source: vendor/3.5.5/source3/auth/auth_compat.c

/* 
   Unix SMB/CIFS implementation.
   Password and authentication handling
   Copyright (C) Andrew Bartlett         2001-2002

   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"

extern struct auth_context *negprot_global_auth_context;
extern bool global_encrypted_passwords_negotiated;

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_AUTH

/****************************************************************************
 COMPATIBILITY INTERFACES:
 ***************************************************************************/

/****************************************************************************
check if a username/password is OK assuming the password is a 24 byte
SMB hash
return True if the password is correct, False otherwise
****************************************************************************/

NTSTATUS check_plaintext_password(const char *smb_name, DATA_BLOB plaintext_password, auth_serversupplied_info **server_info)
{
        struct auth_context *plaintext_auth_context = NULL;
        auth_usersupplied_info *user_info = NULL;
        uint8_t chal[8];
        NTSTATUS nt_status;
        if (!NT_STATUS_IS_OK(nt_status = make_auth_context_subsystem(&plaintext_auth_context))) {
                return nt_status;
        }

        plaintext_auth_context->get_ntlm_challenge(plaintext_auth_context,
                                                   chal);

        if (!make_user_info_for_reply(&user_info, 
                                      smb_name, lp_workgroup(), chal,
                                      plaintext_password)) {
                return NT_STATUS_NO_MEMORY;
        }

        nt_status = plaintext_auth_context->check_ntlm_password(plaintext_auth_context, 
                                                                user_info, server_info); 

        (plaintext_auth_context->free)(&plaintext_auth_context);
        free_user_info(&user_info);
        return nt_status;
}

static NTSTATUS pass_check_smb(struct auth_context *actx,
                               const char *smb_name,
                               const char *domain, 
                               DATA_BLOB lm_pwd,
                               DATA_BLOB nt_pwd,
                               DATA_BLOB plaintext_password,
                               bool encrypted)

{
        NTSTATUS nt_status;
        auth_serversupplied_info *server_info = NULL;
        if (encrypted) {
                auth_usersupplied_info *user_info = NULL;
                if (actx == NULL) {
                        return NT_STATUS_INTERNAL_ERROR;
                }
                make_user_info_for_reply_enc(&user_info, smb_name, 
                                             domain,
                                             lm_pwd, 
                                             nt_pwd);
                nt_status = actx->check_ntlm_password(actx, user_info, &server_info);
                free_user_info(&user_info);
        } else {
                nt_status = check_plaintext_password(smb_name, plaintext_password, &server_info);
        }               
        TALLOC_FREE(server_info);
        return nt_status;
}

/****************************************************************************
check if a username/password pair is ok via the auth subsystem.
return True if the password is correct, False otherwise
****************************************************************************/

bool password_ok(struct auth_context *actx, bool global_encrypted,
                 const char *session_workgroup,
                 const char *smb_name, DATA_BLOB password_blob)
{

        DATA_BLOB null_password = data_blob_null;
        bool encrypted = (global_encrypted && (password_blob.length == 24 || password_blob.length > 46));

        if (encrypted) {
                /* 
                 * The password could be either NTLM or plain LM.  Try NTLM first, 
                 * but fall-through as required.
                 * Vista sends NTLMv2 here - we need to try the client given workgroup.
                 */
                if (session_workgroup) {
                        if (NT_STATUS_IS_OK(pass_check_smb(actx, smb_name, session_workgroup, null_password, password_blob, null_password, encrypted))) {
                                return True;
                        }
                        if (NT_STATUS_IS_OK(pass_check_smb(actx, smb_name, session_workgroup, password_blob, null_password, null_password, encrypted))) {
                                return True;
                        }
                }

                if (NT_STATUS_IS_OK(pass_check_smb(actx, smb_name, lp_workgroup(), null_password, password_blob, null_password, encrypted))) {
                        return True;
                }

                if (NT_STATUS_IS_OK(pass_check_smb(actx, smb_name, lp_workgroup(), password_blob, null_password, null_password, encrypted))) {
                        return True;
                }
        } else {
                if (NT_STATUS_IS_OK(pass_check_smb(actx, smb_name, lp_workgroup(), null_password, null_password, password_blob, encrypted))) {
                        return True;
                }
        }

        return False;
}