/* 
   Unix SMB/CIFS implementation.

   Winbind status program.

   Copyright (C) Tim Potter      2000-2002
   Copyright (C) Andrew Bartlett 2002
   Copyright (C) Francesco Chemolli <kinkie@kame.usr.dsi.unimi.it> 2000 

   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"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_WINBIND

#define SQUID_BUFFER_SIZE 2010

extern int winbindd_fd;

static const char *helper_protocol;
static const char *username;
static const char *domain;
static const char *workstation;
static const char *hex_challenge;
static const char *hex_lm_response;
static const char *hex_nt_response;
static unsigned char *challenge;
static size_t challenge_len;
static unsigned char *lm_response;
static size_t lm_response_len;
static unsigned char *nt_response;
static size_t nt_response_len;

static char *password;

static char winbind_separator(void)
{
	struct winbindd_response response;
	static BOOL got_sep;
	static char sep;

	if (got_sep)
		return sep;

	ZERO_STRUCT(response);

	/* Send off request */

	if (winbindd_request(WINBINDD_INFO, NULL, &response) !=
	    NSS_STATUS_SUCCESS) {
		d_printf("could not obtain winbind separator!\n");
		return '\\';
	}

	sep = response.data.info.winbind_separator;
	got_sep = True;

	if (!sep) {
		d_printf("winbind separator was NULL!\n");
		return '\\';
	}
	
	return sep;
}

static const char *get_winbind_domain(void)
{
	struct winbindd_response response;

	static fstring winbind_domain;

	ZERO_STRUCT(response);

	/* Send off request */

	if (winbindd_request(WINBINDD_DOMAIN_NAME, NULL, &response) !=
	    NSS_STATUS_SUCCESS) {
		d_printf("could not obtain winbind domain name!\n");
		return NULL;
	}

	fstrcpy(winbind_domain, response.data.domain_name);

	return winbind_domain;

}

/* Authenticate a user with a plaintext password */

static BOOL check_plaintext_auth(const char *user, const char *pass, BOOL stdout_diagnostics)
{
	struct winbindd_request request;
	struct winbindd_response response;
        NSS_STATUS result;

	/* Send off request */

	ZERO_STRUCT(request);
	ZERO_STRUCT(response);

	fstrcpy(request.data.auth.user, user);
	fstrcpy(request.data.auth.pass, pass);

	result = winbindd_request(WINBINDD_PAM_AUTH, &request, &response);

	/* Display response */
	
	if (stdout_diagnostics) {
		if ((result != NSS_STATUS_SUCCESS) && (response.data.auth.nt_status == 0)) {
			d_printf("Reading winbind reply failed! (0x01)\n");
		}
		
		d_printf("%s (0x%x)\n", 
			 response.data.auth.nt_status_string, 
			 response.data.auth.nt_status);
	} else {
		if ((result != NSS_STATUS_SUCCESS) && (response.data.auth.nt_status == 0)) {
			DEBUG(1, ("Reading winbind reply failed! (0x01)\n"));
		}
		
		DEBUG(3, ("%s (0x%x)\n", 
			 response.data.auth.nt_status_string, 
			 response.data.auth.nt_status));		
	}
		
        return (result == NSS_STATUS_SUCCESS);
}

static void manage_squid_2_5_basic_request() 
{
	char buf[SQUID_BUFFER_SIZE+1];
	int length;
	char *c, *user, *pass;
	static BOOL err;
  
	if (x_fgets(buf, sizeof(buf)-1, x_stdin) == NULL) {
		DEBUG(1, ("fgets() failed! dying..... errno=%d (%s)\n", errno,
			  strerror(errno)));
		exit(1);    /* BIIG buffer */
	}
    
	c=memchr(buf,'\n',sizeof(buf)-1);
	if (c) {
		*c = '\0';
		length = c-buf;
	} else {
		err = 1;
		return;
	}
	if (err) {
		DEBUG(2, ("Oversized message\n"));
		x_fprintf(x_stderr, "ERR\n");
		err = 0;
		return;
	}

