2 * $Id: uams_dhx_pam.c,v 1.24.6.5.2.2 2008-12-03 19:17:27 didg Exp $
4 * Copyright (c) 1990,1993 Regents of The University of Michigan.
5 * Copyright (c) 1999 Adrian Sun (asun@u.washington.edu)
6 * All Rights Reserved. See COPYRIGHT.
11 #endif /* HAVE_CONFIG_H */
13 #if defined(USE_PAM) && defined(UAM_DHX)
17 #include <atalk/logger.h>
21 #endif /* HAVE_UNISTD_H */
23 #ifdef HAVE_SECURITY_PAM_APPL_H
24 #include <security/pam_appl.h>
26 #ifdef HAVE_PAM_PAM_APPL_H
27 #include <pam/pam_appl.h>
31 #if defined(GNUTLS_DHX)
32 #include <gnutls/openssl.h>
33 #elif defined(OPENSSL_DHX)
34 #include <openssl/bn.h>
35 #include <openssl/dh.h>
36 #include <openssl/cast.h>
38 #include <openssl/rand.h>
40 #else /* OPENSSL_DHX */
44 #endif /* OPENSSL_DHX */
46 #include <atalk/afp.h>
47 #include <atalk/uam.h>
51 #define CRYPTBUFLEN (KEYSIZE*2)
52 #define CRYPT2BUFLEN (KEYSIZE + PASSWDLEN)
53 #define CHANGEPWBUFLEN (KEYSIZE + 2*PASSWDLEN)
55 /* hash a number to a 16-bit quantity */
56 #define dhxhash(a) ((((unsigned long) (a) >> 8) ^ \
57 (unsigned long) (a)) & 0xffff)
60 static CAST_KEY castkey;
61 static struct passwd *dhxpwd;
62 static u_int8_t randbuf[KEYSIZE];
64 /* diffie-hellman bits */
65 static unsigned char msg2_iv[] = "CJalbert";
66 static unsigned char msg3_iv[] = "LWallace";
67 static const u_int8_t p[] = {0xBA, 0x28, 0x73, 0xDF, 0xB0, 0x60, 0x57, 0xD4,
68 0x3F, 0x20, 0x24, 0x74, 0x4C, 0xEE, 0xE7, 0x5B};
69 static const u_int8_t g = 0x07;
72 /* Static variables used to communicate between the conversation function
73 * and the server_login function
75 static pam_handle_t *pamh = NULL;
76 static char *PAM_username;
77 static char *PAM_password;
79 /* PAM conversation function
80 * Here we assume (for now, at least) that echo on means login name, and
81 * echo off means password.
83 static int PAM_conv (int num_msg,
84 const struct pam_message **msg,
85 struct pam_response **resp,
86 void *appdata_ptr _U_) {
88 struct pam_response *reply;
90 #define COPY_STRING(s) (s) ? strdup(s) : NULL
96 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM DHX Conversation Err -- %s",
102 reply = (struct pam_response *)
103 calloc(num_msg, sizeof(struct pam_response));
107 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM DHX Conversation Err -- %s",
113 for (count = 0; count < num_msg; count++) {
116 switch (msg[count]->msg_style) {
117 case PAM_PROMPT_ECHO_ON:
118 if (!(string = COPY_STRING(PAM_username))) {
120 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: username failure -- %s",
126 case PAM_PROMPT_ECHO_OFF:
127 if (!(string = COPY_STRING(PAM_password))) {
129 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: passwd failure: --: %s",
136 #ifdef PAM_BINARY_PROMPT
137 case PAM_BINARY_PROMPT:
138 #endif /* PAM_BINARY_PROMPT */
144 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Binary_Prompt -- %s",
151 reply[count].resp_retcode = 0;
152 reply[count].resp = string;
159 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: PAM Success");
164 for (count = 0; count < num_msg; count++) {
165 if (!reply[count].resp)
167 switch (msg[count]->msg_style) {
168 case PAM_PROMPT_ECHO_OFF:
169 case PAM_PROMPT_ECHO_ON:
170 free(reply[count].resp);
176 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM DHX Conversation Err -- %s",
182 static struct pam_conv PAM_conversation = {
188 static int dhx_setup(void *obj, char *ibuf, int ibuflen _U_,
189 char *rbuf, int *rbuflen)
193 BIGNUM *bn, *gbn, *pbn;
196 /* get the client's public key */
197 if (!(bn = BN_bin2bn(ibuf, KEYSIZE, NULL))) {
199 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM No Public Key -- %s",
206 if (!(gbn = BN_bin2bn(&g, sizeof(g), NULL))) {
