/* 
   Unix SMB/CIFS implementation.
   negprot reply code
   Copyright (C) Andrew Tridgell 1992-1998
   
   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

/* initialise the auth_context for this server and return the cryptkey */
static void get_challenge(struct server_context *smb, char buff[8]) 
{
	NTSTATUS nt_status;
	const uint8 *cryptkey;

	/* muliple negprots are not premitted */
	if (smb->negotiate.auth_context) {
		DEBUG(3,("get challenge: is this a secondary negprot?  auth_context is non-NULL!\n"));
		smb_panic("secondary negprot");
	}

	DEBUG(10, ("get challenge: creating negprot_global_auth_context\n"));

	nt_status = make_auth_context_subsystem(&smb->negotiate.auth_context);

	if (!NT_STATUS_IS_OK(nt_status)) {
		DEBUG(0, ("make_auth_context_subsystem returned %s", nt_errstr(nt_status)));
		smb_panic("cannot make_negprot_global_auth_context!\n");
	}

	DEBUG(10, ("get challenge: getting challenge\n"));
	cryptkey = smb->negotiate.auth_context->get_ntlm_challenge(smb->negotiate.auth_context);
	memcpy(buff, cryptkey, 8);
}

/****************************************************************************
 Reply for the core protocol.
****************************************************************************/
static void reply_corep(struct request_context *req, uint16 choice)
{
	req_setup_reply(req, 1, 0);

	SSVAL(req->out.vwv, VWV(0), choice);

	req->smb->negotiate.protocol = PROTOCOL_CORE;

	req_send_reply(req);
}

/****************************************************************************
 Reply for the coreplus protocol.
this is quite incomplete - we only fill in a small part of the reply, but as nobody uses
this any more it probably doesn't matter
****************************************************************************/
static void reply_coreplus(struct request_context *req, uint16 choice)
{
	uint16 raw = (lp_readraw()?1:0) | (lp_writeraw()?2:0);

	req_setup_reply(req, 13, 0);

	/* Reply, SMBlockread, SMBwritelock supported. */
	SCVAL(req->out.hdr,HDR_FLG,
	      CVAL(req->out.hdr, HDR_FLG) | FLAG_SUPPORT_LOCKREAD);

	SSVAL(req->out.vwv, VWV(0), choice);
	SSVAL(req->out.vwv, VWV(1), 0x1); /* user level security, don't encrypt */	

	/* tell redirector we support
	   readbraw and writebraw (possibly) */
	SSVAL(req->out.vwv, VWV(5), raw); 

	req->smb->negotiate.protocol = PROTOCOL_COREPLUS;

	req_send_reply(req);
}

/****************************************************************************
 Reply for the lanman 1.0 protocol.
****************************************************************************/
static void reply_lanman1(struct request_context *req, uint16 choice)
{
	int raw = (lp_readraw()?1:0) | (lp_writeraw()?2:0);
	int secword=0;
	time_t t = req->request_time.tv_sec;

	req->smb->negotiate.encrypted_passwords = lp_encrypted_passwords();

	if (lp_security() != SEC_SHARE)
		secword |= NEGOTIATE_SECURITY_USER_LEVEL;

	if (req->smb->negotiate.encrypted_passwords)
		secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE;

	req->smb->negotiate.protocol = PROTOCOL_LANMAN1;

	req_setup_reply(req, 13, req->smb->negotiate.encrypted_passwords ? 8 : 0);

	/* SMBlockread, SMBwritelock supported. */
	SCVAL(req->out.hdr,HDR_FLG,
	      CVAL(req->out.hdr, HDR_FLG) | FLAG_SUPPORT_LOCKREAD);

	SSVAL(req->out.vwv, VWV(0), choice);
	SSVAL(req->out.vwv, VWV(1), secword); 
	SSVAL(req->out.vwv, VWV(2), req->smb->negotiate.max_recv);
	SSVAL(req->out.vwv, VWV(3), lp_maxmux());
	SSVAL(req->out.vwv, VWV(4), 1);
	SSVAL(req->out.vwv, VWV(5), raw); 
	SIVAL(req->out.vwv, VWV(6), req->smb->pid);
	put_dos_date(req->out.vwv, VWV(8), t);
	SSVAL(req->out.vwv, VWV(10), TimeDiff(t)/60);