	DEBUG(10, ("Got '%s' from squid (length: %d).\n",buf,length));

	if (buf[0] == '\0') {
		DEBUG(2, ("Invalid Request\n"));
		x_fprintf(x_stderr, "ERR\n");
		return;
	}

	user=buf;

	pass=memchr(buf,' ',length);
	if (!pass) {
		DEBUG(2, ("Password not found. Denying access\n"));
		x_fprintf(x_stderr, "ERR\n");
		return;
	}
	*pass='\0';
	pass++;

	rfc1738_unescape(user);
	rfc1738_unescape(pass);

	if (check_plaintext_auth(user, pass, False)) {
		x_fprintf(x_stdout, "OK\n");
	} else {
		x_fprintf(x_stdout, "ERR\n");
	}
}


static void squid_2_5_basic(void) {
	/* initialize FDescs */
	x_setbuf(x_stdout, NULL);
	x_setbuf(x_stderr, NULL);
	while(1) {
		manage_squid_2_5_basic_request();
	}
}


/* Authenticate a user with a challenge/response */

static BOOL check_auth_crap(void)
{
	struct winbindd_request request;
	struct winbindd_response response;
        NSS_STATUS result;
	/* Send off request */

	ZERO_STRUCT(request);
	ZERO_STRUCT(response);

	fstrcpy(request.data.auth_crap.user, username);

	fstrcpy(request.data.auth_crap.domain, domain);
	fstrcpy(request.data.auth_crap.workstation, workstation);
	
	memcpy(request.data.auth_crap.chal, challenge, MIN(challenge_len, 8));

	memcpy(request.data.auth_crap.lm_resp, lm_response, MIN(lm_response_len, sizeof(request.data.auth_crap.lm_resp)));
        
	memcpy(request.data.auth_crap.nt_resp, nt_response, MIN(nt_response_len, sizeof(request.data.auth_crap.nt_resp)));
        
        request.data.auth_crap.lm_resp_len = lm_response_len;
        request.data.auth_crap.nt_resp_len = nt_response_len;

	result = winbindd_request(WINBINDD_PAM_AUTH_CRAP, &request, &response);

	/* Display response */

	if ((result != NSS_STATUS_SUCCESS) && (response.data.auth.nt_status == 0)) {
		d_printf("Reading winbind reply failed! (0x01)\n");
	}

	d_printf("%s (0x%x)\n", 
		 response.data.auth.nt_status_string, 
		 response.data.auth.nt_status);

        return result == NSS_STATUS_SUCCESS;
}

/* Main program */

enum {
	OPT_USERNAME = 1000,
	OPT_DOMAIN,
	OPT_WORKSTATION,
	OPT_CHALLENGE,
	OPT_RESPONSE,
	OPT_LM,
	OPT_NT,
	OPT_PASSWORD
};

/*************************************************************
 Routine to set hex password characters into an allocated array.
**************************************************************/

void hex_encode(const unsigned char *buff_in, size_t len, char **out_hex_buffer)
{
	int i;
	char *hex_buffer;

	*out_hex_buffer = smb_xmalloc((len*2)+1);
	hex_buffer = *out_hex_buffer;

	for (i = 0; i < len; i++)
		slprintf(&hex_buffer[i*2], 3, "%02X", buff_in[i]);
}

/*************************************************************
 Routine to get the 32 hex characters and turn them
 into a 16 byte array.
**************************************************************/

BOOL hex_decode(const char *hex_buf_in, unsigned char **out_buffer, size_t *size)
{
	int i;
	size_t hex_buf_in_len = strlen(hex_buf_in);
	unsigned char  partial_byte_hex;
	unsigned char  partial_byte;
	char           *hexchars = "0123456789ABCDEF";
	char           *p;
	BOOL           high = True;
	
	if (!hex_buf_in) 
		return (False);
	
	*size = (hex_buf_in_len + 1) / 2;