209 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM No Primes: GBN -- %s",
215 if (!(pbn = BN_bin2bn(p, sizeof(p), NULL))) {
219 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM No Primes: PBN -- %s",
225 /* okay, we're ready */
226 if (!(dh = DH_new())) {
231 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM DH was equal to DH_New... Go figure... -- %s",
237 /* generate key and make sure that we have enough space */
240 if (DH_generate_key(dh) == 0) {
241 unsigned long dherror;
244 ERR_load_crypto_strings();
245 dherror = ERR_get_error();
246 ERR_error_string_n(dherror, errbuf, 256);
248 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Err Generating Key (OpenSSL error code: %u, %s)", dherror, errbuf);
253 if (BN_num_bytes(dh->pub_key) > KEYSIZE) {
254 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Err Generating Key -- Not enough Space? -- %s", strerror(errno));
258 /* figure out the key. store the key in rbuf for now. */
259 i = DH_compute_key(rbuf, bn, dh);
262 CAST_set_key(&castkey, i, rbuf);
264 /* session id. it's just a hashed version of the object pointer. */
265 sessid = dhxhash(obj);
266 memcpy(rbuf, &sessid, sizeof(sessid));
267 rbuf += sizeof(sessid);
268 *rbuflen += sizeof(sessid);
271 BN_bn2bin(dh->pub_key, rbuf);
275 /* buffer to be encrypted */
277 if (uam_afpserver_option(obj, UAM_OPTION_RANDNUM, (void *) randbuf,
281 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Buffer Encryption Err. -- %s",
286 memcpy(rbuf, &randbuf, sizeof(randbuf));
288 /* get the signature. it's always 16 bytes. */
290 if (uam_afpserver_option(obj, UAM_OPTION_SIGNATURE,
291 (void *) &buf, NULL) < 0) {
294 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Signature Retieval Failure -- %s",
299 memcpy(rbuf + KEYSIZE, buf, KEYSIZE);
301 memset(rbuf + KEYSIZE, 0, KEYSIZE);
304 /* encrypt using cast */
305 CAST_cbc_encrypt(rbuf, rbuf, CRYPTBUFLEN, &castkey, msg2_iv,
307 *rbuflen += CRYPTBUFLEN;
310 return AFPERR_AUTHCONT;
316 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Fail - Cast Encryption -- %s",
322 /* -------------------------------- */
323 static int login(void *obj, char *username, int ulen, struct passwd **uam_pwd _U_,
324 char *ibuf, int ibuflen,
325 char *rbuf, int *rbuflen)
327 if (( dhxpwd = uam_getname(obj, username, ulen)) == NULL ) {
328 LOG(log_info, logtype_uams, "uams_dhx_pam.c: unknown username");
332 PAM_username = username;
333 LOG(log_info, logtype_uams, "dhx login: %s", username);
334 return dhx_setup(obj, ibuf, ibuflen, rbuf, rbuflen);
337 /* -------------------------------- */
338 /* dhx login: things are done in a slightly bizarre order to avoid
339 * having to clean things up if there's an error. */
340 static int pam_login(void *obj, struct passwd **uam_pwd,
341 char *ibuf, int ibuflen,
342 char *rbuf, int *rbuflen)
349 /* grab some of the options */
350 if (uam_afpserver_option(obj, UAM_OPTION_USERNAME, (void *) &username, &ulen) < 0) {
351 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: uam_afpserver_option didn't meet uam_option_username -- %s",
356 len = (unsigned char) *ibuf++;
358 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Signature Retieval Failure -- %s",
363 memcpy(username, ibuf, len );
365 username[ len ] = '\0';
367 if ((unsigned long) ibuf & 1) /* pad to even boundary */
370 return (login(obj, username, ulen, uam_pwd, ibuf, ibuflen, rbuf, rbuflen));
373 /* ----------------------------- */
374 static int pam_login_ext(void *obj, char *uname, struct passwd **uam_pwd,
375 char *ibuf, int ibuflen,
376 char *rbuf, int *rbuflen)
384 /* grab some of the options */
385 if (uam_afpserver_option(obj, UAM_OPTION_USERNAME, (void *) &username, &ulen) < 0) {
