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 ***********************************************************************/
38 #include <sys/types.h>
49 #include <pppd/pppd.h>
50 #include <pppd/chap-new.h>
51 #include <pppd/chap_ms.h>
53 #include <pppd/ipcp.h>
54 #include <pppd/mppe.h>
55 #include <pppd/ppp-crypto.h>
59 #define NOT_AUTHENTICATED 0
60 #define AUTHENTICATED 1
62 static char *ntlm_auth = NULL;
64 static int set_ntlm_auth(char **argv)
70 option_error("ntlm_auth-helper argument must be full path");
75 novm("ntlm_auth-helper argument");
78 if (ntlm_auth != NULL)
84 static option_t Options[] = {
85 { "ntlm_auth-helper", o_special, (void *) &set_ntlm_auth,
86 "Path to ntlm_auth executable", OPT_PRIV },
91 winbind_secret_check(void);
93 static int winbind_pap_auth(char *user,
96 struct wordlist **paddrs,
97 struct wordlist **popts);
98 static int winbind_chap_verify(char *user, char *ourname, int id,
99 struct chap_digest_type *digest,
100 unsigned char *challenge,
101 unsigned char *response,
102 char *message, int message_space);
103 static int winbind_allowed_address(u_int32_t addr);
105 char pppd_version[] = PPPD_VERSION;
107 /**********************************************************************
108 * %FUNCTION: plugin_init
114 * Initializes WINBIND plugin.
115 ***********************************************************************/
119 pap_check_hook = winbind_secret_check;
120 pap_auth_hook = winbind_pap_auth;
122 chap_check_hook = winbind_secret_check;
123 chap_verify_hook = winbind_chap_verify;
125 allowed_address_hook = winbind_allowed_address;
127 /* Don't ask the peer for anything other than MS-CHAP or MS-CHAP V2 */
128 chap_mdtype_all &= (MDTYPE_MICROSOFT_V2 | MDTYPE_MICROSOFT);
130 add_options(Options);
132 info("WINBIND plugin initialized.");
136 Routine to get hex characters and turn them into a 16 byte array.
137 the array can be variable length, and any non-hex-numeric
138 characters are skipped. "0xnn" or "0Xnn" is specially catered
141 valid examples: "0A5D15"; "0x15, 0x49, 0xa2"; "59\ta9\te3\n"
146 Unix SMB/CIFS implementation.
147 Samba utility functions
149 Copyright (C) Andrew Tridgell 1992-2001
150 Copyright (C) Simo Sorce 2001-2002
151 Copyright (C) Martin Pool 2003
153 This program is free software; you can redistribute it and/or modify
154 it under the terms of the GNU General Public License as published by
155 the Free Software Foundation; either version 2 of the License, or
156 (at your option) any later version.
158 This program is distributed in the hope that it will be useful,
159 but WITHOUT ANY WARRANTY; without even the implied warranty of
160 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
161 GNU General Public License for more details.
163 You should have received a copy of the GNU General Public License
164 along with this program; if not, write to the Free Software
165 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
168 size_t strhex_to_str(unsigned char *p, size_t len, const char *strhex)
171 size_t num_chars = 0;
172 unsigned char lonybble, hinybble;
173 const char *hexchars = "0123456789ABCDEF";
174 char *p1 = NULL, *p2 = NULL;
176 for (i = 0; i < len && strhex[i] != 0; i++) {
177 if (strncmp(hexchars, "0x", 2) == 0) {
178 i++; /* skip two chars */
182 if (!(p1 = strchr(hexchars, toupper(strhex[i]))))
185 i++; /* next hex digit */
187 if (!(p2 = strchr(hexchars, toupper(strhex[i]))))
190 /* get the two nybbles */
191 hinybble = (p1 - hexchars);
192 lonybble = (p2 - hexchars);
194 p[num_chars] = (hinybble << 4) | lonybble;
203 static const char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
206 * Encode a base64 string into a malloc()ed string caller to free.
