1 /***********************************************************************
5 * WINBIND plugin for pppd. Performs PAP, CHAP, MS-CHAP, MS-CHAPv2
6 * authentication using WINBIND to contact a NT-style PDC.
8 * Based on the structure of the radius module.
10 * Copyright (C) 2003 Andrew Bartlet <abartlet@samba.org>
12 * Copyright 1999 Paul Mackerras, Alan Curry.
13 * (pipe read code from passpromt.c)
15 * Copyright (C) 2002 Roaring Penguin Software Inc.
17 * Based on a patch for ipppd, which is:
18 * Copyright (C) 1996, Matjaz Godec <gody@elgo.si>
19 * Copyright (C) 1996, Lars Fenneberg <in5y050@public.uni-hamburg.de>
20 * Copyright (C) 1997, Miguel A.L. Paraz <map@iphil.net>
22 * Uses radiusclient library, which is:
23 * Copyright (C) 1995,1996,1997,1998 Lars Fenneberg <lf@elemental.net>
24 * Copyright (C) 2002 Roaring Penguin Software Inc.
26 * MPPE support is by Ralf Hofmann, <ralf.hofmann@elvido.net>, with
27 * modification from Frank Cusack, <frank@google.com>.
29 * Updated on 2003-12-12 to support updated PPP plugin API from latest CVS
30 * Copyright (C) 2003, Sean E. Millichamp <sean at bruenor dot org>
32 * This plugin may be distributed according to the terms of the GNU
33 * General Public License, version 2 or (at your option) any later version.
35 ***********************************************************************/
48 #include <sys/types.h>
61 #define NOT_AUTHENTICATED 0
62 #define AUTHENTICATED 1
64 static char *ntlm_auth = NULL;
66 static int set_ntlm_auth(char **argv)
72 option_error("ntlm_auth-helper argument must be full path");
77 novm("ntlm_auth-helper argument");
80 if (ntlm_auth != NULL)
86 static option_t Options[] = {
87 { "ntlm_auth-helper", o_special, (void *) &set_ntlm_auth,
88 "Path to ntlm_auth executable", OPT_PRIV },
93 winbind_secret_check(void);
95 static int winbind_pap_auth(char *user,
98 struct wordlist **paddrs,
99 struct wordlist **popts);
100 static int winbind_chap_verify(char *user, char *ourname, int id,
101 struct chap_digest_type *digest,
102 unsigned char *challenge,
103 unsigned char *response,
104 char *message, int message_space);
105 static int winbind_allowed_address(u_int32_t addr);
107 char pppd_version[] = VERSION;
109 /**********************************************************************
110 * %FUNCTION: plugin_init
116 * Initializes WINBIND plugin.
117 ***********************************************************************/
121 pap_check_hook = winbind_secret_check;
122 pap_auth_hook = winbind_pap_auth;
124 chap_check_hook = winbind_secret_check;
125 chap_verify_hook = winbind_chap_verify;
127 allowed_address_hook = winbind_allowed_address;
129 /* Don't ask the peer for anything other than MS-CHAP or MS-CHAP V2 */
130 chap_mdtype_all &= (MDTYPE_MICROSOFT_V2 | MDTYPE_MICROSOFT);
132 add_options(Options);
134 info("WINBIND plugin initialized.");
138 Routine to get hex characters and turn them into a 16 byte array.
139 the array can be variable length, and any non-hex-numeric
140 characters are skipped. "0xnn" or "0Xnn" is specially catered
143 valid examples: "0A5D15"; "0x15, 0x49, 0xa2"; "59\ta9\te3\n"
148 Unix SMB/CIFS implementation.
149 Samba utility functions
151 Copyright (C) Andrew Tridgell 1992-2001
152 Copyright (C) Simo Sorce 2001-2002
153 Copyright (C) Martin Pool 2003
155 This program is free software; you can redistribute it and/or modify
156 it under the terms of the GNU General Public License as published by
157 the Free Software Foundation; either version 2 of the License, or
158 (at your option) any later version.