386 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: uam_afpserver_option didn't meet uam_option_username -- %s",
394 memcpy(&temp16, uname, sizeof(temp16));
397 if ( !len || len > ulen ) {
398 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Signature Retrieval Failure -- %s",
402 memcpy(username, uname +2, len );
403 username[ len ] = '\0';
405 return (login(obj, username, ulen, uam_pwd, ibuf, ibuflen, rbuf, rbuflen));
408 /* -------------------------------- */
410 static int pam_logincont(void *obj, struct passwd **uam_pwd,
411 char *ibuf, int ibuflen _U_,
412 char *rbuf, int *rbuflen)
415 BIGNUM *bn1, *bn2, *bn3;
421 /* check for session id */
422 memcpy(&sessid, ibuf, sizeof(sessid));
423 if (sessid != dhxhash(obj)) {
425 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM Session ID - DHXHash Mismatch -- %s",
430 ibuf += sizeof(sessid);
432 if (uam_afpserver_option(obj, UAM_OPTION_CLIENTNAME,
433 (void *) &hostname, NULL) < 0)
435 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: unable to retrieve client hostname");
439 CAST_cbc_encrypt(ibuf, rbuf, CRYPT2BUFLEN, &castkey,
440 msg3_iv, CAST_DECRYPT);
441 memset(&castkey, 0, sizeof(castkey));
443 /* check to make sure that the random number is the same. we
444 * get sent back an incremented random number. */
445 if (!(bn1 = BN_bin2bn(rbuf, KEYSIZE, NULL)))
448 if (!(bn2 = BN_bin2bn(randbuf, sizeof(randbuf), NULL))) {
453 /* zero out the random number */
454 memset(rbuf, 0, sizeof(randbuf));
455 memset(randbuf, 0, sizeof(randbuf));
458 if (!(bn3 = BN_new())) {
464 BN_sub(bn3, bn1, bn2);
468 /* okay. is it one more? */
469 if (!BN_is_one(bn3)) {
475 /* Set these things up for the conv function */
476 rbuf[PASSWDLEN] = '\0';
479 err = AFPERR_NOTAUTH;
480 PAM_error = pam_start("netatalk", PAM_username, &PAM_conversation,
482 if (PAM_error != PAM_SUCCESS) {
484 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: PAM_Error: %s",
485 pam_strerror(pamh,PAM_error));
490 /* solaris craps out if PAM_TTY and PAM_RHOST aren't set. */
491 pam_set_item(pamh, PAM_TTY, "afpd");
492 pam_set_item(pamh, PAM_RHOST, hostname);
493 PAM_error = pam_authenticate(pamh,0);
494 if (PAM_error != PAM_SUCCESS) {
495 if (PAM_error == PAM_MAXTRIES)
496 err = AFPERR_PWDEXPR;
498 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: PAM_Error: %s",
499 pam_strerror(pamh, PAM_error));
504 PAM_error = pam_acct_mgmt(pamh, 0);
505 if (PAM_error != PAM_SUCCESS ) {
507 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: PAM_Error: %s",
508 pam_strerror(pamh, PAM_error));
510 if (PAM_error == PAM_NEW_AUTHTOK_REQD) /* password expired */
511 err = AFPERR_PWDEXPR;
512 #ifdef PAM_AUTHTOKEN_REQD
513 else if (PAM_error == PAM_AUTHTOKEN_REQD)
514 err = AFPERR_PWDCHNG;
520 #ifndef PAM_CRED_ESTABLISH
521 #define PAM_CRED_ESTABLISH PAM_ESTABLISH_CRED
523 PAM_error = pam_setcred(pamh, PAM_CRED_ESTABLISH);
524 if (PAM_error != PAM_SUCCESS) {
526 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: PAM_Error: %s",
527 pam_strerror(pamh, PAM_error));
532 PAM_error = pam_open_session(pamh, 0);
533 if (PAM_error != PAM_SUCCESS) {
535 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: PAM_Error: %s",
536 pam_strerror(pamh, PAM_error));
541 memset(rbuf, 0, PASSWDLEN); /* zero out the password */
544 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: PAM Auth OK!");
546 if ( err == AFPERR_PWDEXPR)
551 pam_end(pamh, PAM_error);
553 memset(rbuf, 0, CRYPT2BUFLEN);
558 static void pam_logout() {
559 pam_close_session(pamh, 0);
565 /* change pw for dhx needs a couple passes to get everything all
566 * right. basically, it's like the login/logincont sequence */
