                        } else {
                                make_server_info_pw(server_info, pass->pw_name, pass);
                        }
                } else {
                        /* we need to do somthing more useful here */
                        nt_status = NT_STATUS_NO_SUCH_USER;
                }
        }

        TALLOC_FREE(pass);
        return nt_status;
}

/* module initialisation */
static NTSTATUS auth_init_unix(struct auth_context *auth_context, const char* param, auth_methods **auth_method) 
{
        if (!make_auth_methods(auth_context, auth_method)) {
                return NT_STATUS_NO_MEMORY;
        }

        (*auth_method)->name = "unix";
        (*auth_method)->auth = check_unix_security;
        return NT_STATUS_OK;
}

NTSTATUS auth_unix_init(void)
{
        return smb_register_auth(AUTH_INTERFACE_VERSION, "unix", auth_init_unix);
}