160 This program is distributed in the hope that it will be useful,
161 but WITHOUT ANY WARRANTY; without even the implied warranty of
162 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
163 GNU General Public License for more details.
165 You should have received a copy of the GNU General Public License
166 along with this program; if not, write to the Free Software
167 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
170 size_t strhex_to_str(unsigned char *p, size_t len, const char *strhex)
173 size_t num_chars = 0;
174 unsigned char lonybble, hinybble;
175 const char *hexchars = "0123456789ABCDEF";
176 char *p1 = NULL, *p2 = NULL;
178 for (i = 0; i < len && strhex[i] != 0; i++) {
179 if (strncmp(hexchars, "0x", 2) == 0) {
180 i++; /* skip two chars */
184 if (!(p1 = strchr(hexchars, toupper(strhex[i]))))
187 i++; /* next hex digit */
189 if (!(p2 = strchr(hexchars, toupper(strhex[i]))))
192 /* get the two nybbles */
193 hinybble = (p1 - hexchars);
194 lonybble = (p2 - hexchars);
196 p[num_chars] = (hinybble << 4) | lonybble;
205 static const char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
208 * Encode a base64 string into a malloc()ed string caller to free.
210 *From SQUID: adopted from http://ftp.sunet.se/pub2/gnu/vm/base64-encode.c with adjustments
212 char * base64_encode(const char *data)
215 size_t len = strlen(data);
216 size_t output_len = 4 * ((len + 2) / 3) + 2;
217 const unsigned char *ptr = (const unsigned char *) data;
218 char *result = malloc(output_len); /* get us plenty of space */
221 for (; len >= 3; len -= 3) {
222 bits = (ptr[0] << 16) + (ptr[1] << 8) + ptr[2];
224 result[out_cnt++] = b64[bits >> 18];
225 result[out_cnt++] = b64[(bits >> 12) & 0x3f];
226 result[out_cnt++] = b64[(bits >> 6) & 0x3f];
227 result[out_cnt++] = b64[bits & 0x3f];
233 result[out_cnt++] = b64[bits >> 18];
234 result[out_cnt++] = b64[(bits >> 12) & 0x3f];
235 result[out_cnt++] = (len > 1)? b64[(bits >> 6) & 0x3f]: '=';
236 result[out_cnt++] = '=';
239 result[out_cnt] = '\0'; /* terminate */
243 unsigned int run_ntlm_auth(const char *username,
245 const char *full_username,
246 const char *plaintext_password,
247 const u_char *challenge,
248 size_t challenge_length,
249 const u_char *lm_response,
250 size_t lm_response_length,
251 const u_char *nt_response,
252 size_t nt_response_length,
262 int authenticated = NOT_AUTHENTICATED; /* not auth */
263 int got_user_session_key = 0; /* not got key */
275 /* First see if we have a program to run... */
276 if (ntlm_auth == NULL)
277 return NOT_AUTHENTICATED;
279 /* Make first child */
280 if (pipe(child_out) == -1) {
281 error("pipe creation failed for child OUT!");
282 return NOT_AUTHENTICATED;
285 if (pipe(child_in) == -1) {
286 error("pipe creation failed for child IN!");
287 return NOT_AUTHENTICATED;
290 forkret = safe_fork(child_in[0], child_out[1], 2);
293 *error_string = strdup("fork failed!");
296 return NOT_AUTHENTICATED;
307 /* run winbind as the user that invoked pppd */
309 if (setgid(gid) == -1 || getgid() != gid) {
310 fatal("pppd/winbind: could not setgid to %d: %m", gid);
313 if (setuid(uid) == -1 || getuid() != uid) {
314 fatal("pppd/winbind: could not setuid to %d: %m", uid);
316 execl("/bin/sh", "sh", "-c", ntlm_auth, NULL);
317 fatal("pppd/winbind: could not exec /bin/sh: %m");
324 /* Need to write the User's info onto the pipe */
326 pipe_in = fdopen(child_in[1], "w");
328 pipe_out = fdopen(child_out[0], "r");
330 /* look for session key coming back */
333 char *b64_username = base64_encode(username);
334 fprintf(pipe_in, "Username:: %s\n", b64_username);
339 char *b64_domain = base64_encode(domain);
340 fprintf(pipe_in, "NT-Domain:: %s\n", b64_domain);
345 char *b64_full_username = base64_encode(full_username);
346 fprintf(pipe_in, "Full-Username:: %s\n", b64_full_username);
347 free(b64_full_username);
350 if (plaintext_password) {
351 char *b64_plaintext_password = base64_encode(plaintext_password);
352 fprintf(pipe_in, "Password:: %s\n", b64_plaintext_password);