	/* Create a token value and add it to the outgoing packet. */
	if (req->smb->negotiate.encrypted_passwords) {
		SSVAL(req->out.vwv, VWV(11), 8);
		get_challenge(req->smb, req->out.data);
	}

	req_send_reply(req);	
}

/****************************************************************************
 Reply for the lanman 2.0 protocol.
****************************************************************************/
static void reply_lanman2(struct request_context *req, uint16 choice)
{
	int raw = (lp_readraw()?1:0) | (lp_writeraw()?2:0);
	int secword=0;
	time_t t = req->request_time.tv_sec;

	req->smb->negotiate.encrypted_passwords = lp_encrypted_passwords();
  
	if (lp_security() != SEC_SHARE)
		secword |= NEGOTIATE_SECURITY_USER_LEVEL;

	if (req->smb->negotiate.encrypted_passwords)
		secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE;

	req->smb->negotiate.protocol = PROTOCOL_LANMAN2;

	req_setup_reply(req, 13, 0);

	SSVAL(req->out.vwv, VWV(0), choice);
	SSVAL(req->out.vwv, VWV(1), secword); 
	SSVAL(req->out.vwv, VWV(2), req->smb->negotiate.max_recv);
	SSVAL(req->out.vwv, VWV(3), lp_maxmux());
	SSVAL(req->out.vwv, VWV(4), 1);
	SSVAL(req->out.vwv, VWV(5), raw); 
	SIVAL(req->out.vwv, VWV(6), req->smb->pid);
	put_dos_date(req->out.vwv, VWV(8), t);
	SSVAL(req->out.vwv, VWV(10), TimeDiff(t)/60);

	/* Create a token value and add it to the outgoing packet. */
	if (req->smb->negotiate.encrypted_passwords) {
		SSVAL(req->out.vwv, VWV(11), 8);
		req_grow_data(req, 8);
		get_challenge(req->smb, req->out.data);
	}

	req_push_str(req, NULL, lp_workgroup(), -1, STR_TERMINATE);

	req_send_reply(req);
}


#if 0
/****************************************************************************
 Generate the spnego negprot reply blob. Return the number of bytes used.
****************************************************************************/
static DATA_BLOB negprot_spnego(struct server_context *smb)
{
	DATA_BLOB blob;
	uint8 guid[16];
	const char *OIDs_krb5[] = {OID_KERBEROS5,
				   OID_KERBEROS5_OLD,
				   OID_NTLMSSP,
				   NULL};
	const char *OIDs_plain[] = {OID_NTLMSSP, NULL};
	char *principal;

	smb->negotiate.spnego_negotiated = True;

	memset(guid, 0, 16);
	safe_strcpy((char *)guid, lp_netbios_name(), 16);
	strlower((char *)guid);

#if 0
	/* strangely enough, NT does not send the single OID NTLMSSP when
	   not a ADS member, it sends no OIDs at all

	   we can't do this until we teach our sesssion setup parser to know
	   about raw NTLMSSP (clients send no ASN.1 wrapping if we do this)
	*/
	if (lp_security() != SEC_ADS) {
		memcpy(p, guid, 16);
		return 16;
	}
#endif
	if (lp_security() != SEC_ADS) {
		blob = spnego_gen_negTokenInit(guid, OIDs_plain, "NONE");
	} else {
		asprintf(&principal, "%s$@%s", guid, lp_realm());
		blob = spnego_gen_negTokenInit(guid, OIDs_krb5, principal);
		free(principal);
	}

	return blob;
}
#endif

/****************************************************************************
 Reply for the nt protocol.
****************************************************************************/
static void reply_nt1(struct request_context *req, uint16 choice)
{
	/* dual names + lock_and_read + nt SMBs + remote API calls */
	int capabilities;
	int secword=0;
	time_t t = req->request_time.tv_sec;
	BOOL negotiate_spnego = False;

	capabilities = 
		CAP_NT_FIND | CAP_LOCK_AND_READ | 
		CAP_LEVEL_II_OPLOCKS | CAP_NT_SMBS | CAP_RPC_REMOTE_APIS;

	req->smb->negotiate.encrypted_passwords = lp_encrypted_passwords();