208 *From SQUID: adopted from http://ftp.sunet.se/pub2/gnu/vm/base64-encode.c with adjustments
210 char * base64_encode(const char *data)
213 size_t len = strlen(data);
214 size_t output_len = 4 * ((len + 2) / 3) + 2;
215 const unsigned char *ptr = (const unsigned char *) data;
216 char *result = malloc(output_len); /* get us plenty of space */
219 for (; len >= 3; len -= 3) {
220 bits = (ptr[0] << 16) + (ptr[1] << 8) + ptr[2];
222 result[out_cnt++] = b64[bits >> 18];
223 result[out_cnt++] = b64[(bits >> 12) & 0x3f];
224 result[out_cnt++] = b64[(bits >> 6) & 0x3f];
225 result[out_cnt++] = b64[bits & 0x3f];
231 result[out_cnt++] = b64[bits >> 18];
232 result[out_cnt++] = b64[(bits >> 12) & 0x3f];
233 result[out_cnt++] = (len > 1)? b64[(bits >> 6) & 0x3f]: '=';
234 result[out_cnt++] = '=';
237 result[out_cnt] = '\0'; /* terminate */
241 unsigned int run_ntlm_auth(const char *username,
243 const char *full_username,
244 const char *plaintext_password,
245 const u_char *challenge,
246 size_t challenge_length,
247 const u_char *lm_response,
248 size_t lm_response_length,
249 const u_char *nt_response,
250 size_t nt_response_length,
260 int authenticated = NOT_AUTHENTICATED; /* not auth */
261 int got_user_session_key = 0; /* not got key */
273 /* First see if we have a program to run... */
274 if (ntlm_auth == NULL)
275 return NOT_AUTHENTICATED;
277 /* Make first child */
278 if (pipe(child_out) == -1) {
279 error("pipe creation failed for child OUT!");
280 return NOT_AUTHENTICATED;
283 if (pipe(child_in) == -1) {
284 error("pipe creation failed for child IN!");
285 return NOT_AUTHENTICATED;
288 forkret = safe_fork(child_in[0], child_out[1], 2);
291 *error_string = strdup("fork failed!");
294 return NOT_AUTHENTICATED;
305 /* run winbind as the user that invoked pppd */
307 if (setgid(gid) == -1 || getgid() != gid) {
308 fatal("pppd/winbind: could not setgid to %d: %m", gid);
311 if (setuid(uid) == -1 || getuid() != uid) {
312 fatal("pppd/winbind: could not setuid to %d: %m", uid);
314 execl("/bin/sh", "sh", "-c", ntlm_auth, NULL);
315 fatal("pppd/winbind: could not exec /bin/sh: %m");
322 /* Need to write the User's info onto the pipe */
324 pipe_in = fdopen(child_in[1], "w");
326 pipe_out = fdopen(child_out[0], "r");
328 /* look for session key coming back */
331 char *b64_username = base64_encode(username);
332 fprintf(pipe_in, "Username:: %s\n", b64_username);
337 char *b64_domain = base64_encode(domain);
338 fprintf(pipe_in, "NT-Domain:: %s\n", b64_domain);
343 char *b64_full_username = base64_encode(full_username);
344 fprintf(pipe_in, "Full-Username:: %s\n", b64_full_username);
345 free(b64_full_username);
348 if (plaintext_password) {
349 char *b64_plaintext_password = base64_encode(plaintext_password);
350 fprintf(pipe_in, "Password:: %s\n", b64_plaintext_password);
351 free(b64_plaintext_password);
354 if (challenge_length) {
355 fprintf(pipe_in, "Request-User-Session-Key: yes\n");
357 challenge_hex = malloc(challenge_length*2+1);
359 for (i = 0; i < challenge_length; i++)
360 sprintf(challenge_hex + i * 2, "%02X", challenge[i]);
362 fprintf(pipe_in, "LANMAN-Challenge: %s\n", challenge_hex);
366 if (lm_response_length) {
367 lm_hex_hash = malloc(lm_response_length*2+1);
369 for (i = 0; i < lm_response_length; i++)
370 sprintf(lm_hex_hash + i * 2, "%02X", lm_response[i]);
372 fprintf(pipe_in, "LANMAN-response: %s\n", lm_hex_hash);
376 if (nt_response_length) {
377 nt_hex_hash = malloc(nt_response_length*2+1);