353 free(b64_plaintext_password);
356 if (challenge_length) {
357 fprintf(pipe_in, "Request-User-Session-Key: yes\n");
359 challenge_hex = malloc(challenge_length*2+1);
361 for (i = 0; i < challenge_length; i++)
362 sprintf(challenge_hex + i * 2, "%02X", challenge[i]);
364 fprintf(pipe_in, "LANMAN-Challenge: %s\n", challenge_hex);
368 if (lm_response_length) {
369 lm_hex_hash = malloc(lm_response_length*2+1);
371 for (i = 0; i < lm_response_length; i++)
372 sprintf(lm_hex_hash + i * 2, "%02X", lm_response[i]);
374 fprintf(pipe_in, "LANMAN-response: %s\n", lm_hex_hash);
378 if (nt_response_length) {
379 nt_hex_hash = malloc(nt_response_length*2+1);
381 for (i = 0; i < nt_response_length; i++)
382 sprintf(nt_hex_hash + i * 2, "%02X", nt_response[i]);
384 fprintf(pipe_in, "NT-response: %s\n", nt_hex_hash);
388 fprintf(pipe_in, ".\n");
391 while (fgets(buffer, sizeof(buffer)-1, pipe_out) != NULL) {
392 char *message, *parameter;
393 if (buffer[strlen(buffer)-1] != '\n') {
396 buffer[strlen(buffer)-1] = '\0';
399 if (!(parameter = strstr(buffer, ": "))) {
408 if (strcmp(message, ".") == 0) {
409 /* end of sequence */
411 } else if (strcasecmp(message, "Authenticated") == 0) {
412 if (strcasecmp(parameter, "Yes") == 0) {
413 authenticated = AUTHENTICATED;
415 notice("Winbind has declined authentication for user!");
416 authenticated = NOT_AUTHENTICATED;
418 } else if (strcasecmp(message, "User-session-key") == 0) {
419 /* length is the number of characters to parse */
421 if (strhex_to_str(nt_key, 32, parameter) == 16) {
422 got_user_session_key = 1;
424 notice("NT session key for user was not 16 bytes!");
427 } else if (strcasecmp(message, "Error") == 0) {
428 authenticated = NOT_AUTHENTICATED;
430 *error_string = strdup(parameter);
431 } else if (strcasecmp(message, "Authentication-Error") == 0) {
432 authenticated = NOT_AUTHENTICATED;
434 *error_string = strdup(parameter);
436 notice("unrecognised input from ntlm_auth helper - %s: %s", message, parameter);
441 if (close(child_out[0]) == -1) {
443 notice("error closing pipe?!? for child OUT[0]");
444 return NOT_AUTHENTICATED;
448 if (close(child_in[1]) == -1) {
449 notice("error closing pipe?!? for child IN[1]");
450 return NOT_AUTHENTICATED;
453 while ((wait(&status) == -1) && errno == EINTR && !got_sigterm)
456 if ((authenticated == AUTHENTICATED) && nt_key && !got_user_session_key) {
457 notice("Did not get user session key, despite being authenticated!");
458 return NOT_AUTHENTICATED;
460 return authenticated;
463 /**********************************************************************
464 * %FUNCTION: winbind_secret_check
468 * 0 if we don't have an ntlm_auth program to run, otherwise 1.
470 * Tells pppd that we will try to authenticate the peer, and not to
471 * worry about looking in /etc/ppp/ *-secrets
472 ***********************************************************************/
474 winbind_secret_check(void)
476 return ntlm_auth != NULL;
479 /**********************************************************************
480 * %FUNCTION: winbind_pap_auth
482 * user -- user-name of peer
483 * passwd -- password supplied by peer
484 * msgp -- Message which will be sent in PAP response
485 * paddrs -- set to a list of possible peer IP addresses
486 * popts -- set to a list of additional pppd options
488 * 1 if we can authenticate, -1 if we cannot.
490 * Performs PAP authentication using WINBIND
491 ***********************************************************************/
493 winbind_pap_auth(char *user,
496 struct wordlist **paddrs,
497 struct wordlist **popts)
499 if (run_ntlm_auth(NULL, NULL, user, password, NULL, 0, NULL, 0, NULL, 0, NULL, msgp) == AUTHENTICATED) {
505 /**********************************************************************
506 * %FUNCTION: winbind_chap_auth
508 * user -- user-name of peer
509 * remmd -- hash received from peer
510 * remmd_len -- length of remmd
511 * cstate -- pppd's chap_state structure
513 * AUTHENTICATED (1) if we can authenticate, NOT_AUTHENTICATED (0) if we cannot.