	/* do spnego in user level security if the client
	   supports it and we can do encrypted passwords */
	
	if (req->smb->negotiate.encrypted_passwords && 
	    (lp_security() != SEC_SHARE) &&
	    lp_use_spnego() &&
	    (req->flags2 & FLAGS2_EXTENDED_SECURITY)) {
/* REWRITE		negotiate_spnego = True; 
		capabilities |= CAP_EXTENDED_SECURITY;
*/
	}
	
	if (lp_unix_extensions()) {
		capabilities |= CAP_UNIX;
	}
	
	if (lp_large_readwrite() && (SMB_OFF_T_BITS == 64)) {
		capabilities |= CAP_LARGE_READX | CAP_LARGE_WRITEX | CAP_W2K_SMBS;
	}
	
	if (SMB_OFF_T_BITS >= 64) {
		capabilities |= CAP_LARGE_FILES;
	}

	if (lp_readraw() && lp_writeraw()) {
		capabilities |= CAP_RAW_MODE;
	}
	
	/* allow for disabling unicode */
	if (lp_unicode()) {
		capabilities |= CAP_UNICODE;
	}

	if (lp_nt_status_support()) {
		capabilities |= CAP_STATUS32;
	}
	
	if (lp_host_msdfs()) {
		capabilities |= CAP_DFS;
	}
	
	if (lp_security() != SEC_SHARE) {
		secword |= NEGOTIATE_SECURITY_USER_LEVEL;
	}

	if (req->smb->negotiate.encrypted_passwords) {
		secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE;
	}
	
	req->smb->negotiate.protocol = PROTOCOL_NT1;

	req_setup_reply(req, 17, 0);
	
	SSVAL(req->out.vwv, VWV(0), choice);
	SCVAL(req->out.vwv, VWV(1), secword);

	/* notice the strange +1 on vwv here? That's because
	   this is the one and only SMB packet that is malformed in
	   the specification - all the command words after the secword
	   are offset by 1 byte */
	SSVAL(req->out.vwv+1, VWV(1), lp_maxmux());
	SSVAL(req->out.vwv+1, VWV(2), 1); /* num vcs */
	SIVAL(req->out.vwv+1, VWV(3), req->smb->negotiate.max_recv);
	SIVAL(req->out.vwv+1, VWV(5), 0x10000); /* raw size. full 64k */
	SIVAL(req->out.vwv+1, VWV(7), req->smb->pid); /* session key */
	SIVAL(req->out.vwv+1, VWV(9), capabilities);
	put_long_date(req->out.vwv + VWV(11) + 1, t);
	SSVALS(req->out.vwv+1,VWV(15), TimeDiff(t)/60);
	
	if (!negotiate_spnego) {
		/* Create a token value and add it to the outgoing packet. */
		if (req->smb->negotiate.encrypted_passwords) {
			req_grow_data(req, 8);
			/* note that we do not send a challenge at all if
			   we are using plaintext */
			get_challenge(req->smb, req->out.ptr);
			req->out.ptr += 8;
			SCVAL(req->out.vwv+1, VWV(16), 8);
		}
		req_push_str(req, NULL, lp_workgroup(), -1, STR_UNICODE|STR_TERMINATE|STR_NOALIGN);
		DEBUG(3,("not using SPNEGO\n"));
	} else {
#if 0
		DATA_BLOB blob = negprot_spnego(req->smb);

		req_grow_data(req, blob.length);
		memcpy(req->out.ptr, blob.data, blob.length);
		DEBUG(3,("using SPNEGO\n"));
#else
		exit_server(req->smb, "no SPNEGO please");
#endif
	}
	
	req_send_reply(req);	
}

/* these are the protocol lists used for auto architecture detection:

WinNT 3.51:
protocol [PC NETWORK PROGRAM 1.0]
protocol [XENIX CORE]
protocol [MICROSOFT NETWORKS 1.03]
protocol [LANMAN1.0]
protocol [Windows for Workgroups 3.1a]
protocol [LM1.2X002]
protocol [LANMAN2.1]
protocol [NT LM 0.12]

Win95:
protocol [PC NETWORK PROGRAM 1.0]
protocol [XENIX CORE]
protocol [MICROSOFT NETWORKS 1.03]
protocol [LANMAN1.0]
protocol [Windows for Workgroups 3.1a]
protocol [LM1.2X002]
protocol [LANMAN2.1]
protocol [NT LM 0.12]

Win2K:
protocol [PC NETWORK PROGRAM 1.0]
protocol [LANMAN1.0]
protocol [Windows for Workgroups 3.1a]
protocol [LM1.2X002]
protocol [LANMAN2.1]
protocol [NT LM 0.12]

OS/2:
protocol [PC NETWORK PROGRAM 1.0]
protocol [XENIX CORE]
protocol [LANMAN1.0]
protocol [LM1.2X002]
protocol [LANMAN2.1]
*/

/*
  * Modified to recognize the architecture of the remote machine better.
  *
  * This appears to be the matrix of which protocol is used by which
  * MS product.
       Protocol                       WfWg    Win95   WinNT  Win2K  OS/2
       PC NETWORK PROGRAM 1.0          1       1       1      1      1
       XENIX CORE                                      2             2
       MICROSOFT NETWORKS 3.0          2       2       
       DOS LM1.2X002                   3       3       
       MICROSOFT NETWORKS 1.03                         3
       DOS LANMAN2.1                   4       4       
       LANMAN1.0                                       4      2      3
       Windows for Workgroups 3.1a     5       5       5      3
       LM1.2X002                                       6      4      4
       LANMAN2.1                                       7      5      5
       NT LM 0.12                              6       8      6
  *
  *  tim@fsg.com 09/29/95
  *  Win2K added by matty 17/7/99
  */
  
#define ARCH_WFWG     0x3      /* This is a fudge because WfWg is like Win95 */
#define ARCH_WIN95    0x2
#define ARCH_WINNT    0x4
#define ARCH_WIN2K    0xC      /* Win2K is like NT */
#define ARCH_OS2      0x14     /* Again OS/2 is like NT */
#define ARCH_SAMBA    0x20
 
#define ARCH_ALL      0x3F
 
/* List of supported protocols, most desired first */
static const struct {
	const char *proto_name;
	const char *short_name;
	void (*proto_reply_fn)(struct request_context *req, uint16 choice);
	int protocol_level;
} supported_protocols[] = {
	{"NT LANMAN 1.0",           "NT1",      reply_nt1,      PROTOCOL_NT1},
	{"NT LM 0.12",              "NT1",      reply_nt1,      PROTOCOL_NT1},
	{"LM1.2X002",               "LANMAN2",  reply_lanman2,  PROTOCOL_LANMAN2},
	{"Samba",                   "LANMAN2",  reply_lanman2,  PROTOCOL_LANMAN2},
	{"DOS LM1.2X002",           "LANMAN2",  reply_lanman2,  PROTOCOL_LANMAN2},
	{"LANMAN1.0",               "LANMAN1",  reply_lanman1,  PROTOCOL_LANMAN1},
	{"MICROSOFT NETWORKS 3.0",  "LANMAN1",  reply_lanman1,  PROTOCOL_LANMAN1},
	{"MICROSOFT NETWORKS 1.03", "COREPLUS", reply_coreplus, PROTOCOL_COREPLUS},
	{"PC NETWORK PROGRAM 1.0",  "CORE",     reply_corep,    PROTOCOL_CORE}, 
	{NULL,NULL,NULL,0},
};