567 static int pam_changepw(void *obj, char *username,
568 struct passwd *pwd _U_, char *ibuf, int ibuflen,
569 char *rbuf, int *rbuflen)
571 BIGNUM *bn1, *bn2, *bn3;
580 memcpy(&sessid, ibuf, sizeof(sessid));
581 ibuf += sizeof(sessid);
583 if (!sessid) { /* no sessid -> initialization phase */
584 PAM_username = username;
585 ibuflen -= sizeof(sessid);
586 return dhx_setup(obj, ibuf, ibuflen, rbuf, rbuflen);
590 /* otherwise, it's like logincont but different. */
592 /* check out the session id */
593 if (sessid != dhxhash(obj)) {
595 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Session ID not Equal to DHX Hash -- %s",
601 /* we need this for pam */
602 if (uam_afpserver_option(obj, UAM_OPTION_HOSTNAME,
603 (void *) &hostname, NULL) < 0) {
605 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Hostname Null?? -- %s",
611 /* grab the client's nonce, old password, and new password. */
612 CAST_cbc_encrypt(ibuf, ibuf, CHANGEPWBUFLEN, &castkey,
613 msg3_iv, CAST_DECRYPT);
614 memset(&castkey, 0, sizeof(castkey));
616 /* check to make sure that the random number is the same. we
617 * get sent back an incremented random number. */
618 if (!(bn1 = BN_bin2bn(ibuf, KEYSIZE, NULL))) {
620 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Random Number Not the same or not incremented-- %s",
626 if (!(bn2 = BN_bin2bn(randbuf, sizeof(randbuf), NULL))) {
629 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Random Number Not the same or not incremented -- %s",
635 /* zero out the random number */
636 memset(rbuf, 0, sizeof(randbuf));
637 memset(randbuf, 0, sizeof(randbuf));
639 if (!(bn3 = BN_new())) {
643 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Random Number did not Zero -- %s",
649 BN_sub(bn3, bn1, bn2);
653 /* okay. is it one more? */
655 if (!BN_is_one(bn3)) {
658 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: After Random Number not Zero, is it one more? -- %s",
666 /* Set these things up for the conv function. the old password
669 ibuf[PASSWDLEN + PASSWDLEN] = '\0';
670 PAM_password = ibuf + PASSWDLEN;
672 PAM_error = pam_start("netatalk", username, &PAM_conversation,
674 if (PAM_error != PAM_SUCCESS) {
676 LOG(log_info, logtype_uams, "uams_dhx_pam.c :PAM: Needless to say, PAM_error is != to PAM_SUCCESS -- %s",
681 pam_set_item(lpamh, PAM_TTY, "afpd");
682 pam_set_item(lpamh, PAM_RHOST, hostname);
684 /* we might need to do this as root */
687 PAM_error = pam_authenticate(lpamh, 0);
688 if (PAM_error != PAM_SUCCESS) {
690 pam_end(lpamh, PAM_error);
691 return AFPERR_NOTAUTH;
694 /* clear out old passwd */
695 memset(ibuf + PASSWDLEN, 0, PASSWDLEN);
699 ibuf[PASSWDLEN] = '\0';
701 /* this really does need to be done as root */
702 PAM_error = pam_chauthtok(lpamh, 0);
703 seteuid(uid); /* un-root ourselves. */
704 memset(ibuf, 0, PASSWDLEN);
705 if (PAM_error != PAM_SUCCESS) {
706 pam_end(lpamh, PAM_error);
707 return AFPERR_ACCESS;
715 static int uam_setup(const char *path)
717 if (uam_register(UAM_SERVER_LOGIN_EXT, path, "DHCAST128", pam_login,
718 pam_logincont, pam_logout, pam_login_ext) < 0)
721 if (uam_register(UAM_SERVER_CHANGEPW, path, "DHCAST128",
723 uam_unregister(UAM_SERVER_LOGIN, "DHCAST128");
727 /*uam_register(UAM_SERVER_PRINTAUTH, path, "DHCAST128",
733 static void uam_cleanup(void)
735 uam_unregister(UAM_SERVER_LOGIN, "DHCAST128");
736 uam_unregister(UAM_SERVER_CHANGEPW, "DHCAST128");
737 /*uam_unregister(UAM_SERVER_PRINTAUTH, "DHCAST128"); */
740 UAM_MODULE_EXPORT struct uam_export uams_dhx = {
743 uam_setup, uam_cleanup
746 UAM_MODULE_EXPORT struct uam_export uams_dhx_pam = {
749 uam_setup, uam_cleanup
752 #endif /* USE_PAM && UAM_DHX */