515 * Performs MS-CHAP and MS-CHAPv2 authentication using WINBIND.
516 ***********************************************************************/
519 winbind_chap_verify(char *user, char *ourname, int id,
520 struct chap_digest_type *digest,
521 unsigned char *challenge,
522 unsigned char *response,
523 char *message, int message_space)
525 int challenge_len, response_len;
526 char domainname[256];
530 unsigned char saresponse[MS_AUTH_RESPONSE_LENGTH+1];
532 /* The first byte of each of these strings contains their length */
533 challenge_len = *challenge++;
534 response_len = *response++;
536 /* remove domain from "domain\username" */
537 if ((username = strrchr(user, '\\')) != NULL)
542 strlcpy(domainname, user, sizeof(domainname));
544 /* remove domain from "domain\username" */
545 if ((p = strrchr(domainname, '\\')) != NULL) {
552 /* generate MD based on negotiated type */
553 switch (digest->code) {
557 char *error_string = NULL;
558 u_char *nt_response = NULL;
559 u_char *lm_response = NULL;
560 int nt_response_size = 0;
561 int lm_response_size = 0;
562 u_char session_key[16];
564 if (response_len != MS_CHAP_RESPONSE_LEN)
565 break; /* not even the right length */
567 /* Determine which part of response to verify against */
568 if (response[MS_CHAP_USENT]) {
569 nt_response = &response[MS_CHAP_NTRESP];
570 nt_response_size = MS_CHAP_NTRESP_LEN;
573 lm_response = &response[MS_CHAP_LANMANRESP];
574 lm_response_size = MS_CHAP_LANMANRESP_LEN;
576 /* Should really propagate this into the error packet. */
577 notice("Peer request for LANMAN auth not supported");
578 return NOT_AUTHENTICATED;
579 #endif /* MSLANMAN */
582 /* ship off to winbind, and check */
584 if (run_ntlm_auth(username,
588 challenge, challenge_len,
589 lm_response, lm_response_size,
590 nt_response, nt_response_size,
592 &error_string) == AUTHENTICATED) {
594 mppe_set_chapv1(challenge, session_key);
596 slprintf(message, message_space, "Access granted");
597 return AUTHENTICATED;
601 notice(error_string);
604 slprintf(message, message_space, "E=691 R=1 C=%0.*B V=0",
605 challenge_len, challenge);
606 return NOT_AUTHENTICATED;
611 case CHAP_MICROSOFT_V2:
614 u_char session_key[MD4_SIGNATURE_SIZE];
615 char *error_string = NULL;
617 if (response_len != MS_CHAP2_RESPONSE_LEN)
618 break; /* not even the right length */
620 ChallengeHash(&response[MS_CHAP2_PEER_CHALLENGE], challenge,
623 /* ship off to winbind, and check */
625 if (run_ntlm_auth(username,
631 &response[MS_CHAP2_NTRESP],
634 &error_string) == AUTHENTICATED) {
636 GenerateAuthenticatorResponse(session_key,
637 &response[MS_CHAP2_NTRESP],
638 &response[MS_CHAP2_PEER_CHALLENGE],
639 challenge, user, saresponse);
641 mppe_set_chapv2(session_key, &response[MS_CHAP2_NTRESP],
642 MS_CHAP2_AUTHENTICATOR);
644 if (response[MS_CHAP2_FLAGS]) {
645 slprintf(message, message_space, "S=%s", saresponse);
647 slprintf(message, message_space, "S=%s M=%s",
648 saresponse, "Access granted");
650 return AUTHENTICATED;
654 notice(error_string);
655 slprintf(message, message_space, "E=691 R=1 C=%0.*B V=0 M=%s",
656 challenge_len, challenge, error_string);
659 slprintf(message, message_space, "E=691 R=1 C=%0.*B V=0 M=%s",
660 challenge_len, challenge, "Access denied");
662 return NOT_AUTHENTICATED;
668 error("WINBIND: Challenge type %u unsupported", digest->code);
670 return NOT_AUTHENTICATED;
674 winbind_allowed_address(u_int32_t addr)
676 ipcp_options *wo = &ipcp_wantoptions[0];
677 if (wo->hisaddr !=0 && wo->hisaddr == addr) {