/****************************************************************************
 Reply to a negprot.
****************************************************************************/

void reply_negprot(struct request_context *req)
{
	int Index=0;
	int choice = -1;
	int protocol;
	char *p;
	int arch = ARCH_ALL;

	if (req->smb->negotiate.done_negprot) {
		exit_server(req->smb, "multiple negprot's are not permitted");
	}
	req->smb->negotiate.done_negprot = True;

	p = req->in.data + 1;

	while (p < req->in.data + req->in.data_size) { 
		Index++;
		DEBUG(3,("Requested protocol [%s]\n",p));
		if (strcmp(p,"Windows for Workgroups 3.1a") == 0)
			arch &= ( ARCH_WFWG | ARCH_WIN95 | ARCH_WINNT | ARCH_WIN2K );
		else if (strcmp(p,"DOS LM1.2X002") == 0)
			arch &= ( ARCH_WFWG | ARCH_WIN95 );
		else if (strcmp(p,"DOS LANMAN2.1") == 0)
			arch &= ( ARCH_WFWG | ARCH_WIN95 );
		else if (strcmp(p,"NT LM 0.12") == 0)
			arch &= ( ARCH_WIN95 | ARCH_WINNT | ARCH_WIN2K );
		else if (strcmp(p,"LANMAN2.1") == 0)
			arch &= ( ARCH_WINNT | ARCH_WIN2K | ARCH_OS2 );
		else if (strcmp(p,"LM1.2X002") == 0)
			arch &= ( ARCH_WINNT | ARCH_WIN2K | ARCH_OS2 );
		else if (strcmp(p,"MICROSOFT NETWORKS 1.03") == 0)
			arch &= ARCH_WINNT;
		else if (strcmp(p,"XENIX CORE") == 0)
			arch &= ( ARCH_WINNT | ARCH_OS2 );
		else if (strcmp(p,"Samba") == 0) {
			arch = ARCH_SAMBA;
			break;
		}
 
		p += strlen(p) + 2;
	}
    
	switch (arch) {
		case ARCH_SAMBA:
			set_remote_arch(req->smb, RA_SAMBA);
			break;
		case ARCH_WFWG:
			set_remote_arch(req->smb, RA_WFWG);
			break;
		case ARCH_WIN95:
			set_remote_arch(req->smb, RA_WIN95);
			break;
		case ARCH_WINNT:
			if (req->flags2==FLAGS2_WIN2K_SIGNATURE)
				set_remote_arch(req->smb, RA_WIN2K);
			else
				set_remote_arch(req->smb, RA_WINNT);
			break;
		case ARCH_WIN2K:
			set_remote_arch(req->smb, RA_WIN2K);
			break;
		case ARCH_OS2:
			set_remote_arch(req->smb, RA_OS2);
			break;
		default:
			set_remote_arch(req->smb, RA_UNKNOWN);
		break;
	}
 
	/* possibly reload - change of architecture */
	reload_services(req->smb, True);      
    
	/* Check for protocols, most desirable first */
	for (protocol = 0; supported_protocols[protocol].proto_name; protocol++) {
		p = req->in.data+1;
		Index = 0;
		if ((supported_protocols[protocol].protocol_level <= lp_maxprotocol()) &&
				(supported_protocols[protocol].protocol_level >= lp_minprotocol()))
			while (p < (req->in.data + req->in.data_size)) { 
				if (strequal(p,supported_protocols[protocol].proto_name))
					choice = Index;
				Index++;
				p += strlen(p) + 2;
			}
		if(choice != -1)
			break;
	}
  
	if(choice != -1) {
		sub_set_remote_proto(supported_protocols[protocol].short_name);
		reload_services(req->smb, True);
		supported_protocols[protocol].proto_reply_fn(req, choice);
		DEBUG(3,("Selected protocol %s\n",supported_protocols[protocol].proto_name));
	} else {
		DEBUG(0,("No protocol supported !\n"));
	}
  
	DEBUG(5,("negprot index=%d\n", choice));
}