	*out_buffer = smb_xmalloc(*size);
	
	for (i = 0; i < hex_buf_in_len; i++) {
		partial_byte_hex = toupper(hex_buf_in[i]);

		p = strchr(hexchars, partial_byte_hex);

		if (!p)
			return (False);

		partial_byte = PTR_DIFF(p, hexchars);

		if (high) {
			(*out_buffer)[i / 2] = (partial_byte << 4);
		} else {
			(*out_buffer)[i / 2] |= partial_byte;
		}
		high = !high;
	}
	return (True);
}


int main(int argc, const char **argv)
{
	int opt;

	poptContext pc;
	struct poptOption long_options[] = {
		POPT_AUTOHELP

		{ "helper-protocol", 0, POPT_ARG_STRING, &helper_protocol, OPT_DOMAIN, "operate as a stdio-based helper", "helper protocol to use"},
 		{ "username", 0, POPT_ARG_STRING, &username, OPT_USERNAME, "username"},
 		{ "domain", 0, POPT_ARG_STRING, &domain, OPT_DOMAIN, "domain name"},
 		{ "workstation", 0, POPT_ARG_STRING, &domain, OPT_WORKSTATION, "workstation"},
 		{ "challenge", 0, POPT_ARG_STRING, &hex_challenge, OPT_CHALLENGE, "challenge (HEX encoded)"},
		{ "lm-response", 0, POPT_ARG_STRING, &hex_lm_response, OPT_LM, "LM Response to the challenge (HEX encoded)"},
		{ "nt-response", 0, POPT_ARG_STRING, &hex_nt_response, OPT_NT, "NT or NTLMv2 Response to the challenge (HEX encoded)"},
		{ "password", 0, POPT_ARG_STRING, &password, OPT_PASSWORD, "User's plaintext password"},		
		{ NULL, 0, POPT_ARG_INCLUDE_TABLE, popt_common_debug },
		{ NULL, 0, POPT_ARG_INCLUDE_TABLE, popt_common_configfile },
		{ 0, 0, 0, 0 }
	};

	/* Samba client initialisation */

	dbf = x_stderr;
	
	/* Parse options */

	pc = poptGetContext("ntlm_auth", argc, argv, long_options, 0);

	/* Parse command line options */

	if (argc == 1) {
		poptPrintHelp(pc, stderr, 0);
		return 1;
	}

	pc = poptGetContext(NULL, argc, (const char **)argv, long_options, 
			    POPT_CONTEXT_KEEP_FIRST);

	while((opt = poptGetNextOpt(pc)) != -1) {
		switch (opt) {
		case OPT_CHALLENGE:
			if (!hex_decode(hex_challenge, &challenge, &challenge_len)) {
				fprintf(stderr, "hex decode of %s failed!\n", hex_challenge);
				exit(1);
			}
			break;
		case OPT_LM: 
			if (!hex_decode(hex_lm_response, &lm_response, &lm_response_len)) {
				fprintf(stderr, "hex decode of %s failed!\n", lm_response);
				exit(1);
			}
			break;
		case OPT_NT:
			if (!hex_decode(hex_lm_response, &lm_response, &lm_response_len)) {
				fprintf(stderr, "hex decode of %s failed!\n", lm_response);
				exit(1);
			}
			break;
		}
	}

	if (helper_protocol) {
		if (strcmp(helper_protocol, "squid-2.5-basic")== 0) {
			squid_2_5_basic();
		}
	}

	if (domain == NULL) {
		domain = get_winbind_domain();
	}

	if (workstation == NULL) {
		workstation = "";
	}

	if (challenge) {
		if (!check_auth_crap()) {
			exit(1);
		}
	} else if (password) {
		fstring user;
		snprintf(user, sizeof(user)-1, "%s%c%s", domain, winbind_separator(), username);
		if (!check_plaintext_auth(user, password, True)) {
			exit(1);
		}
	}

	/* Exit code */

	poptFreeContext(pc);
	return 0;
}