379 for (i = 0; i < nt_response_length; i++)
380 sprintf(nt_hex_hash + i * 2, "%02X", nt_response[i]);
382 fprintf(pipe_in, "NT-response: %s\n", nt_hex_hash);
386 fprintf(pipe_in, ".\n");
389 while (fgets(buffer, sizeof(buffer)-1, pipe_out) != NULL) {
390 char *message, *parameter;
391 if (buffer[strlen(buffer)-1] != '\n') {
394 buffer[strlen(buffer)-1] = '\0';
397 if (!(parameter = strstr(buffer, ": "))) {
406 if (strcmp(message, ".") == 0) {
407 /* end of sequence */
409 } else if (strcasecmp(message, "Authenticated") == 0) {
410 if (strcasecmp(parameter, "Yes") == 0) {
411 authenticated = AUTHENTICATED;
413 notice("Winbind has declined authentication for user!");
414 authenticated = NOT_AUTHENTICATED;
416 } else if (strcasecmp(message, "User-session-key") == 0) {
417 /* length is the number of characters to parse */
419 if (strhex_to_str(nt_key, 32, parameter) == 16) {
420 got_user_session_key = 1;
422 notice("NT session key for user was not 16 bytes!");
425 } else if (strcasecmp(message, "Error") == 0) {
426 authenticated = NOT_AUTHENTICATED;
428 *error_string = strdup(parameter);
429 } else if (strcasecmp(message, "Authentication-Error") == 0) {
430 authenticated = NOT_AUTHENTICATED;
432 *error_string = strdup(parameter);
434 notice("unrecognised input from ntlm_auth helper - %s: %s", message, parameter);
439 if (close(child_out[0]) == -1) {
441 notice("error closing pipe?!? for child OUT[0]");
442 return NOT_AUTHENTICATED;
446 if (close(child_in[1]) == -1) {
447 notice("error closing pipe?!? for child IN[1]");
448 return NOT_AUTHENTICATED;
451 while ((wait(&status) == -1) && errno == EINTR && !got_sigterm)
454 if ((authenticated == AUTHENTICATED) && nt_key && !got_user_session_key) {
455 notice("Did not get user session key, despite being authenticated!");
456 return NOT_AUTHENTICATED;
458 return authenticated;
461 /**********************************************************************
462 * %FUNCTION: winbind_secret_check
466 * 0 if we don't have an ntlm_auth program to run, otherwise 1.
468 * Tells pppd that we will try to authenticate the peer, and not to
469 * worry about looking in /etc/ppp/ *-secrets
470 ***********************************************************************/
472 winbind_secret_check(void)
474 return ntlm_auth != NULL;
477 /**********************************************************************
478 * %FUNCTION: winbind_pap_auth
480 * user -- user-name of peer
481 * passwd -- password supplied by peer
482 * msgp -- Message which will be sent in PAP response
483 * paddrs -- set to a list of possible peer IP addresses
484 * popts -- set to a list of additional pppd options
486 * 1 if we can authenticate, -1 if we cannot.
488 * Performs PAP authentication using WINBIND
489 ***********************************************************************/
491 winbind_pap_auth(char *user,
494 struct wordlist **paddrs,
495 struct wordlist **popts)
497 if (run_ntlm_auth(NULL, NULL, user, password, NULL, 0, NULL, 0, NULL, 0, NULL, msgp) == AUTHENTICATED) {
503 /**********************************************************************
504 * %FUNCTION: winbind_chap_auth
506 * user -- user-name of peer
507 * remmd -- hash received from peer
508 * remmd_len -- length of remmd
509 * cstate -- pppd's chap_state structure
511 * AUTHENTICATED (1) if we can authenticate, NOT_AUTHENTICATED (0) if we cannot.
513 * Performs MS-CHAP and MS-CHAPv2 authentication using WINBIND.
514 ***********************************************************************/
517 winbind_chap_verify(char *user, char *ourname, int id,
518 struct chap_digest_type *digest,
519 unsigned char *challenge,
520 unsigned char *response,
521 char *message, int message_space)
523 int challenge_len, response_len;
524 char domainname[256];
528 unsigned char saresponse[MS_AUTH_RESPONSE_LENGTH+1];
530 /* The first byte of each of these strings contains their length */
531 challenge_len = *challenge++;
532 response_len = *response++;
534 /* remove domain from "domain\username" */
535 if ((username = strrchr(user, '\\')) != NULL)
540 strlcpy(domainname, user, sizeof(domainname));
542 /* remove domain from "domain\username" */
543 if ((p = strrchr(domainname, '\\')) != NULL) {
550 /* generate MD based on negotiated type */
551 switch (digest->code) {
555 char *error_string = NULL;
556 u_char *nt_response = NULL;
557 u_char *lm_response = NULL;
558 int nt_response_size = 0;
559 int lm_response_size = 0;
560 u_char session_key[MD4_DIGEST_LENGTH];
562 if (response_len != MS_CHAP_RESPONSE_LEN)
563 break; /* not even the right length */
565 /* Determine which part of response to verify against */
566 if (response[MS_CHAP_USENT]) {
567 nt_response = &response[MS_CHAP_NTRESP];
568 nt_response_size = MS_CHAP_NTRESP_LEN;
570 #ifdef PPP_WITH_MSLANMAN
571 lm_response = &response[MS_CHAP_LANMANRESP];
572 lm_response_size = MS_CHAP_LANMANRESP_LEN;
574 /* Should really propagate this into the error packet. */
575 notice("Peer request for LANMAN auth not supported");
576 return NOT_AUTHENTICATED;
577 #endif /* PPP_WITH_MSLANMAN */
580 /* ship off to winbind, and check */
582 if (run_ntlm_auth(username,
586 challenge, challenge_len,
587 lm_response, lm_response_size,
588 nt_response, nt_response_size,
590 &error_string) == AUTHENTICATED) {
592 mppe_set_chapv1(challenge, session_key);
594 slprintf(message, message_space, "Access granted");
595 return AUTHENTICATED;
599 notice(error_string);
602 slprintf(message, message_space, "E=691 R=1 C=%0.*B V=0",
603 challenge_len, challenge);
604 return NOT_AUTHENTICATED;
609 case CHAP_MICROSOFT_V2:
612 u_char session_key[MD4_DIGEST_LENGTH];
613 char *error_string = NULL;
615 if (response_len != MS_CHAP2_RESPONSE_LEN)
616 break; /* not even the right length */
618 ChallengeHash(&response[MS_CHAP2_PEER_CHALLENGE], challenge,
621 /* ship off to winbind, and check */
623 if (run_ntlm_auth(username,
629 &response[MS_CHAP2_NTRESP],
632 &error_string) == AUTHENTICATED) {
634 GenerateAuthenticatorResponse(session_key,
635 &response[MS_CHAP2_NTRESP],
636 &response[MS_CHAP2_PEER_CHALLENGE],
637 challenge, user, saresponse);
639 mppe_set_chapv2(session_key, &response[MS_CHAP2_NTRESP],
640 MS_CHAP2_AUTHENTICATOR);
642 if (response[MS_CHAP2_FLAGS]) {
643 slprintf(message, message_space, "S=%s", saresponse);
645 slprintf(message, message_space, "S=%s M=%s",
646 saresponse, "Access granted");
648 return AUTHENTICATED;
652 notice(error_string);
653 slprintf(message, message_space, "E=691 R=1 C=%0.*B V=0 M=%s",
654 challenge_len, challenge, error_string);
657 slprintf(message, message_space, "E=691 R=1 C=%0.*B V=0 M=%s",
658 challenge_len, challenge, "Access denied");
660 return NOT_AUTHENTICATED;
666 error("WINBIND: Challenge type %u unsupported", digest->code);
668 return NOT_AUTHENTICATED;
672 winbind_allowed_address(u_int32_t addr)
674 ipcp_options *wo = &ipcp_wantoptions[0];
675 if (wo->hisaddr !=0 && wo->hisaddr == addr) {